Wushan, China

South China Agricultural University commonly referred to as SCAU, is a public university in Guangzhou, China.Founded in 1909. Main campus settles in Wushan, Guangzhou, People's Republic of China. It is a national comprehensive university with long history. The university has 24 colleges/department and more than 40,000 students, including international students from 33 countries. The main feature of the university is biology science. Wikipedia.

Time filter

Source Type

Li J.H.,South China Agricultural University | Li J.H.,University of Macau | Dong S.S.,University of Macau | Shim H.J.,University of Macau
Advanced Materials Research | Year: 2013

An indigenous Pseudomonas sp., isolated from the heavily petroleum-contaminated soil and identified as Pseudomonas plecoglossicida, was evaluated for its aerobic cometabolic removal of mixture of two representative chlorinated aliphatic hydrocarbons (CAHs), cis-1,2-dichloroethylene (cis-DCE) and trichloroethylene (TCE), with BTEX/toluene provided as substrate in a laboratory-scale soil slurry. The aerobic simultaneous bioremoval of the cis-DCE/TCE/BTEX mixture was studied under different conditions. Results showed that the increased BTEX concentration from 400 to 600 mg/kg prolonged the bioremoval of BTEX. The cometabolism of cis-DCE and TCE was significantly greater when toluene was provided as growth substrate compared to the BTEX mixture as substrates. Additionally, the bioremoval of toluene in the treatment with toluene as sole growth substrate was higher compared to the treatment with BTEX mixture as substrate. Results would enhance the applicability of bioremediation technology to the mixed wastes-contaminated sites. © (2013) Trans Tech Publications, Switzerland.

Li Y.,Tel Aviv University | Li Y.,South China Agricultural University | Pang W.,Guangdong University of Technology | Malomed B.A.,Tel Aviv University
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2012

We study modes trapped in a rotating ring carrying the self-focusing (SF) or self-defocusing (SDF) cubic nonlinearity and double-well potential cos2θ, where θ is the angular coordinate. The model, based on the nonlinear Schrödinger (NLS) equation in the rotating reference frame, describes the light propagation in a twisted pipe waveguide, as well as in other optical settings, and also a Bose-Einstein condensate (BEC) trapped in a torus and dragged by the rotating potential. In the SF and SDF regimes, five and four trapped modes of different symmetries are found, respectively. The shapes and stability of the modes and the transitions between them are studied in the first rotational Brillouin zone. In the SF regime, two symmetry-breaking transitions are found, of subcritical and supercritical types. In the SDF regime, an antisymmetry-breaking transition occurs. Ground states are identified in both the SF and SDF systems. © 2012 American Physical Society.

Zhang Z.,University of California at Davis | Liao H.,South China Agricultural University | Lucas W.J.,University of California at Davis
Journal of Integrative Plant Biology | Year: 2014

As an essential plant macronutrient, the low availability of phosphorus (P) in most soils imposes serious limitation on crop production. Plants have evolved complex responsive and adaptive mechanisms for acquisition, remobilization and recycling of phosphate (Pi) to maintain P homeostasis. Spatio-temporal molecular, physiological, and biochemical Pi deficiency responses developed by plants are the consequence of local and systemic sensing and signaling pathways. Pi deficiency is sensed locally by the root system where hormones serve as important signaling components in terms of developmental reprogramming, leading to changes in root system architecture. Root-to-shoot and shoot-to-root signals, delivered through the xylem and phloem, respectively, involving Pi itself, hormones, miRNAs, mRNAs, and sucrose, serve to coordinate Pi deficiency responses at the whole-plant level. A combination of chromatin remodeling, transcriptional and posttranslational events contribute to globally regulating a wide range of Pi deficiency responses. In this review, recent advances are evaluated in terms of progress toward developing a comprehensive understanding of the molecular events underlying control over P homeostasis. Application of this knowledge, in terms of developing crop plants having enhanced attributes for P use efficiency, is discussed from the perspective of agricultural sustainability in the face of diminishing global P supplies. © 2014 Institute of Botany, Chinese Academy of Sciences.

Li Y.,Tel Aviv University | Li Y.,South China Agricultural University | Liu J.,South China Agricultural University | Pang W.,Guangdong University of Technology | Malomed B.A.,Tel Aviv University
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2013

We study the effects of spontaneous symmetry breaking (SSB) in solitons composed of a dipolar Bose-Einstein condensate trapped in a dual-core system with dipole-dipole interactions (DDIs) and hopping between the cores. Two realizations of such a matter-wave coupler are introduced: weakly and strongly coupled. The former is based on two parallel pipe-shaped traps, whereas the latter is represented by a single pipe sliced by an external field into parallel layers. The dipoles are oriented along the axes of the pipes. In these systems, the dual-core solitons feature SSB of the supercritical and subcritical types, respectively. Stability regions are identified for symmetric and asymmetric solitons and nonbifurcating antisymmetric solitons, as well as for symmetric flat states, which may also be stable in the strongly coupled system due to competition between the attractive and repulsive intracore and intercore DDIs. The effects of the contact interactions are considered too. Collisions between moving asymmetric solitons in the weakly symmetric system feature an elastic rebound, a merger into a single breather, and passage accompanied by excitation of intrinsic vibrations of the solitons for small, intermediate, and large collision velocities, respectively. A PT-symmetric version of the weakly coupled system is considered briefly, which may be relevant for matter-wave lasers. Stability boundaries for PT-symmetric and -antisymmetric solitons are identified. © 2013 American Physical Society.

Li Y.,South China Agricultural University | Li Y.,Tel Aviv University | Pang W.,Guangdong University of Technology | Fu S.,Sun Yat Sen University | Malomed B.A.,Tel Aviv University
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2012

We study two-component solitons and their symmetry-breaking bifurcations (SBBs) in linearly coupled photonic systems with a spatially inhomogeneous strength of the coupling. One system models an inverted virtual photonic crystal, built by periodically doping the host medium with atoms implementing the electromagnetically induced transparency (EIT). In this system, two soliton-forming probe beams with different carrier frequencies are mutually coupled by the EIT-induced effective linear interconversion. The system is described by coupled nonlinear Schrödinger (NLS) equations for the probes, with the linear-coupling constant periodically modulated in space according to the density distribution of the active atoms. The type of the SBB changes from sub- to supercritical with the increase of the total power of the probe beams, which does not occur in systems with constant linear-coupling constants. Qualitatively similar results for the SBB of two-component solitons are obtained, in an exact analytical form, in the model of a fused dual-core waveguide, with the linear coupling concentrated at a point. © 2012 American Physical Society.

Li Y.,South China Agricultural University | Li Y.,Tel Aviv University | Liu J.,South China Agricultural University | Pang W.,Guangdong University of Technology | Malomed B.A.,Tel Aviv University
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2013

We demonstrate the existence of one- and two-dimensional (1D and 2D, respectively) bright solitons in the Bose-Einstein condensate with repulsive dipole-dipole interactions induced by a combination of dc and ac polarizing fields, oriented perpendicular to the plane in which the BEC is trapped, assuming that the strength of the fields grows in the radial (r) direction faster than r3. Stable tightly confined 1D and 2D fundamental solitons, twisted solitons in 1D, and solitary vortices in 2D are found in a numerical form. The fundamental solitons remain robust under the action of an expulsive potential, which is induced by the interaction of the dipoles with the polarizing field. The confinement and scaling properties of the soliton families are explained analytically. The Thomas-Fermi approximation is elaborated for fundamental solitons. The mobility of the fundamental solitons is limited to the central area. Stable 1D even and odd solitons are also found in the setting with a double-well modulation function, along with a regime of Josephson oscillations. © 2013 American Physical Society.

Luo Z.,South China Agricultural University | Li Y.,South China Agricultural University | Pang W.,Guangdong University of Technology | Liu Y.,South China Agricultural University
Journal of the Physical Society of Japan | Year: 2013

We study dipolar Bose-Einstein condensate (BEC) solitons in a one-dimensional optical lattice with the combined effect of local and nonlocal nonlinearities. The local nonlinearity is imposed by a magnetic or optical field via the Feshbach (FB) resonance. In contrast, the nonlocal nonlinearity is created by the long-range dipole-dipole interaction among the condensates. The orientations of the dipoles are directed by a rotatable uniform external field, which gives rise to a controllable nonlocal nonlinearity resulting from the angle θ between the direction of the dipole and the elongation of the lattice. If the lattice is sufficiently deep, this model can be described by the Gross-Pitaevskii equation (GPE) with tunable local and nonlocal nonlinear strengths (g and θ respectively). The formation, motion, and collision of the solitons in this system are studied by numerical simulations. The combined effect of the local and nonlocal nonlinearities gives a controllable scheme for all these characteristics via the relation between g and θ.

Liu G.,South China Agricultural University | Liu G.,International Rice Research Institute | Zhu H.,South China Agricultural University | Zhang G.,South China Agricultural University | And 2 more authors.
Theoretical and Applied Genetics | Year: 2012

Abstract:: Twelve single segment substitution lines (SSSLs) in rice, which contain quantitative trait loci (QTLs) for tiller number detected previously, were used to study dynamic expression of the QTLs in this study. These SSSLs and their recipient, Hua-Jing-Xian 74 (HJX74), were used to produce 78 crossing combinations first, and then these combinations and their parents were grown in two planting seasons with three cropping densities. Tiller number was measured at seven developmental stages. QTL effects including main effects (additive, dominance and epistasis), QTL × season and QTL × density interaction effects were analyzed at each measured stage. The additive, dominant and epistatic effects of the 12 QTLs as well as their interaction effects with the seasons and with the densities all display dynamic changes with the development. Eight QTLs are detected with significant additive effects and/or additive × season and/or additive × density interaction effects at least at one developmental stage, and all QTLs have significant dominant and epistatic effects and/or interaction effects involved in. For most of the QTLs dominant effects are much bigger than additive effects, showing overdominance. Each QTL interacts at least with eight other QTLs. Additive and dominant effects of these QTLs are mostly positive while epistatic effects are negative and minor. Most of the QTLs show significant interactions with planting seasons and cropping densities, but the additive effects of QTLs Tn3-1 and Tn3-2, the dominant effects of QTL Tn7 and Tn8, and the epistatic effects of 14 pairs of QTLs are stable across seasons and the dominant effect of QTL Tn3-3 and the epistatic effects of QTL pairs Tn2-1/Tn6-2, Tn2-1/Tn9 and Tn3-3/Tn6-3 are nearly consistent across cropping densities. This paper is the first report of dynamics on dominances and epistasis of QTLs for tiller number in rice and provides abundant information, which is useful to improve rice tiller number via heterosis and/or QTL pyramiding. © 2012 Springer-Verlag.

Tsai W.-C.,National Cheng Kung University | Fu C.-H.,National Cheng Kung University | Hsiao Y.-Y.,National Cheng Kung University | Huang Y.-M.,National Cheng Kung University | And 3 more authors.
Plant and Cell Physiology | Year: 2013

Both floral development and evolutionary trends of orchid flowers have long attracted the interest of biologists. However, expressed sequences derived from the flowers of other orchid subfamilies are still scarce except for a few species in Epidendroideae. In order to broadly increase our scope of Orchidaceae genetic information, we updated the OrchidBase to version 2.0 which has 1,562,071 newly added floral non-redundant transcribed sequences (unigenes) collected comprehensively from 10 orchid species across five subfamilies of Orchidaceae. A total of 662,671,362 reads were obtained by using next-generation sequencing (NGS) Solexa Illumina sequencers. After assembly, on average 156,207 unigenes were generated for each species. The average length of a unigene is 347 bp. We made a detailed annotation including general information, relative expression level, gene ontology (GO), KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway mapping and gene network prediction. The online resources for putative annotation can be searched either by text or by using BLAST, and the results can be explored on the website and downloaded. We have re-designed the user interface in the new version. Users can enter the Phalaenopsis transcriptome or Orchidaceae floral transcriptome to browse or search the unigenes. OrchidBase 2.0 is freely available at http://orchidbase.itps.ncku.edu. tw/. © 2013 The Author 2013. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved.

Ji L.,Biomaterials and Biocatalysts Group | Jiang Z.-D.,South China Agricultural University | Liu Y.,Biomaterials and Biocatalysts Group | Koh C.M.J.,Biomaterials and Biocatalysts Group | Zhang L.-H.,National University of Singapore
Fungal Genetics and Biology | Year: 2010

Ustilago maydis is an important model fungal organism for diverse studies. Little improvement has been made in the method for its transformation since the PEG-mediated transfection of spheroplasts that was reported more than 20 years ago. We have constructed binary T-DNA vectors carrying Hygromycin and Nourseothricin resistance gene cassettes and have developed a highly efficient method for transformation of this fungus based on Agrobacterium tumefaciens-mediated transformation (ATMT). Through a series of optimization, at least 1 × 104 Hygromycin B resistant colony forming units (CFU) have been achieved on each 90 mm agar plate using 106 sporidia. Optimal pH value for ATMT is approximately 5.6. Approximately 96% Hygromycin B-resistant transformants contain a single-copy T-DNA inserted into the nuclear genome. Analysis of 204 T-DNA flanking sequences showed that 15.2% of them were found in the coding sequences and a further 37.25% within 0.5 kb from the coding sequences at the 5′ UTR or promoter regions. In addition, a method for preparation and preservation of transformation-ready T-DNA donor and receptor cells has been developed allowing gene tagging experiments to be performed on-demand. An initial screening of 5000 mutants resulted in the identification of a putative farnesyl transferase beta subunit and a PRE6 homologue as new players of sexual mating in U. maydis. © 2010 Elsevier Inc. All rights reserved.

Shan W.,South China Agricultural University | Kuang J.-F.,South China Agricultural University | Chen L.,South China Agricultural University | Xie H.,South China Agricultural University | And 7 more authors.
Journal of Experimental Botany | Year: 2012

The plant-specific NAC (NAM, ATAF1/2, and CUC2) transcription factors (TFs) play important roles in plant growth, development, and stress responses. However, the precise role of NAC TFs in relation to fruit ripening is poorly understood. In this study, six NAC genes, designated MaNAC1MaNAC6, were isolated and characterized from banana fruit. Subcellular localization showed that MaNAC1MaNAC5 proteins localized preferentially to the nucleus, while MaNAC6 was distributed throughout the entire cell. A transactivation assay in yeast demonstrated that MaNAC4 and MaNAC6, as well as their C-terminal regions, possessed trans-activation activity. Gene expression profiles in fruit with four different ripening characteristics, including natural, ethylene-induced, 1-methylcyclopropene (1-MCP)-delayed, and a combination of 1-MCP with ethylene treatment, revealed that the MaNAC genes were differentially expressed in peel and pulp during post-harvest ripening. MaNAC1 and MaNAC2 were apparently upregulated by ethylene in peel and pulp, consistent with the increase in ethylene production. In contrast, MaNAC3 in peel and pulp and MaNAC5 in peel were constitutively expressed, and transcripts of MaNAC4 in peel and pulp and MaNAC6 in peel decreased, while MaNAC5 or MaNAC6 in pulp increased slightly during fruit ripening. Furthermore, the MaNAC2 promoter was activated after ethylene application, further enhancing the involvement of MaNAC2 in fruit ripening. More importantly, yeast two-hybrid and bimolecular fluorescence complementation analyses confirmed that MaNAC1/2 physically interacted with a downstream component of ethylene signalling, ethylene insensitive 3 (EIN3)-like protein, termed MaEIL5, which was downregulated during ripening. Taken together, these results suggest that MaNACs such as MaNAC1/MaNAC2, may be involved in banana fruit ripening via interaction with ethylene signalling components. © [2012] The Author.

Wang S.-Y.,National Cheng Kung University | Lee P.-F.,Fooyin University | Lee Y.-I.,CSIC - National Museum of Natural Sciences | Hsiao Y.-Y.,National Cheng Kung University | And 5 more authors.
Plant and Cell Physiology | Year: 2011

The orchid floral organs represent novel and effective structures for attracting pollination vectors. In addition, to avoid inbreeding, the androecium and gynoecium are united in a single structure termed the gynostemium. Identification of C-class MADS-box genes regulating reproductive organ development could help determine the level of homology with the current ABC model of floral organ identity in orchids. In this study, we isolated and characterized two C-class AGAMOUS-like genes, denoted CeMADS1 and CeMADS2, from Cymbidium ensifolium. These two genes showed distinct spatial and temporal expression profiles, which suggests their functional diversification during gynostemium development. Furthermore, the expression of CeMADS1 but not CeMADS2 was eliminated in the multitepal mutant whose gynostemium is replaced by a newly emerged flower, and this ecotopic flower continues to produce sepals and petals centripetally. Protein interaction relationships among CeMADS1, CeMADS2 and E-class PeMADS8 proteins were assessed by yeast two-hybrid analysis. Both CeMADS1 and CeMADS2 formed homodimers and heterodimers with each other and the E-class PeMADS protein. Furthermore, transgenic Arabidopsis plants overexpressing CeMADS1 or CeMADS2 showed limited growth of primary inflorescence. Thus, CeMADS1 may have a pivotal C function in reproductive organ development in C. ensifolium. © 2011 The Author.

Ma J.,South China Agricultural University | Ma J.,Sichuan Agricultural University | He Y.,South China Agricultural University | Wu C.,South China Agricultural University | And 3 more authors.
Plant Molecular Biology Reporter | Year: 2012

A somatic embryogenesis receptor-like kinase (SERK) gene, designated as AcSERK1, was isolated from pineapple (Ananas comosus cv. Shenwan). AcSERK1 shared all the characteristic domains of the SERK family, including five leucine-rich repeats, one proline-rich region motif, transmembrane domain, and kinase domains. Somatic embryogenic cultures of pineapple were established following transfer of callus cultures to Murashige and Skoog (1962) medium containing 2,4-dichlorophenoxyacetic acid. The role of AcSERK1 during establishment of somatic embryogenesis in culture was investigated. The AcSERK1 was highly expressed during embryogenic competence acquisition and global embryo formation in culture. These findings were obtained along with morphological changes in callus cultures exhibiting embryogenic potential. Overall, levels of expression of AcSERK1 were lower in nonembryogenic tissues and organs than in embryogenic callus. In situ hybridization analysis revealed that AcSERK1 expression was detected in embryogenic tissues, including single competent cells, meristematic centers wherein embryogenic structures are formed, and global embryos. These results suggested that AcSERK1 expression was associated with induction of somatic embryogenesis and that it could be used as a potential marker gene to monitor the transition of pineapple callus tissues into competent and embryogenic cells and tissues. © 2011 Springer-Verlag.

Pang W.,Guangdong University of Technology | Guo H.,South China Agricultural University | Chen G.,Dongguan University of Technology | Mai Z.,South China Agricultural University
Journal of the Physical Society of Japan | Year: 2014

We study two component solitons in an inverted virtual lattice induced by electromagnetically induced transparency with a random spatial modulation of the density of the potential and the linear coupling between the two components. The randomness can be introduced by a random doping of the active atoms. Solitons and the symmetry breaking of the two components are investigated numerically. By changing the strength of the randomly modulated linear coupling, C0, the location of the solitons can be manipulated and the behavior shows a power P dependence. Compared to an inverted lattice with periodical modulation, the scenario of the SSB process is altered by the random modulation and the number of times that SSB occurs can be manipulated by adjusting the total power.©2014 The Physical Society of Japan.

Liang Y.,South China Agricultural University | Liang Y.,Sun Yat Sen University | Su Z.,Sun Yat Sen University | Luo X.,Sun Yat Sen University
Signal Processing | Year: 2012

Image resizing becomes more and more important in content-aware image displaying. This paper proposes a patchwise scaling method to resize an image to emphasize the important areas and preserve the globally visual effect (smoothness, coherence and integrity). This method for resizing image is based on optimizing the image distance presented in this paper. The image distance is defined based on so-called local bidirectional similarity measurement and smoothness measurement to quantify the quality of resizing outputs. The original image is divided into small important patches and unimportant patches based on an important map. The important map is generated automatically using a novel combination of image edge and saliency measurement. A scaling factor is computed for each small patch. The resized image is produced by iteratively optimizing, which is based on our image distance, the scaling factor for each small patch. Experiments of different type images demonstrate that our method can be effectively used in image processing applications to locally shrink and enlarge important areas while preserving image quality. © 2011 Published by Elsevier B.V. All rights reserved.

Chen J.M.,China Institute of Technology | Liu X.,South China Agricultural University | Zhao Z.X.,South China Agricultural University | Zhong W.T.,South China Agricultural University
Advanced Materials Research | Year: 2013

With the demand for precision management of orchards, 3-D reconstruction of fruit tree canopy is receiving more attention. Using depth image data from Kinect sensor, this article attempts to find the 3-D coordinates of the sensed point on the canopy to get the reconstructed fruit tree canopy quickly. By slicing the point clouds to find its surface-line features and the outer envelope within the same slices is used to reconstruct the fruit tree canopy and calculate the canopy's volume. Tests show that the measuring error for regular cuboid's volume is about 4.2% and the repeated measuring error for citrus tree's volume about 6.9%, indicating that applying Kinect for measuring volume of fruit tree canopy has reasonably high accuracy and reliability. The Kinect, as well as this technique, may well be used in landscape measurement on monitering. © (2013) Trans Tech Publications, Switzerland.

Li Y.,South China Agricultural University | Li Y.,Tel Aviv University | Liu J.,South China Agricultural University | Pang W.,Guangdong University of Technology | Malomed B.A.,Tel Aviv University
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2013

We study two-dimensional (2D) solitons in the mean-field models of ultracold gases with long-range quadrupole-quadrupole interaction (QQI) between particles. The condensate is loaded into a deep optical-lattice (OL) potential, therefore the model is based on the 2D discrete nonlinear Schrödinger equation with contact on site and long-range intersite interactions, which represent the QQI. The quadrupoles are built as pairs of electric dipoles and antidipoles orientated perpendicular to the 2D plane to which the gas is confined. Because the quadrupoles interact with the local gradient of the external field, they are polarized by an inhomogeneous dc electric field that may be supplied by a tapered capacitor. Shapes, stability, mobility, and collisions of fundamental discrete solitons are studied by means of systematic simulations. In particular, threshold values of the norm, which are necessary for the existence of the solitons, are found and anisotropy of their static and dynamical properties is explored. As concerns the mobility and collisions, we analyze such properties for discrete solitons on 2D lattices with long-range intersite interactions. Estimates demonstrate that the setting can be realized under experimentally available conditions, predicting solitons built of ∼10000 particles. © 2013 American Physical Society.

Ye M.,South China Agricultural University | Song Y.,South China Agricultural University | Long J.,South China Agricultural University | Wang R.,South China Agricultural University | And 5 more authors.
Proceedings of the National Academy of Sciences of the United States of America | Year: 2013

Although the function of silicon (Si) in plant physiology has long been debated, its beneficial effects on plant resistance against abiotic and biotic stresses, including insect herbivory, have been well documented. In addition, the jasmonate (JA) signaling pathway plays a crucial role in mediating antiherbivore defense responses in plants. However, potential interactions between JA and Si in response to insect attack have not been examined directly. To explore the role JA may play in Si-enhanced resistance, we silenced the expression of allene oxide synthase (OsAOS; active in JA biosynthesis) and CORONATINE INSENSITIVE1 (OsCOI1; active in JA perception) genes in transgenic rice plants via RNAi and examined resulting changes in Si accumulation and defense responses against caterpillar Cnaphalocrocis medinalis (rice leaffolder, LF) infestation. Si pretreatment increased rice resistance against LF larvae in wild-type plants but not in OsAOS and OsCOI1 RNAi lines. Upon LF attack, wild-type plants subjected to Si pretreatment exhibited enhanced defense responses relative to untreated controls, including higher levels of JA accumulation; increased levels of transcripts encoding defense marker genes; and elevated activities of peroxidase, polyphenol oxidase, and trypsin protease inhibitor. Additionally, reduced Si deposition and Si cell expansion were observed in leaves of OsAOS and OsCOI1 RNAi plants in comparison with wild-type plants, and reduced steady-state transcript levels of the Si transporters OsLsi1, OsLsi2, and OsLsi6 were observed in Si-pretreated plants after LF attack. These results suggest a strong interaction between Si and JA in defense against insect herbivores involving priming of JA-mediated defense responses by Si and the promotion of Si accumulation by JA.

Zhang L.,South China Agricultural University | Zhu S.,South China Agricultural University
Postharvest Biology and Technology | Year: 2014

Leaf yellowing is an early symptom of senescence and greatly affects the commercial value of leafy vegetable products. The ethylene action inhibitor 1-methylcyclopropene (1-MCP) has been widely studied regarding its effects on senescence, but little is known on how it influences the protein expression profile of leafy vegetables in storage. In this study, by using a proteomic approach, changes in proteomic profile induced by 1-MCP in Tsai Tai (Brassica chinensis) leaves during storage under low but non-freezing temperature were investigated. Compared with the control, 1-MCP treatment inhibited leaf etiolation and reduced weight loss of Tsai Tai stored at 1. °C, indicating that it delayed senescence. Two dimensional electrophoresis revealed 16 differentially accumulated protein spots, 12 of which were successfully identified by mass spectrometry. A comparison between the control and the 1-MCP-treated Tsai Tai showed that 1-MCP enhanced levels of four proteins involved in photosynthesis, i.e. photosystem II protein, oxygen-evolving enhancer protein 2, chloroplast ribulose 1,5-bisphosphate carboxylase/oxygenase activase and high molecular weight RuBisCO, inhibited malate dehydrogenase, a key enzyme involved in the tricarboxylic acid cycle, downregulated gibberellin 2-beta-dioxygenase expression, a key enzyme involved in biosynthesis of active gibberellins, and suppressed glutathione s-transferase, an important scavenger for reactive oxygen species. These results imply that 1-MCP could maintain leaf capacity for carbon assimilation, inhibit the tricarboxylic acid cycle, induce biosynthesis of GAs and reduce levels of reactive oxygen species, which together may have contributed to inhibition of leaf yellowing and delay of senescence. © 2013 Elsevier B.V.

Lin B.,South China Agricultural University | Zhuo K.,South China Agricultural University | Wu P.,South China Agricultural University | Cui R.,South China Agricultural University | And 3 more authors.
Molecular Plant-Microbe Interactions | Year: 2013

Secretory effector proteins expressed within the esophageal glands of root-knot nematodes (Meloidogyne spp.) are thought to play key roles in nematode invasion of host roots and in formation of feeding sites necessary for nematodes to complete their life cycle. In this study, a novel effector protein gene designated as Mj-nulg1a, which is expressed specifically within the dorsal gland of Meloidogyne javanica, was isolated through suppression subtractive hybridization. Southern blotting and BLAST search analyses showed that Mj-nulg1a is unique for Meloidogyne spp. A real-time reverse-transcriptase polymerase chain reaction assay showed that expression of Mj-nulg1a was upregulated in parasitic second-stage juveniles and declined in later parasitic stages. MJ-NULG1a contains two putative nuclear localization signals and, consistently, in planta immunolocalization analysis showed that MJ-NULG1a was localized in the nuclei of giant cells during nematode parasitism. In planta RNA interference targeting Mj-nulg1a suppressed the expression of Mj-nulg1a in nematodes and attenuated parasitism ability of M. javanica. In contrast, transgenic Arabidopsis expressing Mj-nulg1a became more susceptible to M. javanica infection than wild-type control plants. These results depict a novel nematode effector that is targeted to giant cell nuclei and plays a critical role in M. javanica parasitism. © 2013 The American Phytopathological Society.

Ouyang Y.,St. Johns River Water Management District | Luo S.M.,Ecological Agriculture Key Laboratory of the Ministry of Agriculture | Luo S.M.,South China Agricultural University | Cui L.H.,South China Agricultural University
Ecological Engineering | Year: 2011

The vertical-flow constructed wetland (VFCW) is a promising engineering technique for removal of excess nutrients and certain pollutants from wastewater and stormwater. The aim of this study was to develop a model using the STELLA software for estimating nitrogen (N) dynamics in an artificial VFCW (i.e., a substrate column with six zones) associated with a growing Cyperus alternifolius species under a wetting (wastewater) -to-drying ratio of 1:3. The model was calibrated by our experimental data with a reasonable agreement prior to its applications. Simulations showed that rates of NH4 +-N and NO3 --N leaching decreased with increasing zone number (or column depth), although such a decrease was much more profound for NH4 +-N. Our simulations further revealed that rate of NH4 +-N leaching decreased with time within each zone, whereas rate of NO3 --N leaching increased with time within each zone. Additionally, both the rates of NH4 +-N and NO3 --N leaching through zones followed the water flow pattern: breakthrough during wetting period and cessation during drying period. In general, the cumulative amounts of total nitrogen (TN) were in the following order: leaching>denitrification>uptake>settlement. About 54% of the TN from the wastewater flowed out of the VFCW system, 18% of TN lost due to denitrification, 6% of TN was taken up by roots of a single plant (one hill), and the rest of 22% TN from the wastewater was removed from other mechanisms, such as volatilization, adsorption, and deposition. This study suggested that to improve the overall performance of a VFCW for N removal, prevention of N leaching loss was one of the major issues. © 2010 Elsevier B.V.

Zhang J.,Guangdong Pharmaceutical University | Zhang J.,Biomedical Research Institute | Lu Y.,Biomedical Research Institute | Yue X.,Biomedical Research Institute | And 6 more authors.
PLoS ONE | Year: 2013

Emerging evidence indicate that microRNAs (miRNAs) may play important roles in cancer. Aberrant expression of miRNAs has been frequently identified in different human malignancies, including colorectal cancer (CRC). However, the mechanism by which deregulated miRNAs impact the development of CRC remains largely elusive. In this study, we show that miR-124 is significantly down-regulated in CRC compared to adjacent non-tumor colorectal tissues. MiR-124 suppresses the expression of STAT3 by directly binding to its 3′-untranslated region (3′-UTR). Overexpression of miR-124 led to increased apoptosis of CRC cells and reduced tumor growth in vitro and in vivo. Knocking down STAT3 expression by specific siRNA suppressed the growth of CRC cells in vitro and in vivo, resembling that of miR-124 overexpression. Moreover, overexpression of STAT3 in miR-124-transfected CRC cells effectively rescued the inhibition of cell proliferation caused by miR-124. These data suggest that miR-124 serves as a tumor suppressor by targeting STAT3, and call for the use of miR-124 as a potential therapeutic tool for CRC, where STAT3 is often hyper-activated. © 2013 Zhang et al.

Wen Y.-W.,South China Agricultural University | Liu C.,National University of Singapore | Yip A.M.,National University of Singapore
Applied Optics | Year: 2010

We consider the recovery of degraded videos without complete knowledge about the degradation. A spatially shift-invariant but temporally shift-varying video formation model is used. This leads to a simple multiframe degradation model that relates each original video frame with multiple observed frames and point spread functions (PSFs). We propose a variational method that simultaneously reconstructs each video frame and the associated PSFs from the corresponding observed frames. Total variation (TV) regularization is used on both the video frames and the PSFs to further reduce the ill-posedness and to better preserve edges. In order to make TV minimization practical for video sequences, we propose an efficient splitting method that generalizes some recent fast single-image TV minimization methods to the multiframe case. Both synthetic and real videos are used to show the performance of the proposed method. © 2010 Optical Society of America.

Miao H.-X.,South China Agricultural University | Qin Y.-H.,South China Agricultural University | Teixeira da Silva J.A.,Kagawa University | Ye Z.-X.,South China Agricultural University | Hu G.-B.,South China Agricultural University
Plant Science | Year: 2011

S-RNase-based self-incompatibility is the most widespread form of genetically controlled mate selection in plants and that S-RNase controls pollination specificity in the pistils. 'Wuzishatangju' (Citrus reticulata Blanco), a nature bud mutant from a self-compatible (SC) cultivar 'Shatangju', displays gametophytic self-incompatibility (GSI). In this study, full-length sequences of cDNA and DNA of the S-RNase homologous gene were obtained from 'Wuzishatangju' and 'Shatangju'. There was no difference in ORF sequences of the S-RNase cDNA between 'Wuzishatangju' and 'Shatangju'. However, 13, 9 and 6 consecutive bases were missing in 'Wuzishatangju' cDNA 5′ UTR, 3′ UTR and genomic DNA, respectively. Tissue-specific expression of the S-RNase gene was detected using semi-quantitative RT-PCR and quantitative real-time PCR. The expression level of the S-RNase gene in styles of 'Wuzishatangju' was approximately 10- and 5-fold higher than that in leaves and pollen, respectively. When 'Wuzishatangju' was self-pollinated, the expression of S-RNase in pistils peaked at 3 days, which was approximately 10-fold higher than that at 4. h and 7 days, while in cross-pollination of 'Wuzishatangju' × 'Shatangju' the expression was very weak at 3 days. Results from a Southern blot showed that two copies of the S-RNase gene existed in genomic DNA of both 'Wuzishatangju' and 'Shatangju'. © 2010 Elsevier Ireland Ltd.

Huang Q.,South China Agricultural University | Huang Q.,City University of Hong Kong | Yang G.,National University of Singapore | Wong D.S.,City University of Hong Kong | Susilo W.,University of Wollongong
International Journal of Information Security | Year: 2011

Designated verifier signature (DVS) allows a signer to convince a designated verifier that a signature is generated by the signer without letting the verifier transfer the conviction to others, while the public can still tell that the signature must be generated by one of them. Strong DVS (SDVS) strengthens the latter part by restricting the public from telling whether the signature is generated by one of them or by someone else. In this paper, we propose two new SDVS schemes. Compared with existing SDVS schemes, the first new scheme has almost the same signature size and meanwhile, is proven secure in the standard model, while the existing ones are secure in the random oracle model. It has tight security reduction to the DDH assumption and the security of the underlying pseudorandom functions. Our second new scheme is the first SDVS supporting non-delegatability, the notion of which was introduced by Lipmaa, Wang and Bao in the context of DVS in ICALP 2005. The scheme is efficient and is provably secure in the random oracle model based on the discrete logarithm assumption and Gap Diffie-Hellman assumption. © 2011 Springer-Verlag.

Mai Z.,South China Agricultural University | Mai Z.,Sun Yat Sen University | Pang W.,Guangdong University of Technology | Wu J.,University of Toronto | Li Y.,South China Agricultural University
Journal of the Physical Society of Japan | Year: 2015

In this work, we study the spontaneous symmetry breaking (SSB) of discrete solitons in two-component waveguide arrays with long-range linearly coupled effect. Stable symmetry and asymmetry two-component discrete solitons are found in the system. The symmetry transition between them are studied. We find that, increasing the strength of the linear long-range coupling, the process of the symmetry breaking from the symmetric soliton to the asymmetric soliton will switch from supercritical to subcritical type. The specific switch point is identified by numerical simulations. Compared to the case with nonlinear long-range couplings, the SSB with linear long-range coupling is opposite in behavior. These findings can help to fill the gap in our general picture of the symmetry breaking against nonlocal effects, and may possible have potential applications in optical communications and all-optical networks. © 2015 The Physical Society of Japan.

Chen J.,U.S. Department of Agriculture | Deng X.,South China Agricultural University | Irey M.,United States Sugar Corporation | Civerolo E.,U.S. Department of Agriculture
Phytopathology | Year: 2010

Huanglongbing (HLB) (yellow shoot disease) is a highly destructive disease that threatens citrus production worldwide. The disease was first observed in Guangdong, P. R. China, over 100 years ago, and was found in Florida, United States, in 2005. 'Candidatus Liberibacter asiaticus' has been associated with HLB in many citrus-growing regions around the world, including Guangdong and Florida. The global epidemiology of HLB, as well as management of the disease, relies on knowledge of 'Ca. L. Asiaticus' populations in different geographical regions around the world. In this study, we identified a genetic marker containing small tandem repeats in the genome of 'Ca. L. Asiaticus' and comparatively analyzed the tandem repeat numbers (TRNs) in 'Ca. L. Asiaticus' populations from Guangdong and Florida. Analyses of TRNs showed that the bacterial population in Guangdong was different from that in Florida. The Guangdong population consisted predominately of strains with a TRN of 7 (TRN7) at a frequency of 47.6%. The Florida population consisted predominately of strains with a TRN of 5 (TRN5) at a frequency of 84.4%. TRNs ranged from 3 to 16. The apparent absence of TRNs of 9, 10, 11, and 12 separated the bacterial strains into two groups: TRNs < 10 (TRN<10) and TRNs > 10 (TRN>10). In Florida, TRN<10 strains (103/109, or 94.5%) were widely distributed in all HLB-affected counties. TRN>10 strains (6/109, or 5.5%) were found in central Florida. This is the first report documenting the differentiation of 'Ca. L. Asiaticus' populations between Asia and North America and the possible presence of two differentially distributed genotypes of 'Ca. L. Asiaticus' in Florida.

Zhang J.,Guangdong University of Technology | Zhao S.-Q.,Guangdong University of Technology | Zhang K.,Guangdong University of Technology | Zhou J.-Q.,Guangdong University of Technology | Cai Y.-F.,South China Agricultural University
Nanoscale Research Letters | Year: 2012

In the present work, ZnO quantum dots (QDs) have been prepared by the sol-gel method, and the performance of the QDs has been improved. The effect of Cd concentration on the structural and luminescent properties of the QDs, as well as the effect of the mass ratio of trioctylphosphine oxide (TOPO)/octadecylamine (ODA), has been investigated. The ZnO and Cd-doped ZnO QDs have hexagonal wurtzite structures and are 3 to 6 nm in diameter. When the Cd content was increased, the QD particle size was reduced; this effect was confirmed in the corresponding ultraviolet-visible spectra. The fluorescence intensity was simultaneously enhanced significantly. Both the UV and fluorescence spectra were blue-shifted. The luminous intensity was further enhanced when the QDs were modified with TOPO/ODA. Fourier transform infrared and X-ray diffraction techniques proved that the polymer successfully coated the surfaces of the QDs. A TOPO/ODA mass ratio of 1:2 was determined to result in the best optical performance among the different ratios examined. The results showed that the described synthetic method is appropriate for the preparation of doped QDs with high-fluorescence quantum efficiency. © 2012 Granitzer et al.

Li J.,University of Macau | Zhang J.,Guangzhou Institute of Landscape Gardening | Lu Y.,South China Agricultural University | Chen Y.,University of Macau | And 2 more authors.
Environmental Monitoring and Assessment | Year: 2012

The total petroleum hydrocarbons (TPH) pollution in regional agricultural soils was investigated. Seventy soil samples collected from surface layers (0-20 cm) and horizons of five selected pedons in the vicinity of a petrochemical complex in Guangzhou, China were analyzed, and the vertical variation and spatial variability of TPH were evaluated. The TPH concentration in top soils around the petrochemical complex ranged from 1,179.3 to 6,354.9 mg kg- 1, with the average of 2,676.6 mg kg- 1. Furthermore, significant differences between land-use types showed that the TPH concentration in top soils was strongly influenced by accidental spills. Both the TPH trends in pedons and the identified hot-spot areas also showed that the accidental explosions or burning accidents were mainly responsible for the pollution. The results reported here suggest that the regular monitoring and inspection shall be conducted for safety and to avoid or minimize the accidents, and the effective measures should be taken to remediate the contaminated areas and to assure that the important industrialization of Guangzhou area would not mean human health risks near the petrochemical complex. © 2011 Springer Science+Business Media B.V.

Gu X.,National University of Singapore | Gu X.,Temasek Life science Laboratory | Le C.,National University of Singapore | Le C.,Temasek Life science Laboratory | And 9 more authors.
Nature Communications | Year: 2013

The developmental transition to flowering is timed by endogenous and environmental signals through multiple genetic pathways. In Arabidopsis, the MADS-domain protein FLOWERING LOCUS C is a potent flowering repressor. Here, we report that the FLOWERING LOCUS C clade member MADS AFFECTING FLOWERING3 acts redundantly with another clade member to directly repress expression of the florigen FLOWERING LOCUS T and inhibit flowering. FLOWERING LOCUS C clade members act in partial redundancy in floral repression and mediate flowering responses to temperature, in addition to their participation in the flowering-time regulation by vernalization and photoperiod. We show that FLOWERING LOCUS C, MADS AFFECTING FLOWERING3 and three other clade members can directly interact with each other and form nuclear complexes, and that FLOWERING LOCUS C-dependent floral repression requires other clade members. Our results collectively suggest that the FLOWERING LOCUS C clade members act as part of several MADS-domain complexes with partial redundancy, which integrate responses to endogenous and environmental cues to control flowering. © 2013 Macmillan Publishers Limited. All rights reserved.

Lu C.-N.,South China Agricultural University | Yuan Z.-G.,South China Agricultural University | Zhang X.-L.,South China Agricultural University | Yan R.,University of Macau | And 3 more authors.
International Immunopharmacology | Year: 2012

Saikosaponin a (SSa) and its epimer saikosaponin d (SSd) are major triterpenoid saponin derivatives from Radix bupleuri (RB), which has been long used in Chinese traditional medicine for treatment of various inflammation-related diseases. In the present study, the anti-inflammatory activity, as well as the underlying mechanism, of SSa and SSd was investigated in lipopolysaccharide (LPS)-induced RAW264.7 cells. Our results demonstrated that both SSa and SSd significantly inhibited the expression of inducible nitric-oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in LPS-induced RAW264.7 cells, and finally resulted in the reduction of nitric oxide (NO) and prostaglandin E2 (PGE2). In addition, LPS-induced production of major pro-inflammatory cytokines: the tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), was suppressed in a dose-dependent manner by the treatment of SSa or SSd in RAW264.7 cells. Further analysis revealed that both SSa and SSd could inhibit translocation of nuclear factor-κB (NF-κB) from the cytoplasm to the nucleus in the LPS-induced RAW264.7 cells. Furthermore, SSa and SSd exhibited significant anti-inflammatory activity in two different murine models of acute inflammation, carrageenan-induced paw edema in rats and acetic acid-induced vascular permeability in mice. In conclusion, SSa and SSd showed potent anti-inflammatory activity through inhibitory effects on NF-κB activation and thereby on iNOS, COX-2 and pro-inflammatory cytokines. © 2012 Elsevier B.V.

He H.,South China Agricultural University | Chen F.,University of Hong Kong | Li H.,South China Agricultural University | Xiang W.,CAS South China Sea Institute of Oceanology | Jiang Y.,Hong Kong Baptist University
Harmful Algae | Year: 2010

Effects of iron (Fe) on growth, biochemical composition and paralytic shellfish poisoning (PSP) toxins production of Alexandrium tamarense were studied. Under Fe-limited conditions (1 nmol L-1 Fe), the alga exhibited a low specific growth rate (0.076 ± 0.017 d-1, n = 3) that was nearly a half of that under Fe-replete conditions (1 μmol L-1 Fe, 0.137 ± 0.00752 d-1, n = 4), and the cell density on day 21 (8210 cells mL-1) was also less than a half of that under Fe-replete conditions (2 × 104 cells mL-1). At the same time, total pigment, chlorophyll a (Chla), protein, carbohydrate contents per cell and Chla/carotenoid ratio decreased. In contrast, the PSP toxins content and the PSP toxicity per cell of the alga increased remarkably. Under Fe-limited conditions, total PSP toxins content and relative toxicity of alga were 2.55- and 2.54-fold of those under Fe-replete conditions, respectively. In addition, the profiles of PSP toxins also changed notably. The cellular content of gonyautoxin 1 + 4 (GTX1 + 4) increased for 5.6-fold along with the decrease of saxitoxin (STX) and gonyautoxin 2 + 3 (GTX2 + 3) contents contrasting to that under Fe-replete conditions. It suggested that the availability of Fe might effectively control the growth and toxic production of the alga and thereby influence the toxic effect of these harmful bloom events. © 2009 Elsevier B.V. All rights reserved.

Baysal O.,Muǧla University | Lai D.,South China Agricultural University | Xu H.-H.,South China Agricultural University | Siragusa M.,CNR Institute of Neuroscience | And 4 more authors.
PLoS ONE | Year: 2013

Beneficial microorganisms (also known as biopesticides) are considered to be one of the most promising methods for more rational and safe crop management practices. We used Bacillus strains EU07, QST713 and FZB24, and investigated their inhibitory effect on Fusarium. Bacterial cell cultures, cell-free supernatants and volatiles displayed varying degrees of suppressive effect. Proteomic analysis of secreted proteins from EU07 and FZB24 revealed the presence of lytic enzymes, cellulases, proteases, 1,4-β-glucanase and hydrolases, all of which contribute to degradation of the pathogen cell wall. Further proteomic investigations showed that proteins involved in metabolism, protein folding, protein degradation, translation, recognition and signal transduction cascade play an important role in the control of Fusarium oxysporum. Our findings provide new knowledge on the mechanism of action of Bacillus species and insight into biocontrol mechanisms. © 2013 Baysal et al.

Miao H.,South China Agricultural University | Qin Y.,South China Agricultural University | Da Silva J.A.T.,Kagawa University | Ye Z.,South China Agricultural University | Hu G.,South China Agricultural University
Molecular Biology Reports | Year: 2013

Self-incompatibility (SI) is one important factor that can result in Citrus seedlessness. However, the molecular mechanism of SI in Citrus is not clear yet. To isolate the pistil's SI-related genes, a suppression subtractive hybridization library was constructed using mature pistils of 'Wuzishatangju' mandarin (SI) as the tester and mature pistils of 'Shatangju' mandarin (self-compatibility, SC) as the driver. 229 differentially expressed cDNA clones from 967 positive clones were sequenced and identified. Differentially expressed ESTs are possibly involved in the SI reaction of 'Wuzishatangju' through a regulating signaling pathway, serine/threonine phosphatase activity, receptor kinase, embryonic development, gibberellin stimulus, or transcription. 11 out of 36 SI candidate genes displayed different expression patterns in various tissues and stages after self- and cross-pollination of 'Wuzishatangju'. The expression of CaBP (WY65), a senescence-protease (WY372), an unknown gene (WY283), and a WRKY (WY17) were up-regulated in the styles of 'Wuzishatangju' while higher expression of WY190 was observed in styles of 'Shatangju'. Highest expression levels of WY65, WY372, an annexin (WY598), the zinc-finger protein (WY376), a C2-protein (WY291), and an unknown gene (WY318) were detected in styles at 3days after self-pollination of 'Wuzishatangju' while lowest levels were observed in styles at 3days after cross-pollination of 'Wuzishatangju'×'Shatangju'. The potential involvement of these genes in the SI reaction is discussed. © 2012 Springer Science+Business Media Dordrecht.

Zhang J.,CAS South China Botanical Garden | Wu K.,CAS South China Botanical Garden | Zeng S.,CAS South China Botanical Garden | Teixeira da Silva J.A.,Kagawa University | And 4 more authors.
BMC Genomics | Year: 2013

Background: Cymbidium sinense belongs to the Orchidaceae, which is one of the most abundant angiosperm families. C. sinense, a high-grade traditional potted flower, is most prevalent in China and some Southeast Asian countries. The control of flowering time is a major bottleneck in the industrialized development of C. sinense. Little is known about the mechanisms responsible for floral development in this orchid. Moreover, genome references for entire transcriptome sequences do not currently exist for C. sinense. Thus, transcriptome and expression profiling data for this species are needed as an important resource to identify genes and to better understand the biological mechanisms of floral development in C. sinense.Results: In this study, de novo transcriptome assembly and gene expression analysis using Illumina sequencing technology were performed. Transcriptome analysis assembles gene-related information related to vegetative and reproductive growth of C. sinense. Illumina sequencing generated 54,248,006 high quality reads that were assembled into 83,580 unigenes with an average sequence length of 612 base pairs, including 13,315 clusters and 70,265 singletons. A total of 41,687 (49.88%) unique sequences were annotated, 23,092 of which were assigned to specific metabolic pathways by the Kyoto Encyclopedia of Genes and Genomes (KEGG). Gene Ontology (GO) analysis of the annotated unigenes revealed that the majority of sequenced genes were associated with metabolic and cellular processes, cell and cell parts, catalytic activity and binding. Furthermore, 120 flowering-associated unigenes, 73 MADS-box unigenes and 28 CONSTANS-LIKE (COL) unigenes were identified from our collection. In addition, three digital gene expression (DGE) libraries were constructed for the vegetative phase (VP), floral differentiation phase (FDP) and reproductive phase (RP). The specific expression of many genes in the three development phases was also identified. 32 genes among three sub-libraries with high differential expression were selected as candidates connected with flower development.Conclusion: RNA-seq and DGE profiling data provided comprehensive gene expression information at the transcriptional level that could facilitate our understanding of the molecular mechanisms of floral development at three development phases of C. sinense. This data could be used as an important resource for investigating the genetics of the flowering pathway and various biological mechanisms in this orchid. © 2013 Zhang et al.; licensee BioMed Central Ltd.

He H.-Q.,Chongqing Academy of Science and Technology | Jiao X.,Taiyuan University of Technology | Chang S.,South China Agricultural University
Molecular Simulation | Year: 2013

WW domain proteins are usually regarded as simple models for understanding the folding mechanism of β-sheet. CC45 is an artificial protein that is capable of folding into the same structure as WW domain. In this article, the replica exchange molecular dynamics simulations are performed to investigate the folding mechanism of CC45. The analysis of thermal stability shows that β-hairpin 1 is more stable than β-hairpin 2 during the unfolding process. Free energy analysis shows that the unfolding of this protein substantially proceeds through solvating the smaller β-hairpin 2, followed by the unfolding of β-hairpin 1. We further propose the unfolding process of CC45 and the folding mechanism of two β-hairpins. These results are similar to the previous folding studies of formin binding protein 28 (FBP28). Compared with FBP28, it is found that CC45 has more aromatic residues in N-terminal loop, and these residues contact with C-terminal loop to form the outer hydrophobic core, which increases the stability of CC45. Knowledge about the stability and folding behaviour of CC45 may help in understanding the folding mechanisms of the β-sheet and in designing new WW domains. © 2013 2013 Taylor & Francis.

Li J.,South China Agricultural University | Dong F.,South China Agricultural University | Lu Y.,South China Agricultural University | Yan Q.,Shanxi Academy of Agricultural Sciences | Shim H.,University of Macau
PLoS ONE | Year: 2014

Foods produced on soils impacted by Pb-Zn mining activities are a potential health risk due to plant uptake of the arsenic (As) associated with such mining. A field survey was undertaken in two Pb-Zn mining-impacted paddy fields in Guangdong Province, China to assess As accumulation and translocation, as well as other factors influencing As in twelve commonly grown rice cultivars. The results showed that grain As concentrations in all the surveyed rice failed national food standards, irrespective of As speciation. Among the 12 rice cultivars, "SY-89" and "DY-162" had the least As in rice grain. No significant difference for As concentration in grain was observed between the rice grown in the two areas that differed significantly for soil As levels, suggesting that the amount of As contamination in the soil is not necessarily the overriding factor controlling the As content in the rice grain. The iron and manganese plaque on the root surface curtailed As accumulation in rice roots. Based on our results, the accumulation of As within rice plants was strongly associated with such soil properties such as silicon, phosphorus, organic matter, pH, and clay content. Understanding the factors and mechanisms controlling As uptake is important to develop mitigation measures that can reduce the amount of As accumulated in rice grains produced on contaminated soils. © 2014 Li et al.

Xu J.,Suzhou University | Rong R.,Suzhou Newpower Biotechnology Institute | Zhang H.Q.,Suzhou University | Shi C.J.,Suzhou Newpower Biotechnology Institute | And 2 more authors.
International Journal for Parasitology | Year: 2010

In this study, a loop-mediated isothermal amplification (LAMP) assay was established to detect Schistosoma japonicum DNA in faecal and serum samples of rabbits, and serum samples of humans infected with S. japonicum. This LAMP assay was based on the sequence of highly repetitive retrotransposon SjR2, and was able to detect 0.08fg S. japonicum DNA, which is 104 times more sensitive than conventional PCR. The LAMP assay was also highly specific for S. japonicum and able to detect S. japonicum DNA in rabbit sera at 1week p.i. Following administration of praziquantel, detection of S. japonicum DNA in rabbit sera became negative at 12weeks post-treatment. These results demonstrated that LAMP was effective for early diagnosis of, and evaluation of therapy effectiveness for, S. japonicum infection. Both PCR and LAMP assays were then used to detect S. japonicum DNA in 30 serum samples from S. japonicum-infected patients and 20 serum samples from healthy persons. The percentage sensitivity of LAMP was 96.7%, whereas that of PCR was only 60%, indicating that LAMP was more sensitive than conventional PCR for clinical diagnosis of schistosomiasis cases in endemic areas. The established LAMP assay should provide a useful and practical tool for the routine diagnosis and therapeutic evaluation of human schistosomiasis. © 2009 Australian Society for Parasitology Inc.

Zhang Q.,Guangdong University of foreign Studies | Xing H.,Guangdong University of Technology | Wu L.,South China Agricultural University
International Journal of Computational Intelligence Systems | Year: 2012

In the present paper, we introduce a new axiomatic definition of the inclusion measure for intuitionistic fuzzy sets (IFSs, for short). The close relationships among entropy, similarity measure, and inclusion measure of IFSs are then discussed in detail. Also, we obtain some important theorems by which the entropy, similarity measure and inclusion measure of IFSs can be transformed into each other based on their axiomatic definitions. Moreover, some formulae for calculating the entropy, similarity measure and inclusion measure of IFSs are put forward. Finally, we compare the proposed new entropy, similarity and distance measures with the existing ones. © 2012 Copyright the authors.

Wisniowski B.,Ojcow National Park | Xu Z.-F.,South China Agricultural University
ZooKeys | Year: 2015

A critical and annotated catalogue of 183 types of Hymenoptera Chrysididae belonging to 124 taxa housed in the Radoszkowski collection is given. Radoszkowski type material from other institutes has also been checked. Six lectotypes are designated in Kraków (ISEA-PAN): Chrysis acceptabilis Radoszkowski, 1891; C. persica Radoczkowsky, 1881; C. daphnis Mocsáry, 1889; C. lagodechii Radoszkowski, 1889; C. remota Mocsáry, 1889 and C. vagans Radoszkowski, 1877. The lectotype of Brugmoia pellucida Radoszkowski, 1877 is designated in Moscow (MMU). Four new combinations are proposed: Philoctetes araraticus (Radoszkowski, 1890), comb. n.; Pseudomalus hypocrita (du Buysson, 1893), comb. n.; Chrysis eldari (Radoszkowski, 1893), comb. n.; and Chrysura mlokosewitzi (Radoszkowski, 1889), comb. n.. Ten new synonyms are given: Chrysis auropunctata Mocsáry, 1889, syn. n. of C. angolensis Radoszkovsky, 1881; C. chrysochlora Mocsáry, 1889, syn. n. and C. viridans Radoszkowski, 1891, syn. n. of C. keriensis Radoszkowski, 1887; C. angustifrons var. ignicollis Trautmann, 1926, syn. n. of C. eldari (Radoszkowski, 1893); C. maracandensis var. simulatrix Radoszkowski, 1891, syn. n. of C. maracandensis Radoszkowski, 1877; C. pulchra Radoszkovsky, 1880, syn. n. of Spinolia dallatorreana (Mocsáry, 1896); C. rubricollis du Buysson, 1900, syn. n. of C. eldari (Radoszkowski, 1893); C. subcoerulea Radoszkowski, 1891, syn. n. of C. chlorochrysa Mocsáry, 1889; C. therates Mocsáry, 1889, syn. n. of C. principalis Smith, 1874; and Notozus komarowi Radoszkowski, 1893, syn. n. of Elampus obesus (Mocsáry, 1890). One species is revaluated: Chrysis chalcochrysa Mocsáry, 1887. Chrysis kizilkumiana Rosa is the new name for C. uljanini Radoszkowski & Mocsáry, 1889 nec Radoszkowski, 1877. Pictures of seventy-seven type specimens are given. © Paolo Rosa et al.

Zhang J.,Guangdong Pharmaceutical University | Luo X.,South China Agricultural University | Li H.,Shanghai JiaoTong University | Yue X.,Guangdong Medical College | And 3 more authors.
Oncology Reports | Year: 2014

Aberrant microRNA (miRNA) expression has been frequently observed in colorectal cancer (CRC), the third most common human cancer in the world. However, the roles of miRNAs in CRC remain poorly understood. The present study explored, identified and characterized the miRNAs that correlate with CRC progression. Deregulated level of microRNA-223 (miR-223) was screened out by miRNA microarray in colorectal tumor tissues and further confirmed by quantitative real-time PCR in a large cohort of CRC samples (n=90). After silencing miR-223 by artificial anti-miR-223 (miR-223-inhibitor), WST-1 and colony formation assays were employed to assess cell proliferation, and cell migration and invasion were evaluated by wound healing test and Transwell assays, respectively. Compared with adjacent non-tumor tissues, 22 miRNAs were screened out in CRC tissues with significance (>2-fold), of which 13 were upregulated and 9 were downregulated. miR-223 is one of the noticeably upregulated miRNAs. Large cohort CRC sample analyses showed that a higher level of miR-223 correlated with a higher clinical stage. Reducing miR-223 expression resulted in a decreased cell proliferation, migration and invasion in CRC cells. miR-223 functions as an oncomiR in CRC, therefore serving as a potential diagnostic and therapeutic target for the treatment of CRC.

Pang W.,Guangdong University of Technology | Wu J.,South China Agricultural University | Yuan Z.,South China Agricultural University | Liu Y.,South China Agricultural University | Chen G.,Dongguan University of Technology
Journal of the Physical Society of Japan | Year: 2011

An optical four-level atomic discrete system in a solid through optical induction is proposed. A theoretical scheme to produce lattice solitons (LSs) in the system is presented by means of the effects of enhanced self-phase modulation and the giant kerr effect in the electromagnetically induced transparency. The power density and the photon flux can be tuned to a very low level by the controlling field and the soliton can propagate with very slow group velocity. By changing the sign of the detuning Δ1, both in-phase and π out-of-phase LSs can be produced in this system. © 2011 The Physical Society of Japan.

A critical and annotated catalogue of the ninety-six type specimens of Chrysididae (Hymenoptera), belonging to sixty-seven species, housed in the insect collection of Maximilian Spinola is given. The neotypes of six species are designated: Chrysis bicolor Lepeletier, 1806; C. comparata Lepeletier, 1806; C. dives Dahlbom, 1854; C. pumila Klug, 1845; C. succincta Linnaeus, 1767; Hedychrum bidentulum Lepeletier, 1806. The lectotypes of twenty-four species are designated: Chrysis aequinoctialis Dahlbom, 1854; C. analis Spinola, 1808; C. assimilis Dahlbom, 1854; C. bihamata Spinola, 1838; C. chilensis Spinola, 1851; C. dichroa Dahlbom, 1854; C. distinguenda Dahlbom, 1854; C. episcopalis Spinola, 1838; C. grohmanni Dahlbom, 1854; C. incrassata Spinola, 1838; C. pallidicornis Spinola, 1838; C. pulchella Spinola, 1808; C. ramburi Dahlbom, 1854; C. refulgens Spinola, 1806; C. splendens Dahlbom, 1854; C. succinctula Dahlbom, 1854; C. versicolor Spinola, 1808; Elampus gayi Spinola, 1851; Hedychrum caerulescens Lepeletier, 1806; He. chloroideum Dahlbom, 1854; He. difficile Spinola, 1851; He. virens Dahlbom, 1854; Holopyga janthina Dahlbom, 1854; Ho. luzulina Dahlbom, 1854. Previous lectotype designations of five species are set aside: Chrysis bicolor Lepeletier, 1806 (designated by Morgan 1984); C. calimorpha Mocsáry, 1882 (designated by Móczár 1965); C. elegans Lepeletier, 1806 (designated by Bohart (in Kimsey and Bohart 1991)); Hedychrum chloroideum Dahlbom, 1854 (designated by Kimsey 1986); He. rutilans Dahlbom, 1854 (designated by Morgan 1984). Three new synonymies are proposed: Hedychrum intermedium Dahlbom, 1845, syn. n. of Holopyga fervida (Fabricius, 1781); Chrysis sicula Dahlbom, 1854, syn. n. of C. elegans Lepeletier, 1806; Chrysis succinctula Dahlbom, 1854, syn. n. of C. germari Wesmael, 1839. Chrysis distinguenda Spinola, 1838, and C. coronata Spinola, 1808, are considered nomina dubia. Hedychrum alterum Lepeletier, 1806, and He. aulicum Spinola, 1843, are considered nomina oblita. Hedychrum rutilans Dahlbom, 1854, and He. niemelai Linsenmaier, 1959, are retained as nomina protecta. The first available name for Chrysis succinctula sensu Linsenmaier is C. tristicula Linsenmaier, 1959, (stat. n.) The current status and validity of some types in the Spinola collection are discussed. Photographs of fifty-three types are given. © Paolo Rosa, Zai-fu Xu.

Elzubeir A.O.,University of Dongola | Chen Y.,South China Agricultural University
AMA, Agricultural Mechanization in Asia, Africa and Latin America | Year: 2013

An experimental solar dryer for dehydration of bulb onion (Allium cepa L.) had been designed by the first author and constructed at the workshop of South China Agricultural University-Guangzhou in which efficiency, cost and durability were optimally combined. The data were recorded by a programmable data acquisition system including microprocessor control, recorded data at ten minutes intervals. During winter season (Dec. 2000), solar heated air was 30.1 °C on average, relative humidity of 59.3 % on average, and flow rate of 72.7 m3/(h.m2. coll.surface). The temperatures rises of solar system was 1.7 °C and 16.1 °C, for those temperatures the average collection efficiency was about 54.7 %. Some drying parameters were calculated and results indicated that the numerical values were satisfactory. A techno-feasibility study gave a good result for the possibility of using the developed dryer in rural area.

He X.-L.,South China Agricultural University | He X.-L.,China Institute of Technology | Li T.-H.,China Institute of Technology | Jiang Z.-D.,South China Agricultural University | Shen Y.-H.,China Institute of Technology
Mycological Progress | Year: 2012

Four new Entoloma s. l. species (E. azureosquamulosum, E. caeruleoflavum, E. hainanense, and E. subtenuicystidiatum) are described from southern China. E. azureosquamulosum fits well within the section Rhamphocystotae, E. caeruleoflavum belongs to the section Entoloma, E. hainanense is placed in the section Calliderma, and E. subtenuicystidiatum is a species in the section Cyanula. Preliminary phylogenetic analyses for the four new species are provided based on ITS and LSU sequences in this paper. © 2012 German Mycological Society and Springer.

Fu C.-H.,National Cheng Kung University | Chen Y.-W.,National Cheng Kung University | Hsiao Y.-Y.,National Cheng Kung University | Pan Z.-J.,National Cheng Kung University | And 5 more authors.
Plant and Cell Physiology | Year: 2011

Orchids are one of the most ecological and evolutionarily significant plants, and the Orchidaceae is one of the most abundant families of the angiosperms. Genetic databases will be useful not only for gene discovery but also for future genomic annotation. For this purpose, OrchidBase was established from 37,979,342 sequence reads collected from 11 in-house Phalaenopsis orchid cDNA libraries. Among them, 41,310 expressed sequence tags (ESTs) were obtained by using Sanger sequencing, whereas 37,908,032 reads were obtained by using next-generation sequencing (NGS) including both Roche 454 and Solexa Illumina sequencers. These reads were assembled into 8,501 contigs and 76,116 singletons, resulting in 84,617 non-redundant transcribed sequences with an average length of 459 bp. The analysis pipeline of the database is an automated system written in Perl and C#, and consists of the following components: automatic pre-processing of EST reads, assembly of raw sequences, annotation of the assembled sequences and storage of the analyzed information in SQL databases. A web application was implemented with HTML and a Microsoft. NET Framework C# program for browsing and querying the database, creating dynamic web pages on the client side, analyzing gene ontology (GO) and mapping annotated enzymes to KEGG pathways. The online resources for putative annotation can be searched either by text or by using BLAST, and the results can be explored on the website and downloaded. Consequently, the establishment of OrchidBase will provide researchers with a high-quality genetic resource for data mining and facilitate efficient experimental studies on orchid biology and biotechnology. The OrchidBase database is freely available at http://lab.fhes.tn.edu.tw/est. © 2011 The Author.

Wahid A.,Bahauddin Zakariya University | Ahmad S.S.,Fatima Jinnah Women University | Zhao Y.,South China Agricultural University | Bell J.N.B.,Imperial College London
Pakistan Journal of Botany | Year: 2012

Study was conducted in the suburbs of Lahore city of Pakistan to ascertain the protective effects of ethylene diurea (EDU) on three cultivars of sesame plants against ambient air pollutants. Seasonal mean 10 hr pollution levels at the site remained very high (O3: 91 ppb; NO2: 38 ppb; SO2: 10 ppb). It was found that plants treated with highest EDU concentration (500 ppm) showed increases in stomatal conductance (52%), transpiration rate (53%) and net photosynthesis rate (61%) compared with non-EDU treated plants. EDU treated plants depicted luxurious vegetative growth with reduced rate of leaf senescence compared to control plants. EDU protection was remarkable on different biochemical attributes with increases recorded in total chlorophyll by 31%, carotenoids by 15%, protein by 62%, and ascorbic acid by 65%. Total dry biomass was increased from 147-197% and root/shoot ratio from 29-37% in EDU-treated plants compared to plant in non-EDU. Seed yield was greater by 33-43% in different sesame cultivars treated with highest EDU concentration than non-EDU plants demonstrating the efficacy of EDU in preventing air pollutants induced yield losses. The results have wider implications in understanding the injurious effects of air pollutants on agroeconomic husbandry in Pakistan.

Teixeira da Silva J.A.,P.O. Box 7 | Aceto S.,University of Naples Federico II | Liu W.,South China Agricultural University | Yu H.,National University of Singapore | Kanno A.,Tohoku University
Scientia Horticulturae | Year: 2014

For ornamental plants, in particular orchids, the flower is central to their beauty and commercial value. The ability to manipulate the floral transition from the vegetative to the reproductive phase and floral traits requires an understanding of the underlying molecular genetic mechanisms and robust transgenic protocols. Using Dendrobium species and hybrids, this review explores the advances that have been made in the genetics of flower development, color and senescence. Although the homologs of several MADS-box genes are still to be found, those that have already been cloned and analyzed bring promise to what has yet to be unraveled about the control of flower color and development. Recent advances in orchid transformation and the introduction of Dendrobium homologs into Arabidopsis thaliana have shed new light on the complexities of flower color and the ABCDE model of flower development in orchids, or the 'orchid code'. © 2014 Elsevier B.V.

Agency: Cordis | Branch: FP7 | Program: CP-SICA | Phase: ENV.2007.;ENV.2007. | Award Amount: 1.91M | Year: 2009

Project partner will complete a detailed multidisciplinary situation analysis of highland aquatic resources, focused on values, livelihoods, conservation issues and wise-use options at five sites in Asia (Guangdong, China; Uttrakhand and West Bengal, India and northern and central Vietnam). Factors assessed will include biodiversity and ecosystem services, including provisioning, regulating, supporting and cultural services. Livelihood strategies of households dependent on ecosystem services derived from highland aquatic resources, in particular poor, food-insecure and vulnerable people, will be assessed within a sustainable livelihoods framework and opportunities to enhance such livelihoods assessed. Institutional features, including local, national and international policy and legislation, trajectories of change, stakeholder values associated with highland aquatic resources and areas of conflict will be assessed. Stakeholder participation will be critical to ensure new knowledge is accessible for collective decision-making and development of policies for the equitable use and conservation; methods and indicators for participatory monitoring and evaluation of ecosystem services and biodiversity will be developed. Action plans will then be formulated with stakeholders to: monitor the health of highland aquatic resources; develop and promote wise-use, and where necessary livelihoods diversification, to enhance poor livelihoods and conservation; integrate sustainable and wise-use, livelihoods diversification and conservation with watershed management priorities throughout the region. Action plans will be implemented by stakeholders at four sites displaying high biodiversity in Asia and the ecosystem, livelihoods and institutional impacts assessed through participatory monitoring and evaluation. Best practices aimed at conserving biodiversity and sustaining ecosystem services will be communicated to potential users to promote uptake and enhanced policy formulation.

News Article | November 19, 2015
Site: news.yahoo.com

LONDON, (Reuters) - A new gene that makes bacteria highly resistant to a last-resort class of antibiotics has been found in people and pigs in China - including in samples of bacteria with epidemic potential, researchers said on Wednesday. The discovery was described as "alarming" by scientists, who called for urgent restrictions on the use of polymyxins - a class of antibiotics that includes the drug colistin and is widely used in livestock farming. "All use of polymyxins must be minimized as soon as possible and all unnecessary use stopped," said Laura Piddock, a professor of microbiology at Britain's Birmingham University who was asked to comment on the finding. Researchers led by Hua Liu from the South China Agricultural University who published their work in the Lancet Infectious Diseases journal found the gene, called mcr-1, on plasmids - mobile DNA that can be easily copied and transferred between different bacteria. This suggests "an alarming potential" for it to spread and diversify between bacterial populations, they said. The team already has evidence of the gene being transferred between common bacteria such as E.coli, which causes urinary tract and many other types of infection, and Klesbsiella pneumoniae, which causes pneumonia and other infections. This suggests "the progression from extensive drug resistance to pandrug resistance is inevitable," they said. "(And) although currently confined to China, mcr-1 is likely to emulate other resistance genes ... and spread worldwide." The discovery of the spreading mcr-1 resistance gene echoes news from 2010 of another so-called "superbug" gene, NDM-1, which emerged in India and rapidly spread around the world. Piddock and others said global surveillance for mcr-1 resistance is now essential to try to prevent the spread of polymyxin-resistant bacteria. China is one of the world's largest users and producers of colistin for agriculture and veterinary use. Worldwide demand for the antibiotic in agriculture is expected to reach almost 12,000 tonnes per year by the end of 2015, rising to 16,500 tonnes by 2021, according to a 2015 report by the QYResearch Medical Research Center. In Europe, 80 percent of polymixin sales - mainly colistin - are in Spain, Germany and Italy, according to the European Medicines Agency's Surveillance of Veterinary Antimicrobial Consumption (ESVAC) report. For the China study, researchers collected bacteria samples from pigs at slaughter across four provinces, and from pork and chicken sold in 30 open markets and 27 supermarkets in Guangzhou between 2011 and 2014. They also analyzed bacteria from patients with infections at two hospitals in Guangdong and Zhejiang. They found a high prevalence of the mcr-1 gene in E coli samples from animals and raw meat. Worryingly, the proportion of positive samples increased from year to year, they said, and mcr-1 was also found in 16 E.coli and K.pneumoniae samples from 1,322 hospitalized patients. David Paterson and Patrick Harris from Australia's University of Queensland, writing a commentary in the same journal, said the links between agricultural use of colistin, colistin resistance in slaughtered animals, colistin resistance in food, and colistin resistance in humans were now complete. "One of the few solutions to uncoupling these connections is limitation or cessation of colistin use in agriculture," they said. "Failure to do so will create a public health problem of major dimensions."

News Article | February 21, 2017
Site: cen.acs.org

Anyone who has ever been to a farm knows there’s no shortage of drool dangling from the mouths of barnyard animals. Those super-active salivary glands could someday be put to good use, according to a new study. Zhenfang Wu and colleagues at the South China Agricultural University transformed the salivary glands of mice into miniature bioreactors for producing human nerve growth factor (NGF) proteins in their spit (Sci. Rep. 2017, DOI: 10.1038/srep41270). “This is the first paper that reports production of therapeutic protein from transgenic animals’ saliva,” Wu says. Protein drugs, such as blood clotting factors and insulin, are often produced in large vats of genetically engineered cells. Sometimes yields are low, and if bacterial or yeast cells are used, the protein drugs may lack the appropriate chemical modifications that occur in mammalian cells, such as glycosylation. To get around that limitation, some scientists have turned to harvesting the proteins from transgenic animals. Two therapeutic proteins produced in in the milk of genetically modified animals, ATryn and Ruconest, have been approved for use in Europe and the U.S. In the new study, Wu’s team looked to produce NGF. Scientists have studied human NGF because of its therapeutic implications in a number of neurological diseases, including Alzheimer’s, Parkinson’s, spinal cord injury, and glaucoma. Surprisingly, NGF is produced in both mouse and human saliva, but Wu and colleagues engineered mice to produce human NGF protein in their salivary glands instead of the mouse version. To collect the NGF protein, the researchers anesthetized the mice and administered pilocarpine hydrochloride, a known salivary stimulant. After purifying NGF from the saliva, the team showed that the protein was functional, triggering rat adrenal gland cells to become neuronlike. “Currently we are working on using this process in pigs,” Wu says, adding that his team has already developed methods for “repeated, long-term and large-volume collection of saliva from pigs.” “The production of pharmaceutical proteins from transgenic animals is developing slowly. This is the case even for the production from milk, which is likely the best system,” says Louis-Marie Houdebine, an expert on producing drugs in transgenic animals at the French National Institute for Agricultural Research. Enqi Liu of the Laboratory Animal Center at Xi’an Jiaotong University School of Medicine says that compared with milk, saliva would be especially “susceptible to microbial contamination,” posing a further complication for purifying the proteins. But could scientists produce a high enough concentration of a protein and collect a large enough volume of saliva to make spit a viable option? “In theory, I think it could work,” says Karen Beauchemin, a ruminant nutrition scientist at Agriculture & Agri-Food Canada. Beauchemin says that dairy cows produce more than 200 L of saliva in a single day to buffer fermentation in the rumen, the cow’s first of four stomachs. Like humans, pigs have only one stomach. Wu says that swine produce about 15 L of saliva per day, and his team has been able to collect 3 L of spit per day from pigs, for 40 days straight, without any apparent harm to the animals. Houbedine points out that salivary glands are not the first unusual tissue researchers have attempted to tap for protein production. Other researchers have proposed to engineer bladder epithelium and male epididymis tissues for collecting therapeutic proteins in animal urine and semen, respectively. “These two systems were soon abandoned,” he says, perhaps because of low yield, and also the foreseeable difficultly in marketing such a product.

Chen S.,South China Agricultural University | Chen S.,Agency for Science, Technology and Research Singapore | Hu W.,South China Agricultural University | Xiao Y.,South China Agricultural University | And 3 more authors.
PLoS ONE | Year: 2012

3-Phenoxybenzoic acid (3-PBA) is of great environmental concern with regards to endocrine disrupting activity and widespread occurrence in water and soil, yet little is known about microbial degradation in contaminated regions. We report here that a new bacterial strain isolated from soil, designated DG-02, was shown to degrade 95.6% of 50 mg·L-1 3-PBA within 72 h in mineral salt medium (MSM). Strain DG-02 was identified as Bacillus sp. based on the morphology, physio-biochemical tests and 16S rRNA sequence. The optimum conditions for 3-PBA degradation were determined to be 30.9°C and pH 7.7 using response surface methodology (RSM). The isolate converted 3-PBA to produce 3-(2-methoxyphenoxy) benzoic acid, protocatechuate, phenol, and 3,4-dihydroxy phenol, and subsequently transformed these compounds with a qmax, Ks and Ki of 0.8615 h-1, 626.7842 mg·L-1 and 6.7586 mg·L-1, respectively. A novel microbial metabolic pathway for 3-PBA was proposed on the basis of these metabolites. Inoculation of strain DG-02 resulted in a higher degradation rate on 3-PBA than that observed in the non-inoculated soil. Moreover, the degradation process followed the first-order kinetics, and the half-life (t1/2) for 3-PBA was greatly reduced as compared to the non-inoculated control. This study highlights an important potential application of strain DG-02 for the in situ bioremediation of 3-PBA contaminated environments. © 2012 Chen et al.

Huang Q.,South China Agricultural University | Wong D.S.,City University of Hong Kong | Susilo W.,University of Wollongong
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2014

How to sign an electronic contract online between two parties (say Alice and Bob) in a fair manner is an interesting problem, and has been studied for a long time. Optimistic Fair Exchange (OFE) is an efficient solution to this problem, in which a semi-trusted third party named arbitrator is called in to resolve a dispute if there is one during an exchange between Alice and Bob. Recently, several extensions of OFE, such as Ambiguous OFE (AOFE) and Perfect AOFE (PAOFE), have been proposed to protect the privacy of the exchanging parties. These variants prevent any outsider including the arbitrator from telling which parties are involved in the exchange of signatures before the exchange completes. However, in PAOFE, AOFE, and all the current work on OFE, the arbitrator can always learn the signer's signature at (or before) the end of a resolution, which is undesirable in some important applications, for example, signing a contract between two parties which do not wish others to find out even when there is a dispute that needs a resolution by the arbitrator. In this work, we introduce a new notion called Privacy-Preserving Optimistic Fair Exchange (P2 OFE), in which other than Alice and Bob, no one else, including the arbitrator, can collect any evidence about an exchange between them even after the resolution of a dispute. We formally define P2 OFE and propose a security model. We also propose a concrete and efficient construction of P2 OFE, and prove its security based on the Strong Diffie-Helllman and Decision Linear assumptions in the standard model. © 2014 Springer International Publishing.

Wang C.,Institute of Molecular and Cell Biology | Ye F.,Nanyang Technological University | Kumar V.,Nanyang Technological University | Gao Y.-G.,Institute of Molecular and Cell Biology | And 3 more authors.
Nucleic Acids Research | Year: 2014

Pseudomonas aeruginosa relies on cell motility and ability to form biofilms to establish infections; however, the mechanism of regulation remains obscure. Here we report that BswR, a xenobiotic response element-type transcriptional regulator, plays a critical role in regulation of bacterial motility and biofilm formation in P. aeruginosa. Transcriptomic and biochemical analyses showed that BswR counteracts the repressor activity of MvaT, controls the transcription of small RNA rsmZ and regulates the biogenesis of bacterial flagella the crystal structure of BswR was determined at 2.3 Å resolution; the monomer comprises a DNA-binding domain with a helix-turn-helix motif in the N terminus and two helices (α6 and α7) with a V-shaped arrangement in the C-terminus. In addition to the contacts between the parallel helices α5 of two monomers, the two helical extensions (α6 and α7) intertwine together to form a homodimer, which is the biological function unit. Based on the result of DNase I protection assay together with structural analysis of BswR homodimer, we proposed a BswR-DNA model, which suggests a molecular mechanism with which BswR could interact with DNA. Taken together, our results unveiled a novel regulatory mechanism, in which BswR controls the motility and biofilm formation of P. aeruginosa by modulating the transcription of small RNA rsmZ. © 2014 The Author(s). Published by Oxford University Press.

Yue L.,CAS Guangzhou Institute of Energy Conversation | Yue L.,Yancheng Institute of Technology | Zhang W.,Yancheng Institute of Technology | Yang J.,South China Agricultural University | Zhang L.,CAS Guangzhou Institute of Energy Conversation
Electrochimica Acta | Year: 2014

A novel Si/porous-C composite with buffering voids was prepared by the co-assembly of phenol-formaldehyde resin, SiO2 and Si nanoparticles, followed by a carbonizing process and subsequent removal of SiO2 template. Si nanoparticle was coated with a layer of porous carbon shell with rationally designed void in between which provides the accommodating space for the volume change of Si over cycling. The as-prepared composite electrode exhibited good electrochemical performances as an anode material in lithium-ion cells, showing a stable reversible capacity of 980 mAh g-1 over 80 cycles with small capacity fade of 0.17%/cycle and high rate capability (721 mAh g-1 at 2000 mA g-1). © 2014 Elsevier Ltd.

Chen G.,Dongguan University of Technology | Luo Z.,South China Agricultural University | Wu J.,University of Toronto | Wu M.,Dongguan University of Technology
Journal of the Physical Society of Japan | Year: 2013

We study the possibility of switching the types of symmetry breaking bifurcation (SBB) in the cylinder shell waveguide with helical double-well potential along propagation direction. This model is described by the onedimensional nonlinear Schrödinger (NLS) equation. The symmetry- and antisymmetry-breakings can be caused by increasing the applied voltage onto the waveguide in the self-focusing and -defocusing cases, respectively. In the selffocusing case, the type of SBB can be switched from supercritical to subcritical. While in the self-defocusing case, the type of SBB can not be switched because only one type of SBB is found. © 2013 The Physical Society of Japan.

Deng Y.,Institute of Molecular and Cell Biology | Deng Y.,South China Agricultural University | Lim A.,Institute of Molecular and Cell Biology | Lee J.,Institute of Molecular and Cell Biology | And 5 more authors.
BMC Microbiology | Year: 2014

Background: Extensive use of antibiotics has fostered the emergence of superbugs that are resistant to multidrugs, which becomes a great healthcare and public concern. Previous studies showed that quorum sensing signal DSF (diffusible signal factor) not only modulates bacterial antibiotic resistance through intraspecies signaling, but also affects bacterial antibiotic tolerance through interspecies communication. These findings motivate us to exploit the possibility of using DSF and its structurally related molecules as adjuvants to influence antibiotic susceptibility of bacterial pathogens. Results: In this study, we have demonstrated that DSF signal and its structurally related molecules could be used to induce bacterial antibiotic susceptibility. Exogenous addition of DSF signal (cis-11-methyl-2-dodecenoic acid) and its structural analogues could significantly increase the antibiotic susceptibility of Bacillus cereus, possibly through reducing drug-resistant activity, biofilm formation and bacterial fitness. The synergistic effect of DSF and its structurally related molecules with antibiotics on B. cereus is dosage-dependent. Combination of DSF with gentamicin showed an obviously synergistic effect on B. cereus pathogenicity in an in vitro model. We also found that DSF could increase the antibiotic susceptibility of other bacterial species, including Bacillus thuringiensis, Staphylococcus aureus, Mycobacterium smegmatis, Neisseria subflava and Pseudomonas aeruginosa. Conclusion: The results indicate a promising potential of using DSF and its structurally related molecules as novel adjuvants to conventional antibiotics for treatment of infectious diseases caused by bacterial pathogens. © 2014 Deng et al.; licensee BioMed Central Ltd.

Hua L.,South China Agricultural University | Wu J.,Japan National Institute of Agrobiological Science | Chen C.,South China Agricultural University | Wu W.,South China Agricultural University | And 6 more authors.
Theoretical and Applied Genetics | Year: 2012

We report the isolation of Pi1, a gene conferring broad-spectrum resistance to rice blast (Magnaporthe oryzae). Using loss- and gain-of-function approaches, we demonstrate that Pi1 is an allele at the Pik locus. Like other alleles at this locus, Pi1 consists of two genes. A functional nucleotide polymorphism (FNP) was identified that allows differentiation of Pi1 from other Pik alleles and other non-Pik genes. A extensive germplasm survey using this FNP reveals that Pi1 is a rare allele in germplasm collections and one that has conferred durable resistance to a broad spectrum of pathogen isolates. © 2012 Springer-Verlag.

Nie P.-Y.,Guangdong University of Finance | Chen Y.-H.,South China Agricultural University
Energy Sources, Part B: Economics, Planning and Policy | Year: 2016

This research focuses on price discrimination policy in a duopoly market structure of firms purchasing energy from a monopolist supplier. The results indicate that the price discrimination of energy reduces social welfare and harms efficient firms, helping explain bans on price discrimination. Firms with lower efficiency benefit from price discrimination, while firms with higher efficiency suffer. Although the profits of efficient producers are reduced under price discrimination, the monopolist energy supplier is prone to price discrimination. The results from this research indicate that price discrimination for energy input is irrational. © 2016 Taylor & Francis Group, LLC.

Yuen T.H.,University of Hong Kong | Wong D.S.,City University of Hong Kong | Susilo W.,University of Wollongong | Huang Q.,South China Agricultural University
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2011

Since the introduction of concurrent signatures, the authorship binding of concurrent signatures has always been initiator-controlled, that is, only the initiator of a concurrent signature exchange can control "whether" and "when" to convert the exchanging ambiguous signatures to publicly verifiable ones concurrently. This binding control is not negotiable. In some applications however, this limitation is undesirable, and instead, as of optimistic fair exchange does, letting the responder control "whether" and "when" to have exchanged ambiguous signatures bound is needed. This motivates us towards constructing a new concurrent signature variant which supports negotiation between the original initiator-controlled binding and a new responder-controlled binding. In this paper, we formalize the notion and propose the first construction, which allows either the initiator or the responder to control "whether" and "when" the binding of the exchanging ambiguous signatures will take place concurrently. The scheme is backward compatible to the original concurrent signature and is also comparable in performance to the existing ones. © 2011 Springer-Verlag.

Nie P.-Y.,Guangdong University of Finance and Economics | Yang Y.-C.,Guangdong University of foreign Studies | Chen Y.-H.,South China Agricultural University | Wang Z.-H.,Guangdong University of Finance and Economics
Applied Energy | Year: 2016

Establishing a game theory model, this paper captures the effects of output subsidy on energy efficiency under Cournot competition and Stackelberg competition. Three types of subsidies are considered in the model, namely without subsidy, unilateral subsidy and bilateral subsidy. The findings indicate that firms without subsidy are not willing to improve energy efficiency. Also, subsidy stimulates the subsidized firms' outputs while deters the outputs of other firms. Meanwhile, the equilibrium subsidy intensity depends on firms' position. Furthermore, the minimal subsidy budgets under different situations are presented. Especially, given the fixed subsidy budget, the output of the subsidized firm is the highest if this firm plays the leading position. In addition, certain subsidy can reduce the total emission, while overdue subsidy cannot reach the environmental object. © 2016 Elsevier Ltd.

Sun J.,Beijing Technology and Business University | Zhu J.,Beijing Technology and Business University | Liu X.,South China Agricultural University | Du H.,Beijing Technology and Business University
Materials Research Bulletin | Year: 2013

Er3+/Ho3+/Yb3+/Tm3+ co-doped YVO4 phosphors were synthesized by the conventional solid-state reaction. Under 980 nm laser diode excitation, intense red, green and blue up-conversion emissions were observed for the Yb3+/Er3+, Yb3+/Ho3+ and Yb3+/Tm3+ couples in the YVO4 host, respectively, which were due to the successive energy transfer from Yb3+ to Er3+, Ho3+ or Tm 3+. Bright white luminescence upon 980 nm near-infrared excitation can be observed for the sample at the optimum chemical composition of YVO 4:10%Yb3+/1%Tm3+/0.3%Ho3+/0. 2%Er3+. Under different excitation pump powers, the obtained optimal color coordinate (0.323, 0.325) is very close to the standard white light (0.333, 0.333) coordinate. © 2013 Elsevier Ltd.

Chen S.,South China Agricultural University | Chen S.,Institute of Molecular and Cell Biology | Dong Y.H.,Institute of Molecular and Cell Biology | Chang C.,Institute of Molecular and Cell Biology | And 7 more authors.
Bioresource Technology | Year: 2013

Brevibacterium aureum DG-12, a new bacterial strain isolated from active sludge, was able to degrade and utilize cyfluthrin as a growth substrate in the mineral medium. Response surface methodology using central composite rotatable design of cultural conditions was successfully employed for optimization resulting in 88.6% degradation of cyfluthrin (50mgL-1) within 5days. The bacterium degraded cyfluthrin by cleavage of both the carboxylester linkage and diaryl bond to form 2,2,3,3-tetramethyl-cyclopropanemethanol, 4-fluoro-3-phenexy-benzoic acid, 3,5-dimethoxy phenol, and phenol, and subsequently transformed these compounds with a maximum specific degradation rate, half-saturation constant and inhibition constant of 1.0384day-1, 20.4967mgL-1, and 141.9013mgL-1, respectively. A novel degradation pathway for cyfluthrin was proposed based on analysis of these metabolites. In addition, this strain was found capable of degrading a wide range of synthetic pyrethroid insecticides. Our results suggest that B. aureum DG-12 may be an ideal microorganism for bioremediation of the pyrethroid-contaminated environments. © 2013 Elsevier Ltd.

Yang Y.-Y.,China National Analytical Center Guangzhou | Tang Y.-Z.,South China Agricultural University | Fan C.-L.,Jinan University | Luo H.-T.,China National Analytical Center Guangzhou | And 2 more authors.
Journal of Separation Science | Year: 2010

A method based on accelerated solvent extraction combined with rapid-resolution LC-MS for efficient extraction, rapid separation, online identification and accurate determination of the saikosaponins (SSs) in Radix bupleuri (RB) was developed. The RB samples were extracted by accelerated solvent extraction using 70% aqueous ethanol v/v as solvent, at a temperature of 120°C and pressure of 100 bar, with 10 min of static extraction time and three extraction cycles. Rapid-resolution LC separation was performed by using a C18 column at gradient elution of water (containing 0.5% formic acid) and acetonitrile, and the major constituents were well separated within 20 min. A TOF-MS and an IT-MS were used for online identification of the major constituents, and 27 SSs were identified or tentatively identified. Five major bioactive SSs (SSa, SSc, SSd, 6″-O-acetyl-SSa and 6″-O-acetyl-SSd) with obvious peak areas and good resolution were chosen as benchmark substances, and a triple quadrupole MS operating in multiple-reaction monitoring mode was used for their quantitative analysis. A total of 16 RB samples from different regions of China were analyzed. The results indicated that the method was rapid, efficient, accurate and suitable for use in the quality control of RB. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA.

Li W.,Hainan University | Li Y.-J.,South China Agricultural University | Yang R.-L.,South China Agricultural University
Modern Food Science and Technology | Year: 2013

To evaluate the phenolic contents, antioxidant and antiproliferative activities of phenolic extracts from 12 tropical fruits, the total phenolic content was determined by Folin-Ciocalteu method and the antioxidant activity was measured with oxygen radical absorbance capacity activities (ORAC). The ferric reducing ability of plasma (FRAP), and the antiproliferative activity against human hepatoma cells (HepG2) were analyzed by MTT assay. It was founda that the total phenolic contents ranged from 26.17 to 229.67 mg gallic acid equivalents (GAE) per 100g fresh weight (FW). Averrhoa carambola had the highest phenolic content, being of 8.87-fold higher than Persea americana which had the lowest phenolic content. The ORAC and FRAP values were in the ranges of 607.05~2631.17 μmol TE/100g FW and 462.12~1067.92 μmol TE/100g FW, respectively. Averrhoa carambola showed the highest ORAC value which was 4.33 times higher than Carica papaya, and the higherst FRAP value which was 2.31 times higher than Persea Americana. The limits of IC50 values against HepG2 cells were from 31.79 to 66.93 mg/mL. Carica papaya had the lowest antiproliferative activity, with a 2.11-fold higher IC50 value compared to Averrhoa carambola with the highest antiproliferative activity. In addition, the total phenolic contents showed significant correlations with ORAC (R2=0.7839), FRAP (R2=0.7636) and IC50 values against HepG2 cells (R2=0.8847).

Morris K.,University of Warwick | Linkies A.,Albert Ludwigs University of Freiburg | Muller K.,Albert Ludwigs University of Freiburg | Oracz K.,Albert Ludwigs University of Freiburg | And 4 more authors.
Plant Physiology | Year: 2011

The completion of germination in Lepidium sativum and other endospermic seeds (e.g. Arabidopsis [Arabidopsis thaliana]) is regulated by two opposing forces, the growth potential of the radicle (RAD) and the resistance to this growth from the micropylar endosperm cap (CAP) surrounding it. We show by puncture force measurement that the CAP progressively weakens during germination, and we have conducted a time-course transcript analysis of RAD and CAP tissues throughout this process. We have also used specific inhibitors to investigate the importance of transcription, translation, and posttranslation levels of regulation of endosperm weakening in isolated CAPs. Although the impact of inhibiting translation is greater, both transcription and translation are required for the completion of endosperm weakening in the whole seed population. The majority of genes expressed during this process occur in both tissues, but where they are uniquely expressed, or significantly differentially expressed between tissues, this relates to the functions of the RAD as growing tissue and the CAP as a regulator of germination through weakening. More detailed analysis showed that putative orthologs of cell wall-remodeling genes are expressed in a complex manner during CAP weakening, suggesting distinct roles in the RAD and CAP. Expression patterns are also consistent with the CAP being a receptor for environmental signals influencing germination. Inhibitors of the aspartic, serine, and cysteine proteases reduced the number of isolated CAPs in which weakening developed, and inhibition of the 26S proteasome resulted in its complete cessation. This indicates that targeted protein degradation is a major control point for endosperm weakening. © 2011 American Society of Plant Biologists.

Zhou J.,South China Agricultural University | Zhang H.,Institute of Molecular and Cell Biology | Wu J.,Institute of Molecular and Cell Biology | Liu Q.,South China Agricultural University | And 5 more authors.
Molecular Plant-Microbe Interactions | Year: 2011

Dickeya zeae is the causal agent of the rice foot rot disease, but its mechanism of infection remains largely unknown. In this study, we identified and characterized a novel gene designated as zmsA. The gene encodes a large protein of 2,346 amino acids in length, which consists of multidomains arranged in the order of N-terminus, β-ketoacyl synthase, acyl transferase, acyl carrier protein, β-ketoacyl reductase, dehydratase. This multidomain structure and sequence alignment analysis suggest that ZmsA is a member of the polyketide synthase family. Mutation of zmsA abolished antimicrobial activity and attenuated the virulence of D. zeae. To determine the relationship between antimicrobial activity and virulence, active compounds were purified from D. zeae EC1 and were structurally characterized. This led to identification of two polyamino compounds, i.e., zeamine and zeamine II, that were phytotoxins and potent antibiotics. These results have established the essential role of ZmsA in zeamine biosynthesis and presented a new insight on the molecular mechanisms of D. zeae pathogenicity. © 2011 The American Phytopathological Society.

Huang Q.,South China Agricultural University | Wong D.S.,City University of Hong Kong | Susilo W.,University of Wollongong
Information Sciences | Year: 2015

How to sign an electronic contract online between two parties (say Alice and Bob) in a fair manner is an interesting problem, and has been extensively studied for a long time. Optimistic Fair Exchange (OFE) is an efficient solution to it, in which a semi-trusted third party, named the arbitrator, is responsible for resolving any dispute that may arise during an exchange between Alice and Bob. Recently, several variants of OFE, such as Ambiguous OFE (AOFE) and Perfect AOFE (PAOFE), have been introduced to protect the privacy of Alice and Bob. These primitives prevent any outsider from telling which parties are involved in an exchange of digital signatures before the exchange completes. However, in PAOFE, AOFE and all the existing works on OFE, the arbitrator can always learn the signer's full signature at (or even before) the end of resolution, which is undesirable in some important applications, for example, signing a contract between two parties which do not want others to find out even when there is a dispute that needs resolution by the arbitrator. In this work, we introduce a new notion called Privacy-Preserving Optimistic Fair Exchange (P2OFE) for protecting the privacy of users, in which other than Alice and Bob, no one else including the arbitrator, can collect any evidence about an exchange between them even after the resolution of a dispute. We formally define P2OFE and present the corresponding security models and propose a concrete and efficient construction of P2OFE. We also discuss about several extensions about implementation. Our scheme is proved to be secure under the given security models based on the Strong Diffie-Helllman and Decision Linear assumptions without relying on the random oracle heuristic. © 2015 Elsevier Inc. All rights reserved.

Chen Z.,South China Agricultural University | Sun L.,South China Agricultural University | Sun L.,Hainan University | Liu P.,South China Agricultural University | And 4 more authors.
Plant Physiology | Year: 2015

Manganese (Mn) toxicity is a major constraint limiting plant growth on acidic soils. Superior Mn tolerance in Stylosanthes spp. has been well documented, but its molecular mechanisms remain largely unknown. In this study, superior Mn tolerance in Stylosanthes guianensis was confirmed, as reflected by a high Mn toxicity threshold. Furthermore, genetic variation of Mn tolerance was evaluated using two S. guianensis genotypes, which revealed that the Fine-stem genotype had higher Mn tolerance than the TPRC2001-1 genotype, as exhibited through less reduction in dry weight under excess Mn, and accompanied by lower internal Mn concentrations. Interestingly, Mn-stimulated increases in malate concentrations and exudation rates were observed only in the Fine-stem genotype. Proteomic analysis of Fine-stem roots revealed that S. guianensis Malate Dehydrogenase1 (SgMDH1) accumulated in response to Mn toxicity. Western-blot and quantitative PCR analyses showed that Mn toxicity resulted in increased SgMDH1 accumulation only in Fine-stem roots, but not in TPRC2001-1. The function of SgMDH1-mediated malate synthesis was verified through in vitro biochemical analysis of SgMDH1 activities against oxaloacetate, as well as in vivo increased malate concentrations in yeast (Saccharomyces cerevisiae), soybean (Glycine max) hairy roots, and Arabidopsis (Arabidopsis thaliana) with SgMDH1 overexpression. Furthermore, SgMDH1 overexpression conferred Mn tolerance in Arabidopsis, which was accompanied by increased malate exudation and reduced plant Mn concentrations, suggesting that secreted malate could alleviate Mn toxicity in plants. Taken together, we conclude that the superior Mn tolerance of S. guianensis is achieved by coordination of internal and external Mn detoxification through malate synthesis and exudation, which is regulated by SgMDH1 at both transcription and protein levels. © 2015 American Society of Plant Biologists. All rights reserved.

Huang Q.,South China Agricultural University | Wong D.S.,City University of Hong Kong | Susilo W.,University of Wollongong
Information Sciences | Year: 2011

Optimistic Fair Exchange (OFE) of digital signatures allows two parties to exchange their signatures in a fair manner so that a third party, called the arbitrator, gets involved only when there is a dispute. Previous work on OFE considers the two parties as individuals and there is no formal study on the scenario where the two parties are two groups of users. In this paper, we formalize this new variant and call it a Group-oriented Optimistic Fair Exchange (GOFE). GOFE allows two users from two different groups to exchange signatures on behalf of their groups in a fair and anonymous manner. We formalize the notion by providing the first set of security models for GOFE, and show that it is closely related to Ambiguous OFE (AOFE) proposed by Huang et al. in Asiacrypt 2008. In particular, we propose a generic transformation which converts a GOFE to an AOFE. We also give an efficient and concrete GOFE construction and prove its security under the security models we defined. The security of the scheme relies on the decision linear assumption and strong Diffie-Hellman assumption in the random oracle model. © 2011 Elsevier Inc. All rights reserved.

Huang Q.,South China Agricultural University | Wong D.S.,City University of Hong Kong | Susilo W.,University of Wollongong
IEEE Transactions on Information Forensics and Security | Year: 2011

Designated confirmer signature (DCS) extends the undeniable signature so that a party called confirmer can also confirm/disavow nonself-authenticating signatures on the signer's behalf. Previous DCS schemes, however, can let a signer confirm a valid signature but not disavow an invalid one, while only a confirmer can. It remains open to construct a DCS which also allows the signer to disavow. In this work, we propose new security models for formalizing the signer's ability to disavow. We propose a new DCS scheme and prove its security without random oracles. The new DCS scheme is efficient and also convertible. A signature in this new DCS consists of only three bilinear group elements. This is much shorter than any of the existing schemes. In addition, the scheme can be extended to support multiple confirmers and threshold conversion. Adding a confirmer incurs the addition of only one group element in a signature. Furthermore, we propose an efficient construction of ambiguous optimistic fair exchange (AOFE) of digital signatures based on the new DCS scheme. A partial AOFE signature consists of three elements in an elliptic curve group and four in group ${\BBZ}-p$, and a full signature has only three group elements, which are shorter than those in Garay 's scheme (Crypto 1999) and Huang 's scheme (Asiacrypt 2008). © 2006 IEEE.

Wu B.Q.,South China Agricultural University | Zhang T.,National Institute of Parasitic Diseases | Guo L.Q.,South China Agricultural University | Lin J.F.,South China Agricultural University
Poultry Science | Year: 2011

A novel Bacillus subtilis KD1 strain was isolated and identified from healthy broilers, and its phylogenetic classification was subsequently analyzed. To evaluate its probiotic availability, its growth characteristics and tolerance for the gut environment were evaluated in vitro. The results suggest that B. subtilis KD1 is superior in secreting neutral protease and is highly tolerant of gastric acid and bile salt. In the logarithmic growth phase, the neutral protease reached a maximum of 1,369.3 U/mL. When all live bacteria had become spores in the broth, B. subtilis KD1 was freeze dried and fed to broilers at 10 9, 5 × 10 9, and 1010 bacilli/kg of feed. The animal trial results suggest that the addition of the new strain significantly improved intestinal flora by increasing lactobacilli and reducing Escherichia coli (P < 0.05) as compared with the control; hence, B. subtilis KD1 is a promising probiotic organism in broilers. © 2011 Poultry Science Association Inc.

Gan Y.,South China University of Technology | Luo Y.,South China University of Technology | Feng Q.,Guangzhou China Resources Thermal Power Co. | Shi Y.,South China Agricultural University
Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery | Year: 2014

The characteristics of ethanol-air microscale laminar-flow diffusion combustion were investigated. Combined with experimental study and numerical simulation, the effects of surface heat loss on the flame stability in the confined space were systematically analyzed. The surface heat loss was controlled by electrical heating inside. According to the results, the electrical heating reduced the effects of heat loss and enhanced the stability effectively. Using the appropriate electrical heating power, it reached the widest stability limits of combustion. The flame feature size and temperature distribution were both changed by the electrical heating. The electrical heating raised the flame temperature. The chemical reaction rate became bigger, and the micro-flame shifed upstream. Within a certain range, the electrical heating increase was greater than the increase of the heat loss. The electrical heating inhibited the heat loss and enhanced the stability.

Bi H.,University of Illinois at Urbana - Champaign | Wang H.,South China Agricultural University | Cronan J.E.,University of Illinois at Urbana - Champaign
Chemistry and Biology | Year: 2013

Summary In the classical anaerobic pathway of unsaturated fatty acid biosynthesis, that of Escherichia coli, the double bond is introduced into the growing acyl chain by the FabA dehydratase/isomerase. Another dehydratase, FabZ, functions in the chain elongation cycle. In contrast, Aerococcus viridans has only a single FabA/FabZ homolog we designate FabQ. FabQ can not only replace the function of E. coli FabZ in vivo, but it also catalyzes the isomerization required for unsaturated fatty acid biosynthesis. Most strikingly, FabQ in combination with E. coli FabB imparts the surprising ability to bypass reduction of the trans-2-acyl-ACP intermediates of classical fatty acid synthesis. FabQ allows elongation by progressive isomerization reactions to form the polyunsaturated fatty acid, 3-hydroxy-cis-5, 7-hexadecadienoic acid, both in vitro and in vivo. FabQ therefore provides a potential pathway for bacterial synthesis of polyunsaturated fatty acids. © 2013 Elsevier Ltd.

Liu Q.,South China Agricultural University | Mathanker S.K.,University of Illinois at Urbana - Champaign | Zhang Q.,Washington State University | Hansen A.C.,University of Illinois at Urbana - Champaign
Transactions of the ASABE | Year: 2012

Miscanthus × giganteus is emerging as one of the most promising crops suitable for biomass production, as it requires low inputs and produces high yields. Miscanthus harvesting using forage and hay equipment presents a challenge because of the thickness and hardness of miscanthus stems. Biomechanical properties of the miscanthus stems were investigated for use in designing better harvesting and size reduction equipment. Material testing equipment was used to study cutting force, shearing strength, tensile strength, and bending strength. The cutting force was determined at the first internode, whereas other properties were determined at internodes one through seven. The shear strength of miscanthus stems at the first or second internode was about double that at internodes three through seven. Tensile strength of the cortex in the cross-sectional direction was about 0.4% of tensile strength in the longitudinal direction. Shearing strength of the cortex was 7.0 and 65.0 MPa and tensile strength was 288.1 and 1.1 MPa in the longitudinal and cross-sectional directions, respectively. The modulus of elasticity of miscanthus stems increased from 4,600 to 11,300 MPa as the internode number increased from first to seventh. The maximum cutting force to cut miscanthus stems was 83.0 N mm -1 for a flat blade and 54.6 N mm -1 for a serrated blade. The specific cutting energy was 87.5 mJ mm -2 for the flat blade and 66.1 mJ mm-2 for the serrated blade. Analysis revealed that the serrated blade employed less energy-demanding modes of failure than the flat blade, resulting in lower cutting energy and reduced cutting force. The results of this study may be useful in designing harvesting and size reduction equipment employing optimum failure modes to minimize the energy or to achieve desired quality of cut. © 2012 American Society of Agricultural and Biological Engineers.

Wang C.,Institute of Molecular and Cell Biology | Yan C.,South-Central University for Nationalities | Fuqua C.,Indiana University Bloomington | Zhang L.-H.,South China Agricultural University
Journal of Bacteriology | Year: 2014

Quorum sensing (QS) is a widespread mechanism of bacterial communication in which individual cells produce and respond to small chemical signals. In Agrobacterium tumefaciens, an acylhomoserine lactone-dependent QS mechanism is known to regulate the replication and conjugation of the tumor-inducing (Ti) plasmid. Most of the QS regulatory proteins are encoded within the Ti plasmid. Among them, TraI is the LuxI-type enzyme synthesizing the QS signal N-3-oxooctanoyl-L-homoserine lactone (3OC8HSL), TraR is the LuxR-type transcriptional factor that recognizes 3OC8HSL, and TraM is an antiactivator that antagonizes TraR. Recently, we identified a TraM homolog encoded by the traM2 gene in the chromosomal background of A. tumefaciens A6. In this study, we further identified additional homologs (TraI2 and TraR2) of TraI and TraR in this strain. We showed that similar to TraI, TraI2 could predominantly synthesize the QS signal 3OC8HSL. We also showed that TraR2 could recognize 3OC8HSL and activate the tra box-containing promoters as efficiently as TraR. Further analysis showed that traM2, traI2, and traR2 are physically linked on a mobile genetic element that is not related to the Ti plasmid. These findings indicate that A. tumefaciens A6 carries a second QS system that may play a redundant role in the regulation of the replication and conjugation of the Ti plasmid. © 2014, American Society for Microbiology.

Huang Q.,South China Agricultural University | Wong D.S.,City University of Hong Kong | Susilo W.,University of Wollongong
Information Sciences | Year: 2013

Ambiguous Optimistic Fair Exchange (AOFE), introduced by Huang et al. in ASIACRYPT 2008, is an extension of OFE that enhances the fairness of the two communicating parties in the exchange of signatures. The first scheme was proven secure without random oracles while its partial signature contains dozens of group elements. Recently, interactive AOFE was introduced and the construction is more practical, where a partial signature only contains three group elements. It is based on the existence of Designated Confirmer Signature (DCS) with a special property where one is able to sample a confirmer signature efficiently from a signer's signature space. Nevertheless, we note that there are only a few DCS schemes that have this special property. Security of the interactive AOFE construction relies on the q-Computational and Decisional Hidden Strong Diffie-Hellman assumptions. In this paper, we propose a new construction of interactive AOFE from DCS, where the underlying DCS is standard and does not require any special property. We also propose a new DCS construction. By applying our transformation from DCS to interactive AOFE, we build a concrete interactive AOFE which is secure under more standard number-theoretic assumptions, namely Strong Diffie-Hellman and Decision Linear assumptions, without random oracles. A partial signature of the interactive AOFE contains six group elements, while a full signature contains two only. © 2012 Elsevier Inc. All rights reserved.

Li B.,University for Business Studies | Zhou Y.,South China University of Technology | Wang X.,South China Agricultural University
International Journal of Production Research | Year: 2013

This paper investigates the problem of channel choice game in two power-imbalanced supply chains consisting of the leader supply chain and the follower supply chain. We assume that there exists symmetric and asymmetric cost information between the two supply chains, and that the two chains as well as the two members in each chain follow the Stackelberg game setting. We analyse four competition scenarios: both chains are decentralised, where individual members of both supply chains maximise their own profits by independently selecting their price policies; both chains are integrated, where manufacturers and retailers coordinate their decisions to maximise supply chain profits; the leader chain is decentralised and the follower integrated; the leader is integrated and the follower decentralised. The primary objective of this paper is to investigate the influence of power imbalance, information asymmetries, and the degree of product substitutability under channel choice equilibrium. We find that, in contrast to earlier literature where all manufacturers share equal or balanced decision-making power, an integrated distribution channel is the dominant strategy for the leader under symmetric and asymmetric information Stackelberg game. As the degree of product substitutability increases, the follower will gradually switch from integrated distribution channel to decentralised distribution channel; the follower can gain from constructing a decentralised distribution channel as the prediction accuracy of the leader increases. © 2013 Taylor & Francis.

Zhu L.,South China Agricultural University | Lin J.,South China Agricultural University | Ma J.,South China Agricultural University | Cronan J.E.,University of Illinois at Urbana - Champaign | And 2 more authors.
Antimicrobial Agents and Chemotherapy | Year: 2010

Triclosan, a very widely used biocide, specifically inhibits fatty acid synthesis by inhibition of enoyl-acyl carrier protein (ACP) reductase. Escherichia coli FabI is the prototypical triclosan-sensitive enoyl-ACP reductase, and E. coli is extremely sensitive to the biocide. However, other bacteria are resistant to triclosan, because they encode triclosan-resistant enoyl-ACP reductase isozymes. In contrast, the triclosan resistance of Pseudomonas aeruginosa PAO1 has been attributed to active efflux of the compound (R. Chuanchuen, R. R. Karkhoff-Schweizer, and H. P. Schweizer, Am. J. Infect. Control 31:124-127, 2003). We report that P. aeruginosa contains two enoyl-ACP reductase isozymes, the previously characterized FabI homologue plus a homologue of FabV, a triclosan-resistant enoyl-ACP reductase recently demonstrated in Vibrio cholerae. By deletion of the genes encoding P. aeruginosa FabI and FabV, we demonstrated that FabV confers triclosan resistance on P. aeruginosa. Upon deletion of the fabV gene, the mutant strain became extremely sensitive to triclosan (>2,000-fold more sensitive than the wild-type strain), whereas the mutant strain lacking FabI remained completely resistant to the biocide. Copyright © 2010, American Society for Microbiology. All Rights Reserved.

Zhou L.,Shanghai JiaoTong University | Wang J.-Y.,Shanghai JiaoTong University | Wang J.,South China Agricultural University | Poplawsky A.,University of Idaho | And 6 more authors.
Molecular Microbiology | Year: 2013

The diffusible factor synthase XanB2, originally identified in Xanthomonas campestris pv. campestris (Xcc), is highly conserved across a wide range of bacterial species, but its substrate and catalytic mechanism have not yet been investigated. Here, we show that XanB2 is a unique bifunctional chorismatase that hydrolyses chorismate, the end-product of the shikimate pathway, to produce 3-hydroxybenzoic acid (3-HBA) and 4-HBA. 3-HBA and 4-HBA are respectively associated with the yellow pigment xanthomonadin biosynthesis and antioxidant activity in Xcc. We further demonstrate that XanB2 is a structurally novel enzyme with three putative domains. It catalyses 3-HBA and 4-HBA biosynthesis via a unique mechanism with the C-terminal YjgF-like domain conferring activity for 3-HBA biosynthesis and the N-terminal FGFG motif-containing domain responsible for 4-HBA biosynthesis. Furthermore, we show that Xcc produces coenzyme Q8 (CoQ8) via a new biosynthetic pathway independent of the key chorismate-pyruvate lyase UbiC. XanB2 is the alternative source of 4-HBA for CoQ8 biosynthesis. The similar CoQ8 biosynthetic pathway, xanthomonadin biosynthetic gene cluster and XanB2 homologues are well conserved in the bacterial species within Xanthomonas, Xylella, Xylophilus, Pseudoxanthomonas, Rhodanobacter, Frateuria, Herminiimonas and Variovorax, suggesting that XanB2 may be a conserved metabolic link between the shikimate pathway, ubiquinone and xanthomonadin biosynthetic pathways in diverse bacteria. © 2012 Blackwell Publishing Ltd.

Liu Y.,South China Agricultural University | Chen X.,South China Agricultural University | Duan S.,Jinan University | Feng Y.,South China Agricultural University | An M.,Charles Sturt University
Dose-Response | Year: 2011

Allelopathy arises from the release of chemicals by one plant species that affect other species in its vicinity, usually to their detriment. Allelopathic effects have been demonstrated to be limiting factors for species distributions and ecological processes in some natural or agricultural communities. Based on the biphasic hormetic responses of plants to allelochemicals, ecological-limiting-factor models were introduced into the An-Johnson-Lovett hormesis model to improve modelling the phenomenon of allelopathic hormesis and to better reflect the nature of allelopathy as a limiting factor in ecological processes. Outcomes of the models have been compared for several sets of experimental data from the literature and good agreement between the models and data was observed, which indicates that the new models give some insight into the ecological mechanisms involved and may provide more options for modelling the allelopathic phenomenon as well as platforms for further research on plant allelopathic hormesis. © 2011 University of Massachusetts.

Ouyang Y.,St. Johns River Water Management District | Zhang J.E.,South China Agricultural University | Lin D.,Hainan University | Liu G.D.,University of Florida
Journal of Soils and Sediments | Year: 2010

Background, aim, and scope Atrazine (2-chloro-4-ethylamino- 6-isopropylamino-1,3,5-triazine) is one of the most widely used herbicides for broadleaf weed and certain annual grass controls and is popular because of its effectiveness and low cost. Losses of atrazine from agricultural lands into adjacent surface water and underlying groundwater have raised public concerns. Several computer models have been developed for atrazine runoff in watersheds. One limitation for most of these models, however, is that vast amounts of input parameters are required for simulations. These input parameters are sometimes difficult to obtain through the experimental measurements for model calibrations, validations, and applications. Therefore, a need exists to develop a simple and yet a realistic modeling tool that can be used for effectively investigating atrazine dynamics in agricultural soils. This study was designed to meet this need. Materials and methods A model was developed based on atrazine dynamics in agricultural soils. These dynamics include atrazine (1) application to soil, (2) loss from surface runoff, (3) volatilization, (4) sorption, (5) degradation, (6) root uptake, and (7) leaching. The model was constructed using the commercially available package Structural Thinking, Experiential Learning Laboratory with Animation (STELLA) and calibrated using field data prior to its applications. Results and discussion A simulation scenario was then performed to predict atrazine fate in a 1-ha field. Simulation results showed that atrazine runoff and leaching occurred within the first coupled rainfall events with a duration of about 40 days after its application to the soil. This occurred because atrazine was strongly adsorbed by the soil in addition to its degradation by soil microorganisms, volatilization to the atmosphere, and uptake by roots. The maximum adsorption rate of atrazine was found in 1 day and reached an equilibrium condition in about 100 days. Two degradation phases, namely, the fast and slow phases, were observed in this simulation. The fast degradation phase occurred within 1 week after atrazine application, whereas the slow degradation phase took place after 1 week of the atrazine application. About 25% of the total applied atrazine still remained in the soil at the end of the simulation period (120 days). Of which, almost all of them were retained in the solid phase. Conclusions A very good agreement was obtained between the model predictions and the field measurements. The model was quite successfully applied to predict the complex behaviors of atrazine in the soil. Recommendations and perspectives This study suggests that the model, developed with STELLA, has great potentials as a modeling tool for effective investigations of atrazine dynamics in agricultural soils due to its being simple and yet realistic. © Springer-Verlag 2009.

Higashi T.,Tokyo University of Agriculture and Technology | Yunghui M.,South China Agricultural University | Komatsuzaki M.,Ibaraki University | Miura S.,Japan National Agriculture and Food Research Organization | And 4 more authors.
Soil and Tillage Research | Year: 2014

No-tillage, cover crops, and N fertilization play important roles in conserving or increasing soil organic carbon (SOC). However, the effects of their interaction are less well known, particularly in Asian countries. We examined the effects of three tillage management systems, moldboard plow/rotary harrow (MP), rotary cultivator (RC), and no-tillage (NT); three winter cover crop types (FL: fallow, RY: rye, and HV hairy vetch); and two nitrogen fertilization rates (0 and 100kgNha-1 for upland rice and 0 and 20kgNha-1 for soybean production) on changes in SOC. Vertical distributions at 0-2.5, 2.5-7.5, 7.5-15, and 15-30cm depths of soil carbon content and bulk density were measured each year. From 2003 to 2011, NT and RC management increased SOC by 10.2 and 9.0Mgha-1, whereas SOC under the MP system increased only by 6.4Mgha-1. Cover crop species also significantly increased SOC in the same period by 13.4 and 8.6Mgha-1 for rye and hairy vetch, respectively, although SOC with fallow increased only by 5.4Mgha-1. Continuous soil management for 9 years enhanced SOC accumulation. Summer crop species between upland rice and soybean strongly affected SOC; the SOC increases were 0.29Mgha-1year-1 for the upland rice rotation and 1.84Mgha-1year-1 for the soybean rotation. However, N fertilization levels did not significantly affect SOC. These results suggest that the NT system and rye cover crop enhance carbon sequestration in Kanto, Japan, but that their contributions differ depending on the combination of main and cover crops. © 2014 .

Yang C.,Guangdong Industry Technical College | Yang C.,University of Tennessee at Knoxville | Wei H.,University of Tennessee at Knoxville | Wei H.,Lamar University | And 7 more authors.
Journal of Materials Chemistry A | Year: 2015

Polymer nanocomposites exhibit unique physicochemical properties that cannot be obtained with individual components acting alone. Polymer nanocomposites have attracted significant research interests due to their promising potential for versatile applications ranging from environmental remediation, energy storage, electromagnetic (EM) absorption, sensing and actuation, transportation and safety, defense systems, information industry, to novel catalysts, etc. In particular, polymer nanocomposites have attracted intensive research interest for solving both energy and environmental issues. This review paper mainly focuses on the most recent advances in polymer nanocomposites for energy storage (i.e., electrochemical capacitors and batteries), energy saving (i.e., electrochromic devices and carbon dioxide capture), and anticorrosion (conductive and non-conductive polymer nanocomposite anticorrosive coatings) applications. © The Royal Society of Chemistry.

Qahri-Saremi H.,University of Illinois at Springfield | Qahri-Saremi H.,DePaul University | Turel O.,California State University, Fullerton | Turel O.,South China Agricultural University
Computers and Education | Year: 2016

This study focuses on three objectives. First, it investigates distinctive profiles of adolescents based on combinations of their levels of behavioral, cognitive, and emotional engagement with school. Second, it examines whether adolescents' educational development outcomes (GPA) and extent of use of utilitarian (school-oriented) and hedonic (social media and videogames) information technologies (IT) vary as a function of their school engagement profiles. Third, it probes the mediation effects of adolescents' extent of use of utilitarian and hedonic IT on the relation between the different school engagement dimensions and educational development outcomes. The sample (n = 6885) was drawn from a large nationally representative dataset that is part of a series of annual surveys of American adolescents. Latent profile analysis identified five distinctive profiles of adolescents based on the combinations of their levels of three school engagement dimensions. The results of ANCOVA analyses indicated that these profiles differ in the use of utilitarian and hedonic IT as well as GPAs. Moreover, results of structural equation modeling showed that while the extent of use of hedonic IT partially mediated the effect of school engagement dimensions on GPA, the extent of use of utilitarian IT did not. Considering the importance of adolescents' school engagement for their development and the essential role of IT in adolescents’ lives, our findings make important contributions to the literature and shed light on promising avenues for future research. © 2016 Elsevier Ltd

Li Y.-W.,Sun Yat Sen University | Li X.,Sun Yat Sen University | Xiao X.-X.,Sun Yat Sen University | Zhao F.,Chinese Academy of Fishery Sciences | And 3 more authors.
Developmental and Comparative Immunology | Year: 2014

Tumor necrosis factor receptor (TNFR)-associated factor 6 (TRAF6) is a crucial signal transducer in both the TNFR superfamily and Toll-like receptor/interleukin 1R family. Although significant progress has been made in clarifying the role of TRAF6 in mammals, the function of TRAF6 in fish is still poorly understood. In this study, we cloned the orange-spotted grouper (Epinephelus coioides) TRAF6 (EcTRAF6) cDNA, with an open reading frame of 1713. bp encoding 570 amino acids. Sequence analysis indicated that EcTRAF6 contains the four characteristic domains conserved in the TRAF family, including an N-terminal RING finger, two zinc fingers, a coiled-coil domain, and a C-terminal MATH domain. Homology alignment and phylogenetic analysis demonstrated that EcTRAF6 shares high sequence identity with TRAF6 of other fish species. The EcTRAF6 gene contains seven exons and six introns, which is similar to the organization in ayu, but not in the common carp, human, or mouse (six exons and five introns). EcTRAF6 transcripts were broadly expressed in all tissues tested, and increased after infection with Cryptocaryon irritans. Intracellular localization showed EcTRAF6 was distributed mainly in the cytoplasm. Over-expression of wild type (WT) EcTRAF6, truncated forms of EcTRAF6, including δZinc finger 2 and δMATH, and a mutant of C78A activated NF-κB strongly in HEK293T cells; whereas truncations, including δRING, δZinc finger 1 and δcoiled-coiled, and a mutant of K132R induced the activity of NF-κB slightly compared to WT EcTRAF6, implying the latter has a more crucial role in downstream signal transduction. Together, these results suggested EcTRAF6 functions like that of mammals to activate NF-κB, and it might have an important role in host defense against parasitic infections. © 2013 Elsevier Ltd.

Liu J.-Q.,Sichuan University | Duan Y.-W.,CAS Kunming Institute of Botany | Hao G.,South China Agricultural University | Ge X.-J.,CAS South China Botanical Garden | Sun H.,CAS Kunming Institute of Botany
Journal of Systematics and Evolution | Year: 2014

As the highest and largest plateau in the world, the Qinghai-Tibet Plateau, with its numerous endemic species, is one of the important alpine biodiversity hotspots. Only recently have the evolutionary histories and underlying adaptations of these alpine plants become clear, through research mostly based on testable experiments and analyses. In this issue, we collected a total of 13 papers related to such aims. In addition, we selected a few published papers to highlight the major findings in the recent past. We also outlined the outlook and direction of future research. © 2014 Institute of Botany, Chinese Academy of Sciences.

Li C.,Guangdong Academy of Agricultural Sciences | Chen S.,Fujian Academy of Agricultural science | Zuo C.,South China Agricultural University | Sun Q.,Guangdong Academy of Agricultural Sciences | And 3 more authors.
European Journal of Plant Pathology | Year: 2011

Fusarium oxysporum f. sp. cubense (Foc) is the causal pathogen of Fusarium wilt of banana. To understand infection of banana roots by Foc race 4, we developed a green fluorescent protein (GFP)-tagged transformant and studied pathogenesis using fluorescence microscopy and confocal laser scanning microscopy. The transformation was efficient, and GFP expression was stable for at least six subcultures with fluorescence clearly visible in both hyphae and spores. The transformed Foc isolate also retained its pathogenicity and growth pattern, which was similar to that of the wild type. The study showed that: (i) Foc race 4 was capable of invading the epidermal cells of banana roots directly; (ii) potential invasion sites include epidermal cells of root caps and elongation zone, and natural wounds in the lateral root base; (iii) in banana roots, fungal hyphae were able to penetrate cell walls directly to grow inside and outside cells; and (iv) fungal spores were produced in the root system and rhizome. To better understand the interaction between Foc race 4 and bananas, nine banana cultivars were inoculated with the GFP-transformed pathogen. Root exudates from these cultivars were collected and their effect on conidia of the GFP-tagged Foc race 4 was determined. Our results showed that roots of the Foc race 4-susceptible banana plants were well colonized with the pathogen, but not those of the Foc race 4-resistant cultivars. Root exudates from highly resistant cultivars inhibited the germination and growth of the Fusarium wilt pathogen; those of moderately resistant cultivars reduced spore germination and hyphal growth, whereas the susceptible cultivars did not affect fungal germination and growth. The results of this work demonstrated that GFP-tagged Foc race 4 isolates are an effective tool to study plant-fungus interactions that could potentially be used for evaluating resistance in banana to Foc race 4 by means of root colonization studies. Banana root exudates could potentially also be used to identify cultivars in the Chinese Banana Germplasm Collection with resistance to the Fusarium wilt pathogen. © 2011 KNPV.

Wang X.R.,South China Agricultural University | Zhu X.W.,South China Agricultural University | Kong X.C.,South China Agricultural University | Mota M.M.,University of Évora
Journal of Applied Entomology | Year: 2011

Pine wilt disease (PWD) caused by pinewood nematode (PWN) Bursaphelenchus xylophilus has originated serious loss to pine forestry around the world. Monochamus alternatus is the most important vector of B. xylophilus in Japan and China. It is necessary to develop an efficient method to store M. alternatus for subsequent PCR detection of B. xylophilus. In the present study, beetle samples carrying nematodes were stored in 75% alcohol. A simple procedure was firstly developed for isolating B. xylophilus DNA in 2 mg stored beetle tissue carrying nematodes for subsequent nematode detection by PCR amplification. The B. xylophilus- specific amplicon of 403 bp (DQ855275) was generated by PCR assay from the stored beetle tissue. To our knowledge, this is the first report of a rapid detection of the pine wood nematode -B. xylophilus in stored M. alternatus by rDNA amplification established without a separate nematode extraction. This result will provide a useful method to detect B. xylophilus in stored M. alternatus. © 2010 Blackwell Verlag, GmbH.

Pang X.,South China Agricultural University | Pang X.,North University of China | Yang B.,Shaanxi Normal University | Huang Q.,South China Agricultural University
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2012

We consider the following problem: a user with either limited resources or limited expertise wants to outsource its private documens, which are associated with noisy keywords, to an untrusted cloud server in a private manner, while maintaining the ability to retrieve the stored data in a fault-tolerant manner. For example, the organization of homeland security wishes to outsource its private criminal database comprised of a set of criminal dossiers to the cloud server in encrypted form and hopes to retrieve encrypted dossiers by biometrics. In this paper, we first present a general framework for searching on private-key encrypted data by noisy keywords in a fault-tolerant manner. Then we propose a concrete scheme which is proved secure against an adaptive adversary under well-defined security definition. It achieves search in two rounds of communication, and requires an amount of work from the server that is linear in the number of noisy keywords. © 2012 Springer-Verlag.

Yang B.,Shaanxi Normal University | Zhang M.,Shaanxi Normal University | Zhang M.,South China Agricultural University | Zhang M.,Kyushu University
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2012

We propose a leakage-resilient unbounded extensible set delegation encryption scheme, which tolerates amount of bounded key leakage and supports unbounded delegation depth. Our scheme provides the tolerance of key continual leakage that can capture both memory leakage and continual leakage, which has appealing applications since there are multiple secret keys per identity set and also can periodically update and refresh the secret key. We construct the scheme in composite order bilinear groups and prove the security with dual system encryption methodology. © 2012 Springer-Verlag.

Kong C.-H.,China Agricultural University | Chen X.-H.,South China Agricultural University | Hu F.,South China Agricultural University | Zhang S.-Z.,China Agricultural University
Pest Management Science | Year: 2011

Background: One promising area of paddy weed control is the potential for exploiting the weed-suppressing ability of rice. This study was conducted to develop commercially acceptable allelopathic rice cultivars using crosses between allelopathic rice variety PI312777 and commercial Chinese cultivars (N2S, N9S, Huahui354, Peiai64S and Tehuazhan35), and to assess their weed suppression and grain yield in paddy fields in relation to their parents. Results: There was a positive dominance in the crosses Huahui354 × PI312777 and N2S × PI312777 but recessive or negative dominance in N9S × PI312777, Peiai64S × PI312777 and Tehuazhan35 × PI312777. Huahui354 × PI312777 and N2S × PI312777 showed stronger weed suppression than their parents and other crosses. Finally, an F8 line with an appearance close to Huahui354 and a magnitude of weed suppression close to PI312777 was obtained from Huahui354 × PI312777. This line, named Huagan-3, was released as a first commercially acceptable allelopathic rice cultivar in China. The grain yield and quality of Huagan-3 met the commercial standard of the local rice industry. Huagan-3 greatly suppressed paddy weeds, although suppression was influenced by year-to-year variation and plant density. There was no certain yield reduction in Huagan-3 even under a slight infestation of barnyard grass in paddy fields. Conclusion: The successful breeding of Huagan-3 with high yield and strong weed suppression may be incorporated into present rice production systems to minimise the amount of herbicide used. © 2011 Society of Chemical Industry.

Zhang H.,South China Agricultural University | Kalkman V.J.,National Museum of Natural History | Tong X.,South China Agricultural University
International Journal of Odonatology | Year: 2011

A synopsis of the genus Philosina is provided. Larvae of the two known species, P. alba and P. buchi are described for the first time. The distribution of both species is discussed and information on behaviour and habitat is summarized. The specialized larvae of Philosina show a strong resemblance to those of Rhinagrion, suggesting that they are sister genera. The unique characters of the larva, especially the arrangement and structure of the caudal lamellae, mean that neither genus fits into any of the currently recognized families of Zygoptera. It is noted that these genera could be placed in their own family.However, caution is exercised pending a better understanding of the family Megapodagrionidae based on DNA work,and they are therefore retained in Megapodagrionidae. © 2011 Worldwide Dragonfly Association.

Liu Y.-Y.,South China Agricultural University | Wang Y.,China Agricultural University | Walsh T.R.,Heath Park Hospital | Yi L.-X.,South China Agricultural University | And 16 more authors.
The Lancet Infectious Diseases | Year: 2016

Background: Until now, polymyxin resistance has involved chromosomal mutations but has never been reported via horizontal gene transfer. During a routine surveillance project on antimicrobial resistance in commensal Escherichia coli from food animals in China, a major increase of colistin resistance was observed. When an E coli strain, SHP45, possessing colistin resistance that could be transferred to another strain, was isolated from a pig, we conducted further analysis of possible plasmid-mediated polymyxin resistance. Herein, we report the emergence of the first plasmid-mediated polymyxin resistance mechanism, MCR-1, in Enterobacteriaceae. Methods: The mcr-1 gene in E coli strain SHP45 was identified by whole plasmid sequencing and subcloning. MCR-1 mechanistic studies were done with sequence comparisons, homology modelling, and electrospray ionisation mass spectrometry. The prevalence of mcr-1 was investigated in E coli and Klebsiella pneumoniae strains collected from five provinces between April, 2011, and November, 2014. The ability of MCR-1 to confer polymyxin resistance in vivo was examined in a murine thigh model. Findings: Polymyxin resistance was shown to be singularly due to the plasmid-mediated mcr-1 gene. The plasmid carrying mcr-1 was mobilised to an E coli recipient at a frequency of 10-1 to 10-3 cells per recipient cell by conjugation, and maintained in K pneumoniae and Pseudomonas aeruginosa. In an in-vivo model, production of MCR-1 negated the efficacy of colistin. MCR-1 is a member of the phosphoethanolamine transferase enzyme family, with expression in E coli resulting in the addition of phosphoethanolamine to lipid A. We observed mcr-1 carriage in E coli isolates collected from 78 (15%) of 523 samples of raw meat and 166 (21%) of 804 animals during 2011-14, and 16 (1%) of 1322 samples from inpatients with infection. Interpretation: The emergence of MCR-1 heralds the breach of the last group of antibiotics, polymyxins, by plasmid-mediated resistance. Although currently confined to China, MCR-1 is likely to emulate other global resistance mechanisms such as NDM-1. Our findings emphasise the urgent need for coordinated global action in the fight against pan-drug-resistant Gram-negative bacteria. Funding: Ministry of Science and Technology of China, National Natural Science Foundation of China. © 2016 Elsevier Ltd.

Li P.,China Agricultural University | Zhu Y.,China Agricultural University | He S.,China Agricultural University | Fan J.,South China Agricultural University | And 2 more authors.
Journal of Agricultural and Food Chemistry | Year: 2012

Diacetyl is a natural byproduct of fermentation and known to be an important flavor compound in many food products. Because of the potential undesirable effects of diacetyl on health safety and beer flavor, determination of its concentration in beer samples is essential and its analytical methods have attracted close attention recently. The aim of the present work is to develop and validate a novel high-performance liquid chromatography method for the quantification of diacetyl in beer based on the derivatization reaction of diacetyl with 4-nitro-o-phenylenediamine (NPDA). After the derivatization with NPDA in pH 3.0 at 45 °C for 20 min, diacetyl was separated on a kromasil C 18 column at room temperature in the form of the resulting 6-nitro-2,3-dimethylquinoxaline and detected by the ultraviolet detector at 257 nm. The results showed that the correlation coefficient for the method was 0.9992 in the range of 0.0050-10.0 mg L -1 and the limit of detection was 0.0008 mg L -1 at a signal-to-noise ratio of 3. The applicability of the proposed method was evaluated in the analysis of beer samples with the recovery range of 94.0-99.0% and relative standard deviation range of 1.20-3.10%. The concentration levels of diacetyl detected in beer samples from 12 brands ranged from 0.034 to 0.110 mg L -1. The proposed method showed efficient chromatographic separation, excellent linearity, and good repeatability that can be applied to quantification of diacetyl in beer samples. © 2012 American Chemical Society.

Liang Q.,South China Agricultural University | Cheng X.,China Agricultural University | Cheng X.,Guangzhou Academy of Agricultural science | Mei M.,China Agricultural University | And 2 more authors.
Annals of Botany | Year: 2010

Background and Aims: Low phosphorus (P) availability is a major constraint to soybean growth and production, especially in tropical and subtropical areas. Root traits have been shown to play critical roles in P efficiency in crops. Identification of the quantitative trait loci (QTLs) conferring superior root systems could significantly enhance genetic improvement in soybean P efficiency. Methods: A population of 106 F9 recombinant inbred lines (RILs) derived from a cross between BD2 and BX10, which contrast in both P efficiency and root architecture, was used for mapping and QTL analysis. Twelve traits were examined in acid soils. A linkage map was constructed using 296 simple sequence repeat (SSR) markers with the Kosambi function, and the QTLs associated with these traits were detected by composite interval mapping and multiple-QTL mapping. Key Results: The first soybean genetic map based on field data from parental genotypes contrasting both in P efficiency and root architecture was constructed. Thirty-one putative QTLs were detected on five linkage groups, with corresponding contribution ratios of 9 1-31 1 %. Thirteen putative QTLs were found for root traits, five for P content, five for biomass and five for yield traits. Three clusters of QTLs associated with the traits for root and P efficiency at low P were located on the B1 linkage group close to SSR markers Satt519 and Satt519-Sat-128, and on the D2 group close to Satt458; and one cluster was on the B1 linkage group close to Satt519 at high P. Conclusions: Most root traits in soybean were conditioned by more than two minor QTLs. The region closer to Satt519 on the B1 linkage group might have great potential for future genetic improvement for soybean P efficiency through root selection. © The Author 2010.

Zhong X.-L.,South China Agricultural University | Zhong X.-L.,Nanjing University | Zhong X.-L.,CAS Nanjing Institute of Soil Science | Zhou S.-L.,Nanjing University | And 2 more authors.
Journal of Hazardous Materials | Year: 2011

Mobility and bioavailability of soil heavy metals strongly depend on their fractions. Secondary-phase fraction (SPF) of heavy metal, including acid-soluble, reducible and oxidizable fractions, is considered as direct and potential hazardous fraction to organisms. The ratio of SPF to the total concentration of heavy metal represents its bioavailability. In this study, 126 topsoil samples were collected in Kunshan, Jiangsu, China. Fraction concentrations of heavy metals, and their bioavailability and spatial distributions were determined, and relationships between their fractions and types of industry zones were analyzed. Results showed that Cd and Pb had the greatest SPFs among all metals (78.61% and 62.60%, respectively). Great SPFs of Cd and Pb were observed in the dyeing and paper-making industry zone, while great SPFs of Cr, Cu, Zn, Ni were in the smelting and plating industry zone. For most metals, fraction distributions were controlled by soil organic matter and clay contents. Spatial principal component analysis showed SPFs of heavy metals can be explained by two principle components (PCs). PC1 represented SPFs of Cd, Cr, Cu, Pb and Zn, while PC2 represented SPFs of Ni and Co. The spatial distributions of SPFs were influenced by geochemical character, industrial sewage irrigation and soil physico-chemical properties. © 2011 Elsevier B.V.

Wu W.-H.,CAS Institute of Botany | Wu W.-H.,South China Agricultural University | Meng T.,CAS Institute of Botany | Xu W.-B.,CAS Institute of Botany | And 2 more authors.
Phytotaxa | Year: 2012

A new species of Gesneriaceae from Southwest Guangxi, China is described here as Primulina sinovietnamica. This previously unknown species is morphologically similar to P. pungentisepala and P. ningmingensis, but can be distinguished from the latter two taxa by several non-overlapping morphological characters. This hypothesis is consistent with the molecular phylogenetic tree based on sequences of the chloroplast matK gene, confirming evolutionary affinity of the new species to the two morphologically similar taxa. The three sampled individuals from the two presently known populations of the new species cluster together in the phylogenetic analysis, separated from the other two closest taxa by two common base substitutions, confirming the recognition of this new species. © 2012 Magnolia Press.

Yang F.,Henan University of Science and Technology | Yang F.,South China Agricultural University | Li Z.L.,South China Agricultural University | Shan Q.,Chinese Academy of Fishery Sciences | Zeng Z.L.,South China Agricultural University
Journal of Veterinary Pharmacology and Therapeutics | Year: 2014

The pharmacokinetics of doxycycline was studied in plasma after a single dose (20 mg/kg) of intravenous or oral administration to tilapia (Oreochromis aureus × Oreochromis niloticus) reared in fresh water at 24 °C. Plasma samples were collected from six fish per sampling point. Doxycycline concentrations were determined by high-performance liquid chromatography with a 0.005 μg/mL limit of detection, then were subjected to noncompartmental analysis. Following oral administration, the double-peak phenomenon was observed, and the first (Cmax1) and second (Cmax2) peaks were 1.99 ± 0.43 μg/mL at 2.0 h and 2.27 ± 0.38 μg/mL at 24.0 h, respectively. After the intravenous injection, a Cmax2 (12.12 ± 1.97 μg/mL) was also observed, and initial concentration of 45.76 μg/mL, apparent elimination rate constant (λz) of 0.018 per h, apparent elimination half-life (t1/2λz) of 39.0 h, systemic total body clearance (Cl) of 41.28 mL/h/kg, volume of distribution (Vz) of 2323.21 mL/kg, and volume of distribution at steady-state (Vss) of 1356.69 mL/kg were determined, respectively. While after oral administration, the λz, t1/2λz, and bioavailability of doxycycline were 0.009 per h, 77.2 h, and 23.41%, respectively. It was shown that doxycycline was relatively slowly and incompletely absorbed, extensively distributed, and slowly eliminated in tilapia, in addition, doxycycline might undergo enterohepatic recycling in tilapia. © 2014 John Wiley & Sons Ltd.

Sellamuthu R.,International Rice Research Institute | Sellamuthu R.,Tamil Nadu Agricultural University | Liu G.F.,International Rice Research Institute | Liu G.F.,South China Agricultural University | And 2 more authors.
Field Crops Research | Year: 2011

Drought is a major constraint for rice production and yield stability in rainfed ecosystems, especially when it occurs during the reproductive stage. Combined genetic and physiological analysis of reproductive-growth traits and their effects on yield and yield components under drought stress is important for dissecting the biological bases of drought resistance and for rice yield improvement in water-limited environments. A subset of a doubled haploid (DH) line population of CT9993-5-10-1-M/IR62266-42-6-2 was evaluated for variation in plant water status, phenology, reproductive-growth traits, yield and yield components under reproductive-stage drought stress and irrigated (non-stress) conditions in the field. Since this DH line population was previously used in extensive quantitative trait loci (QTLs) mapping of various drought resistance component traits, we aimed at identifying QTLs for specific reproductive-growth and yield traits and also to validate the consensus QTLs identified earlier in these DH lines using meta-analysis. DH lines showed significant variation for plant water status, reproductive-growth traits, yield and yield components under drought stress. Total dry matter, number of panicles per plant, harvest index, panicle harvest index, panicle fertility, pollen fertility, spikelet fertility and hundred grain weight had significant positive correlations with grain yield under drought stress. A total of 46 QTLs were identified for the various traits under stress and non-stress conditions with phenotypic effect ranging from 9.5 to 35.6% in this study. QTLs for panicle exsertion, peduncle length and pollen fertility, identified for the first time in this study, could be useful in marker-assisted breeding (MAB) for drought resistance in rice. A total of 97 QTLs linked to plant growth, phenology, reproductive-growth traits, yield and its components under non-stress and drought stress, identified in this study as well as from earlier published information, were subjected to meta-analysis. Meta-analysis identified 23 MQTLs linked to plant phenology and production traits under stress conditions. Among them, four MQTLs viz., 1.3 for plant height, 3.1 for days to flowering, 8.1 for days to flowering or delay in flowering and 9.1 for days to flowering are true QTLs. Consensus QTLs for reproductive-growth traits and grain yield under drought stress have been identified on chromosomes 1 and 9 using meta-QTL analysis in these DH lines. These MQTLs associated with reproductive-growth, grain yield and its component traits under drought stress could be useful targets for drought resistance improvement in rice through MAB and/or map-based positional analysis of candidate genes. © 2011 Elsevier B.V.

Peng C.-C.,South China Agricultural University | Xu Y.-H.,China Agricultural University | Xu Y.-H.,Peking Union Medical College | Xi R.-C.,South China Agricultural University | Zhao X.-L.,South China Agricultural University
Scientia Horticulturae | Year: 2011

Sucrose transporters or carriers (SUTs or SUCs) play a crucial role in the cell-to-cell distribution of sucrose throughout the plant. Our data demonstrated that MdSUT1 is expressed almost ubiquitously in leaves, shoots, flowers and fruits, and the MdSUT1 was localized in plasma membranes of both sieve element/companion cell complex and storage parenchyma cells in apple fruits detected by immuno-gold labeling. The MdSUT1 expression was rapidly up-regulated by abscisic acid (ABA) at the translational levels in the treatments of the fruit tissues. Ten μmolL-1 ABA and gibberellin acid (GA) induced MdSUT1 protein amounts dramatically, whereas 6-benzyl aminopurine (6-BA), indole-3-acetic acid (IAA) and cis-(-) ABA showed no distinct induction effect. These results suggest that MdSUT1 may be a component of ABA signaling pathways involved in the regulation of photoassimilate transport. ABA could function in plant sucrose trans-membrane transport, thus providing a clue that may help to unravel cross-talk between plant hormone and sucrose signaling pathway. © 2011 Elsevier B.V.

Lin J.,China Agricultural University | Wang R.,University of Arkansas | Jiao P.,South China Agricultural University | Li Y.,CAS Institute of Semiconductors | And 4 more authors.
Biosensors and Bioelectronics | Year: 2015

Early screening of suspected cases is the key to control the spread of avian influenza (AI) H5N1. In our previous studies, an impedance biosensor with an interdigitated array microelectrode based biochip was developed and validated with pure AI H5 virus, but had limitations in cost and reliability of the biochip, specificity of the antibody against Asian in-field H5N1 virus and detection of H5N1 virus in real samples. The purpose of this study is to develop a low-cost impedance immunosensor for rapid detection of Asian in-field AI H5N1 virus in chicken swabs within 1h and validate it with the H5N1 virus. Specific monoclonal antibodies against AI H5N1 virus were developed by fusion of mouse myeloma cells with spleen cells isolated from an H5N1-virus-immunized mouse. Dot-ELISA analysis demonstrated that the developed antibodies had good affinity and specificity with the H5N1 virus. The microelectrodes were redesigned with compact size, fabricated using an improved wet-etching micro-fabrication process with a higher qualified production rate of 70-80%, and modified with the antibodies by the Protein A method. Equivalent circuit analysis indicated that electron transfer resistor was effective with the increase in impedance after capturing of the H5N1 viruses. Linear relationship between impedance change and logarithmic value of H5N1 virus at the concentrations from 2-1 to 24 HAU/50μl was found and the lower limit of detection was 2-1 HAU/50μl. No obvious interferences from non-target viruses such as H6N2, H9N2, Newcastle disease virus, and infectious bronchitis virus were found. Chicken swab tests showed that the impedance immunosensor had a comparable accuracy with real-time RT-PCR compared to viral isolation. © 2014 Elsevier B.V.

Liu Y.,CAS Institute of Botany | Xu W.-B.,CAS Institute of Botany | Xu W.-B.,South China Agricultural University | Huang Y.-S.,CAS Institute of Botany
Nordic Journal of Botany | Year: 2011

Primulina guangxiensis Yan Liu & W. B. Xu, a new species of Gesneriaceae from Guangxi, China, is described and illustrated. The new species is related to Primulina tabacum Hance, but differs in the leaf blade being obliquely ovate to obliquely oblong-ovate, 2.5-6.0×1.3-4.3 cm, eith margin entire to repand and base inequilateral, petiole slimly terete, 1.5-6.0 cm long, ca 2-3 mm across, cymes 1-2-branched, 1-5-flowered and corolla tube hypocrateriform, 20-25 mm long, 2 mm across. The new species is rare, currently known only from one site in a karst cave in western Guangxi. © 2011 The Authors. Nordic Journal of Botany © 2011 Nordic Society Oikos.

Deng Y.-T.,South China Agricultural University | Deng Y.-T.,Chinese Academy of Fishery Sciences | Zeng Z.-L.,South China Agricultural University | Tian W.,South China Agricultural University | And 2 more authors.
Frontiers in Microbiology | Year: 2013

16S rRNA methylase and QepA, a fluoroquinolone efflux pump, are new mechanisms of resistance against aminoglycosides and fluoroquinolone, respectively. One of 16S rRNA methylase genes, rmtB, was found to be associated with qepA, were both located on the same transposable element. In this study, we intended to determine the current prevalence and characteristics of the 16S rRNA methylase genes and qepA, and to study the association between rmtB and qepA. A total of 892 Escherichia coli isolates were collected from various diseased food-producing animals in China from 2004 to 2008 and screened by PCR for 16S rRNA methylase genes and qepA. About 12.6% (112/892) and 0.1% (1/892) of isolates that were highly resistant to amikacin were positive for rmtB and armA, respectively. The remaining five 16S rRNA methlyase genes were not detected. Thirty-six (4.0%) strains carried qepA. About 32.1% of rmtB-positive strains harbored qepA, which was not detected in rmtB-negative strains. Most strains were clonally unrelated, while identical PFGE profiles of rmtB-positive isolates were found in the same farm indicating clonal transmission. Conjugation experiments showed that rmtB was transferred to the recipients, and qepA also cotransferred with rmtB in some cases. The spread of E. coli of food animal origin harboring both rmtB and qepA suggests that surveillance for antimicrobial resistance of animal origin as well as the study of the mechanisms of resistance should be undertaken. © 2013 Deng, Zeng, Tian, Yang and Liu.

Xu L.,South China Agricultural University | Xu Z.-F.,Hengyang Normal University
Journal of Polymer Research | Year: 2012

Molecularly imprinted polymers on the surface of multiwalled carbon nanotubes (MWNTs) have been developed for selective recognition for Ribavirin. The composites (MWNTs/MIPs) were prepared by using Ribavirin as the template molecule, acrylamide (AAM) as the functional monomer, N, N- methylenebisacrylamide (NNMBA) as the cross-linker. MWNTs/MIPs obtained were characterized by fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). The properties such as adsorption dynamics, special binding, and the selective recognition ability were evaluated. The adsorption equilibrium was arrived in about 4 h which indicated that the adsorption kinetic was comparatively fast. The results of binding and selectivity experiments showed that the MWNTs/MIPs could bind the template molecule selectively in aqueous media. © Springer Science+Business Media B.V. 2012.

Fang S.,South China Agricultural University | Gao X.,South China Agricultural University | Deng Y.,China Agricultural University | Chen X.,China Agricultural University | Liao H.,South China Agricultural University
Plant Physiology | Year: 2011

Root is a primary organ to respond to environmental stimuli and percept signals from neighboring plants. In this study, root responses in maize (Zea mays)/soybean (Glycine max) intercropping systems recognized soil phosphorus (P) status and neighboring plants in the field. Compared to self culture, the maize variety GZ1 intercropping with soybean HX3 grew much better on low P, but not in another maize variety, NE1. This genotypic response decreased with increasing distance between plants, suggesting that root interactions were important. We further conducted a detailed and quantitative study of root behavior in situ using a gel system to reconstruct the three-dimensional root architecture. The results showed that plant roots could integrate information on P status and root behavior of neighboring plants. When intercropped with its kin, maize or soybean roots grew close to each other. However, when maize GZ1 was grown with soybean HX3, the roots on each plant tended to avoid each other and became shallower on stratified P supply, but not found with maize NE1. Furthermore, root behavior in gel was highly correlated to shoot biomass and P content for field-grown plants grown in close proximity. This study provides new insights into the dynamics and complexity of root behavior and kin recognition among crop species in response to nutrient status and neighboring plants. These findings also indicate that root behavior not only depends on neighbor recognition but also on a coordinated response to soil P status, which could be the underlying cause for the different growth responses in the field. © 2011 American Society of Plant Biologists.

Li Z.,Oklahoma State University | Wang N.,Oklahoma State University | Hong T.,South China Agricultural University
Transactions of the ASABE | Year: 2010

Wireless sensor network (WSN) technology is a promising solution for large-scale, real-time, and continuous soil property data acquisition. However, the applications are still very limited due to a lack of understanding of in-field data transmission performance of a WSN. In this study, commercial 2.4 GHz wireless sensor modules (referred to as "motes") and a hand-held spectrum analyzer were used to set up a test platform to evaluate radio propagation performance. Indexed packets transmitted from a module were captured by the spectrum analyzer to measure path-loss through received signal strength (RSS) and synchronously received by another module, called the base station, to calculate packet delivery rate (PDR). Experiments were conducted in a wheat field of an experimental farm of Oklahoma State University. Canopy height, transmitter height, receiver height, and transmitter-to-receiver distance (T-R distance) were considered as impact factors on radio propagation. Correlation analysis was used to evaluate the relationship between path-loss and PDR. The results indicated that, as plant height increased, path-loss and PDR became more correlated with each other. A distance of 70 m was defined as a stable communication distance for 2.4 GHz in-field WSN applications. Four models were developed to predict the path-loss based on the log of T-R distance and transmitter and receiver heights under conditions of clear line-of-sight and three different plant canopy heights. The R 2 values of the models were 0.601, 0.599, 0.674, and 0.776, respectively. Their standard errors of the estimate were 3.761, 3.199 3.518, and 2.889, respectively. ©; 2010 American Society of Agricultural and Biological Engineers.

Lv S.,South China Agricultural University | Lv S.,Beihang University | Qiao L.,Beihang University
International Journal of Computer Integrated Manufacturing | Year: 2014

It is of more practical significance to carry out research on the integrated process planning and scheduling/rescheduling (IPPSR) to achieve a global improvement for the performance of a manufacturing system with sustained pursuit and various uncertainties. In this paper, a framework and a unified dynamic rescheduling model for IPPSR with three typical types of situations normally encountered in a production system, i.e. arrival of new jobs, machine breakdown and order cancellation have been constructed. Meanwhile, an improved evolutionary algorithm (IEA) for the integrated process planning and scheduling (IPPS) to generate an optimal initial scheduling plan has been developed. In order to improve the performance of the algorithm for IPPS and facilitate the extension of it to rescheduling situation, new genetic representation for the scheduling plan combined with process plans and corresponding genetic operators are developed. Based on the dynamic rescheduling model and initial optimised result, the integrated rescheduling strategies for the above three types of situations have been developed. In order to verify the feasibility and performance of the proposed strategies, experimental studies were conducted and comparisons were made for different performance measures; the results show that the proposed approaches not only provide more effective result for IPPS but also for integrated rescheduling with the above three types of uncertainties. © 2013 Taylor & Francis.

Li M.-W.,Guangdong Ocean University | Song H.-Q.,Lanzhou Veterinary Research Institute | Li C.,Sichuan Provincial Center for Animal Disease Prevention and Control | Lin H.-Y.,Guangdong Ocean University | And 3 more authors.
International Journal of Infectious Diseases | Year: 2011

Sparganosis is an infection of humans and animals caused by the plerocercoid larvae (spargana) of various diphyllobothroid tapeworms belonging to the genus Spirometra. Sparganosis has been reported sporadically around the world, and a higher prevalence of the disease occurs in several Asian countries, including South Korea, Japan, Thailand, and China. To date, a total of more than 1000 cases of human sparganosis have been reported in 25 provinces in mainland China. Sparganosis is emerging in mainland China because of food consumption habits and the unusual practice of treating wounds or other lesions with poultices of frog or snake flesh. This article reviews the current status of sparganosis in mainland China. Increased public awareness about the risks associated with eating raw food and strengthened food safety measures are needed. © 2010 International Society for Infectious Diseases.

Wang J.,South China Agricultural University | Shan Q.,Chinese Academy of Fishery Sciences | Ding H.,South China Agricultural University | Liang C.,South China Agricultural University | Zeng Z.,South China Agricultural University
Antimicrobial Agents and Chemotherapy | Year: 2014

Cefquinome is a cephalosporin with broad-spectrum antibacterial activity, including activity against Staphylococcus aureus. The objective of our study was to examine the in vivo activity of cefquinome against S. aureus strains by using a neutropenic mouse thigh infection model. Cefquinome kinetics and protein binding in infected neutropenic mice were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS). In vivo postantibiotic effects (PAEs) were determined after a dose of 100 mg/kg of body weight in mice infected with S. aureus strain ATCC 29213. The animals were treated by subcutaneous injection of cefquinome at doses of 2.5 to 320 mg/kg of body weight per day divided into 1, 2, 3, 6, or 12 doses over 24 h. Cefquinome exhibited time-dependent killing and produced in vivo PAEs at 2.9 h. The percentage of time that serum concentrations were above the MIC (%T>MIC) was the pharmacokinetic-pharmacodynamic (PK-PD) index that best described the efficacy of cefquinome. Subsequently, we employed a similar dosing strategy by using increasing total cefquinome doses that increased 4-fold and were administered every 4 h to treat animals infected with six additional S. aureus isolates. A sigmoid maximum effect (Emax) model was used to estimate the magnitudes of the ratios of the%T that the free-drug serum concentration exceeded the MIC (%T>fMIC) associated with net bacterial stasis, a 0.5-log10 CFU reduction from baseline, and a 1-log10 CFU reduction from baseline; the respective values were 30.28 to 36.84%, 34.38 to 46.70%, and 43.50 to 54.01%. The clear PAEs and potent bactericidal activity make cefquinome an attractive option for the treatment of infections caused by S. aureus. © 2014, American Society for Microbiology.

Xiong W.,Sun Yat Sen University | Xiong W.,South China Agricultural University | Zhong F.,Sun Yat Sen University | Fan S.,Sun Yat Sen University | Fan S.,Shaanxi Normal University
Computer Physics Communications | Year: 2012

Whereas the stability of a pure critical system is determined by the sign of its specific-heat critical exponent α according to Harris criterion, whether a d-dimensional dirty system should satisfy ν≥2/d and α<0 or not has been a controversial issue for several decades, where ν is its correlation-length critical exponent. Here, contrary to recent analytical and numerical results, we find for the three-dimensional three-state random-bond Potts model whose pure version exhibits a first-order phase transition a random fixed point whose ν<2/d and α>0 using a finite-time scaling combining with extended dynamic Monte Carlo renormalization-group method. This suggests further studies are still needed to clarify the issue in three-dimensional systems. © 2012 Elsevier B.V. All rights reserved.

Jiang X.,South China Normal University | Li H.,South China Agricultural University | Wang T.,South China Agricultural University | Wang T.,CAS Institute of Botany | And 5 more authors.
Plant Journal | Year: 2012

Chloroplast biogenesis needs to be well coordinated with cell division and cell expansion during plant growth and development to achieve optimal photosynthesis rates. Previous studies showed that gibberellins (GAs) regulate many important plant developmental processes, including cell division and cell expansion. However, the relationship between chloroplast biogenesis with cell division and cell expansion, and how GA coordinately regulates these processes, remains poorly understood. In this study, we showed that chloroplast division was significantly reduced in the GA-deficient mutants of Arabidopsis (ga1-3) and Oryza sativa (d18-AD), accompanied by the reduced expression of several chloroplast division-related genes. However, the chloroplasts of both mutants exhibited increased grana stacking compared with their respective wild-type plants, suggesting that there might be a compensation mechanism linking chloroplast division and grana stacking. A time-course analysis showed that cell expansion-related genes tended to be upregulated earlier and more significantly than the genes related to chloroplast division and cell division in GA-treated ga1-3 leaves, suggesting the possibility that GA may promote chloroplast division indirectly through impacting leaf mesophyll cell expansion. Furthermore, our cellular and molecular analysis of the GA-response signaling mutants suggest that RGA and GAI are the major repressors regulating GA-induced chloroplast division, but other DELLA proteins (RGL1, RGL2 and RGL3) also play a role in repressing chloroplast division in Arabidopsis. Taken together, our data show that GA plays a critical role in controlling and coordinating cell division, cell expansion and chloroplast biogenesis through influencing the DELLA protein family in both dicot and monocot plant species. © 2012 Blackwell Publishing Ltd.

Wei Z.B.,South China Agricultural University | Guo X.F.,South China Agricultural University | Wu Q.T.,South China Agricultural University | Long X.X.,South China Agricultural University | Penn C.J.,Oklahoma State University
International Journal of Phytoremediation | Year: 2011

Phytoextraction using hyperaccumulating plants is generally time-consuming and requires the cessation of agriculture. We coupled chelators and a co-cropping system to enhance phytoextraction rates, while allowing for agricultural production. An experiment on 1 m 3 lysimeter beds was conducted with a co-cropping system consisting of the hyperaccumulator Sedum alfredii and low-accumulating corn (Zea Mays, cv. Huidan-4), with addition of a mixture of chelators (MC), to assess the efficiency of chelator enhanced co-crop phytoextraction and the leaching risk caused by the chelator. The results showed that the addition of MC promoted the growth of S. alfredii in the first crop (spring-summer season) and significantly increased the metal phytoextraction. The DTPA-extractable and total metal concentrations in the topsoil were also reduced more significantly with the addition of MC compared with the control treatments. However, mono-cropped S. alfredii without MC was more suitable for maximizing S. alfredii growth and therefore phytoextraction of Zn and Cd during the autumn-winter seasons. No adverse impact to groundwater due to MC application was observed during the experiments with three crops and three MC applications. But elevated total Cd and Pb concentrations among subsoils compared to the initial subsoil concentrations were found for the co-crop + MC treatment after the third crop. © Taylor & Francis Group, LLC.

Liu J.,South China Agricultural University | Yang B.,Shaanxi Normal University
Proceedings - 2015 2nd International Conference on Information Science and Control Engineering, ICISCE 2015 | Year: 2015

Modular exponentiations are widely used in discrete-log based cryptographic protocols. Most researches have been done for outsourcing exponentiation modular a prime, while less work has been done for outsourcing exponentiation modular a composite. In this paper, we first raise a new secure outsourcing algorithm for exponentiation modular a composite in the one malicious model. Then, we prove that this algorithm is secure in the one-malicious model and give efficiency analysis later. Comparing with other algorithms, ours is more efficient for composite modular exponentiation. Finally, we use this algorithm to realize a outsource-secure algorithm for Shamir's Identitybased Signature scheme. © 2015 IEEE.

Li Y.-Q.,South China Agricultural University | Kong D.-X.,CAS Institute of Botany | Huang R.-S.,Guangxi University | Liang H.-L.,CAS Institute of Botany | And 2 more authors.
Industrial Crops and Products | Year: 2013

To investigate the effect of the developmental stages of the cassia leaf on the yields and composition of its essential oils, volatile compounds of cassia leaves at different developmental stages were detected by GC-MS and FT-IR analysis. The relationships between the oil cell ontogeny and oil accumulation with essential oil yields and compositions were systematically analyzed. The results indicated that the leaves of the 2-year-old branch had the highest density of oil cells (6.91n/mm2) and the maximum percentage of oil cells at the oil saturation stage (48.05%), which coincided with the highest oil yield (2.12%) and trans-cinnamaldehyde content (66.47%). The oils were less accumulated in the 1-4 leaves of annual branch and were mostly disintegrated in the leaves of 4 years old branch, therefore the lower percentages of oil cells at oil saturation stage (6.72 and 33.71%, respectively) resulted in the lower oil yields (1.01 and 0.54%, respectively) and lower percentages of trans-cinnamaldehyde (57.89% and 61.57%, respectively). Curve fitting of the FT-IR results agreed with that of the GC-MS analysis. These results can provide reference information for the rational utilization of cinnamon resources and harvest of cassia leaves. © 2013 Elsevier B.V.

Tian J.,South China Agricultural University | Wang X.,South China Agricultural University | Tong Y.,CAS Institute of Genetics and Developmental Biology | Chen X.,China Agricultural University | Liao H.,South China Agricultural University
Current Opinion in Biotechnology | Year: 2012

Phosphorus (P) is one of the three macronutrients for plants. Because of its low mobility and high fixation in soils, low P availability is a worldwide constraint for crop productivity. Molecular biology provides great opportunities to improve P efficiency in plants. However, transgenic plants cannot be commercialized before integrating all the knowledge on bottlenecks for improving P efficiency of crops/pastures. This review intends to summarize the main strategies of bioengineering to improve P efficiency of crops/pastures, including conventional and molecular assisted breeding, identification and application of key genes for biotech plants. It highlights recent advances in the understanding of improving P efficiency through the integration of bioengineering with P fertilization and cultivation management. © 2012 Elsevier Ltd.

Li Y.-Q.,South China Agricultural University | Kong D.-X.,CAS Institute of Botany | Wu H.,South China Agricultural University | Wu H.,Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm | Wu H.,State Key Laboratory for Conservation and Utilization of Subtropical Agro bioresources
Industrial Crops and Products | Year: 2013

In this work, the volatile compounds of cinnamon barks from three species and seven habitats were detected and identified for the first time by GC-MS and FTIR analysis. GC-MS analysis indicated that the main compound in the volatile oils of nine samples was trans-cinnamaldehyde (66.28-81.97%). Cinnamomum loureirii had the highest volatile oil yield (3.08%) and in that yield was a high percentage of trans-cinnamaldehyde (81.97%). Cinnamomum verum contained significant quantities of eugenol, and Cinnamomum cassia had more abundant α-guaiene compared with C. loureirii and C. verum. Hierarchical cluster analysis, similarity evaluation and principal component analysis showed that the nine samples were effectively identified and evaluated. Load factor analysis revealed that the differences in the volatile compounds of the nine samples were mainly reflected in the aldehyde, alcohol, alkane and eugenol contents. Our research indicated that GC-MS and FTIR techniques, combined with chemometrics, proved to be an effective strategy for identifying the species and for determining their geographical distribution, especially in the assessment of cinnamon quality for use in raw herbal medicines. © 2012 Elsevier B.V.

Wang X.,South China Agricultural University | Shen J.,China Agricultural University | Liao H.,South China Agricultural University
Plant Science | Year: 2010

Phosphorus (P) is one of the major factors worldwide limiting crop growth. Enhancing P efficiency in plants can be achieved through improving P acquisition, utilization, or both. Which of these approaches is more critical for enhancing P efficiency in crops, particularly in intensive cropping systems? P availability is unevenly distributed through the soil profile. Most modern crop cultivars are selected through conventional breeding approaches for better adaptation to stratified soil P by root architectural and morphological traits that allow for more P acquisition from the P-rich soil surface zone. Conversely, most crops have relatively efficient P uptake capacity but low P translocation and remobilization. Hence, phosphorus utilization efficiency (PUE) becomes a significant bottleneck for further improvements in crop P efficiency. Furthermore, the modification of root systems requires additional carbon input, and thus crops might sacrifice carbohydrates for higher yield to meet demand for P acquisition. With the support from soybean transformation studies, we speculate that enhancement of PUE might become a potentially powerful strategy for increasing P efficiency in modern crops grown in intensive cropping systems. © 2010 Elsevier Ireland Ltd.

Zhang M.,South China Agricultural University | Zhang M.,Kyushu University | Yang B.,Shaanxi Normal University | Takagi T.,Kyushu University
Computer Journal | Year: 2013

Recent research shows that many public-key or identity-based encryption schemes are vulnerable to side-channel attacks on the keys by the interaction of an adversary with a physical device. To tolerate the possible key leakage, leakage-resilient cryptography models a class of leakage output by allowing the adversary to be able to specify a computable leakage function and obtaining the partial keys or other possibly internal states from the output of function. In this article, we propose a leakage-resilient hidden-vector encryption (HVE) scheme that supports the predicate operators such as conjunction, disjunction, comparison, range query and subset query, etc. The proposed scheme is leakage-resilient attribute-hiding secure in the sense that the adversary cannot only obtain the tokens of non-match vectors but also learn amount of key information of the vector that matches the challenge vector. To the best of our knowledge, this is the first HVE that supports token-leakage resilience. We prove the security with a series of computationally indistinguishable games that uses the dual system encryption mechanism. We also analyze and discuss the performance of leakage bound parameters and leakage fraction in the practical security level. Finally, we also give an extensive scheme to achieve the security of both attribute-hiding and payload-hiding, and analyze the performance in larger alphabets. © 2012 The Author.

He D.,South China Agricultural University | Partridge S.R.,University of Sydney | Shen J.,China Agricultural University | Zeng Z.,South China Agricultural University | And 4 more authors.
Antimicrobial Agents and Chemotherapy | Year: 2013

The chimeric blaCTX-M-123 gene was identified in two ceftazidime-resistant Escherichia coli isolates from animals in different Chinese provinces. Like other CTX-M-1/9 group hybrids (CTX-M-64 and CTX-M-132), the ends (amino acids 1 to 135 and 234 to 291) of CTX-M-123 match CTX-M-15 while the central part (122 to 241) matches CTX-M-14. blaCTX-M-123 is carried on related, but not identical,90-kb IncI1 plasmids in the two isolates, and one isolate simultaneously carries the group 1 blaCTX-M-55 gene on an additional IncI2 plasmid. Copyright © 2013, American Society for Microbiology. All Rights Reserved.

Lu Y.-M.,University of South China | Le X.-Y.,University of South China | Le X.-Y.,South China Agricultural University
Chinese Journal of Inorganic Chemistry | Year: 2011

Ternary copper(II) complexes containing aromatic amine and L-α-amino acid attract abroad attention since the complexes can be used as chemical nucleases, SOD mimics and the regulators of plants growth against the environmental menaces. This paper summarizes the recent research advancement of ternary copper (II) complexes containing aromatic amine and L-α-amino acid, which focuses chiefly on the structure and application of this kind of complexes.

Yang X.,University of South China | Song J.,Agriculture and Agri Food Canada | Fillmore S.,Agriculture and Agri Food Canada | Pang X.,South China Agricultural University | Zhang Z.,University of South China
Postharvest Biology and Technology | Year: 2011

Banana (Musa AAA group) is one of the most consumed fruits in the world. It has been reported that chlorophyll breakdown and color formation in banana is inhibited by ripening temperatures above 24°C. At this temperature thylakoid membranes are retained resulting in reduced chlorophyll degradation. In this study, green mature, untreated banana fruit were obtained from a local wholesale market and half of the fruit were subjected to ethylene treatment at 10μLL -1 for 24d. After ethylene treatment, both treated and untreated fruit were stored at 20°C or 30°C for 7d. Fruit were sampled after 0, 1, 4 and 7d of storage and evaluated for color, chlorophyll fluorescence, volatile production and expression of genes related to volatile biosynthesis. Storage at 30°C reduced yellow color development in the peel, decreased chlorophyll fluorescence (Fv/Fm), but increased Fo, indicating possible heat stress of the fruit. A total of 19 volatile compounds were identified using SPME/GC/MS. Both ethylene treatment and high temperature enhanced volatile production. The increase of Fo and hexanoate and acetate esters are coincided with the stress of high temperature. Using real time PCR (qPCR), expression of genes related to volatile biosynthesis including branched-chain amino acid transaminase (BCAT), lipoxygenase (LOX), hydroperoxide lyase (HPL), pyruvate decarbolxylase (PDC), alcohol dehydrogenases (ADH, short and medium chains), and alcohol acetyl transferase (AAT) were investigated in both peel and pulp tissues. Among the tested genes, BCAT, HPL, ADH and AAT in peel and pulp tissues increased significantly in response to ethylene and storage at 30°C. PDC, ADH and BCAT (in pulp tissue) were induced by storage at 30°C in ethylene-treated fruit. LOX decreased during ripening and storage at 30°C in the peel, but increased in the pulp tissue of ethylene-treated fruit. This study demonstrates that both ethylene and high temperature influence volatile biosynthesis in banana fruit at the transcriptional level and confirms findings that high temperature causes stress in banana fruit during ripening. © 2011.

Li X.,South China Agricultural University | Yu J.,Wuhan University of Technology | Yu J.,King Abdulaziz University | Jaroniec M.,Kent State University
Chemical Society Reviews | Year: 2016

As a green and sustainable technology, semiconductor-based heterogeneous photocatalysis has received much attention in the last few decades because it has potential to solve both energy and environmental problems. To achieve efficient photocatalysts, various hierarchical semiconductors have been designed and fabricated at the micro/nanometer scale in recent years. This review presents a critical appraisal of fabrication methods, growth mechanisms and applications of advanced hierarchical photocatalysts. Especially, the different synthesis strategies such as two-step templating, in situ template-sacrificial dissolution, self-templating method, in situ template-free assembly, chemically induced self-transformation and post-synthesis treatment are highlighted. Finally, some important applications including photocatalytic degradation of pollutants, photocatalytic H2 production and photocatalytic CO2 reduction are reviewed. A thorough assessment of the progress made in photocatalysis may open new opportunities in designing highly effective hierarchical photocatalysts for advanced applications ranging from thermal catalysis, separation and purification processes to solar cells. © 2016 The Royal Society of Chemistry.

Fu X.-B.,South China Agricultural University | Liu D.-D.,South China Agricultural University | Lin Y.,South China Agricultural University | Hu W.,South China Agricultural University | And 3 more authors.
Dalton Transactions | Year: 2014

Two new water-soluble copper(ii)-dipeptide complexes: [Cu(glygly)(PyTA)] ClO4·1.5H2O (1) and [Cu(glygly)(PzTA)]ClO 4·1.5H2O (2) (glygly = glycylglycine anion, PyTA = 2,4-diamino-6-(2′-pyridyl)-1,3,5-triazine and PzTA = 2,4-diamino-6- (2′-pyrazino)-1,3,5-triazine), utilizing two interrelated DNA base-like ligands (PyTA and PzTA), have been synthesized and characterized. The structure elucidation for 1 performed by single crystal X-ray diffraction showed a one dimensional chain conformation in which the central copper ions arrange in a five-coordinate distorted square-pyramidal geometry. Spectroscopic titration, viscosity and electrophoresis measurements revealed that the complexes bound to DNA via an outside groove binding mode, and cleaved pBR322 DNA efficiently in the presence of ascorbate, probably via an oxidative mechanism with the involvement of OH and O2 -. Notably, the complexes exhibited considerable in vitro cytotoxicity against four human carcinoma cell lines (HepG2, HeLa, A549 and U87) with IC50 values ranging from 41.68 to 159.17 μM, in addition to their excellent SOD mimics (IC50 ∼ 0.091 and 0.114 μM). Besides, multispectroscopic evidence suggested their HSA-binding at the cavity containing Trp-214 in subdomain IIA with moderate affinity, mainly via hydrophobic interaction. Further, the molecular docking technique utilized for ascertaining the mechanism and mode of action towards DNA and HSA theoretically verified the experimental results. © 2014 the Partner Organisations.

Wen L.-F.,Sun Yat Sen University | Wen L.-F.,South China Agricultural University | He J.-G.,Sun Yat Sen University
British Journal of Nutrition | Year: 2012

The aim of the present study was to evaluate the feasibility of an antimicrobial peptide, cecropin A(1-11)-D(12-37)-Asn (CADN), as an alternative to antibiotic growth promoter (AGP) in poultry diets. A total of 1500 14-d-old indigenous male chickens (222 (sd 13)g) were randomly allocated to five groups with five replicate cages of sixty birds each, and fed ad libitum five grower diets and subsequently five finisher diets for 14d each. The diets were made up by supplementing their basal diets with a CADN liquid sample (CADNL) at 0, 2, 4, 6 and 8ml/kg, respectively. During the feeding period, a metabolic experiment was carried out to determine the apparent digestibility of diethyl ether extract, nitrogen retention and apparent metabolisable energy of the diet sample fed to each cage of chicks. At the end of the feeding experiment, one chick from each cage was killed for bacteriological, light microscopic and scanning electron microscopic examination of the intestinal villi. CADN had a negative linear, positive quadratic and negative linear effect on feed intake (F), weight gain (G) and feed:gain ratio (F:G), respectively, for the growers; it had a quadratic effect on F, G or F:G for the finishers; it increased nutrient utilisation for both growers and finishers; it decreased aerobic bacterial counts in both jejunal and caecal digesta in a dose-dependent manner; it enhanced intestinal villus heights in a dose-dependent manner and made the duodenum villi of the CADNL8 group at 42d appear as a netted leaf-like structure. CADN is therefore a possible alternative to AGP in broiler feeds. © 2012 The Authors.

Xiong W.,Sun Yat Sen University | Xiong W.,South China Agricultural University | Zhong F.,Sun Yat Sen University | Yuan W.,Sun Yat Sen University | Fan S.,Sun Yat Sen University
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2010

We have investigated the critical behavior of a three-dimensional random-bond Ising model for a series of the disorder strength by a finite-time scaling combining with Monte Carlo renormalization-group method in the presence of a linearly varying temperature. The method enables us to estimate a lot of critical exponents of both static and dynamic nature independently as well as the critical temperatures. The static exponents obtained agree well with most existing results, verify both the hyperscaling and the Rushbrooke scaling laws and their combined scaling law, which in turn validate their asymptotic nature, and corroborate the universality of the relevant random fixed point with respect to the forms of disorder. The dynamic critical exponent z is estimated to 2.114(51), which is compatible with those obtained from experiments and renormalization-group analyses. The exponents at low and high disorder strengths do not satisfy all scaling laws and are argued to be crossover exponents that reflect crossover from the random fixed point to the pure and the percolation fixed point. They also indicate that the exponents that were previously suggested to be a distinct universality class for strong disorder strength in the literature may be just crossover. Our results demonstrate the effectiveness of the finite-time scaling method. © 2010 The American Physical Society.

Situ H.,South China Agricultural University | Hu X.,Shandong University of Technology
Quantum Information Processing | Year: 2016

We study the relative entropy of coherence under the effect of certain one-qubit channels that are Markovian and noisy. The cohering power and decohering power of phase damping, amplitude damping, flip and depolarizing channels are analytically calculated. For phase damping channel, the decohering power on the (Formula presented.) and z bases is the same. The same phenomenon is observed for the flip and depolarizing channels. Further, we show that weak measurement and its reversal can be employed to suppress the decohering power of the amplitude damping channel. © 2016 Springer Science+Business Media New York

Wang C.,Sun Yat Sen University | Wang C.,South China Agricultural University | Ni J.,Sun Yat Sen University | Huang J.,Sun Yat Sen University
IEEE Transactions on Information Forensics and Security | Year: 2012

Achieving robustness, imperceptibility and high capacity simultaneously is of great importance in digital watermarking. This paper presents a new informed image watermarking scheme with high robustness and simplified complexity at an information rate of 1/64 bit/pixel. Firstly, a Taylor series approximated locally optimum test (TLOT) detector based on the hidden Markov model (HMM) in the wavelet domain is developed to tackle the problem of unavailability of exact embedding strength in the receiver due to informed embedding. Then based on the TLOT detector and the concept of dirty-paper code design, new HMM-based spherical codes are constructed to provide an effective tradeoff between robustness and distortion. The process of informed embedding is formulated as an optimization problem under the robustness and distortion constraints and the genetic algorithm (GA) is then employed to solve this problem. Moreover, the perceptual distance in the wavelet domain is also developed and incorporated into the GA-based optimization. Simulation results demonstrate that the proposed informed watermarking algorithm has high robustness against common attacks in signal processing and shows a comparable performance to the state-of-the-art scheme with a greatly reduced arithmetic complexity. © 2012 IEEE.

Liu G.-H.,Chinese Academy of Agricultural Sciences | Liu G.-H.,Hunan Agricultural University | Gasser R.B.,University of Melbourne | Su A.,Chinese Academy of Agricultural Sciences | And 9 more authors.
PLoS Neglected Tropical Diseases | Year: 2012

The whipworm, Trichuris trichiura, causes trichuriasis in ~600 million people worldwide, mainly in developing countries. Whipworms also infect other animal hosts, including pigs (T. suis), dogs (T. vulpis) and non-human primates, and cause disease in these hosts, which is similar to trichuriasis of humans. Although Trichuris species are considered to be host specific, there has been considerable controversy, over the years, as to whether T. trichiura and T. suis are the same or distinct species. Here, we characterised the entire mitochondrial genomes of human-derived Trichuris and pig-derived Trichuris, compared them and then tested the hypothesis that the parasites from these two host species are genetically distinct in a phylogenetic analysis of the sequence data. Taken together, the findings support the proposal that T. trichiura and T. suis are separate species, consistent with previous data for nuclear ribosomal DNA. Using molecular analytical tools, employing genetic markers defined herein, future work should conduct large-scale studies to establish whether T. trichiura is found in pigs and T. suis in humans in endemic regions. © 2012 Liu et al.

Dai Z.,Sun Yat Sen University | Liu H.,Sun Yat Sen University | Shen Y.,South China Agricultural University | Su X.,Sun Yat Sen University | And 3 more authors.
Analytical Chemistry | Year: 2012

Coumaphos, an organophosphorus pesticide (OP) used worldwide, has raised serious public concerns due to its positive association with major types of cancer. Herein, a novel method for attomolar coumaphos detection was developed on the basis of an electrochemical displacement immunoassay coupled with oligonucleotide sensing. An optimized displacement immunoassay was constructed to improve the binding efficiency of an antigen-antibody pair, and a guanine-rich single-strand DNA label, in combination with oligonucleotide sensing, was used to amplify the detection signal with "direct" relationship to the analyte. As a result, coumaphos was sensitively determined from the enhanced catalytic cycle of guanine-Ru(bpy)3 2+ by chronoamperometry. The limit of detection (LOD) was down to 0.18 ng L -1 (S/N = 3), which is equal to 49.6 amol in a sample solution of 100 μL. In comparison with conventional methods, the proposed method has the lowest LOD and better accessibility to high-throughput sensing systems. Besides, it can complete the whole analysis process in under 50 min and exhibits good performance of excellent selectivity to the OPs. With regard to the advantages of rapidity, convenience, low cost, and ease of operation, the proposed method has provided a promising platform capable of fast and in-field OP detection, which may make the system promising for potential applications in the detection of other small molecules. © 2012 American Chemical Society.

Zhou X.,Zhanjiang Normal University | Jin B.,Zhanjiang Normal University | Chen R.,Zhanjiang Normal University | Peng F.,South China University of Technology | Fang Y.,South China Agricultural University
Materials Research Bulletin | Year: 2013

A facile approach for the preparation of Fe3O 4/g-C3N4 nanospheres with good porous structure has been demonstrated by a hydrothermal method. The as-synthesized samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), ultraviolet-visible light (UV-vis) absorbance spectra and X-ray photoelectron spectroscopy (XPS). The photocatalytic decomposition of methyl orange (MO) by the as-prepared samples was carried out under visible light irradiation. The reusability and magnetic properties were also investigated. The results revealed that the porous Fe 3O4/g-C3N4 nanospheres showed considerable photocatalytic activity, and exhibited excellent reusability and magnetic properties with almost no change after five runs. © 2012 Elsevier Ltd.

Li R.,Sun Yat Sen University | Dan X.,South China Agricultural University | Li A.,Sun Yat Sen University
Fish and Shellfish Immunology | Year: 2013

A novel antimicrobial and antiparasitic protein (APP/SR-LAAO) isolated from serum of the rabbitfish (Siganus oramin) was confirmed to be lethal to Cryptocaryon irritans, an important marine parasitic ciliate that causes marine white spot disease in a variety of wild and cultured fish. In this study, a recombinant SR-LAAO (rSR-LAAO) was expressed on a large scale in Escherichia coli Rosetta-gami™(DE3)pLysS cells. rSR-LAAO was expressed as an inactive form in the inclusion bodies. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay showed that after purification, refolding and ultrafiltration, rSR-LAAO had a significantly cytotoxic effect on C. irritans theronts. Using light microscopy, scanning electron microscopy and fluorescence microscopy, we found that theronts rapidly became weakly motile, cilia became detached, cells became rounded, membranes eventually lysed in different cell positions and cytoplasmic contents leaked out of the cell. These results suggested the recombinant SR-LAAO was significantly lethal to C.irritans and the death process of the parasite incubated with rSR-LAAO was remarkably similar compared to the SR-LAAO group as reported earlier. © 2013 Elsevier Ltd.

Ling S.,South China Agricultural University | Ling S.,Sun Yat Sen University | Zhang R.,Sun Yat Sen University
Ecotoxicology and Environmental Safety | Year: 2011

The ultrastructure of Nilaparvata lugens brain cells was damaged by treatment at different fipronil concentrations. The cell showed swollen mitochondria and vacuolization, but no mitochondrial cristae. Rough endoplasmic reticulum (RER) fragmentation and degranulation were seen. The dilatation of endoplasmic reticulum cisterns was very prominent, and the predominant lamellar RERs were arranged chaotically. The Golgi apparatus demonstrated obvious changes in configuration, as dilated with closed cisternae and atypical vesicles. The mitochondria mainly showed large vacuolization in muscles. Nuclear degeneration and condensation and increased numbers of large hydropic vacuoles and lysosomes were observed. It was concluded that the effect on cellular components was fipronil-specific. Changes in cellular ultrastructure seem to be an appropriate ecotoxicological indicator of the insecticide's efficacy. © 2011 Elsevier Inc.

Liu J.,Sun Yat Sen University | Yang B.,South China Agricultural University
IEEE Transactions on Information Forensics and Security | Year: 2011

Providing security services for multicast, such as traffic integrity, authentication, and confidentiality, requires securely distributing a group key to group receivers. In the literature, this problem is called multicast key distribution (MKD). A famous MKD protocol-one-way function tree (OFT)-has been found vulnerable to collusion attacks. Solutions to prevent these attacks have been proposed, but at the cost of a higher communication overhead than the original protocol. In this paper, we prove falsity of a recently-proposed necessary and sufficient condition for a collusion attack on the OFT protocol to exist by a counterexample and give a new necessary and sufficient condition for nonexistence of any type of collusion attack on it. We instantiate the general notion of OFT to obtain a particular type of cryptographic construction named homomorphic one-way function tree (HOFT). We propose two structure-preserving graph operations on HOFTs, tree product and tree blinding. One elegant quality possessed by HOFTs is that handling (adding, removing, or changing) leaf nodes in a HOFT can be achieved by using tree product without compromising its structure. We provide algorithms for handling leaf nodes in a HOFT. Employing HOFTs and related algorithms, we put forward a collusion-resistant MKD protocol without losing any communication efficiency compared to the original OFT protocol. We also prove the security of our MKD protocol in a symbolic security model. © 2011 IEEE.

Hu H.Q.,Guangdong Ocean University | Li X.S.,South China Agricultural University | He H.,Guangdong Ocean University
Biological Control | Year: 2010

Understanding the mechanisms of the antagonistic endophytic bacteria is helpful in controlling plant diseases. An endophytic bacterium, Bg-C31, from mangrove was found to be antagonistic to some fungal and bacterial pathogens of plants and to be effective in the biocontrol of Capsicum bacterial wilt in pot and field trials. Bg-C31 was identified as Bacillus amyloliquefaciens by biochemical and physiological tests as well as sequences of 16S rDNA and the LCI gene. The antimicrobial substance produced by Bg-C31 was identified as a protein, which is resistant to protease k and heat, by ammonium sulfate precipitation and butanol extraction. The antagonistic gene was located in the chromosome by plasmid curing. A 29. kDa fusion protein of the LCI gene was expressed. Antimicrobial activity of the fusion protein to Ralstonia solanacearum was detected on gels in situ, indicating that the LCI gene could potentially be used to produce transgenic plants that are resistant to bacterial infection. © 2010.

Chen Z.,South China Agricultural University | Liu J.,South China Agricultural University | Fu S.,Sun Yat Sen University | Fu S.,Israel Electric | And 2 more authors.
Optics Express | Year: 2014

We introduce a 2D network built of PT - symmetric dimers with on-site cubic nonlinearity, the gain and loss elements of the dimers being linked by parallel square-shaped lattices. The system may be realized as a set of PT - symmetric dual-core waveguides embedded into a photonic crystal. The system supports PT - symmetric and antisymmetric fundamental solitons (FSs) and on-site-centered solitary vortices (OnVs). Stability of these discrete solitons is the central topic of the consideration. Their stability regions in the underlying parameter space are identified through the computation of stability eigenvalues, and verified by direct simulations. Symmetric FSs represent the system's ground state, being stable at lowest values of the power, while anti-symmetric FSs and OnVs are stable at higher powers. Symmetric OnVs, which are also stable at lower powers, are remarkably robust modes: on the contrary to other PT - symmetric states, unstable OnVs do not blow up, but spontaneously rebuild themselves into stable FSs. © 2014 Optical Society of America.

Huang Z.,South China University of Technology | Huang Z.,Key Laboratory of Pollution Control and Ecosystem Restoration in Industry Clusters | Huang Z.,Key Laboratory Of Environmental Protect And Eco Remediation Of Guangdong Regular Higher Education Institutions | Wu P.,South China University of Technology | And 6 more authors.
Journal of Materials Chemistry A | Year: 2014

The synthesis of a layer-by-layer ordered nanohybrid with a sandwich structure was based on electrostatically driven self-assembly between the negatively charged carboxyl graphene monolayer and the positively charged ZnAl-layered double hydroxide nanosheets. The characteristics of the layer-by-layer ordered nanohybrid were investigated by SEM, TEM, AFM and XRD. The enhanced photocatalytic activity of the calcined product was determined by the photocatalytic degradation of the cationic dye methylene blue (MB) and anionic dye orange G (OG) under visible light. The enhanced photocatalytic efficiency was mainly attributed to the effective electronic coupling between graphene and calcined ZnAl-LDH. Additionally, the chemical stability of the calcined ZnAl-LDH is significantly improved by hybridization of graphene and this is attributed to the protection provided by the close contacted graphene with highly stability. This work also establishes a simple method for fabricating graphene-based nanohybrids with a sandwich structure. © 2014 the Partner Organisations.

Li H.,South China Agricultural University | Deng Z.,South China Agricultural University | Huang J.,South China Agricultural University | Fu S.,Sun Yat Sen University | Li Y.,South China Agricultural University
Optics Letters | Year: 2015

All-optical soliton diode (AOSD) is proposed based on a sandwich nonlinear Bragg-grating structure: a linearly chirped Bragg-grating linked to a uniform Bragg-grating and again to a chirped Bragg-grating. The nonreciprocity is achieved by introducing two spatially asymmetric chirped Bragg-gratings with optical nonlinearity. High transmission ratio up to 150 is obtained when launching a picosecond Gaussian pulse into the setting. We find that such pulses in a form of solitons propagate at a rather small velocity (<0.03c) when pulse wavelength is selected in the vicinity of photonic bandgap. © 2015 Optical Society of America.

Zhai C.,South China Agricultural University | Zhang Y.,South China Agricultural University | Yao N.,Sun Yat Sen University | Lin F.,South China Agricultural University | And 4 more authors.
PLoS ONE | Year: 2014

Pik-h, an allele of Pik, confers resistance against the rice blast pathogen Magnaporthe oryzae . Its positional cloning has shown that it comprises a pair of NBS-LRR genes, Pikh-1 and Pikh-2. While Pikh-1 appears to be constitutively transcribed, the transcript abundance of Pikh-2 responds to pathogen challenge. The Pikh-1 CC (coiled coil) domain interacts directly with both AvrPik-h and Pikh-2. Transient expression assays demonstrated that Pikh-2 mediates the initiation of the host defence response. Nucleocytoplasmic partitioning of both Pikh-1 and Pikh-2 is required for their functionalities. In a proposed mechanistic model of Pik-h resistance, it is suggested that Pikh-1 acts as an adaptor between AvrPik-h and Pikh-2, while Pikh-2 transduces the signal to trigger Pik-h- specific resistance. © 2014 Zhai et al.

Song G.,South China Agricultural University | Liu H.,CAS Shanghai Institute of Materia Medica | Zhang W.,Fudan University | Geng M.,CAS Shanghai Institute of Materia Medica | Li Y.,Fudan University
Bioorganic and Medicinal Chemistry | Year: 2010

A series of anthracene l-rhamnopyranosides were designed and synthesized in a practical way and their cytotoxic activity was examined in vitro. Most compounds exhibited both potent cytotoxicity against several tumor cell lines and high DNA binding capacity. The preliminary results showed that subtle modifications of rhamnosyl moiety in anthracene rhamnosides with acetyl group had a selective toxicity for different tumor cells and the displacement of C-10 carbonyl group in emodin by acetylmethylene group was helpful to improve the inhibitory activity. Lipophilicity of the anthracene glycosides was not a crucial factor for cytotoxicity and most molecules with good cytotoxicity could inhibit the catalytic activity of Top2α. © 2010 Elsevier Ltd. All rights reserved.

Zhou X.,Zhanjiang Normal University | Jin B.,Zhanjiang Normal University | Li L.,Zhanjiang Normal University | Peng F.,South China University of Technology | And 3 more authors.
Journal of Materials Chemistry | Year: 2012

A carbon nitride/TiO 2 nanotube array (CN/TNT) heterojunction photocatalyst with visible-light response was prepared by a simple electrochemical method. The photocatalyst was characterized by X-ray powder diffraction (XRD), field-emission scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FT-IR). The photoelectrochemical properties and photocatalytic activities of the obtained-samples were systematically tested under visible light irradiation. The activity of heterojunction photocatalyst CN/TNTs is higher than that of TNTs. The obviously increased performance of CN/TNTs is ascribed mainly to enhancement of electron-hole separations both at the interface and in the semiconductors. © 2012 The Royal Society of Chemistry.

Qiu H.,South China Agricultural University | Du Y.,South China Normal University | Yao Z.,Sun Yat Sen University
Mathematical Methods in the Applied Sciences | Year: 2013

In this paper, we consider the three-dimensional generalized Boussinesq equations, a system of equations resulting from replacing the Laplacian - Δ in the usual Boussinesq equations by a fractional Laplacian (- Δ)α. We prove the local existence in time and obtain a regularity criterion of solution for the generalized Boussinesq equations by means of the Littlewood-Paley theory and Bony's paradifferential calculus. The results in this paper can be regarded as an extension to the Serrin-type criteria for Navier-Stokes equations and magnetohydrodynamics equations, respectively. Copyright © 2012 John Wiley & Sons, Ltd.

Chen M.J.,Sun Yat Sen University | Chen M.J.,South China Agricultural University | Shen H.,Sun Yat Sen University | Li X.,South China Agricultural University | Liu H.F.,South China Agricultural University
Applied Surface Science | Year: 2014

A stable water-based magnetic fluid was prepared by synthesizing sodium oleate bilayer-coated Fe3O4 nanoparticles via chemical coprecipitation. The adsorption mechanism about excessive sodium oleate coated on particles' surfaces below and above the isoelectric point of Fe 3O4 colloid was proposed. Based on this, a novel and facile phase-transform method to transform hydrophilic particles to lipophilic ones has been schemed by adjusting pH value or adding ethanol. The results showed two different transformation mechanisms. In the acid precipitation method, the bilayer-coated structure was retained, which made the hexane magnetic fluid more stable. © 2014 Published by Elsevier B.V.

He G.,South China Agricultural University | Chen H.,Sun Yat Sen University
Applied Mechanics and Materials | Year: 2011

Handheld electronic devices promote M-learning greatly. Foreign language learners favour the learning environment in handheld electronic devices. The authors explore the features of language learning in handheld electronic devices from the prospective of language input theory.The paper discusses the comprehension, nature and authenticity, abundance and varieties in language learning with handheld electronic devices. © (2011) Trans Tech Publications, Switzerland.

Qin L.,South China Agricultural University | Xu J.,South China Agricultural University | Wu Z.,South China Agricultural University | Zhang Z.,South China Agricultural University | And 3 more authors.
Cellular Signalling | Year: 2013

Notch signaling is an evolutionarily conserved cell-cell communication mechanism involved in the regulation of cell proliferation, differentiation and fate decisions of mammalian cells. In the present study, we investigated the possible requirement for Notch signaling in the proliferation and differentiation of porcine satellite cells. We show that Notch1, 2 and 3 are expressed in cultured porcine satellite cells. Knock-down of NOTCH1, but not NOTCH2 and NOTCH3, decreases the proliferation of porcine satellite cells. In contrast, enhancement of NOTCH1 expression via treatment of porcine satellite cells with recombinant NF-κB increases the proliferation of porcine satellite cells. The alteration of porcine satellite cell proliferation is associated with significant changes in the expression of cell cycle related genes (cyclin B1, D1, D2, E1 and p21), myogenic regulatory factors (MyoD and myogenin) and the Notch effector Hes5. In addition, alteration of Notch1 expression in porcine satellite cells causes changes in the expression of GSK3β-3. Taken together, these findings suggest that of the four notch-related genes, Notch1is likely to be required for regulating the proliferation and therefore the maintenance of porcine satellite cells in vivo, and do so through activation of the Notch effector gene Hes5. © 2012 Elsevier Inc.

Shen G.,Louisiana State University Health Sciences Center | Shen G.,University of Texas Health Science Center at San Antonio | Zhou E.,Louisiana State University Health Sciences Center | Zhou E.,South China Agricultural University | And 2 more authors.
Eukaryotic Cell | Year: 2012

Human Wiskott-Aldrich syndrome protein (WASP) is a scaffold linking upstream signals to the actin cytoskeleton. In response to intersectin ITSN1 and Rho GTPase Cdc42, WASP activates the Arp2/3 complex to promote actin polymerization. The human pathogen Cryptococcus neoformans contains the ITSN1 homolog Cin1 and the WASP homolog Wsp1, which share more homology with human proteins than those of other fungi. Here we demonstrate that Cin1, Cdc42/Rac1, and Wsp1 function in an effector pathway similar to that of mammalian models. In the cin1 mutant, expression of the autoactivated Wsp1-B-GBD allele partially suppressed the mutant defect in endocytosis, and expression of the constitutively active CDC42 Q61L allele restored normal actin cytoskeleton structures. Similar phenotypic suppression can be obtained by the expression of a Cdc42-green fluorescent protein (GFP)-Wsp1 fusion protein. In addition, Rac1, which was found to exhibit a role in early endocytosis, activates Wsp1 to regulate vacuole fusion. Rac1 interacted with Wsp1 and depended on Wsp1 for its vacuolar membrane localization. Expression of the Wsp1-B-GBD allele restored vacuolar membrane fusion in the rac1 mutant. Collectively, our studies suggest novel ways in which this pathogenic fungus has adapted conserved signaling pathways to control vesicle transport and actin organization, likely benefiting survival within infected hosts. © 2012, American Society for Microbiology.

Yang W.,South China Agricultural University | Wu H.-X.,South China Agricultural University | Xu H.-H.,South China Agricultural University | Hu A.-L.,Guizhou University | Lu M.-L.,South China Agricultural University
Journal of Agricultural and Food Chemistry | Year: 2011

Phloem-mobile insecticides are preferred to achieve economically useful activity. However, only a few phloem-mobile synthetic insecticides are available. One approach to converting nonmobile insecticides into phloem-mobile types is introducing sugar to the parent compound. To test whether the addition of a glucose group to a non-phloem-mobile insecticide enables conversion into phloem-mobile, N-[3-cyano-1-[2,6-dichloro-4-(trifluoromethyl)phenyl]-4- [(trifluoromethyl)sulfinyl]-1H-pyrazol-5-yl]-1-(β-d-glucopyranosyl)-1H-1,2, 3-triazole-4-methanamine (GTF) was prepared through click chemistry. A phloem-mobility test in Ricinus communis L. seedlings confirmed that GTF was mobile in the sieve tubes. Although GTF exhibited lower insecticidal activity against the third-instar larvae of Pzlutella xylostella than fipronil did, it can be reconverted into fipronil in adult plants of castor bean, thereby offsetting the decrease of insecticidal activity. Therefore, the presence of a glucose core confers phloem mobility to fipronil. © 2011 American Chemical Society.

Zhu Y.,South China Agricultural University | Fang J.,Sun Yat Sen University
Medical Decision Making | Year: 2016

The classification tree is a valuable methodology for predictive modeling and data mining. However, the current existing classification trees ignore the fact that there might be a subset of individuals who cannot be well classified based on the information of the given set of predictor variables and who might be classified with a higher error rate; most of the current existing classification trees do not use the combination of variables in each step. An algorithm of a logistic regression-based trichotomous classification tree (LRTCT) is proposed that employs the trichotomous tree structure and the linear combination of predictor variables in the recursive partitioning process. Compared with the widely used classification and regression tree through the applications on a series of simulated data and 2 real data sets, the LRTCT performed better in several aspects and does not require excessive complicated calculations. © The Author(s) 2016.

Li Y.-W.,Sun Yat Sen University | Mo X.-B.,Sun Yat Sen University | Zhou L.,South China Agricultural University | Li X.,Sun Yat Sen University | And 3 more authors.
Developmental and Comparative Immunology | Year: 2014

Interleukin 1 (IL-1) receptor-associated kinase (IRAK) family members are crucial signal transducer in the Toll-like receptor/IL-1R signal pathway, which mediates downstream signal cascades involved in the innate and adaptive immune responses. In this study, we identified an IRAK-4 protein (EcIRAK-4) in the orange-spotted grouper (Epinephelus coioides), with an N-terminal death domain, a proST domain, and a central kinase domain, similar to that of other fishes and mammals. A sequence alignment and phylogenic analysis demonstrated that full-length EcIRAK-4 shares a high degree of sequence identity with those of other fishes, especially the roughskin sculpin, and their death domains and kinase domains share greater identity than their proST domains. A conservation analysis indicated that most of the functional sites in mammalian IRAK-4 are conserved in IRAK-4 of the grouper and other fishes, with the exception of the sites of interaction with IRAK-2 and one autophosphorylation site within the activation loop. EcIRAK-4 is broadly expressed in all the tissues examined, with highest expression in the head kidney and liver. After infection with Cryptocaryon irritans, EcIRAK-4 expression was significantly upregulated, especially in the skin, which suggests that this molecule is involved in the host's defense against parasitic infection. Surprisingly, after cotransfection with grouper MyD88, EcIRAK-4 significantly impaired the NF-κB activity induced by MyD88. EcIRAK-4 was uniformly distributed throughout the cytoplasm in HeLa cells. These findings suggest that although IRAK-4 is evolutionarily conserved between fish and mammals, its signal transduction function is markedly different. © 2014 Elsevier Ltd.

Huang X.-Z.,Sun Yat Sen University | Li Y.-W.,Sun Yat Sen University | Mai Y.-Z.,Sun Yat Sen University | Luo X.-C.,South China University of Technology | And 2 more authors.
Developmental and Comparative Immunology | Year: 2014

Nonspecific cytotoxic cells (NCCs) are an important cytotoxic cell population in the innate teleost immune system. The receptor designated "NCC receptor protein 1" (NCCRP-1) has been reported to be involved in the recognition and activation of NCCs. In this study, the full-length cDNA of Epinephelus coioides NCCRP-1 (ecnccrp-1) was cloned. The open reading frame (ORF) of ecnccrp-1 is 699bp, encoding a 232 amino acid protein that includes proline-rich motifs at the N-terminus and is related to the F-box associated family. Although a bioinformatics analysis showed that EcNCCRP-1 had no signal peptide or transmembrane helices, a polyclonal antibody directed against recombinant EcNCCRP-1 efficiently labeled a membrane protein in the head kidney, detected with Western blot analysis, which indicated that the protein localized to the cell surface. RT-PCR showed that the constitutive expression of ecnccrp-1 was higher in the lymphoid organs, such as the trunk kidney, spleen, head kidney, and thymus, and lower in brain, heart, fat, liver, muscle, and skin. After infection with Cryptocaryon irritans, the transcription of ecnccrp-1 was analyzed at the infected sites (skin and gills) and in the systemic immune organs (head kidney and spleen). At the infected sites, especially the skin, ecnccrp-1 expression was upregulated at 6h post infection, reaching peak expression on day 3 post the primary infection. However, the expression patterns differed in the systemic immune organs. In the spleen, ecnccrp-1 was gradually increased in the early infection period and decreased sharply on day 3 post the primary infection, whereas in the head kidney, the transcription of ecnccrp-1 was depressed during almost the whole course of infection. An immunohistochemical analysis showed that EcNCCRP-1+ cells accumulated at the sites of infection with C. irritans. These results suggested that NCCs were involved in the process of C. irritans infection in E. coioides. © 2014.

Yang S.,South China Agricultural University | Zhou W.,South China Agricultural University | Ge C.,South China Agricultural University | Liu X.,South China Agricultural University | And 2 more authors.
RSC Advances | Year: 2013

The newly functional polymeric semiconductor materials, mesoporous graphitic carbon nitride (g-C3N4), have been synthesized by using a general and efficient sol-gel synthetic approach. By means of transmission electron microscopy (TEM), we accomplished a systematic analysis on the morphology changes and the final formation of the mesoporous g-C 3N4 product during the whole synthesis process. Our results indicate that the sol-gel synthetic method is a simple, efficient and viable technique to the large-scale production of mesoporous polymeric materials. This proposed technique also allows controlled development and tailored design of the pore structures, which is of crucial importance for the application of mesoporous polymeric g-C3N4. In order to effectively improve the photocatalytic activity of the g-C3N 4, the uniform size of the AgBr nanoparticles (NPs) were successfully loaded into the holes of the carbon nitride by a simple adsorption-deposition method, which exhibits excellent visible-light-driven photocatalytic activity for degradation of Methyl Orange dye (MO). © 2013 The Royal Society of Chemistry.

Zuo R.-J.,Xiamen University | Zuo R.-J.,South China Agricultural University | Zhao Y.-C.,Northeast Agricultural University | Lei W.,Northeast Agricultural University | And 4 more authors.
FEBS Letters | Year: 2014

Although decidualization is crucial for the establishment of successful pregnancy, the molecular mechanism underlying decidualization remains poorly understood. Crystallin αB (CryAB), a small heat shock protein (sHSP), is up-regulated and phosphorylated in mouse decidua. In mouse primary endometrial stromal cells, CryAB is induced upon progesterone treatment via HIF1α. In addition, CryAB is strongly phosphorylated through the p38-MAPK pathway under stress or during in vitro decidualization. Knockdown of CryAB results in the increase of apoptosis of stromal cells and inhibits decidualization under oxidative or inflammatory stress. Our data indicate that CryAB protects decidualization against stress conditions. © 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Zhang Y.,University of Florida | Jalan N.,University of Florida | Zhou X.,University of Florida | Goss E.,University of Florida | And 4 more authors.
ISME Journal | Year: 2015

Understanding the evolutionary history and potential of bacterial pathogens is critical to prevent the emergence of new infectious bacterial diseases. Xanthomonas axonopodis subsp. Citri (Xac) (synonym X. Citri subsp. Citri), which causes citrus canker, is one of the hardest-fought plant bacterial pathogens in US history. Here, we sequenced 21 Xac strains (14 XacA, 3 XacA∗ and 4 XacAw) with different host ranges from North America and Asia and conducted comparative genomic and evolutionary analyses. Our analyses suggest that acquisition of beneficial genes and loss of detrimental genes most likely allowed XacA to infect a broader range of hosts as compared with XacAw and XacA∗. Recombination was found to have occurred frequently on the relative ancient branches, but rarely on the young branches of the clonal genealogy. The ratio of recombination/ mutation ρ/θ was 0.0790±0.0005, implying that the Xac population was clonal in structure. Positive selection has affected 14% (395 out of 2822) of core genes of the citrus canker-causing Xanthomonas. The genes affected are enriched in 'carbohydrate transport and metabolism' and 'DNA replication, recombination and repair' genes (Po0.05). Many genes related to virulence, especially genes involved in the type III secretion system and effectors, are affected by positive selection, further highlighting the contribution of positive selection to the evolution of citrus canker-causing Xanthomonas. Our results suggest that both metabolism and virulence genes provide advantages to endow XacA with higher virulence and a wider host range. Our analysis advances our understanding of the genomic basis of specialization by positive selection in bacterial evolution. © 2015 International Society for Microbial Ecology All rights reserved.

Xu W.,Chinese University of Hong Kong | Xu W.,CAS Nanjing Institute of Soil Science | Jia L.,Chinese University of Hong Kong | Jia L.,Inner Mongolia Agricultural University | And 5 more authors.
New Phytologist | Year: 2013

Maintenance of root growth is essential for plant adaptation to soil drying. Here, we tested the hypothesis that auxin transport is involved in mediating ABA's modulation by activating proton secretion in the root tip to maintain root growth under moderate water stress. Rice and Arabidopsis plants were raised under a hydroponic system and subjected to moderate water stress (-0.47 MPa) with polyethylene glycol (PEG). ABA accumulation, auxin transport and plasma membrane H+-ATPase activity at the root tip were monitored in addition to the primary root elongation and root hair density. We found that moderate water stress increases ABA accumulation and auxin transport in the root apex. Additionally, ABA modulation is involved in the regulation of auxin transport in the root tip. The transported auxin activates the plasma membrane H+-ATPase to release more protons along the root tip in its adaption to moderate water stress. The proton secretion in the root tip is essential in maintaining or promoting primary root elongation and root hair development under moderate water stress. These results suggest that ABA accumulation modulates auxin transport in the root tip, which enhances proton secretion for maintaining root growth under moderate water stress. © 2012 New Phytologist Trust.

Zhang W.-F.,South China Agricultural University | Zhang W.-F.,Washington University in St. Louis | Tang G.,Washington University in St. Louis | Dai D.-Q.,Sun Yat Sen University | Nehorai A.,Washington University in St. Louis
Optics Letters | Year: 2011

Because of the limited approximation capability of using fixed basis functions, the performance of reflectance estimation obtained by traditional linear models will not be optimal. We propose an approach based on the regularized local linear model. Our approach performs efficiently and knowledge of the spectral power distribution of the illuminant and the spectral sensitivities of the camera is not needed. Experimental results show that the proposed method performs better than some well-known methods in terms of both reflectance error and colorimetric error. © 2011 Optical Society of America.

Wang C.,South China Agricultural University | Ni J.,Sun Yat Sen University
Proceedings - 2015 International Conference on Intelligent Information Hiding and Multimedia Signal Processing, IIH-MSP 2015 | Year: 2015

Compressing the encrypted data remains a challenging task. In this paper, we propose a new compression scheme using the integer lifting wavelet transform (ILWT). In particular, the original image is decomposed with the ILWT, and the coarsest and detail subbands are encrypted via the stream and permutation ciphers, respectively. These encrypted subbands are then transmitted to the third party like network or storage service providers, and imposed with the lossless and lossy compression, respectively. Upon receiving the compressed and encrypted bit stream, the receiver conducts the successive decompression and decryption to reconstruct the original image. Experimental simulations show that the proposed algorithm achieves favorable rate-distortion performance with low computational time and reasonable high-level security. Also, it obtains significant improvement over the prior art and considerably outperforms the conventional JPEG with original, unencrypted images as inputs. © 2015 IEEE.

Liang C.,South China Agricultural University | Liang C.,Cornell University | Pineros M.A.,Cornell University | Tian J.,South China Agricultural University | And 7 more authors.
Plant Physiology | Year: 2013

Low pH, aluminum (Al) toxicity, and low phosphorus (P) often coexist and are heterogeneously distributed in acid soils. To date, the underlying mechanisms of crop adaptation to these multiple factors on acid soils remain poorly understood. In this study, we found that P addition to acid soils could stimulate Al tolerance, especially for the P-efficient genotype HN89. Subsequent hydroponic studies demonstrated that solution pH, Al, and P levels coordinately altered soybean (Glycine max) root growth and malate exudation. Interestingly, HN89 released more malate under conditions mimicking acid soils (low pH, +P, and +Al), suggesting that root malate exudation might be critical for soybean adaptation to both Al toxicity and P deficiency on acid soils. GmALMT1, a soybean malate transporter gene, was cloned from the Al-treated root tips of HN89. Like root malate exudation, GmALMT1 expression was also pH dependent, being suppressed by low pH but enhanced by Al plus P addition in roots of HN89. Quantitative real-time PCR, transient expression of a GmALMT1-yellow fluorescent protein chimera in Arabidopsis protoplasts, and electrophysiological analysis of Xenopus laevis oocytes expressing GmALMT1 demonstrated that GmALMT1 encodes a root cell plasma membrane transporter that mediates malate efflux in an extracellular pH-dependent and Al-independent manner. Overexpression of GmALMT1 in transgenic Arabidopsis, as well as overexpression and knockdown of GmALMT1 in transgenic soybean hairy roots, indicated that GmALMT1-mediated root malate efflux does underlie soybean Al tolerance. Taken together, our results suggest that malate exudation is an important component of soybean adaptation to acid soils and is coordinately regulated by three factors, pH, Al, and P, through the regulation of GmALMT1 expression and GmALMT1 function. © 2013 American Society of Plant Biologists. All Rights Reserved.

Chen L.,State Key Laboratory for Conservation and Utilization of Subtropical Agro Bioresources | Chen L.,Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms | Chen L.,South China Agricultural University | Liu Y.-G.,State Key Laboratory for Conservation and Utilization of Subtropical Agro Bioresources | And 2 more authors.
Annual Review of Plant Biology | Year: 2014

In plants, male sterility can be caused either by mitochondrial genes with coupled nuclear genes or by nuclear genes alone; the resulting conditions are known as cytoplasmic male sterility (CMS) and genic male sterility (GMS), respectively. CMS and GMS facilitate hybrid seed production for many crops and thus allow breeders to harness yield gains associated with hybrid vigor (heterosis). In CMS, layers of interaction between mitochondrial and nuclear genes control its male specificity, occurrence, and restoration of fertility. Environment-sensitive GMS (EGMS) mutants may involve epigenetic control by noncoding RNAs and can revert to fertility under different growth conditions, making them useful breeding materials in the hybrid seed industry. Here, we review recent research on CMS and EGMS systems in crops, summarize general models of male sterility and fertility restoration, and discuss the evolutionary significance of these reproductive systems. Copyright © 2014 by Annual Reviews.

Li J.-M.,Sun Yat Sen University | Zhao M.-X.,Sun Yat Sen University | Su H.,Sun Yat Sen University | Wang Y.-Y.,Sun Yat Sen University | And 4 more authors.
Biomaterials | Year: 2011

The functional quantum dots (QDs) were specifically designed to overcome barriers in siRNA delivery such as siRNA protection, cellular penetration, endosomal release, carrier unpacking, intracellular transport and gene silencing. In this paper, two l-arginine-functional-modifi{ligature}ed CdSe/ZnSe QDs were synthesized as siRNA carriers to silence HPV18 E6 gene in HeLa cells. Using such constructs, these QDs showed significantly low cellular cytotoxicity and good siRNA protection. Flow cytometric and confocal microscopic analyses confirmed that the QDs delivered siRNA into HeLa cells efficiently. Importantly, superior gene silencing efficiency was achieved as evaluated by Reverse Transcription-PCR (RT-PCR) and Western blotting and HeLa cells growth was inhibited in xCELLigence installation analysis and MTT assay when treated with QD-siRNA complexes. Interestingly, the QDs coated with β-CD- l-Arg showed optimized property compared with those coated with l-Arg. Furthermore, these QDs complexes could also be used as nanocrystal probing agents, allowing real-time tracking and localization of QDs during delivery and transfection. The properties and capabilities of these QDs showed that amino acid-modifi{ligature}ed QDs could be used as useful siRNA carriers to effectively silence a target gene as well as fluorescence probes to analyze intracellular imaging in vivo. © 2011 Elsevier Ltd.

Xu C.,Sun Yat Sen University | Xu C.,South China Agricultural University | Chen Z.,Sun Yat Sen University | Chen D.,Sun Yat Sen University | And 2 more authors.
Applied Physics Letters | Year: 2010

A controllable pump-pulse-number magneto-optical Kerr technique combined with an initializing field scanning approach is developed to eliminate and identify memory and accumulation effects, respectively, from external field history and multiple pulse excitations. A series of anomalous loops of GdFeCo films are measured for different amount of pump pulses using this technique, revealing that serious memory and accumulation effects exist in continuous-pulse-pumped anomalous hysteresis loops which show illusory information of hot coercivity and degree of magnetization reversal. Single-pulse-induced anomalous loop reveals that the hot coercivity shown by continuous-pulse-pumped anomalous loops is not the minimum external field that drives real magneto-optical recording. © 2010 American Institute of Physics.

Jiang D.,South China Agricultural University | Zheng X.,South China Agricultural University | Shao G.,Sun Yat Sen University | Ling Z.,South China Agricultural University | Xu H.,South China Agricultural University
Journal of Agricultural and Food Chemistry | Year: 2014

A series of novel phenyl pyrazole inner salt derivatives based on fipronil were designed and synthesized in the search for dual-target insecticides. These compounds were designed to target two families of nicotinic acetylcholine receptors and γ-aminobutyric acid receptors. The insecticidal activities of the new compounds against diamondback moth (Plutella xylostella) were evaluated. The results of bioassays indicated that most of the inner salts showed moderate to high activities, of which the phenyl pyrazole inner salts containing quinoline had excellent biological activity. Previous structure-activity relationship studies revealed that a suitable structure of the quaternary ammonium salts was critical for the bioactivity of phenyl pyrazole inner salts, which contribute to exposing the cationic nitrogen to bind to the receptor (for instance, nicotinic acetylcholine receptors) and possibly interact with the receptor via hydrogen bonding and cooperative π-π interaction. The present work demonstrates that the insecticidal potency of phenyl pyrazole inner salts holds promise for the development new dual-target phenyl pyrazole insecticides. © 2014 American Chemical Society.

Li Y.,Sun Yat Sen University | Li Y.,South China Agricultural University | Malomed B.A.,Tel Aviv University | Feng M.,Sun Yat Sen University | Zhou J.,Sun Yat Sen University
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2010

We introduce two models of quasidiscrete optical systems: an array of waveguides doped by four-level N-type atoms, and a nonlinear checkerboard pattern, formed by doping with three-level atoms of the Λ-type. The dopant atoms are driven by external fields, to induce the effect of the electromagnetically induced transparency (EIT). These active systems offer advantages and additional degrees of freedom, in comparison with ordinary passive waveguiding systems. In the array of active waveguides, the driving field may adjust linear and nonlinear propagation regimes for a probe signal. The nonlinear checkerboard system supports the transmission of stable spatial solitons and their "fuzzy" counterparts, straight or oblique. © 2010 The American Physical Society.

Zhou A.,South China Agricultural University | Lin L.,South China Agricultural University | Liang Y.,South China Agricultural University | Benjakul S.,Prince of Songkla University | And 2 more authors.
Food Chemistry | Year: 2014

Changes of physicochemical properties in natural actomyosin (NAM) from threadfin bream (Nemipterus spp.) induced by high hydrostatic pressure (200, 400, 600 MPa for 10, 30, 50 min) were studied. The increase in turbidity of NAM was coincidental with the decrease in protein solubility with increasing pressure and time, suggesting the formation of protein aggregates. SDS-PAGE showed that polymerisation and degradation of myosin heavy chain were induced by high pressure. Ca2+-ATPase activity of NAM treated by high pressure was lost, suggesting the denaturation of myosin and the dissociation of actomyosin complex. Surface hydrophobicity of NAM increased when the pressure and pressurization time increased, indicating that the exposed hydrophobic residues increased upon application of high pressure. Decrease in total sulfhydryl content and increase in surface-reactive sulfhydryl content of NAM samples were observed with the extension of pressurizing time, indicating the formation of disulphide bonds through oxidation of SH groups or disulphide interchanges. The above changes of physicochemical properties suggested conformational changes of NAM from muscle of threadfin bream induced by high hydrostatic pressure. © 2014 Elsevier Ltd. All rights reserved.

Wang J.,South China Agricultural University | Wang J.,Jilin University | Tong X.,South China Agricultural University
Journal of Insect Science | Year: 2012

Litterdwelling thrips are an important component of soil macroinvertebrates in tropical and subtropical regions. However, little is known about assemblage composition, seasonal abundance and vertical distribution of litterdwelling thrips. A survey of forest litterdwelling thrips and other soil macroinvertebrates was conducted in an urban forest remnant at Guangzhou, China during 20042005 and 20082009. A total of 835 Tullgren samples were collected during the study. Thysanoptera constituted 6.5% of total litterdwelling macroinvertebrate individuals extracted, representing three families, 19 genera, and 25 species. Psalidothrips ascitus Ananthakrishnan (Thysanoptera: Phlaeothripidae) and Hyidiothrips guangdongensis Wang, Tong and Zhang represented 78.5% of all individuals of litterdwelling thrips during the survey. Numbers of species and density of leaflitter thrips fluctuated between different months. Density of litter thrips increased from March until October, reaching a maximum of 41.1 individuals/m2 followed by a decrease. In January and February only a few larval thrips were present. Species diversity gradually increased from July (four species) to December (10 species), and then declined rapidly. The vertical distribution showed that the leaflitter thrips species richness and abundance decreased significantly with soil depth; they were found only in the litter layer and upper soil layer (0-5 cm in depth) and were entirely absent in deeper soil layers. The results suggest that litterdwelling thrips are a common group of litter invertebrates with high species diversity in subtropical regions. These urban forest remnants should be given special consideration in forest conservation planning, because of their significance as refugia for the litter invertebrate assemblages, especially for leaflitter thrips. © This is an open access paper. We use the Creative Commons Attribution 3.0 license that permits unrestricted use, provided that the paper is properly attributed.

Wang H.,Cornell University | Wang H.,South China Agricultural University | Ma F.,Cornell University | Cheng L.,Cornell University
Planta | Year: 2010

Metabolite profiles and activities of key enzymes in the metabolism of organic acids, nitrogen and amino acids were compared between chlorotic leaves and normal leaves of 'Honeycrisp' apple to understand how accumulation of non-structural carbohydrates affects the metabolism of organic acids, nitrogen and amino acids. Excessive accumulation of non-structural carbohydrates and much lower CO 2 assimilation were found in chlorotic leaves than in normal leaves, confirming feedback inhibition of photosynthesis in chlorotic leaves. Dark respiration and activities of several key enzymes in glycolysis and tricarboxylic acid (TCA) cycle, ATP-phosphofructokinase, pyruvate kinase, citrate synthase, aconitase and isocitrate dehydrogenase were significantly higher in chlorotic leaves than in normal leaves. However, concentrations of most organic acids including phosphoenolpyruvate (PEP), pyruvate, oxaloacetate, 2-oxoglutarate, malate and fumarate, and activities of key enzymes involved in the anapleurotic pathway including PEP carboxylase, NAD-malate dehydrogenase and NAD-malic enzyme were significantly lower in chlorotic leaves than in normal leaves. Concentrations of soluble proteins and most free amino acids were significantly lower in chlorotic leaves than in normal leaves. Activities of key enzymes in nitrogen assimilation and amino acid synthesis, including nitrate reductase, glutamine synthetase, ferredoxin and NADH-dependent glutamate synthase, and glutamate pyruvate transaminase were significantly lower in chlorotic leaves than in normal leaves. It was concluded that, in response to excessive accumulation of non-structural carbohydrates, glycolysis and TCA cycle were up-regulated to "consume" the excess carbon available, whereas the anapleurotic pathway, nitrogen assimilation and amino acid synthesis were down-regulated to reduce the overall rate of amino acid and protein synthesis. © 2010 Springer-Verlag.

Chen J.,South China Agricultural University | Chen J.-Y.,South China Agricultural University | Wang J.-N.,Guangdong Ocean University | Kuang J.-F.,South China Agricultural University | And 2 more authors.
Gene | Year: 2012

CONSTANS (CO) gene is a key transcription regulator that controls the long-day induction of flowering in Arabidopsis plant. However, CO gene involved in fruit ripening and stress responses is poorly understood. In the present study, a novel cDNA encoding CONSTANS-like gene, designated as MaCOL1 was isolated and characterized from banana fruit. The full length cDNA sequence was 1887. bp with an open reading frame (ORF) of 1242. bp, encoding 414 amino acids with a molecular weight of 46.20. kDa and a theoretical isoelectric point of 5.40. Sequence alignment showed that MaCOL1 contained two B-box zinc finger motifs and a CCT domain. In addition, MaCOL1 showed transcriptional activity in yeast and was a nucleus-localized protein. Real-time PCR analysis showed that MaCOL1 was differentially expressed among various banana plant organs, with higher expression in flower. Expression of MaCOL1 in peel changed slightly, while accumulation of MaCOL1 transcripts in pulp obviously increased during natural or ethylene-induced fruit ripening, suggesting that MaCOL1 might be associated with the pulp ripening of banana fruit. Moreover, accumulation of MaCOL1 transcript was obviously enhanced by abiotic and biotic stresses, such as chilling and pathogen Colletotrichum musae infection. Taken together, our results suggest that MaCOL1 is a transcription activator and may be involved in fruit ripening and stress responses. © 2012 Elsevier B.V.

Cao S.,South China Agricultural University | Cao S.,South China Normal University | Shan C.-J.,South China Normal University | Shan C.-J.,Hubei Normal University | And 4 more authors.
Journal of the Optical Society of America B: Optical Physics | Year: 2015

We numerically investigate the ground state, the Raman-driving dynamics, and the nonlinear excitations of a realized spin-orbit-coupled Bose-Einstein condensate in a 1D harmonic trap. Depending on the Raman coupling and the interatomic interactions, three ground-state phases are identified: stripe, plane wave, and zero-momentum phases. A narrow parameter regime with coexistence of stripe and zero-momentum or plane wave phases in real space is found. Several sweeps progress across different phases by driving the Raman coupling linearly in time are simulated and the nonequilibrium dynamics of the system in these sweeps are studied. We find several kinds of nonlinear excitations, with the particular dark solitons excited in the sweep from the stripe phase to the plane wave or zero-momentum phase within the trap. Moreover, the number and the stability of the dark solitons can be controlled in the driving, which provides a direct and easy way to generate dark solitons and study their dynamics and interaction properties. © 2015 Optical Society of America.

Tian L.,CAS Shanghai Institutes for Biological Sciences | Guo E.,South China Agricultural University | Diao Y.,CAS Shanghai Institutes for Biological Sciences | Zhou S.,CAS Shanghai Institutes for Biological Sciences | And 4 more authors.
BMC Genomics | Year: 2010

Background: Insect innate immunity can be affected by juvenile hormone (JH) and 20-hydroxyecdysone (20E), but how innate immunity is developmentally regulated by these two hormones in insects has not yet been elucidated. In the silkworm, Bombyx mori, JH and 20E levels are high during the final larval molt (4 M) but absent during the feeding stage of 5thinstar (5 F), while JH level is low and 20E level is high during the prepupal stage (PP). Fat body produces humoral response molecules and hence is considered as the major organ involved in innate immunity.Results: A genome-wide microarray analysis of Bombyx fat body isolated from 4 M, 5 F and PP uncovered a large number of differentially-expressed genes. Most notably, 6 antimicrobial peptide (AMP) genes were up-regulated at 4 M versus PP suggesting that Bombyx innate immunity is developmentally regulated by the two hormones. First, JH treatment dramatically increased AMP mRNA levels and activities. Furthermore, 20E treatment exhibited inhibitory effects on AMP mRNA levels and activities, and RNA interference of the 20E receptor EcR-USP had the opposite effects to 20E treatment.Conclusion: Taken together, we demonstrate that JH acts as an immune-activator while 20E inhibits innate immunity in the fat body during Bombyx postembryonic development. © 2010 Tian et al; licensee BioMed Central Ltd.

Liu P.,South China Agricultural University | Liang S.,South China Agricultural University | Yao N.,Sun Yat Sen University | Wu H.,South China Agricultural University
Trees - Structure and Function | Year: 2012

Previously, we found that secretory cell degradation typically occurred through programmed cell death during secretory cavity development in Citrus sinensis L. (Osbeck). This finding indicated that secretory cavities could be utilized as a new cell biology model for investigating the regulatory mechanisms of plant programmed cell death. To study further the programmed cell death during secretory cavity development in Citrus fruit, we studied the morphogenetic characteristics of secretory cavities during their development in Citrus grandis cv. Tomentosa. Using light microscope- and electron microscope-TUNEL assays, immunohistochemistry and immunocytochemistry, we described the precise spatial and temporal alterations in caspase 3-like distribution, chromatin condensation and DNA fragmentation during the programmed cell death of secretory cavity cells. Caspase 3-like was found to be significantly located in both the cytoplasm and the nucleus of secretory cavity cells undergoing programmed cell death, and caspase 3-like is closely associated with chromatin condensation and DNA fragmentation. Interestingly, both caspase 3-like and DNA fragmentation were detected in the nucleoli. Our findings suggest that caspase 3-like may be involved in the programmed cell death of secretory cavity cells, especially in chromatin condensation, DNA fragmentation, nuclear degradation and the degradation of certain organelles. © 2012 Springer-Verlag.

Liang C.-Y.,South China Agricultural University | Liang C.-Y.,Cornell University | Chen Z.-J.,South China Agricultural University | Yao Z.-F.,South China Agricultural University | And 2 more authors.
Journal of Integrative Plant Biology | Year: 2012

Protein dephosphorylation mediated by protein phosphatases plays a major role in signal transduction of plant responses to environmental stresses. In this study, two putative protein phosphatases, PvPS2:1 and PvPS2:2 were identified and characterized in bean (Phaseolus vulgaris). The two PvPS2 members were found to be localized to the plasma membrane and the nucleus by transient expression of PvPS2:GFP in onion epidermal cells. Transcripts of the two PvPS2 genes were significantly increased by phosphate (P i) starvation in the two bean genotypes, G19833 (a P-efficient genotype) and DOR364 (a P-inefficient genotype). However, G19833 exhibited higher PvPS2:1 expression levels than DOR364 in both leaves and roots during P i starvation. Increased transcription of PvPS2:1 in response to P i starvation was further verified through histochemical analysis of PvPS2:1 promoter fusion ß-glucuronidase (GUS) in transgenic Arabidopsis plants. Analysis of PvPS2:1 overexpression lines in bean hairy roots and Arabidopsis showed that PvS2:1 was involved in root growth and P accumulation. Furthermore, expression levels of two P i starvation responsive genes were upregulated and the APase activities were enhanced in the overexpressing PvPS2:1 Arabidopsis lines. Taken together, our results strongly suggested that PvPS2:1 positively regulated plant responses to P i starvation, and could be further targeted as a candidate gene to improve crop P efficiency. © 2012 Institute of Botany, Chinese Academy of Sciences.

Li X.,South China Agricultural University | Zhao J.,South China Agricultural University | Walk T.C.,Golden Fidelity LLC | Liao H.,South China Agricultural University
Applied Microbiology and Biotechnology | Year: 2014

Expansins are plant cell wall-loosening proteins encoded by a superfamily of genes including α-expansin, β-expansin, expansin-like A, and expansin-like B proteins. They play a variety of biological roles during plant growth and development. Expansin genes have been reported in many plant species, and results primarily from graminaceous members indicate that β-expansins are more abundant in monocots than in dicots. Soybean [Glycine max (L.) Merr] is an important legume crop. This work identified nine β-expansin gene family members in soybean (GmEXPBs) that were divided into two distinct classes based on phylogeny and gene structure, with divergence between the two groups occurring more in introns than in exons. A total of 887 hormone-responsive and environmental stress-related putative cis-elements from 188 families were found in the 2-kb upstream region of GmEXPBs. Variations in number and type of cis-elements associated with each gene indicate that the function of these genes is differentially regulated by these signals. Expression analysis confirmed that the family members were ubiquitously, yet differentially expressed in soybean. Responsiveness to nutrient deficiency stresses and regulation by auxin (indole-3-acetic acid) and cytokinin (6-benzylaminopurine) varied among GmEXPBs. In addition, most β-expansin genes were associated with symbiosis of soybean inoculated with Rhizobium or abuscular mycorrhizal fungi (AMF). Taken together, these results systematically investigate the characteristics of the entire GmEXPB family in soybean and comprise the first report analyzing the relationship of GmEXPBs with rhizobial or AMF symbiosis. This information is a valuable step in the process of understanding the expansin protein functions in soybean and opens avenues for continued researches. © 2013 Springer-Verlag.

Li L.-F.,CAS South China Botanical Garden | Li L.-F.,Sun Yat Sen University | Hakkinen M.,University of Helsinki | Yuan Y.-M.,Firmenich | And 2 more authors.
Molecular Phylogenetics and Evolution | Year: 2010

Musaceae is a small paleotropical family. Three genera have been recognised within this family although the generic delimitations remain controversial. Most species of the family (around 65 species) have been placed under the genus Musa and its infrageneric classification has long been disputed. In this study, we obtained nuclear ribosomal ITS and chloroplast (atpB-rbcL, rps16, and trnL-F) DNA sequences of 36 species (42 accessions of ingroups representing three genera) together with 10 accessions of ingroups retrieved from GenBank database and 4 accessions of outgroups, to construct the phylogeny of the family, with a special reference to the infrageneric classification of the genus Musa. Our phylogenetic analyses elaborated previous results in supporting the monophyly of the family and suggested that Musella and Ensete may be congeneric or at least closely related, but refuted the previous infrageneric classification of Musa. None of the five sections of Musa previously defined based on morphology was recovered as monophyletic group in the molecular phylogeny. Two infrageneric clades were identified, which corresponded well to the basic chromosome numbers of x= 11 and 10/9/7, respectively: the former clade comprises species from the sections Musa and Rhodochlamys while the latter contains sections of Callimusa, Australimusa, and Ingentimusa. © 2010 Elsevier Inc.

Mo Z.-Q.,South China Agricultural University | Li Y.-W.,Sun Yat Sen University | Zhou L.,South China Agricultural University | Li A.-X.,Sun Yat Sen University | And 2 more authors.
Fish and Shellfish Immunology | Year: 2015

MCSF and its well-known receptor MCSFR had been well studied in humans, regulating the differentiation, proliferation, and survival of the mononuclear phagocyte system. IL-34, which is an alternative ligand of MCSF receptor, was recently identified as a novel cytokine and functionally overlaps with MCSF. However, the functional study of these receptors and their ligands in fish are largely unknown. In the present study, the cDNA of two potential grouper MCSFR ligands have been cloned, EcIL-34 (657bp) and EcMCSF2 (804bp), as well as an additional copy of grouper MCSFR, EcMCSFR2 (3141bp). Sequence analysis showed that these three molecules had higher identities with other fish counterparts compared to mammals and their conserved structures and important functional residues were also analyzed. Tissue distribution analysis showed that EcIL-34 is dominant in brain, gill and spleen compared to EcMCSF2, which is dominant in head kidney, trunk kidney, skin, heart and muscle. EcMCSFR1 was dominant in the most tissues except head kidney and liver compared to EcMCSFR2. The different tissue distribution patterns of these two grouper MCSF receptors and their two ligands indicate the different mononuclear phagocyte differentiation and activation modes in different tissues. In Cryptocaryon irritans infected grouper, EcIL-34 and EcMCSFR2 were the most strongly up-regulated ligand and receptor in the infected sites, gill and skin. Their up-regulation confirmed the proliferation and activation of phagocytes in C. irritans infected sites, which would improve the antigen presentation and elicit the host local specific immune response. In C. irritans infected grouper head kidney, both ligands EcIL-34 and EcMCSF2 (especially EcMCSF2) were up-regulated, but both receptors EcMCSFR1 and EcMCSFR2 were down-regulated, which indicated that the phagocytes differentiation and proliferation may have occurred in this hemopoietic organ, and after that they migrated to the infected cites. The down-regulation of EcIL-34 and EcMCSF2 and no significant change of EcMCSFR1 and EcMCSFR2 in most time point of grouper spleen showed it was less involved in phagocytes response to C. irritans infection. © 2014 Elsevier Ltd. All rights reserved.

Liu F.,Sun Yat Sen University | Tang Y.,Sun Yat Sen University | Du R.,Sun Yat Sen University | Yang H.,Sun Yat Sen University | And 2 more authors.
Plant and Soil | Year: 2010

Positive root response to metals may enhance metal accumulation for greater requirement in hyperaccumulators. The effects of spatially heterogeneous Zn/Cd addition on root allocation, metal accumulation, and growth of the Zn/Cd hyperaccumulator Sedum alfredii were assessed in a pot experiment. Young shoots of S. alfredii were grown with or without supplied Zn/Cd. Two concentrations were used of each metal, and each metal concentration had one homogeneous and two heterogeneous treatments. Growth increased by 1. 6-3. 2 times with the increasing overall dose of Zn/Cd addition, and shoot biomass was positively correlated with shoot Zn/Cd concentration (P < 0. 001). In all heterogeneous treatments, the plants consistently allocated approximately 90% of root biomass to the metal-enriched patches, and shoot Zn/Cd contents were greater than or similar to those in the homogeneous treatment at each metal concentration. Plants in the control treatment showed symptoms of Zn deficiency, although their shoots had Zn concentrations 100-fold higher than the critical deficiency value for most plants. We conclude that S. alfredii has evolved root foraging mechanisms associated with its greater requirements for Zn/Cd. These results could have important implications both for phytoremediation and for investigation of positive role of Cd in higher plants. © Springer Science + Business Media B.V. 2009.

Song Z.-J.,CAS Chengdu Institute of Biology | Song Z.-J.,South China Agricultural University | Xu X.-M.,Chinese Academy of Sciences | Deng W.-L.,Chinese Academy of Sciences | And 3 more authors.
Organic Letters | Year: 2011

An unprecedented dimeric triterpenoid, designated dibelamcandal A, with a six-membered ring linking two iridal type triterpenoid nuclei, was isolated from the rhizome of Belamcanda chinensis. Its structure was determined by extensive spectroscopic measurements, including IR, ESI-MS, HR-ESI-MS, and 1D and 2D NMR. It demonstrated significant molluscicide activity against Pomacea canaliculata. © 2011 American Chemical Society.

Jia J.-L.,South China Agricultural University | Jia J.-L.,Tsinghua University | Xu H.-H.,South China Agricultural University | Zhang G.-R.,Tsinghua University | And 2 more authors.
Nanotechnology | Year: 2012

Nearly monodisperse Au nanorods (NRs) with different aspect ratios were separated from home-synthesized polydisperse samples using a gradient centrifugation method. The morphology, size and its distribution, and photo-absorption property were analyzed by transmission electron microscopy, atomic force microscopy and UV-visible spectroscopy. Subsequently, using colloidal Au NRs (36.2 nm ×10.7 nm) with 97.4% yield after centrifugation and Au nanospheres (NSs) (22.9 ± 1.0 nm in diameter) with 97.6% yield as Au substrates, surface-enhanced Raman scattering (SERS) spectra of 2,4-dichlorophenoxyacetic acid (2,4-D) were recorded using laser excitation at 632.8 nm. Results show that surface enhancement factors (EF) for Au NRs and NSs are 6.2 × 105 and 5.7 × 104 using 1.0 × 10-6 M 2,4-D, respectively, illustrating that EF value is a factor of ∼10 greater for Au NRs substrates than for Au NSs substrates. As a result, large EF are a mainly result of chemical enhancement mechanisms. Thus, it is expected that Au NPs can find a comprehensive SERS application in the trace detection of pesticide residues. © 2012 IOP Publishing Ltd.

Li S.,Jinan University | Shi R.,South China Agricultural University | Shi R.,Shanxi Medical University | Wang Q.,Jinan University | And 2 more authors.
Gene | Year: 2012

Spermatogonial stem cells (SSCs) provide the foundation for spermatogenesis and male fertility. However, spermatogenesis has direct links with some adhesion molecules on SSCs membrane. B1-integrin (CD29) is such a kind of adhesion molecule and a biomarker of pig's SSCs. Therefore, quantitative characteristics of β1-integrin expression level in a single cell could help us to capture the signal switch and understand the mechanism of spermatogenesis. In this study, atomic force microscopy (AFM) was used to obtain the morphology and ultrastructure of SSCs at nanometer level, and the CD29 Ab-functionalized AFM tip was used to examine β1-integrin distribution on the cell membrane. There were many force-binding spots on about 50% of cell membrane binding to the CD29 Ab-functionalized AFM tip, and the mean bind rupture force was 283.63 ± 12.56PN which was much larger than the non-specific average force 70.75 ± 10.95PN. Meanwhile, β1-integrin on SSCs membrane was distributed non-uniformly, and there were some β1-integrins appeared to be expressed as 150-350. nm nanoclusters on the membrane. Our results discovered the structure of SSCs at nanometer level by AFM. The force between β1-integrin antigen-antibody interactions and the distribution of β1-integrin protein on SSCs membrane were also firstly demonstrated. © 2011.

Qiu H.,South China Agricultural University | Du Y.,South China Normal University | Yao Z.,Sun Yat Sen University
Nonlinear Analysis: Real World Applications | Year: 2011

In this paper, we consider the two-dimensional Newton-Boussinesq equations with the incompressibility condition. We obtain a regularity criterion for the Newton-Boussinesq equations by virtue of the commutator estimate. © 2011 Elsevier Ltd. All rights reserved.

Chen X.,Guangdong Ocean University | Wu G.,South China Agricultural University | Huang Z.,South China Agricultural University
International Journal of Biological Macromolecules | Year: 2013

The polysaccharides extracted by hot water and precipitated by 50% ethanol from the fruiting bodies of cultured Cordyceps militaris (W-CBP50) were introduced. Antioxidant activities of W-CBP50, W-CBP50 I (obtained from W-CBP50 purified by Sephadex G-100 chromatography) and W-CBP50 II (obtained from W-CBP50I purified by Sephadex G-200 chromatography) were evaluated and structural features of W-CBP50 II were analyzed. The polysaccharide W-CBP50 II was able to scavenge the stable free radical 1,1-diphenyl-2-picrylhyrazyl (DPPH), while W-CBP50 and W-CBP50I could scavenge DPPH, hydroxyl and superoxide radical. Structural characteristics of W-CBP50 II were investigated using GPC, GC-MS, 1H NMR and IR. The results showed that it was mainly composed of α-glucose, α-mannose, α-galactose and α-arabinose with α-type glycosidic linkage and the molecular weight of its main component was 8.97kD. © 2013 Elsevier B.V.

Lin Z.-T.,South China Agricultural University | Song K.,Sun Yat Sen University | Bin J.-P.,Southern Medical University | Liao Y.-L.,Southern Medical University | Jiang G.-B.,South China Agricultural University
Journal of Materials Chemistry | Year: 2011

Blood compatibility exerts an essential role in designing medical materials. The negative surface charge possessed by N-succinyl-chitosan (SCCS) has the benefit of being nonthrombogenic. To enhance the self-aggregation of SCCS, 2-hydroxy-3-(octadecyloxy)propyl groups (HOP) were employed as hydrophobic groups on SCCS to synthesise amphiphilic chitosan derivatives (HOPSCCS). The degree of succinyl substitution (DS) significantly influenced the water solubility of SCCS. Due to the intermolecular electrostatic attraction, SCCS (H-DS39.1) was water-insoluble, while SCCS (H-DS67.51, 78.6) were water-soluble. The substitution degree of HOP was 0.99-4.05%. The size of HOPSCCS micelles mainly ranged from 117 nm to 194 nm, and their critical micelle concentrations (CMC) were in the range of 1.42-4.24 × 10 -3 mg mL -1, and their surface had a negative charge ranging from -27.0 mV to -35.6 mV, suggesting that they possessed excellent stability and dispersion stability which was beneficial to prolong their circulation half-life and reduce the frequency of drug use. Aspirin was encapsulated into HOPSCCS, and the value of maximum drug loading capacity (LC) reached 18.5%, indicating that it can be an effective vehicle for aspirin and a good strategy for the use of aspirin. 1H NMR confirmed the aggregation behaviour of the micelles. Aspirin-loaded HOPSCCS, HOPSCCS/aspirin mixture and the influence of DS of SCCS on order structure were measured by FTIR. Thermal behaviour was determined by DTA/TG. Anticoagulant assays indicated that HOPSCCS had a slight anticoagulant property. Cell toxicity assessment, anticoagulant assays and hemolysis test suggested that HOPSCCS possessed low cytotoxicity and excellent hemocompatibility as a potential drug carrier for systemic administration and therapy of some blood diseases. © 2011 The Royal Society of Chemistry.

Li Z.,Sun Yat Sen University | Li Z.,Guangxi Normal University | Li Q.,Guangxi Normal University | Fang Y.,Guangxi Normal University | And 4 more authors.
Journal of Materials Chemistry | Year: 2011

A new class of micro/nano composite architecture, characterized by radially grown MnO2 nanoneedles on high specific surface area (SSA) mesoporous carbon microspheres (MCMs), is presented for the first time as electrode materials for electrochemical capacitors (ECs). This unique architecture could be considered as an omnibearing oriented 1-D nanostructure which possesses high power features for EC applications. When evaluated for electrochemical capacitance performance in a non-aqueous electrolyte, this composite architecture demonstrates improved electrochemical properties with maximum specific energy and energy density of 164 W h kg-1 and 25 kW h L-1, respectively. This enhanced performance could be mainly attributed to the integration of efficient double layer capacitance and tremendous pseudo-capacitance from MCMs and MnO2. Our findings suggest that this composite architecture might be used as a promising anode material for high performance ECs. © 2011 The Royal Society of Chemistry.

Li J.-M.,Sun Yat Sen University | Wang Y.-Y.,Sun Yat Sen University | Wang Y.-Y.,Jinan University | Zhao M.-X.,Sun Yat Sen University | And 6 more authors.
Biomaterials | Year: 2012

Co-delivery of siRNA and chemotherapeutic agents has been developed to combat multidrug resistance in cancer therapy. Recently, we developed a series of quantum dots (QDs) functionalized by β-cyclodextrin (β-CD) coupled to amino acids, some of which can be used to facilitate the delivery of siRNA. In this study, two CdSe/ZnSe QDs modified with β-CD coupled to L-Arg or L-His were used to simultaneously deliver doxorubicin (Dox) and siRNA targeting the MDR1 gene to reverse the multidrug resistance of HeLa cells. In this co-delivery system, Dox was firstly encapsulated into the hydrophobic cavities of β-CD, resulting in bypass of P-glycoprotein (P-gp)-mediated drug efflux. After complex formation of the mdr1 siRNA with Dox-loaded QDs via electrostatic interaction, significant down-regulation of mdr1 mRNA levels and P-gp expression was achieved as shown by RT-PCR and Western blotting experiments, respectively. The number of apoptotic HeLa cells after treatment with the complexes substantially exceeded the number of apoptotic cells induced by free Dox only. The intrinsic fluorescence of the QDs provided an approach to track the system by laser confocal microscopy. These multifunctional QDs are promising vehicles for the co-delivery of nucleic acids and chemotherapeutics and for real-time tracking of treatment. © 2011 Elsevier Ltd.

Lu Y.,South China Agricultural University | Lu Y.,University of Aberdeen | Dong F.,South China Agricultural University | Deacon C.,University of Aberdeen | And 3 more authors.
Environmental Pollution | Year: 2010

The consumption of paddy rice (Oryza sativa L.) is a major inorganic arsenic exposure pathway in S.E. Asia. A multi-location survey was undertaken in Guangdong Province, South China to assess arsenic accumulation and speciation in 2 rice cultivars, one an Indica and the other a hybrid Indica. The results showed that arsenic concentrations in rice tissue increased in the order grain < husk < straw < root. Rice grain arsenic content of 2 rice cultivars was significant different and correlated with phosphorus concentration and molar ratio of P/As in shoot, being higher for the Indica cultivar than for the hybrid Indica, which suggests altering shoot phosphorus status as a promising route for breeding rice cultivars with reduced grain arsenic. Speciation of grain arsenic, performed using HPLC-ICP-MS, identified inorganic arsenic as the dominant arsenic species present in the rice grain. © 2009 Elsevier Ltd. All rights reserved.

Zhao M.-L.,South China Agricultural University | Wang J.-N.,South China Agricultural University | Wang J.-N.,Guangdong Ocean University | Shan W.,South China Agricultural University | And 8 more authors.
Plant, Cell and Environment | Year: 2013

MYC2, a basic helix-loop-helix (bHLH) transcription factor, is a key regulator in the activation of jasmonate (JA) response. However, the molecular details of MYC2 involving in methyl jasmonate (MeJA)-induced chilling tolerance of fruit remain largely unclear. In the present work, two MYC2 genes, MaMYC2a and MaMYC2b, and one homolog of the inducer of the C-repeat-binding factor (CBF) gene, MaICE1 were isolated and characterized from banana fruit. MaMYC2s and MaICE1 were found to be all localized in the nucleus. In addition, the proline-rich domain (PRD) and the acidic domain (AD) in the N-terminus were important for the transcriptional activation of MaMYC2 in yeast cells. Unlike MaICE1's constitutive expression, MaMYC2a and MaMYC2b were induced rapidly following MeJA treatment during cold storage. Moreover, protein-protein interaction analysis confirmed that MaMYC2s interacted with MaICE1. The expression of ICE-CBF cold-responsive pathway genes including MaCBF1, MaCBF2, MaCOR1, MaKIN2, MaRD2 and MaRD5 was also significantly induced by MeJA. Taken together, our work provides strong evidence that MaMYC2 is involved in MeJA-induced chilling tolerance in banana fruit through physically interacting and likely functionally coordinating with MaICE1, revealing a novel mechanism for ICE1 in response to cold stress as well as during development of induced chilling tolerance. Two MYC2 genes, MaMYC2a and MaMYC2b, and one homolog of the inducer of the CBF gene, MaICE1 were isolated and characterized from banana fruit. MaMYC2a and MaMYC2b were induced rapidly following MeJA treatment during cold storage. MaMYC2s interacted with MaICE1, thus our work provides strong evidence that MaMYC2 is involved in MeJA-induced chilling tolerance in banana fruit through physically interacting and likely functionally coordinating with MaICE1, revealing a novel mechanism for ICE1 in response to cold stress as well as during development of induced chilling tolerance. © 2012 Blackwell Publishing Ltd.

Li Y.,Sun Yat Sen University | Li Y.,South China Agricultural University | Malomed B.A.,Tel Aviv University | Malomed B.A.,ICFO - Institute of Photonic Sciences | And 2 more authors.
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2011

We demonstrate that spatial solitons undergo two consecutive spontaneous symmetry breakings (SSBs), with the increase of the total power, in nonlinear photonic crystals (PhCs) built as arrays of alternating linear and nonlinear stripes, in the case when the maxima of the effective refractive index coincide with the minima of the self-focusing coefficient and vice versa (i.e., the corresponding linear and nonlinear periodic potentials are in competition). This setting may be induced, as a virtual PhC, by means of the electromagnetically induced-transparency (EIT) technique, in a uniform optical medium. It may also be realized as a Bose-Einstein condensate (BEC) subject to the action of the combined periodic optical potential and periodically modulated Feshbach resonance. The first SSB happens at the center of a linear stripe, pushing a broad low-power soliton into an adjacent nonlinear stripe and gradually suppressing side peaks in the soliton's shape. Then the soliton restores its symmetry, being pinned to the midpoint of the nonlinear stripe. The second SSB occurs at higher powers, pushing the narrow soliton off the center of the nonlinear channel, while the soliton keeps its internal symmetry. The results are obtained by means of numerical and analytical methods. They may be employed to control switching of light beams by means of the varying power. © 2011 American Physical Society.

Wang R.-L.,South China Agricultural University | Wang R.-L.,Sun Yat Sen University | Zeng R.-S.,South China Agricultural University | Peng S.-L.,Sun Yat Sen University | And 3 more authors.
Weed Research | Year: 2011

Numerous studies have shown that elevated CO 2 levels promote liana establishment in forests, thus suggesting their increased prevalence in the future in these habitats. Limited information exists, however, concerning the effects of potentially increasing global temperatures on these plants. The invasive liana Ipomoea cairica has infested many forests in South China. We hypothesised that elevated temperature could change the resource allocation pattern and allelopathic potential of this plant, resulting in increased invasiveness. We compared seed germination, growth rates and leachate phytotoxicity of I. cairica at three temperatures (22, 26 and 30°C). The seed germination rates of I. cairica were 11.6%, 21.2% and 26.4% at 22, 26 and 30°C respectively. Elevated temperature resulted in significant changes in morphology and biomass allocation of I. cairica. Shoot biomass of the plant increased, while the root biomass decreased with increasing temperature. Phytotoxicity of aqueous leachates from fresh leaves of I. cairica varied depending on receptor plants, but showed the strongest phytotoxic effects at the highest temperature (30°C). Our results provide key information concerning the effects of elevated temperatures on the allelopathic potential, germination and growth of I. cairica and indicate that global warming could increase the invasiveness of this species. © 2011 The Authors. Weed Research © 2011 European Weed Research Society.

Yang X.,South China University of Technology | Wang H.,South China University of Technology | Li J.,South China Agricultural University | Zheng W.,South China Agricultural University | And 4 more authors.
Chemistry - A European Journal | Year: 2013

As some of the most interesting metal-free catalysts, carbon nanotubes (CNTs) and other carbon-based nanomaterials show great promise for some important chemical reactions, such as the selective oxidation of cyclohexane (C6H12). Due to the lack of fundamental understanding of carbon catalysis in liquid-phase reactions, we have sought to unravel the role of CNTs in the catalytic oxidation of C6H12 through a combination of kinetic analysis, in situ spectroscopy, and density functional theory. The catalytic effect of CNTs originates from a weak interaction between radicals and their graphene skeletons, which confines the radicals around their surfaces. This, in turn, enhances the electron-transfer catalysis of peroxides to yield the corresponding alcohol and ketone. Cyclohexane oxidation over nanotubes: A weak interaction between radicals and graphene skeletons significantly promotes the catalytic oxidation of cyclohexane by confining the radicals around the surfaces of CNTs (see scheme). This, in turn, enhances the electron-transfer catalysis of peroxides to yield the corresponding alcohol and ketone. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Chen Z.,South China Agricultural University | Cui Q.,South China Agricultural University | Liang C.,South China Agricultural University | Liang C.,Cornell University | And 4 more authors.
Proteomics | Year: 2011

Symbiotic nitrogen fixation is a high-phosphorus demand process. Proteomic analysis was performed to identify the differentially expressed proteins in soybean nodules under phosphate starvation, and qRT-PCR was subsequently conducted to examine the expression patterns of the genes encoding the identified proteins. There were 44 phosphate-starvation responsive proteins identified from soybean nodules. Among them, 14 plant and 3 rhizobial proteins were up-regulated, whereas 13 plant and 14 rhizobial proteins were down-regulated by phosphate starvation. The qRT-PCR assays verified that gene expression correlated with 11 of the 14 up-regulated proteins from plants, but only 4 of 13 down-regulated proteins were correlated to the expression of the corresponding genes, suggesting that most up-regulated proteins may be controlled at the transcriptional level, whereas down-regulated proteins were controlled at the post-transcriptional level. Furthermore, a group of genes exhibited differential responses to phosphate starvation in nodules versus roots, suggesting that different adaptive responses might occur between roots and nodules. To our best knowledge, this is the first study to reveal differential protein profiles of nodules responding to phosphate starvation through proteomic analysis, which could result in a relatively comprehensive understanding of molecular mechanisms through which soybean nodules adapt to phosphorus stress. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Li Y.-W.,Sun Yat Sen University | Luo X.-C.,South China University of Technology | Dan X.-M.,South China Agricultural University | Qiao W.,Sun Yat Sen University | And 2 more authors.
Fish and Shellfish Immunology | Year: 2012

TLR21, a non-mammalian Toll like receptor, was recently identified in chicken as a pattern recognition receptor of unmethyl-CpG ODN, functionally similar to that of mammalian TLR9. Its role in fish immune defense and whether it is involved in anti-parasite immunity has not yet been proven. In this study, we identified a cDNA sequence encoding orange-spotted grouper Toll-like receptor 21 (EcTLR21), the open reading frame (ORF) was 2937bp encoding a putative polypeptide of 979 amino acid residues. Some conserved motifs in mammalian TLR9 were also conserved in grouper and other fish species' TLR9 and TLR21. Tissue distribution analysis indicated that EcTLR21 is broadly expressed in all the tissue we tested except muscle. High expression levels were found in the head kidney, trunk kidney, spleen and heart. Post Cryptocaryon irritans infection, TLR21 and TLR9 transcripts were induced at the local infection sites (skin and gill), while suppressed in systemic immune organs (spleen and head kidney), indicating that these two receptors may play a role in host anti-parasitic immune responses. © 2011 Elsevier Ltd.

Yang D.,Qingdao University | Yang D.,Queensland University of Technology | Zhao J.,Queensland University of Technology | Liu H.,Queensland University of Technology | And 8 more authors.
Chemistry - A European Journal | Year: 2013

Cerium ions (Ce3+) can be selectively doped into the TiO2(B) core of TiO2(B)/anatase core-shell nanofi- bers by means of a simple one-pot hydrothermal treatment of a starting material of hydrogen trititanate (H2Ti3O7) nanofibers. These Ce3+ ions (0.202 nm) are located on the (110) lattice planes of the TiO2(B) core in tunnels (width0.297 nm). The introduction of Ce3+ ions reduces the defects of the TiO2(B) core by inhibiting the faster growth of (110) lattice planes. More importantly, the redox potential of the Ce3+/Ce4+ couple (E8(Ce3+/Ce4+)=1. 715 V versus the normal hydrogen electrode) is more negative than the valence band of TiO2(B). Therefore, once the Ce3+ -doped nanofibers are irradiated by UV light, the doped Ce3+ ions-in close vicinity to the interface between the TiO2(B) core and anatase nanoshell- can efficiently trap the photogenerated holes. This facilitates the migration of holes from the anatase shell and leaves more photogenerated electrons in the anatase nanoshell, which results in a highly efficient separation of photogenerated charges in the anatase nanoshell. Hence, this enhanced charge-separation mechanism accelerates dye degradation and alcohol oxidation processes. The one-pot treatment doping strategy is also used to selectively dope other metal ions with variable oxidation states such as Co2+ /3+ and Cu+/2+ ions. The doping substantially improves the photocatalytic activity of the mixed-phase nanofibers. In contrast, the doping of ions with an invariable oxidation state, such as Zn2+ , Ca 2+, or Mg2+, does not enhance the photoactivity of the mixed-phase nanofibers as the ions could not trap the photogenerated holes. © 2013 Wiley-VCH Verlag GmbHandCo.

Li Q.,Wuhan University of Technology | Li Q.,South-Central University for Nationalities | Li X.,South China Agricultural University | Wageh S.,King Abdulaziz University | And 3 more authors.
Advanced Energy Materials | Year: 2015

Heterogeneous photocatalysis using semiconductors and renewable solar energy has been regarded as one of the most promising processes to alleviate, and even solve, both the world crises of energy supply and environmental pollution. In the past few years, many encouraging achievements have been made in the research area of graphene-based semiconductor photocatalysts. Among them, CdS/graphene nanocomposites have attracted extensive attention as an important kind of photocatalyst in chemical and material science, due to its superior photocatalytic activity and photostability under visible-light irradiation. The aim here is to address the enhancement mechanism of the photocatalytic performance of CdS/graphene composite photocatalysts, and systematically summarize recent progress regarding the design and synthesis of CdS/graphene nanocomposites. These nanocomposites are promising for a great diversity of applications in visible-light photocatalytic fields, including artificial photosynthetic systems (photocatalytic hydrogen production and CO2 reduction), environmental remediation, and organic photosynthesis. Special attention is given to the photocatalytic hydrogen production and pollutant photodegradation over CdS/graphene nanocomposite photocatalysts. Furthermore, perspectives on CdS/graphene-based materials are discussed, including the various remaining challenges for large-scale applications, identifying prospective areas for related research in this field. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Li Y.-W.,Sun Yat Sen University | Luo X.-C.,South China University of Technology | Dan X.-M.,South China Agricultural University | Huang X.-Z.,Sun Yat Sen University | And 3 more authors.
Fish and Shellfish Immunology | Year: 2011

Cryptocaryon irritans is one of the most important ectoparasites of marine fish, and can have a devastating effect on aquacultured fish populations. The role of TLR signaling pathways in anti-parasitic immune responses is poorly understood in fish. In this paper, we first cloned Epinephelus coioides MyD88 full-length cDNA (EcMyD88) and its respective gene. The open reading frame (ORF) of cDNA is 873. bp encoding 291 amino acid residues. Similar to other species, the EcMyD88 gene contains of five conserved exons and four diverse introns. The constitutive expression of EcMyD88 was detected in the gill, trunk kidney, head kidney, spleen, and heart in high concentrations, while the skin, brain, liver, and muscles contained much lower titers, indicating that EcMyD88 may play a crucial role in host innate immunologic surveillance. To identify the potential role of TLR pathways in fish anti- C. irritans immune responses, we chose three important molecules involved in anti-parasite responses, TLR2, MyD88 and IL-1β to indicate TLR pathway's signal-in, signal transduction, and signal-out functions, respectively. The expression profile of these three genes was detected in grouper infected by C. irritans. Results showed these molecules each experience significant changes within the skin, gill (two infected mucosal sites), head kidney and spleen (two systematic immune organs) after C. irritans infection. These findings indicate the TLR signaling pathway may play an important role in host defense against C. irritans. © 2011 Elsevier Ltd.

van Dam N.M.,Radboud University Nijmegen | Qiu B.-L.,South China Agricultural University | Hordijk C.A.,Netherlands Institute of Ecology | Vet L.E.M.,Netherlands Institute of Ecology | And 2 more authors.
Journal of Chemical Ecology | Year: 2010

Plants under attack by aboveground herbivores emit complex blends of volatile organic compounds (VOCs). Specific compounds in these blends are used by parasitic wasps to find their hosts. Belowground induction causes shifts in the composition of aboveground induced VOC blends, which affect the preference of parasitic wasps. To identify which of the many volatiles in the complex VOC blends may explain parasitoid preference poses a challenge to ecologists. Here, we present a case study in which we use a novel bioinformatics approach to identify biologically relevant differences between VOC blends of feral cabbage (Brassica oleracea L.). The plants were induced aboveground or belowground with jasmonic acid (JA) and shoot feeding caterpillars (Pieris brassicae or P. rapae). We used Partial Least Squares-Discriminant Analysis (PLSDA) to integrate and visualize the relation between plant-emitted VOCs and the preference of female Cotesia glomerata. Overall, female wasps preferred JA-induced plants over controls, but they strongly preferred aboveground JA-induced plants over belowground JA-induced plants. PLSDA revealed that the emission of several monoterpenes was enhanced similarly in all JA-treated plants, whereas homoterpenes and sesquiterpenes increased exclusively in aboveground JA-induced plants. Wasps may use the ratio between these two classes of terpenes to discriminate between aboveground and belowground induced plants. Additionally, it shows that aboveground applied JA induces different VOC biosynthetic pathways than JA applied to the root. Our bioinformatic approach, thus, successfully identified which VOCs matched the preferences of the wasps in the various choice tests. Additionally, the analysis generated novel hypotheses about the role of JA as a signaling compound in aboveground and belowground induced responses in plants. © 2010 The Author(s).

Wei H.,South China Agricultural University | Aengwanich W.,Mahasarakham University
International Journal of Poultry Science | Year: 2012

The objective of this study was to evaluate the biosecurity levels of Poultry Production Clusters (PPCs) in Thailand. Biosecurity levels of poultry farms in the PPCs were determined with criteria specified in biosecurity score form in 3 provinces i.e., Mahasarakham (contract farm with company), Nakhon Phanom (cooperative farm) and Nong Khai (individual farm) in the Northeast region of Thailand. In each province, biosecurity levels were evaluated both in the controlled group and in the cluster (15 farms each). Biosecurity scores were compared between farms in the controlled group and the cluster and among 3 provinces. From the results, it was found that scores of attractiveness to wild bird, measures for visitors and traders, measures for equipments and vehicles of poultry farm, local environment, measures taken at the entrances to poultry sheds in poultry farms and biosecurity plans of poultry farmers in Mahasarakham were significantly higher than in Nakhon Phanom and Nong Khai (p<0.05). The score of measures related to staffs of the poultry farms in Nakhon Phanom was significantly higher than those in Nong Khai (p<0.05). The score of feed quality in Mahasarakham and Nong Khai was significantly higher than that in Nakhon Phanom (p<0.05). In Mahasarakham, scores of local environment and biosecurity plans of poultry farmers of the controlled group were significantly higher than those of the cluster (p<0.05). In Nakhon Phanom, scores of attractiveness to wild bird, measures for incoming poultry, measures for visitors, measures taken at the entrances to poultry sheds and biosecurity plans of poultry farmers in controlled group were significantly higher than in the cluster (p<0.05). This demonstrated that biosecurity levels of contract farm with company were better than cooperative and individual ones. The difference of biosecurity levels was due to the farming pattern, farm's ecology, the compliance to governmental measures and policies and the ability to invest in biosecurity system of each group. As a result, the scores of biosecurity differed. © Asian Network for Scientific Information, 2012.

Wang J.,South China Agricultural University | Cox D.G.,University of Mississippi | Ding W.,South China Agricultural University | Huang G.,South China Agricultural University | And 2 more authors.
Marine Drugs | Year: 2014

Three new resveratrol derivatives, namely, resveratrodehydes A-C (1-3), were isolated from the mangrove endophytic fungus Alternaria sp. R6. The structures of these compounds were elucidated by analysis of their MS, 1D and 2D NMR spectroscopic data. All compounds showed broad-spectrum inhibitory activities against three human cancer cell lines including human breast MDA-MB-435, human liver HepG2, and human colon HCT-116 by MTT assay (IC 50 < 50 μM). Among them, compounds 1 and 2 both exhibited marked cytotoxic activities against MDA-MB-435 and HCT-116 cell lines (IC 50 < 10 μM). Additionally, compounds 1 and 3 showed moderate antioxidant activity by DPPH radical scavenging assay. © 2014 by the authors; licensee MDPI.

Liu D.,South China Agricultural University | Liu D.,Louisiana State University | Chen H.,South China Agricultural University | Chang P.R.,Agriculture and Agri Food Canada | And 3 more authors.
Bioresource Technology | Year: 2010

Despite the biodegradability, non-toxicity, and renewability, commercially available soy protein-based adhesives still have not been widely adopted by industry, partially due to their disappointing performances, i.e., low glue strength in the dry state and no glue strength in the wet state. In this study, biomimetic soy protein/CaCO3 hybrid wood glue was devised and an attempt made to improve the adhesion strength. The structure and morphology of the adhesive and its fracture bonding interface and adhesion strength were investigated. Results showed that the compact rivets or interlocking links, and ion crosslinking of calcium, carbonate, hydroxyl ions in the adhesive greatly improving the water-resistance and bonding strength of soy protein adhesives. Glue strength of soy protein hybrid adhesive was higher than 6 MPa even after three water-immersion cycles. This green and sustainable proteinous hybrid adhesive, with high glue strength and good water-resistance, is a good substitute for formaldehyde wood glues. © 2010 Elsevier Ltd.

Liu D.,South China Agricultural University | Liu D.,Louisiana State University | Zhong T.,South China Agricultural University | Chang P.R.,Agriculture and Agri Food Canada | And 2 more authors.
Bioresource Technology | Year: 2010

Using a method of combined HNO3-KClO3 treatment and sulfuric acid hydrolysis, bamboo cellulose crystals (BCCs) were prepared and used to reinforce glycerol plasticized starch. The structure and morphology of BCCs were investigated using X-ray diffraction, electron microscopy, and solid-state 13C NMR. Results showed that BCCs were of typical cellulose I structure, and the morphology was dependent on its concentration in the suspension. BCC of 50-100 nm were assembled into leaf nervations at low concentration (i.e. 0.1 wt.% of solids), but congregated into a micro-sized "flower" geometry at high concentration (i.e. 10.0 wt.% of solids). Tensile strength and Young's modulus of the starch/BCC composite films (SBC) were enhanced by the incorporation of the crystals due to reinforcement of BCCs and reduction of water uptake. BCCs at the optimal 8% loading level exhibited a higher reinforcing efficiency for plasticized starch plastic than any other loading level. Crown Copyright © 2009.

Zhou C.-S.,Sun Yat Sen University | Ye C.-D.,South China Agricultural University
Acta Geographica Sinica | Year: 2013

Since China's economic reform in the post-1990s, urban spatial growth has experienced tremendous changes. By using methods, such as spatial econometrics and topological analysis, this paper analyzes the features and causes of spatial growth in 52 Chinese metropolises based on images of land use and relevant socio-economic statistical data from 1990 to 2008. The research results indicate that: urban space grows rapidly especially after 2000 in general but shows a decelerating trend with a lowering rank in the population-size hierarchy; the growth trend of urban spatial elements inclines to be new and diverse; the growth of urban spatial structure shows a zonary and polycentric pattern; the growth of spatial morphology displays a pattern of decentralization and fragmentation; the urban spatial growth patterns are mainly axial and jumping oriented. Furthermore, we find that the major causes of urban spatial growth in Chinese metropolises are fast economic growth, rapid urbanization and GDP-oriented view of achievement in city government. Finally, the paper argues that the main problems of urban spatial growth in Chinese metropolises are excessive growth of the scale, scattered structure and fragmented morphology. Thus we suggest that the urban growth policy should focus on scale control, structure optimization and spatial compactness.

Hu A.-L.,South China Agricultural University | Hu A.-L.,Guizhou University | Yang W.,South China Agricultural University | Xu H.-H.,South China Agricultural University
Journal of Photochemistry and Photobiology B: Biology | Year: 2010

Some compounds that contain glucose groups can be transported across the plasma membrane into the cells through hexose transporters. To test the hypothesis that glucose-conjugated insecticides also have similar uptake and translocation properties, a novel fluorescent conjugate (12) was prepared by conjugating glucose and 7-nitrobenz-2-oxa-1,3-diazole with 4-iodo-1-phenylpyrazoles. Its fluorescence spectra and uptake by suspension-cultured tobacco (Nicotiana tabacum L.cv.) cells were studied. The fluorescence spectra showed long wavelengths with maximum emission at 530 nm. After incubating tobacco cell suspensions in 10 μM conjugate for 0.5 h, green fluorescence of 12 was clearly visible in the cells under fluorescence microscopy. After 2 h of incubation, more than 70% of 12 was absorbed. Carbonyl cyanide m-chlorophenylhydrazone, phloridzin and glucose drastically inhibited uptake. In concentration-dependent uptakes, the uptake rate of 12 showed a saturable component and was in accordance with Michaelis-Menten kinetics. The results proved that the glucose moiety can guide 12 into tobacco cells and that hexose transporters mediated the uptake. © 2010.

Yu X.,University of California at Los Angeles | Jiang J.,University of California at Los Angeles | Sun J.,University of California at Los Angeles | Sun J.,South China Agricultural University | Zhou Z.H.,University of California at Los Angeles
eLife | Year: 2015

mRNA transcription in dsRNA viruses is a highly regulated process but the mechanism of this regulation is not known. Here, by nucleoside triphosphatase (NTPase) assay and comparisons of six high-resolution (2.9–3.1 A°) cryo-electron microscopy structures of cytoplasmic polyhedrosis virus with bound ligands, we show that the large sub-domain of the guanylyltransferase (GTase) domain of the turret protein (TP) also has an ATP-binding site and is likely an ATPase. S-adenosyl-Lmethionine (SAM) acts as a signal and binds the methylase-2 domain of TP to induce conformational change of the viral capsid, which in turn activates the putative ATPase. ATP binding/hydrolysis leads to an enlarged capsid for efficient mRNA synthesis, an open GTase domain for His217-mediated guanylyl transfer, and an open methylase-1 domain for SAM binding and methyl transfer. Taken together, our data support a role of the putative ATPase in mediating the activation of mRNA transcription and capping within the confines of the virus. © Yu et al.

Blouin M.,University Paris Est Creteil | Hodson M.E.,University of York | Delgado E.A.,Terranova Lombricultores | Baker G.,CSIRO | And 8 more authors.
European Journal of Soil Science | Year: 2013

Biodiversity is responsible for the provision of many ecosystem services; human well-being is based on these services, and consequently on biodiversity. In soil, earthworms represent the largest component of the animal biomass and are commonly termed 'ecosystem engineers'. This review considers the contribution of earthworms to ecosystem services through pedogenesis, development of soil structure, water regulation, nutrient cycling, primary production, climate regulation, pollution remediation and cultural services. Although there has been much research into the role of earthworms in soil ecology, this review demonstrates substantial gaps in our knowledge related in particular to difficulties in identifying the effects of species, land use and climate. The review aims to assist people involved in all aspects of land management, including conservation, agriculture, mining or other industries, to obtain a broad knowledge of earthworms and ecosystem services. © 2013 British Society of Soil Science.

Li N.,South China Agricultural University | Hong W.,South China Agricultural University | Huang H.,University of South Florida | Lu H.,Sun Yat Sen University | And 2 more authors.
PLoS ONE | Year: 2012

As an important structure in membrane proteins, transmembrane domains have been found to be crucial for properly targeting the protein to cell membrane as well as carrying out transport functions in transporters. Computer analysis of OATP sequences revealed transmembrane domain 2 (TM2) is among those transmembrane domains that have high amino acid identities within different family members. In the present study, we identify four amino acids (Asp70, Phe73, Glu74, and Gly76) that are essential for the transport function of OATP1B1, an OATP member that is specifically expressed in the human liver. A substitution of these four amino acids with alanine resulted in significantly reduced transport activity. Further mutagenesis showed the charged property of Asp70 and Glu74 is critical for proper function of the transporter protein. Comparison of the kinetic parameters indicated that Asp70 is likely to interact with the substrate while Glu74 may be involved in stabilizing the binding site through formation of a salt-bridge. The aromatic ring structure of Phe73 seems to play an important role because substitution of Phe73 with tyrosine, another amino acid with a similar structure, led to partially restored transport function. On the other hand, replacement of Gly76 with either alanine or valine could not recover the function of the transporter. Considering the nature of a transmembrane helix, we proposed that Gly76 may be important for maintaining the proper structure of the protein. Interestingly, when subjected to transport function analysis of higher concentration of esteone-3-sulfate (50 μM) that corresponds to the low affinity binding site of OATP1B1, mutants of Phe73, Glu74, and Gly76 all showed a transport function that is comparable to that of the wild-type, suggesting these amino acids may have less impact on the low affinity component of esteone-3-sulfate within OATP1B1, while Asp 70 seems to be involved in the interaction of both sites. © 2012 Li et al.

Chen L.-N.,Sun Yat Sen University | Yang K.,South China Agricultural University
Xitong Gongcheng Lilun yu Shijian/System Engineering Theory and Practice | Year: 2013

Based on HAR-GARCH model and HAR-CJ model, this article proposes an adaptive asymmetry HAR-D-CJ-FIGARCH model and utilizes it to conduct a volatility forecast. And then this article investigates the various properties of volatility simultaneously by utilizing the proposed model and the high-frequency data from SSEC from 2000 to 2008. Finally this article employs the SPA test to evaluate and compare the out-of-sample forecast performance of 7 high-frequency volatility models. The results show that the high-frequency volatility in Chinese stock markets has long term memory, structural breaks, asymmetry, and day-of-the-week effects. The structural breaks can only partially explain the long memory. The continuous components of high-frequency volatility have strong long-term memory, and the long-term memory of jump components is very weak. As compared to the other 6 models, the proposed model improves the in-sample fitting significantly, and provides the best out-of-sample forecast.

Zhang X.,University of California at Los Angeles | Ding K.,University of California at Los Angeles | Yu X.,University of California at Los Angeles | Chang W.,University of California at Los Angeles | And 3 more authors.
Nature | Year: 2015

Viruses in the Reoviridae, like the triple-shelled human rotavirus and the single-shelled insect cytoplasmic polyhedrosis virus (CPV), all package a genome of segmented double-stranded RNAs (dsRNAs) inside the viral capsid and carry out endogenous messenger RNA synthesis through a transcriptional enzyme complex (TEC). By direct electron-counting cryoelectron microscopy and asymmetric reconstruction, we have determined the organization of the dsRNA genome inside quiescent CPV (q-CPV) and the in situ atomic structures of TEC within CPV in both quiescent and transcribing (t-CPV) states. We show that the ten segmented dsRNAs in CPV are organized with ten TECs in a specific, non-symmetric manner, with each dsRNA segment attached directly to a TEC. The TEC consists of two extensively interacting subunits: an RNA-dependent RNA polymerase (RdRP) and an NTPase VP4. We find that the bracelet domain of RdRP undergoes marked conformational change when q-CPV is converted to t-CPV, leading to formation of the RNA template entry channel and access to the polymerase active site. An amino-terminal helix from each of two subunits of the capsid shell protein (CSP) interacts with VP4 and RdRP. These findings establish the link between sensing of environmental cues by the external proteins and activation of endogenous RNA transcription by the TEC inside the virus. © 2015 Macmillan Publishers Limited. All rights reserved.

Hu K.-Z.,Sun Yat Sen University | Wang H.,Sun Yat Sen University | Huang T.,Sun Yat Sen University | Tang G.,Sun Yat Sen University | And 3 more authors.
Nuclear Medicine and Biology | Year: 2013

Introduction: N-position radiolabeled amino acids, such as N-(2-[18F]fluoropropionyl)-L-methionine ([18F]FPMET) as a derivative of L-methionine (MET), can potentially serve as a PET tracer for tumor imaging. In the current study, radiosynthesis and biological evaluation of [18F]FPMET as a new PET tumor agent are performed. Methods: [18F]FPMET was synthesized by reacting 4-nitrophenyl 2-[18F]fluoropropionate ([18F]NFP) with MET. In vitro competitive inhibition and protein incorporation experiments were performed with Hepa1-6 hepatoma cell lines. The biodistribution of [18F]FPMET was determined in S180 fibrosarcoma-bearing mice. PET/CT studies of [18F]FPMET were conducted in S180 fibrosarcoma-bearing mice, A549 lung adenocarcinoma-bearing nude mice, and PC-3 prostate cancer-bearing nude mice. Results: [18F]FPMET was synthesized in 72%±4% uncorrected radiochemical yield (n=10) from [18F]NFP. In vitro experiments showed that [18F]FPMET was primarily transported through Na+-dependent system A, system ASC, and system B0,+, and was not incorporated into protein. Biodistribution and PET/CT imaging studies indicated that [18F]FPMET could delineate S180 fibrosarcoma, A549 lung adenocarcinoma, and PC-3 prostate cancer. Conclusion: An efficient synthesis of N-position [18F]labeled amino acids with a classic [18F]NFP prosthetic group is developed. The results support that [18F]FPMET seems to be a potential tracer for tumor imaging with PET. © 2013 Elsevier Inc.

Tian L.,CAS Shanghai Institutes for Biological Sciences | Tian L.,Southwest University | Ma L.,CAS Shanghai Institutes for Biological Sciences | Guo E.,CAS Shanghai Institutes for Biological Sciences | And 6 more authors.
Autophagy | Year: 2013

Autophagy is finely regulated at multiple levels and plays crucial roles in development and disease. In the fat body of the silkworm, Bombyx mori, autophagy occurs and Atg gene expression peaks during the nonfeeding molting and pupation stages when the steroid hormone (20-hydroxyecdysone; 20E) is high. Injection of 20E into the feeding larvae upregulated Atg genes and reduced TOR C1 activity resulting in autophagy induction in the fat body. Conversely, RN Ai knockdown of the 20E receptor partner (USP) or targeted overexpression of a dominant negative mutant of the 20E receptor (EcRDN) in the larval fat body reduced autophagy and downregulated the Atg genes, confirming the importance of 20E-induction of Atg gene expression during pupation. Moreover, in vitro treatments of the larval fat body with 20E upregulated the Atg genes. Five Atg genes were potentially 20E primary-responsive, and a 20E response element was identified in the Atg1 (ortholog of human ULK1) promoter region. Furthermore, RN Ai knockdown of 4 key genes (namely Br-C, E74, HR3 and βftz-F1) in the 20E-triggered transcriptional cascade reduced autophagy and downregulated Atg genes to different levels. Taken together, we conclude that in addition to blocking TOR C1 activity for autophagosome initiation, 20E upregulates Atg genes to induce autophagy in the Bombyx fat body. © 2013 Landes Bioscience.

Luo D.,South China Agricultural University | Luo D.,Guangxi University | Xu H.,South China Agricultural University | Xu H.,Northwest University, China | And 17 more authors.
Nature Genetics | Year: 2013

Plant cytoplasmic male sterility (CMS) results from incompatibilities between the organellar and nuclear genomes and prevents self pollination, enabling hybrid crop breeding to increase yields. The Wild Abortive CMS (CMS-WA) has been exploited in the majority of 'three-line' hybrid rice production since the 1970s, but the molecular basis of this trait remains unknown. Here we report that a new mitochondrial gene, WA352, which originated recently in wild rice, confers CMS-WA because the protein it encodes interacts with the nuclear-encoded mitochondrial protein COX11. In CMS-WA lines, WA352 accumulates preferentially in the anther tapetum, thereby inhibiting COX11 function in peroxide metabolism and triggering premature tapetal programmed cell death and consequent pollen abortion. WA352-induced sterility can be suppressed by two restorer-of-fertility (Rf) genes, suggesting the existence of different mechanisms to counteract deleterious cytoplasmic factors. Thus, CMS-related cytoplasmic-nuclear incompatibility is driven by a detrimental interaction between a newly evolved mitochondrial gene and a conserved, essential nuclear gene. © 2013 Nature America, Inc. All rights reserved.

Su C.,University of Tennessee at Knoxville | Shwab E.K.,University of Tennessee at Knoxville | Zhou P.,South China Agricultural University | Zhu X.Q.,South China Agricultural University | Dubey J.P.,U.S. Department of Agriculture
Parasitology | Year: 2010

The development of simple, sensitive and rapid methods for the detection and identification of Toxoplasma gondii is important for the diagnosis and epidemiological studies of the zoonotic disease toxoplasmosis. In the past 2 decades, molecular methods based on a variety of genetic markers have been developed, each with its advantages and limitations. The application of these methods has generated invaluable information to enhance our understanding of the epidemiology, population genetics and phylogeny of T. gondii. However, since most studies focused solely on the detection but not genetic characterization of T. gondii, the information obtained was limited. In this review, we discuss some widely used molecular methods and propose an integrated approach for the detection and identification of T. gondii, in order to generate maximum information for epidemiological, population and phylogenetic studies of this key pathogen. © 2009 Cambridge University Press.

Zhou X.,South China University of Technology | Zhou X.,Zhanjiang Normal University | Peng F.,South China University of Technology | Wang H.,South China University of Technology | And 2 more authors.
Chemical Communications | Year: 2012

Nanoscaled nitrogen doped anatase TiO 2 with dominant (001) facets, which exhibited high photocatalytic activity and excellent photoelectrochemical properties under visible light irradiation, was successfully synthesized by solvothermal treatment of TiN in acidic NaBF 4 solution for the first time. © 2012 The Royal Society of Chemistry.

Gu J.,Sun Yat Sen University | Xu H.,U.S. Center for Disease Control and Prevention | Lau J.T.F.,Sun Yat Sen University | Lau J.T.F.,Chinese University of Hong Kong | And 6 more authors.
Addiction | Year: 2012

Aims To investigate the incidence of dropout and the prevalence of poor adherence among newly admitted first-time clients of methadone maintenance treatment (MMT) clinics, and the associations between MMT-related misconceptions and these two treatment outcomes. Design A cohort study (maximum follow-up period=17.6 months) was conducted. Setting Three of the nine MMT clinics in Guangzhou, China participated in the study. Participants The sample included 158 newly admitted first-time MMT clients. Measurements Information collected included background characteristics, history of drug use, MMT-related misconceptions, dropout during the entire study period and poor adherence within the first 6 months since admission to MMT. Findings Of all newly admitted MMT clients, 98.2% possessed at least one and 50.6% possessed all four types of MMT-related misconception; 51.3% had dropped out before the completion of the study [95% confidence interval (CI): 43.5-59.1%] and 62% exhibited poor adherence within the first 6 months since admission (95% CI: 54.2-69.6%). Adjusting for significant background variables, the number of misconceived responses predicted significantly both dropout [hazard ratio (HR)=3.80 for two to three misconceived items, HR=7.13 for four misconceived items, with zero to one misconceived item being the reference] and poor adherence within the first 6 months [relative risk (RR)=4.13 for two to three misconceived items; RR=4.40 for four misconceived items, with zero to one misconceived item being the reference. Conclusions Among opiate addicts in China prescribed methadone maintenance therapy for the first time, misconceptions about this medication are prevalent and are associated with poor adherence to the medication regimen and a high a rate of dropout from the treatment programme. © 2012 Society for the Study of Addiction.

Tang G.,Sun Yat Sen University | Tang G.,Southern Medical University | Tang X.,South China Agricultural University | Wang X.,Southern Medical University
Journal of Labelled Compounds and Radiopharmaceuticals | Year: 2010

A fully automated synthesis of N-succinimidyl 4-[18F] fluorobenzoate ([18F]SFB) was carried out by a convenient three-step, one-pot procedure on the modified TRACERlab FXFN synthesizer, including [18F]fluorination of ethyl 4-(trimethylammonium triflate)benzoate as the precursor, saponification of the ethyl 4-[ 18F]fluorobenzoate with aqueous tetrapropylammonium hydroxide instead of sodium hydroxide, and conversion of 4-[18F]fluorobenzoate salt ([18F]FBA) to [18F]SFB treated with N,N,N′,N′- tetramethyl-O-(N-succinimidyl)uranium tetrafluoroborate (TSTU). The purified [18F]SFB was used for the labeling of Tat membrane-penetrating peptide (containing the Arg-Lys-Lys-Arg-Arg-Arg-Arg-Arg-Arg-Arg-Arg-Pro-Leu-Gly- Leu-Ala-Gly-Glu-Glu-Glu-Glu-Glu-Glu-Glu sequence, [18F]CPP) through radiofluorination of lysine amino groups. The uncorrected radiochemical yields of [18F]SFB were as high as 25-35% (based on [18F] fluoride) (n = 10) with a synthesis time of ∼40 min. [18F]CPP was produced in an uncorrected radiochemical yields of 10-20% (n = 5) within 30 min (based on [18F]SFB). The radiochemical purities of [ 18F]SFB and [18F]CPP were greater than 95%. Copyright © 2010 John Wiley & Sons, Ltd.

Xiong W.,South China Agricultural University | Xiong W.,Sun Yat Sen University | Dai Y.,Nanjing Normal University
Journal of Statistical Mechanics: Theory and Experiment | Year: 2012

The nature of the three-dimensional random-field Ising model with a bimodal probability distribution is investigated using finite-time scaling combined with the Monte Carlo renormalization group method, in the presence of a linearly varying temperature. Our results support the existence of a first-order phase transition for this model, obtained through reducing the influence of finite-size effects. The critical exponents are estimated to be ν = 0.74(3), β = 0.27(1), α = - 0.023(5), and γ = 1.48(3) with corrections to the scaling. The Rushbrooke scaling law is satisfied with these exponents, and in turn identifies the asymptotic critical behavior. © 2012 IOP Publishing Ltd.

Wang C.,Rutgers University | Wen X.,South China Agricultural University
Insects | Year: 2011

The bed bug resurgence in North America, Europe, and Australia has elicited interest in investigating the causes of the widespread and increasing infestations and in developing more effective control strategies. In order to extend global perspectives on bed bug management, we reviewed bed bug literature in China by searching five Chinese language electronic databases. We conducted telephone interviews of staff from 77 Health and Epidemic Prevention Stations in six Chinese cities in November 2010. We also conducted telephone interviews of 68 pest control firms in two cities during March 2011. Two species of bed bugs (Cimex lectularius L. and Cimex hemipterus (F.)) are known to occur in China. These were common urban pests before the early1980s. Nationwide Four-Pest Elimination campaigns (bed bugs being one of the targeted pests) were implemented in China from 1960 to the early 1980s. These campaigns succeeded in the elimination of bed bug infestations in most communities. Commonly used bed bug control methods included applications of hot water, sealing of bed bug harborages, physical removal, and applications of residual insecticides (mainly organophosphate sprays or dusts). Although international and domestic travel has increased rapidly in China over the past decade (2000-2010), there have only been sporadic new infestations reported in recent years. During 1999-2009, all documented bed bug infestations were found in group living facilities (military dormitories, worker dormitories, and prisons), hotels, or trains. One city (Shenzhen city near Hong Kong) experienced significantly higher number of bed bug infestations. This city is characterized by a high concentration of migratory factory workers. Current bed bug control practices include educating residents, washing, reducing clutter, putting items under the hot sun in summer, and applying insecticides (pyrethroids or organophosphates). There have not been any studies or reports on bed bug insecticide resistance. Difficulties of control were noted in our surveys of dormitories in which crowded living, seasonal worker migration, and financial constraints contributed to control failures. This study supports the following conclusions: (1) the bed bug infestation in China dramatically decreased following the campaigns from 1960 to the early 1980s; (2) In our survey of Health and Epidemics Prevention Stations, no bed bug cases were reported in Beijing and Shanghai for the past 12 months, but complaints were reported in Guangzhou, Lanzhou, Urumqi, and Shenzhen; (3) Current bed bug infestations primarily are reported in crowded living environments or transient environments such as worker dormitories and military dormitories. These findings suggest that community-wide bed bug monitoring and control campaigns are necessary for effective control of bed bug infestations as a societal response. © 2011 by the authors; licensee MDPI, Basel, Switzerland.

Zhang J.-E.,South China Agricultural University | Liu J.-L.,Guangzhou Research Institute of Environmental Protection | Ouyang Y.,St. Johns River Water Management District | Liao B.-W.,Chinese Academy of Forestry | Zhao B.-L.,South China Agricultural University
Ecological Engineering | Year: 2010

Mangrove wetlands are important in the removal of nutrients, heavy metals, and organic pollutants from wastewater within estuarine systems due to the presence of oxidized and reduced conditions, periodic flooding by incoming and outgoing tides, and high clay and organic matter content. This study investigated the removal efficiency of nutrients and heavy metals from wastewater by the mangrove Sonneratia apetala Buch-Ham in a simulated wetland. Eight different treatments, namely, three concentration levels of wastewaters, with and without planting of the mangrove species, and one control (with salted water) each for both with and without planting of the mangrove species, were employed in this study. Results showed that the amounts of total mangrove biomass from different treatments were in the following order: PL-TW (planted with ten times higher-than-normal wastewater concentration) > PL-FW (planted with five times higher-than-normal wastewater concentration) > PL-SW (planted with normal wastewater concentration) > PL-NW (planted with no wastewater), whereas the magnitude of the heavy metal contents in the biomass was in the following order: Cu > Pb > Cd > Zn. Very good linear correlations existed between the biomass and the nutrients or heavy metals. The Sonneratia apetala Buch-Ham species had its own selectivity for uptake of heavy metals regardless of the initial heavy metal contents and was more effective in the removal of nutrients than heavy metals. Our study suggested that mangrove wetlands with Sonneratia apetala Buch-Ham species had great potential for the removal of nutrients and heavy metals in coastal areas. © 2010 Elsevier B.V. All rights reserved.

Hoang A.T.,Plant Protection Research Institute | Zhang H.-M.,Zhejiang Academy of Agricultural Sciences | Yang J.,Zhejiang Academy of Agricultural Sciences | Chen J.-P.,Zhejiang Academy of Agricultural Sciences | And 4 more authors.
Plant Disease | Year: 2011

A novel dwarf and twisting syndrome first observed on rice in Nghe An Province, Vietnam, in 2009 has spread rapidly to the other 19 provinces of North and Central Vietnam. Infected rice plants showed stunting, darkening of leaves, twisting of leaf tips, and splitting of leaf margins. At a later stage, white waxy enations that eventually turned black were observed on the underside of leaf blades, leaf sheaths, and culms. The disease also infected maize after rice was harvested. Infected maize plants were stunted and dark green with small enations along the minor veins on the back of leaves. The disease agent has now been identified as Southern rice black-streaked dwarf virus (SRBSDV) recently reported from Southern China. Typical fijivirus viroplasms containing crystalline arrayed spherical virions approximately 70 to 75 nm in diameter were observed under the electron microscope in ultrathin sections of infected rice leaves. The virus was transmitted to rice and maize seedlings by the white-backed planthopper (Sogatella furcimera). A one-step reverse transcription-polymerase chain reaction (RTPCR) protocol was used to confirm the presence of SRBSDV in 477 samples of rice or maize from 29 provinces among 5 agroecological regions in North and Central Vietnam. Rice black-streaked dwarf virus was not detected in these samples. Partial sequences of RNA segments 4 and 10 from several isolates showed very low genetic divergences between isolates from Vietnam and China, suggesting a common origin, and phylogenetic analysis confirmed the placement of SRBSDV as a distinct virus within subgroup 2 of the genus Fijivirus. © 2011 The American Phytopathological Society.

Si C.,South China Agricultural University | Ma Y.,South China Agricultural University | Ma Y.,Chinese Research Academy of Environmental Sciences | Lin C.,University of Southern Queensland
Journal of Hazardous Materials | Year: 2013

The capacity of red mud to sequester CO2 varied markedly due to differences in bauxite type, processing and disposal methods. Calcium carbonates were the dominant mineral phases responsible for the carbon sequestration in the investigated red mud types. The carbon sequestration capacity of red mud was not fully exploited due to shortages of soluble divalent cations for formation of stable carbonate minerals. Titanate and silicate ions were the two major oxyanions that appeared to strongly compete with carbonate ions for the available soluble Ca. Supply of additional soluble Ca and Mg could be a viable pathway for maximizing carbon sequestration in red mud and simultaneously reducing the causticity of red mud. It is roughly estimated that over 100 million tonnes of CO2 have been unintentionally sequestered in red mud around the world to date through the natural weathering of historically produced red mud. Based on the current production rate of red mud, it is likely that some 6 million tonnes of CO2 will be sequestered annually through atmospheric carbonation. If appropriate technologies are in place for incorporating binding cations into red mud, approximately 6 million tonnes of additional CO2 can be captured and stored in the red mud while the hazardousness of red mud is simultaneously reduced. © 2012 Elsevier B.V.

Jiang H.-X.,South China Agricultural University | Tang D.,South China Agricultural University | Liu Y.-H.,South China Agricultural University | Zhang X.-H.,South China Agricultural University | And 5 more authors.
Journal of Antimicrobial Chemotherapy | Year: 2012

Objective: To determine the molecular epidemiology of extended-spectrum β-lactamases (ESBLs) and plasmid-mediated quinolone resistance (PMQR) in Escherichia coli isolated from farmed fish in China. Methods: E. coli was isolated from fish gut samples from fish farmed throughout Guangdong province and tested for the presence of the β-lactamase genes and PMQR-encoding genes using PCR and DNA sequence analysis. Co-transfer of plasmids encoding for ESBLs as well as PMQR determinants was explored by conjugation into E. coli. Results: A total of 218 non-duplicate E. coli were recovered from fish gut samples. β-Lactamase genes were identified in 19 (17%) of 112 strains with reduced susceptibility to ampicillin, and PMQR genes were identified in 59 (73.8%) of 80 strains with reduced susceptibility to ciprofloxacin. Only three ESBL genes were identified in three isolates: blaCTX-M-14, blaCTX-M-79 and blaSHV-27. PMQR gene screening identified qnr genes (n = 59) as the most common, including qnrB (n = 33), qnrS (n = 21) and qnrD (n = 5), with aac(6')-Ib-cr (n = 6) being rarely found. The co-carriage of two or three PMQR genes in one strain was found in 7 (11.9%) isolates. The ESBL gene blaCTX-M-79 was found to be co-carried with qnrS. Co-transfer of qnrS was observed with blaCTX-M-79. Conclusions: Our study is the first to demonstrate the existence of high levels of mobile genes conferring reduced susceptibility to fluoroquinolones as well as the presence of ESBL genes in fish produced in China, and identifies a significant reservoir of antibiotic resistance genes relevant to human medicine. © The Author 2012. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved.

Azevedo C.O.,Federal University of Espirito Santo | Xu Z.,South China Agricultural University | Beaver R.A.,161 2 Mu 5
Zootaxa | Year: 2011

Pristapenesia asiatica sp. nov. is described and illustrated from two female specimens collected in China and Thailand. This species is readily recognized by the absence of a tubular radial vein in the fore wings. A key to world fossil and living species of Pristapenesia is provided Copyright © 2011 Magnolia Press.

Cuthbertson A.G.S.,UK Environment Agency | Qiu B.-L.,South China Agricultural University | Murchie A.K.,Agri Food and Biosciences Institute of Northern Ireland
Insects | Year: 2014

The increasing concern over the continued use of pesticides is pressurising apple growers to look for alternatives to chemical pest control. The re-discovery, and subsequent conservation, of the beneficial predatory mite, Anystis baccarum (Linnaeus) (Acari: Anystidae), in Bramley apple orchards in Northern Ireland offers a potential alternative control component for incorporation into integrated pest management strategies. Anystis baccarum readily feeds upon economically important invertebrate pest species including European fruit tree red spider mite, Panonychus ulmi (Koch) (Acari: Tetranychidae) and show a level of compatibility with chemical pesticides. Recent mis-identification by apple growers of this beneficial mite species had resulted in unnecessary pesticide applications being applied within Northern Irish apple orchards. However, dissemination of information to the apple growers and promotion of the benefits this mite offers in apple orchards has helped to conserve its populations. Apple growers, across the United Kingdom, must be encouraged to be aware of A. baccarum, and indeed all predatory fauna, within their orchards and seek to conserve populations. In doing so, it will ensure that the British apple market remains an environmentally sustainable production system. © 2014 by the authors; licensee MDPI, Basel, Switzerland.

Liang X.-M.,South China Agricultural University | Liang X.-M.,China Institute of Veterinary Drugs Control | Guo G.-F.,China Institute of Veterinary Drugs Control | Huang X.-H.,South China Agricultural University | And 2 more authors.
Journal of Surgical Research | Year: 2014

Background Mitogen-activated protein kinases (MAPKs) and nuclear factor-kappa B (NF-κB) signaling pathways are pleiotropic regulator of many genes involved in lipopolysaccharide (LPS)-induced acute lung injury (ALI). The present study aimed to reveal the protective effect of isotetrandrine (ITD), a small molecule inhibitor, on various aspects of LPS-induced inflammation in vitro and in vivo. Methods In vitro, RAW 264.7 cells were pretreated with different dose of ITD 1 h before treatment with 1 mg/L of LPS. In vivo, to induce ALI, male BALB/c mice were injected intranasally with LPS and treated with ITD (20 and 40 mg/kg) 1 h before LPS. Results In vitro, the cytokine levels of tumor necrosis factor-α, interleukin (IL)-1β, and IL-6 in supernatant were reduced by ITD. Meanwhile, in vivo, pulmonary inflammatory cell infiltration, myeloperoxidase activity, total cells, neutrophils, macrophages, along with the levels of tumor necrosis factor-α, IL-1β, and IL-6 in bronchoalveolar lavage fluid were dose-dependently attenuated by ITD. Furthermore, our data showed that ITD significantly inhibited the activation of MAPK and NF-κB, which are induced by LPS in ALI model. Conclusions These results suggested that ITD dose-dependently suppressed the severity of LPS-induced ALI by inactivation of MAPK and NF-κB, which may involve the inhibition of tissue oxidative injury and pulmonary inflammatory process. © 2014 Elsevier Inc. All rights reserved.

Zhao J.,University of Florida | Cui J.,Nanjing Agricultural University | Liu J.,South China Agricultural University | Liao F.,Guangdong Academy of Agricultural Sciences | And 3 more authors.
Plant Cell, Tissue and Organ Culture | Year: 2012

This study established a method of regenerating Spathiphyllum 'Supreme' through direct somatic embryogenesis. Somatic embryos occurred in leaf and petiole explants cultured in the dark on a Murashige and Skoog basal medium supplemented with 2.27, 4.54, or 9.08 μM N-phenyl-N′-1,2,3-thiadiazol-5-ylurea (TDZ) in combination with 1.08 μM α-naphthalene acetic acid or 2.26 μM 2,4-dichlorophenoxyacetic acid (2,4-D). Explants with somatic embryos were transferred to fresh medium containing the same concentrations of growth regulators under lighted conditions for embryo conversion. The highest frequencies of leaf explants with somatic embryos and embryo conversion were both 84.4 %, which were induced by 9.08 μM TDZ with 2.26 μM 2,4-D. The frequencies for somatic embryo induction and embryo conversion were both 100 % when petiole explants were induced by 4.54 μM TDZ with 2.26 μM 2,4-D. The number of plantlets produced per leaf explant and petiole explant were as high as 67.4 and 74.4, respectively. Plantlets after transplanting to a soilless substrate grew vigorously in a shaded greenhouse. Liners were stable without phenotypic variation. Flow cytometry analysis of randomly selected plants showed that they all had a single identical peak. The mean nuclear DNA index for 'Supreme' was 1.568, and the nuclear DNA content was 14. 222 pg 2C -1. The estimated genome size for 'Supreme' was 6,954. 5 Mbp 1C -1 with a CV at 4.008 %. The results suggest that the regenerated plants have a stable ploidy level and this established regeneration method can be used for highly effective propagation of uniform Spathiphyllum 'Supreme'. © 2012 Springer Science+Business Media B.V.

He X.-L.,Guangdong Institute of Microbiology | He X.-L.,Sichuan Academy of Agriculture science | Li T.-H.,Guangdong Institute of Microbiology | Xi P.-G.,South China Agricultural University | And 2 more authors.
Fungal Diversity | Year: 2013

Taxonomy and phylogeny of Entoloma s.l. subgenus Pouzarella in China are carried out based on morphological characters and molecular data. Seven species in subg. Pouzarella are recognized in China and a key to these species is provided. Five species, Entoloma changchunense, E. crassicystidiatum, E. furfuraceum, E. subaraneosum and E. tenuissimum, are described as new; a new Chinese record E. dysthaloides is also presented in this paper. Among them, E. crassicystidiatum was discovered from southern China, and the others were found in northeastern China. Molecular phylogeny of subg. Pouzarella were conducted based on nLSU, mtSSU and RPB2, and the phylogenetic positions of the five new species are discussed. The placement of subg. Pouzarella in Entoloma s.l. clade is well resolved in all analyses presented here, and the monophyly of subg. Pouzarella is strongly supported by the morphological and molecular phylogeny. The infrageneric classifications in this group were not well recovered in the present study; and further studies based on more samples and gene loci are needed to a better understanding of the infrageneric taxa in subg. Pouzarella in the future. © 2012 Mushroom Research Foundation.

Yang H.,CAS Shenzhen Institutes of Advanced Technology | Yang H.,South China Agricultural University | Shao L.,CAS Shenzhen Institutes of Advanced Technology | Shao L.,University of Sheffield | And 4 more authors.
Neurocomputing | Year: 2011

The goal of this paper is to review the state-of-the-art progress on visual tracking methods, classify them into different categories, as well as identify future trends. Visual tracking is a fundamental task in many computer vision applications and has been well studied in the last decades. Although numerous approaches have been proposed, robust visual tracking remains a huge challenge. Difficulties in visual tracking can arise due to abrupt object motion, appearance pattern change, non-rigid object structures, occlusion and camera motion. In this paper, we first analyze the state-of-the-art feature descriptors which are used to represent the appearance of tracked objects. Then, we categorize the tracking progresses into three groups, provide detailed descriptions of representative methods in each group, and examine their positive and negative aspects. At last, we outline the future trends for visual tracking research. © 2011 Elsevier B.V.

Huang S.,South China Agricultural University | Jin L.,South China University of Technology | Fang Y.,Northeastern University | Wei X.,South China University of Technology
Neurocomputing | Year: 2014

Heterogeneous Feature Fusion Machines (HFFM) is a kernel based logistic regression model that effectively fuses multiple features for visual recognition tasks. However, the batch mode solution for HFFM, 'Block Coordinate Gradient Descent' (BCGD) has the same low efficiency and poor scalability as the most batch algorithms do. In this paper, we describe a newly developed online learning algorithm in multiple Reproducing Kernel Hilbert Spaces for solving HFFM model. This new algorithm is called OLHFFM, i.e. Online HFFM. OLHFFM is novel combination of kernel-based learning technique with dual averaging gradient descent methods. In addition, group LASSO regularization technique is used in OLHFFM for finding important explanatory coefficients that are related to support samples in group manner. The effectiveness of OLHFFM has been demonstrated by a number of experiments that were conducted on public event, object dataset, as well as on large scale handwritten digital dataset. Using the OLHFFM approach, we have achieved almost equivalent recognition performance to that using batch-mode approach. Experiments conducted on both MIT Caltech-6 and challenging VOC2011 TrainVal object datasets show that OLHFFM is superior in performance to kernel based online learning approaches such as ILK or NORMA. In addition, the classification performance of OLHFFM approach as demonstrated by the experiments conducted on large scale MNIST dataset is comparable to or better than that of the current state-of-the-art online multiple kernel learning approaches such as OM-2, UFO-MKL, OMCL and OMKL. Extensive experiments on visual data classification demonstrate the effectiveness and robustness of the new OLHFFM approach. © 2013 Elsevier B.V.

Wei Y.-Z.,South China Agricultural University | Wei Y.-Z.,Chinese Academy of Sciences | Hu F.-C.,South China Agricultural University | Hu F.-C.,Hainan Academy of Agricultural science | And 4 more authors.
PLoS ONE | Year: 2011

Litchi has diverse fruit color phenotypes, yet no research reflects the biochemical background of this diversity. In this study, we evaluated 12 litchi cultivars for chromatic parameters and pigments, and investigated the effects of abscisic acid, forchlorofenron (CPPU), bagging and debagging treatments on fruit coloration in cv. Feizixiao, an unevenly red cultivar. Six genes encoding chalcone synthase (CHS), chalcone isomerase (CHI), flavanone 3-hydroxylase (F3H), dihydroflavonol 4-reductase (DFR), anthocyanidin synthase (ANS) and UDP-glucose: flavonoid 3-O-glucosyltransferase (UFGT) were isolated from the pericarp of the fully red litchi cv. Nuomici, and their expression was analyzed in different cultivars and under the above mentioned treatments. Pericarp anthocyanin concentration varied from none to 734 mg m-2 among the 12 litchi cultivars, which were divided into three coloration types, i.e. non-red ('Kuixingqingpitian', 'Xingqiumili', 'Yamulong'and 'Yongxing No. 2′), unevenly red ('Feizixiao' and 'Sanyuehong') and fully red ('Meiguili', 'Baila', Baitangying' 'Guiwei', 'Nuomici' and 'Guinuo'). The fully red type cultivars had different levels of anthocyanin but with the same composition. The expression of the six genes, especially LcF3H, LcDFR, LcANS and LcUFGT, in the pericarp of non-red cultivars was much weaker as compared to those red cultivars. Their expression, LcDFR and LcUFGT in particular, was positively correlated with anthocyanin concentrations in the pericarp. These results suggest the late genes in the anthocyanin biosynthetic pathway were coordinately expressed during red coloration of litchi fruits. Low expression of these genes resulted in absence or extremely low anthocyanin accumulation in non-red cultivars. Zero-red pericarp from either immature or CPPU treated fruits appeared to be lacking in anthocyanins due to the absence of UFGT expression. Among these six genes, only the expression of UFGT was found significantly correlated with the pericarp anthocyanin concentration (r = 0.84). These results suggest that UFGT played a predominant role in the anthocyanin accumulation in litchi as well as pericarp coloration of a given cultivar. © 2011 Wei et al.

Ouyang Y.,U.S. Department of Agriculture | Luo S.M.,South China Agricultural University | Cui L.H.,South China Agricultural University | Wang Q.,University of Florida | Zhang J.E.,South China Agricultural University
Ecological Engineering | Year: 2011

Agricultural, industrial, and urban activities are the major sources for eutrophication of surface water ecosystems. Currently, determination of nutrients in surface water is primarily accomplished by manually collecting samples for laboratory analysis, which requires at least 24h. In other words, little to no effort has been devoted to monitoring real-time variations of nutrients in surface water ecosystems due to the lack of suitable and/or cost-effective wireless sensors. However, when considering human health or instantaneous outbreaks such as algal blooms, timely water-quality information is very critical. In this study, we developed a new paradigm of a dynamic data-driven application system (DDDAS) for estimating the real-time loads of nitrogen (N) in a surface water ecosystem. This DDDAS consisted of the following components: (1) a Visual Basic (VB) program for downloading US Geological Survey real-time chlorophyll and discharge data from the internet; (2) a STELLA model for evaluating real-time N loads based on the relationship between chlorophyll and N as well as on river discharge; (3) a batch file for linking the VB program and STELLA model; and (4) a Microsoft Windows Scheduled Task wizard for executing the model and displaying outputs on a computer screen at selected schedules. The DDDAS was validated using field measurements with a very good agreement prior to its applications. Results show that the real-time loads of TN (total N) and NOx (nitrate and nitrite) varied from positive to negative with the maximums of 1727kg/h TN and 118kg/h NOx and the minimums of -2483kg/h TN and -168kg/h NOx at the selected site. The negative loads occurred because of the back flow of the river in the estuarine environment. Our study suggests that the DDDAS developed in this study was feasible for estimating the real-time variations of TN and NOx in the surface water ecosystem. © 2011.

Li K.,South China Agricultural University | Li K.,Jiangxi University of Science and Technology | Chen G.,Jiangxi University of Science and Technology
International Journal of Wireless and Mobile Computing | Year: 2013

To overcome the drawbacks of traditional complex community network division algorithms, such as low accuracy, high time complexity and easily being trapped into local optimum, a novel complex community network division algorithm is proposed by using Multi-Gene Families (MGF). The proposed approach first encodes the node ID and the community type into two different MGFs, respectively, and then encodes the relationship of the two MGFs into the chromosome through a mapping function. Moreover, in order to prevent premature and speed up convergence, the elite migration strategy is utilised throughout the evolution process, such as gene selection, chromosome crossover, chromosome inversion, restricted permutation. The experiments and analyses show that our approach is better than the traditional evolutionary algorithm in terms of efficiency and accuracy. Copyright © 2013 Inderscience Enterprises Ltd.

Xue X.,South China Agricultural University | Li S.-J.,South China Agricultural University | Ahmed M.Z.,South China Agricultural University | Ahmed M.Z.,University of Pretoria | And 3 more authors.
PLoS ONE | Year: 2012

Background: The whitefly Bemisia tabaci is cryptic species complex composed of numerous species. Individual species from the complex harbor a diversity of bacterial endosymbionts including Wolbachia. However, while Wolbachia is known to have a number of different roles, its role in B. tabaci is unclear. Here, the antibiotic rifampicin is used to selectively eliminate Wolbachia from B. tabaci so as to enable its roles in whitefly development and reproduction to be explored. The indirect effects of Wolbachia elimination on the biology of Encarsia bimaculata, a dominant parasitoid of B. tabaci in South China, were also investigated. Methodology/Principal Finding: qRT-PCR and FISH were used to show that after 48 h exposure to 1.0 mg/ml rifampicin, Wolbachia was completely inactivated from B. tabaci Mediterranean (MED) without any significant impact on either the primary symbiont, Portiera aleyrodidarum or any of the other secondary endosymbionts present. For B. tabaci MED, Wolbachia was shown to be associated with decreased juvenile development time, increased likelihood that nymphs completed development, increased adult life span and increased percentage of female progeny. Inactivation was associated with a significant decrease in the body size of the 4th instar which leads us to speculate as to whether Wolbachia may have a nutrient supplementation role. The reduction in nymph body size has consequences for its parasitoid, E. bimaculata. The elimination of Wolbachia lead to a marked increase in the proportion of parasitoid eggs that completed their development, but the reduced size of the whitefly host was also associated with a significant reduction in the size of the emerging parasitoid adult and this was in turn associated with a marked reduction in adult parasitoid longevity. Conclusions/Significance: Wolbachia increases the fitness of the whitefly host and provides some protection against parasitization. These observations add to our understanding of the roles played by bacterial endosymbionts. © 2012 Xue et al.

Xu Z.,South China Agricultural University | Olmi M.,University of Tuscia | Guglielmino A.,University of Tuscia | Chen H.,South China Agricultural University
Florida Entomologist | Year: 2011

Dryinidae (Hymenoptera: Chrysidoidea) are parasitoids of Hemiptera Auchenorrhyncha. The genus Dryinus Latreille, 1804, is present in all zoogeographical regions and about 242 species have been described. Dryinus anotaulicus sp. nov. is described from Jiujialing, Baisha County (Hainan Province, China). A check-list of Dryinidae from Hainan Province, China, is presented, and is accessible online at Supplementary material http://www.fcla.edu/FlaEnt/fe944.htm#InfoLink2.

Tian M.,South China Agricultural University | Deuve T.,Museum national d'Histoire naturelle
ZooKeys | Year: 2016

The jianfengling species group of the termitophilous carabid genus Orthogonius MacLeay, 1825 is defined and reviewed. This species group ranges from southern China, crossing Indochina and Myanmar to eastern India. To date, the jianfengling species group is composed of ten species, including six new species which are hereinafter described and illustrated: O. wrasei sp. n. (Myanmar), O. bellus sp. n. and O. limbourgi sp. n. (Vietnam), O. politior sp. n., O. aberlenci sp. n. (Laos) and O. meghalayaensis sp. n. (India). Habitus, elytral apices and male genitalia of all species are illustrated. A key to species and a distribution map of jianfengling species group are provided. © Mingyi Tian, Thierry Deuve.

Zhu H.,Guangdong Institute of Microbiology | Guo J.,Guangdong Institute of Microbiology | Chen M.,Guangdong Institute of Microbiology | Feng G.,Guangdong Institute of Microbiology | Yao Q.,South China Agricultural University
PLoS ONE | Year: 2012

Heavy-metal-tolerant bacteria, GIMN1.004T, was isolated from mine soils of Dabaoshan in South China, which were acidic (pH 2-4) and polluted with heavy metals. The isolation was Gram-negative, aerobic, non-spore-forming, and rod-shaped bacteria having a cellular width of 0.5-0.6 μm and a length of 1.3-1.8 μm. They showed a normal growth pattern at pH 4.0-9.0 in a temperature ranging from 5°C to 40°C.The organism contained ubiquinone Q-8 as the predominant isoprenoid quinine, and C16:0, summed feature 8 (C18:1ω7c and C18:1ω6c), C18:0, summed feature 3 (C16:1ω7c or iso-C15:0 2-OH), C17:0 cyclo, C18:1ω9c, C19:0 cyclo ω8c, C14:0 as major fatty acid. These profiles were similar to those reported for Burkholderia species. The DNA G+C % of this strain was 61.6%. Based on the similarity to 16S rRNA gene sequence, GIMN1.004T was considered to be in the genus Burkholderia. The similarities of 16S rRNA gene sequence between strain GIMN1.004T and members of the genus Burkholderia were 96-99.4%, indicating that this novel strain was phylogenetically related to members of that genus. The novel strain showed the highest sequence similarities to Burkholderia soli DSM 18235T (99.4%); Levels of DNA-DNA hybridization with DSM 18235T was 25%. Physiological and biochemical tests including cell wall composition analysis, differentiated phenotype of this strain from that closely related Burkholderia species. The isolation had great tolerance to cadmium with MIC of 22 mmol/L, and adsorbability of 144.94 mg/g cadmium,and it was found to exhibit antibiotic resistance characteristics. The adsorptive mechanism of GIMN1.004T for cadmium depended on the action of the amide,carboxy and phosphate of cell surface and producing low-molecular-weight (LMW) organic acids to complex or chelated Cd2+.Therefore, the strain GIMN1.004T represented a new cadmium resistance species, which was tentatively named as Burkholderia dabaoshanensis sp. nov. The strain type is GIMN1.004T (= CCTCC M 209109T = NRRL B-59553T). © 2012 Zhu et al.

Zhou Z.,Shanghai Normal University | Sun Y.,Shanghai Normal University | Shen J.,Shanghai Normal University | Wei J.,Shanghai Normal University | And 7 more authors.
Biomaterials | Year: 2014

The development of photothermal agents (PTAs) with good stability, low toxicity, highly targeting ability and photothermal conversion efficiency is an essential pre-requisite to near-infrared photothermal therapy (PTT) invivo. Herein, we report the readily available PEGylated Fe@Fe3O4 NPs, which possess triple functional properties in one entity - targeting, PTT, and imaging. Compared to Au nanorods, they exhibit comparable photothermal conversion efficiency (~20%), and much higher photothermal stability. They also show a high magnetization value and transverse relaxivity (~156mm-1s-1), which should be applied for magnetic targeting MRI. With the Nd-Fe-B magnet (0.5T) beside the tumour for 12h on the xenograft HeLa tumour model, PEGylated Fe@Fe3O4 NPs exhibit an obvious accumulation. In tumour, the intensity of MRI signal is ~ three folds and the increased temperature is ~ two times than those without magnetic targeting, indicating the good magnetic targeting ability. Notably, the intrinsic high photothermal conversion efficiency and selective magnetic targeting effect of the NPs in tumour play synergistically in highly efficient ablation of cancer cells invitro and invivo. © 2014 Elsevier Ltd.

Ahmed M.Z.,South China Agricultural University | Ahmed M.Z.,University of Pretoria | de Barro P.J.,CSIRO | Ren S.-X.,South China Agricultural University | And 2 more authors.
PLoS ONE | Year: 2013

Bemisia tabaci (Hemiptera: Aleyrodidae) is a globally distributed pest composed of at least 34 morphologically indistinguishable cryptic species. At least seven species of endosymbiont have been found infecting some or all members of the complex. The origin(s) of the associations between specific endosymbionts and their whitefly hosts is unknown. Infection is normally vertical, but horizontal transmission does occur and is one way for new infections to be introduced into individuals. The relationships between the different members of the cryptic species complex and the endosymbionts have not been well explored. In this study, the phylogenies of different cryptic species of the host with those of their endosymbionts were compared. Of particular interest was whether there was evidence for both coevolution and horizontal transmission. Congruence was observed for the primary endosymbiont, Portiera aleyrodidarum, and partial incongruence in the case of two secondary endosymbionts, Arsenophonus and Cardinium and incongruence for a third, Wolbachia. The patterns observed for the primary endosymbiont supported cospeciation with the host while the patterns for the secondary endosymbionts, and especially Wolbachia showed evidence of host shifts and extinctions through horizontal transmission rather than cospeciation. Of particular note is the observation of several very recent host shift events in China between exotic invader and indigenous members of the complex. These shifts were from indigenous members of the complex to the invader as well as from the invader to indigenous relatives. © 2013 Ahmed et al.

Zhu G.,South China Agricultural University | Liu Y.,Hong Kong Baptist University | Liu Y.,Shandong Agricultural University | Ye N.,Hong Kong Baptist University | And 2 more authors.
Physiologia Plantarum | Year: 2011

Earlier studies showed that sugars as signaling molecules play pivotal roles in the regulation of seed germination. ABA biosynthesis upregulation is suggested as one of the possible mechanisms mediating the glucose-induced delay in seed germination. In this study, the role of ABA catabolism in glucose-induced inhibition was investigated. Using Arabidopsis thaliana seeds, the results show that the repression of ABA catabolism by diniconazole aggravated the glucose-induced delay in seed germination. The transcript and protein profiles of CYP707A2, a key gene encoding ABA 8′-hydroxylase in ABA catabolism in Arabidopsis, were significantly decreased by exogenous glucose treatment. Transgenic experiments confirmed that the over-expression of the CYP707A2 gene alleviated the glucose-induced inhibition effect, whereas the cyp707a2 mutant seeds displayed a hypersensitivity to glucose during imbibition. Exogenous glucose also arrested the early seedling development of Arabidopsis. The CYP707A2 over-expression seedlings exhibited lower ABA levels and seemed less sensitive to exogenous glucose compared with wild type seedlings. In summary, the glucose-induced delay in seed germination and seedling development is directly related to the suppression of ABA catabolism through the repression of the CYP707A2 expression. © 2011 Physiologia Plantarum.

Xu Z.,South China Agricultural University | Olmi M.,University of Tuscia | He J.,Zhejiang University
Florida Entomologist | Year: 2011

Anteon nanlingense sp. nov. and Anteon longum sp. nov. are described from Nanling National Nature Reserve (Guangdong, P.R. China). A check-list of Dryinidae from Nanling National Nature Reserve is presented.

Xu K.,Nanjing University of Aeronautics and Astronautics | Liu M.,Nanjing Normal University | Liu M.,South China Agricultural University | Ch. Das K.,Sungkyunkwan University | And 3 more authors.
Match | Year: 2014

This survey outlines results on graphs extremal with respect to distance-based indices, with emphasis on the Wiener index, hyper-Wiener index, harary index, wiener polarity index, reciprocal complementary Wiener index, and terminal Wiener index.

Xu Z.,South China Agricultural University | Olmi M.,Tropical Entomology Research Center | Guglielmino A.,University of Tuscia
Florida Entomologist | Year: 2012

Embolemidae (Hymenoptera: Chrysidoidea) are parasitoids of Hemiptera Auchenorrhyncha. The genus Embolemus Westwood, 1833 is present in all zoogeographical regions and 32 species have been described. Embolemus sensitivus sp. nov. is described from the following localities of China: Naban River National Nature Reserve (Yunnan), Mt. Lushan (Taiwan), Mt. Wuyishan (Fujian), Mt. Qinliangfeng and Mt. Wuyanling (Zhejiang). Translation provided by the authors.

Xu Z.,South China Agricultural University | Olmi M.,Tropical Entomology Research Center | Guglielmino A.,University of Tuscia
Florida Entomologist | Year: 2012

Embolemidae (Hymenoptera: Chrysidoidea) are parasitoids of Hemiptera Auchenorrhyncha. The genus Ampulicomorpha Ashmead, 1893, is present in all zoogeographical regions and 20 species have been described. Ampulicomorpha sinensis sp. nov. is described from the Nanling National Nature Reserve (Guangdong, China). Translation provided by the authors.

Xu Z.,South China Agricultural University | Olmi M.,Tropical Entomology Research Center | Guglielmino A.,University of Tuscia | Chen H.,South China Agricultural University
Zootaxa | Year: 2012

Five subfamilies, 11 genera and 77 species of Dryinidae are listed from Guangdong Province. Two new species, Anteon pteromaculatum Xu, Olmi, Guglielmino & Chen, sp. nov. and Dryinus nanlingensis Xu, Olmi, Guglielmino & Chen, sp. nov. are described from Nanling National Nature Reserve. New synonymies are proposed for Dryinus indicus (Kieffer, 1914) (=Chlorodryinus koreanus Móczár, 1983, syn. nov.; Dryinus masneri Olmi, 2009, syn. nov.), Gonatopus nearcticus (Fenton, 1927) (=Acrodontochelys sinensis Olmi, 1984, syn. nov.). Ten species, Anteon atrum Olmi, 1998, A. silvicolum Olmi, 1984, A. viraktamathi Olmi, 1987, Deinodryinus asiaticus Olmi, 1984, Dryinus krombeini Ponomarenko, 1981, Neodryinus sumatranus Enderlein, 1907, Gonatopus malesiae (Olmi, 1984), Gonatopus validus (Olmi, 1984), G. plebeius (Perkins, 1912), and G. asiaticus (Olmi, 1984) are newly recorded from China. Anteon nanlingense Xu, Olmi & He, 2011 is newly recorded from Indonesia. Twenty-seven species are newly recorded from Guangdong Province. Ten species, in-cluding new ones, are known from Guangdong Province only. Copyright © 2012 · Magnolia Press.

Ye N.,Hong Kong Baptist University | Zhu G.,South China Agricultural University | Liu Y.,Shandong Agricultural University | Zhang A.,Nanjing Agricultural University | And 5 more authors.
Journal of Experimental Botany | Year: 2012

The antagonism between abscisic acid (ABA) and gibberellin (GA) plays a key role in controlling seed germination, but the mechanism of antagonism during this process is not known. The possible links among ABA, reactive oxygen species (ROS), ascorbic acid (ASC), and GA during rice seed germination were investigated. Unlike in non-seed tissues where ROS production is increased by ABA, ABA reduced ROS production in imbibed rice seeds, especially in the embryo region. Such reduced ROS also led to an inhibition of ASC production. GA accumulation was also suppressed by a reduced ROS and ASC level, which was indicated by the inhibited expression of GA biosynthesis genes, amylase genes, and enzyme activity. Application of exogenous ASC can partially rescue seed germination from ABA treatment. Production of ASC, which acts as a substrate in GA biosynthesis, was significantly inhibited by lycorine which thus suppressed the accumulation of GA. Consequently, expression of GA biosynthesis genes was suppressed by the low levels of ROS and ASC in ABA-treated seeds. It can be concluded that ABA regulates seed germination in multiple dimensions. ROS and ASC are involved in its inhibition of GA biosynthesis. © 2011 The Author(s).

Xu Z.,South China Agricultural University | Olmi M.,University of Tuscia | He J.,Zhejiang University
Oriental Insects | Year: 2010

Two new species, Anteon tenuitarse and A. pilosum (Dryinidae: Anteoninae) from Hainan and Zhejiang Provinces, and from Hainan and Ningxia Hui Nationality Autonomous Region of China, respectively are described. Keys for differentiating these given. Types deposited with the College of Nature Resources and Environment, South China Agricultural University, Guangzhou, P. R. China.

Chen L.,Nara Institute of Science and Technology | Chen L.,South China Agricultural University | Shimamoto K.,Nara Institute of Science and Technology
Journal of General Plant Pathology | Year: 2011

Molecular chaperones and co-chaperones are proteins that aid in the folding and assembly of other macromolecular structures or complexes. Although growing evidence suggests that molecular chaperones and co-chaperones play critical roles in plant innate immunity, the molecular mechanism of how these proteins contribute to defense signaling remains largely unknown. In this review, we highlight the cytoplasmic chaperones, endoplasmic reticulum (ER) resident lectin chaperones, and enzymes that have been identified from genetic and "omic" approaches and shown to be involved in plant-microbe interactions. We also discuss the roles of molecular chaperones in plant innate immunity and emerging mechanisms underlying the biogenesis of plant pathogen-associated molecular pattern receptors in the ER. © 2010 The Phytopathological Society of Japan and Springer.

Long X.-X.,South China Agricultural University | Chen X.-M.,South China Agricultural University | Wong J.W.-C.,Hong Kong Baptist University | Wei Z.-B.,South China Agricultural University | Wu Q.-T.,South China Agricultural University
Transactions of Nonferrous Metals Society of China (English Edition) | Year: 2013

Three bacterial endophytes of Sedum alfredii, VI8L2, II8L4 and VI8R2, were examined for promoting soil Zn bioavailability and Zn accumulation in S. alfredii. Results showed that three strains were re-introduced into S. alfredii rhizosphere soils under Zn stress and resulted in better plant growth, as roots biomass increased from 80% to 525% and shoot biomass from 11% to 47% compared with the uninoculated ones. Strains IV8L2, II8L 4 and IV8R2 significantly increased shoot and root Zn concentrations in the ZnCO3 contaminated soil. Inoculation with strain IV8L2 resulted in 44% and 39% higher shoot and root Zn concentrations, while strain IV8R2 significantly decreased shoot Zn concentration in the Zn3(PO4) 2 contaminated soils. In the aged contaminated soil, isolates IV 8L2, II8L4 and IV8R 2 significantly increased root Zn concentration, but decreased shoot Zn concentration of Sedum alfredii. It suggested that endophytes might be used for enhancing phytoextraction efficiency. © 2013 The Nonferrous Metals Society of China.

Xinxian L.,South China Agricultural University | Xuemei C.,South China Agricultural University | Yagang C.,South China Agricultural University | Woon-Chung W.J.,Hong Kong Baptist University | And 2 more authors.
World Journal of Microbiology and Biotechnology | Year: 2011

The aim of this study was to isolate and characterize endophytic bacteria from roots, stems and leaves of Zn/Cd hyperaccumulator Sedum alfredii. Endophytic bacteria were observed in roots, stems and leave of S. alfredii, with a significantly higher density in roots, followed by leave and stems. A total of fourteen bacterial endophytes were isolated and are closely related phylogenetically to Pseudomonas, Bacillus, Stenotrophomonas, Acinetobacte by 16S rRNA sequence analysis. Most of the endophytic bacteria were found to exhibit high Zn and Cd resistance characteristics, but difference existed among this isolates. The fourteen endophytic bacteria all had the capacity to produce IAA. Moreover, strains VI8L1, VI8L2, VI8L4, VI8R2, VI8R3 and II2R3 could solubilize Ca3(PO4)2, strains VI8L2, II8L4 and VI8R2 could produce siderophore, and strains VI8L2 and VI8R3 had the capacity of nitrogen fixation. Both plate and broth assay proved that strain VI8L1, VI8L2, II8L4 and VI8R2 were able to effectively solubilize ZnCO3 and Zn3(PO4)2. The filtrate liquid media after growth of strains VI8L1, VI8L2, II8L4 and VI8R2 extracted much higher Zn from artificially ZnCO3 and Zn3(PO4)2 contaminated soils than those extracted by axenic SMS broth, and the filtrates of the culture media supporting growth of strains VI8L2, II8L4 and VI8R2 also extracted significantly greater quantities of Zn from the Dabaoshan contaminated soils. This Zn mobilizing, plant growth promoting and metal resistant endophytic bacteria may offer promise as inoculants to increase soil Zn bioavailability and improve growth and Zn accumulation by S. alfredii. © 2010 Springer Science+Business Media B.V.

Xu Z.,South China Agricultural University | Olmi M.,University of Tuscia | He J.,Zhejiang University
Florida Entomologist | Year: 2010

Two new species, Anteon liui sp. nov. and Anteon zhangae sp. nov., are described from China. The first species was collected in Henan Province, Mt. Baiyunshan, and Zhejiang Province, Mt. Fenyangshan; the second species was collected in Guizhou Province, Mt. Leigongshan. Anteon liui can be recognized from the related Oriental species A. hirashimai Olmi 1993 and A. austini Olmi 1991 by the different length of notauli (reaching about 0.65 length of scutum in A. liui, reaching 0.30.4 length of scutum in A. hirashimai and A. austini). Anteon zhangae can be recognized from the related Oriental species A. muiri Olmi 1984 by the following characters: in A. muiri, notauli reaching about 0.65 length of scutum; scutum weakly punctate; head with OOL more than twice as long as OL; in A. zhangae, notauli reaching about 0.8 length of scutum; scutum sculptured by large and deep punctures similar to areolae; head with OOL slightly longer than OL.

Tian M.,South China Agricultural University | Deuve T.,Museum national d'Histoire naturelle
ZooKeys | Year: 2016

The sarawakensis species group of the termitophilous carabid genus Orthogonius MacLeay, 1825 is defined and reviewed. Members of this species group are distributed in Southeast Asia and represented by four species, including two new species: Orthogonius sabahicus sp. n. (Sabah, northern Borneo, Malaysia) and Orthogonius morvanianus sp. n. (southern Thailand). A key to all species of the species group is also provided. © Mingyi Tian, Thierry Deuve.

Chen W.,South China Agricultural University | Yao X.,South China Agricultural University | Yao X.,Hebei University | Cai K.,South China Agricultural University | Chen J.,South China Agricultural University
Biological Trace Element Research | Year: 2011

Drought is a major constraint for rice production in the rainfed lowlands in China. Silicon (Si) has been verified to play an important role in enhancing plant resistance to environmental stress. Two near-isogenic lines of rice (Oryza sativa L.), w-14 (drought susceptible) and w-20 (drought resistant), were selected to study the effects of exogenous Si application on the physiological traits and nutritional status of rice under drought stress. In wet conditions, Si supply had no effects on growth and physiological parameters of rice plants. Drought stress was found to reduce dry weight, root traits, water potential, photosynthetic parameters, basal quantum yield (F v/F 0), and maximum quantum efficiency of PSII photochemistry (F v/F m) in rice plants, while Si application significantly increased photosynthetic rate (Pr), transpiration rate (Tr), F v/F 0, and F v/F m of rice plants under drought stress. In addition, water stress increased K, Na, Ca, Mg, Fe content of rice plants, but Si treatment significantly reduced these nutrient level. These results suggested that silicon application was useful to increase drought resistance of rice through the enhancement of photochemical efficiency and adjustment of the mineral nutrient absorption in rice plants. © 2010 Springer Science+Business Media, LLC.

Wang L.,South China Agricultural University | Li Y.,South China Agricultural University | Chu J.,University of Leeds | Chu J.,South China University of Technology | And 3 more authors.
Molecular Biology Reports | Year: 2012

A loop-mediated isothermal amplification (LAMP) method for rapid detection of the food-borne L. monocytogenes strains had been developed and evaluated in this study. The optimal reaction condition was 65°C for 45 min, with the detection limit as 1 pg DNA/tube and 100 CFU/reaction. Application of the established LAMP assay was performed on 182 food-borne L. monocytogenes strains using a rapid procedure and easy result confirmation, with the sensitivity of LAMP versus PCR assays as 96.7% (176/182) and 91.2% (166/182), respectively; with 100% specificity, positive predictive value (PPV) and negative predictive value (NPV) for both assays. © 2011 Springer Science+Business Media B.V.

Ye N.,Hong Kong Baptist University | Zhu G.,South China Agricultural University | Liu Y.,Shandong Agricultural University | Li Y.,Hong Kong Baptist University | Zhang J.,Hong Kong Baptist University
Plant and Cell Physiology | Year: 2011

The production of both ABA and H 2O 2 is induced by drought and can act as signals under stress conditions. We investigated the relationships between ABA, H 2O 2 and catalase (CAT) in rice leaves when rice seedlings were treated with polyethylene glycol as water stress treatment. As a key gene in ABA biosynthesis, OsNCED3 was significantly induced in rice by water stress treatment and such induction preceded the rapid increase in ABA. Water stress inhibited the expression of CATA and CATC but substantially enhanced the expression of CATB. Exogenously applied ABA promoted the expression of CATB also and inhibited the expression of CATC in a concentration-dependent manner. When ABA production was inhibited by using ABA biosynthesis inhibitors nordihydroguaiaretic acid and tungstate, expression of CATB was also subdued while CATC was enhanced under the water stress. Accumulation of H 2O 2 was also reduced when endogenous ABA production was inhibited and showed a correlation with the total activity of catalases. Our results suggest that water stress-induced ABA prevents the excessive accumulation of H 2O 2, through the induction of the expression of CATB gene during water stress. © 2011 The Author.

Zhu G.,South China Agricultural University | Ye N.,Hong Kong Baptist University | Yang J.,Yangzhou University | Peng X.,South China Agricultural University | Zhang J.,Hong Kong Baptist University
Journal of Experimental Botany | Year: 2011

Later-flowering spikelets in a rice panicle, referred to as the inferior spikelets, are usually poorly filled and often limit the yield potential of some rice cultivars. The physiological and molecular mechanism for such poor grain filling remains unclear. In this study the differentially expressed genes in starch synthesis and hormone signalling between inferior and superior spikelets were comprehensively analysed and their relationships with grain filling was investigated. DNA microarray and real-time PCR analysis revealed that a group of starch metabolism-related genes showed enhanced expression profiles and had higher transcript levels in superior spikelets than in inferior ones at the early and middle grain-filling stages. Expression of the abscisic acid (ABA) synthesis genes, 9-cis-epoxycarotenoid dioxygenase 1 (NCED1) and NCED5, and the ethylene synthesis genes, 1-aminocyclopropane-1-carboxylate oxidase 1 (ACO1) and ACO3, declined with development of the caryopses. Meanwhile, if compared with inferior spikelets, expression of these genes in superior spikelets decreased faster and had lower transcript profiles, especially for ethylene. ABA concentration and ethylene evolution rate showed similar trends to their gene expression. Exogenous supply of ABA reduced the sucrose synthase (SUS) mRNA level and its enzyme activity in detached rice grains, while exogenously supplied ethephon (an ethylene-releasing reagent) suppressed the expression of most starch synthesis genes; that is, SUS, ADP-glucose pyrophosphorylase (AGPase), and soluble starch synthase (SSS), and down-regulated their enzyme activities. In summary, it is concluded that the relatively high concentrations of ethylene and ABA in inferior spikelets suppress the expression of starch synthesis genes and their enzyme activities and consequently lead to a low grain-filling rate. © 2011 The Author(s).

Liu P.,South China Agricultural University | Chen Y.,South China Agricultural University | Tang W.,SoftPark of Guangdong | Yue Q.,Guangdong Nortel Telecommunications Co.
Advances in Intelligent and Soft Computing | Year: 2012

Mobile data mining is an exciting research area that aims at finding interesting patterns from datasets on mobile platform. Limited to the computing power and operating system of traditional mobile devices, mobile data mining lacks attention before. Nowadays mobile devices have a stronger and stronger computation power also the advanced operating system supporting the demand of data mining anywhere and anytime. This paper presents and implements a Java based framework to extend data mining tool Weka to mobile platform. It provides a friendly graphic user interface and simplifies the classification, clustering and associate rule mining functions on android platforms. As an example of usage, we test the model on some datasets and illustrate the feasibility of the proposed approach. A Java implementation of the model demonstrated in this article is available from mobileWeka project website. http://mobileweka. googlecode.com/files/MobileWeka.zip . © 2012 Springer-Verlag GmbH.

Cao H.,South China Agricultural University | Wang X.,South China Agricultural University | Gao J.,Yunnan University | Prigent S.R.,Academia Sinica, Taiwan | And 3 more authors.
Molecular Phylogenetics and Evolution | Year: 2011

Phylogenetic relationships of 26 Phortica species were investigated based on DNA sequence data of two mitochondrial (ND2, COI) and one nuclear (28S rRNA) genes. Five monophyletic groups were recovered in the genus Phortica, of which three were established as new subgenera, Alloparadisa, Ashima, and Shangrila. The subgenus Allophortica was suggested as the most basal lineage in Phortica, followed by the lineage of P. helva+P. sobodo+P. varipes. The remaining Phortica species, most of Oriental distribution, formed a monophyletic group, and were subdivided into three lineages (i.e., the subgenera Ashima, Phortica, and Shangrila). The subgenera Shangrila and Phortica were suggested as sister taxa, and four clades were recovered in the subgenus Ashima. The result of reconstruction of ancestral distribution and estimation of divergence times indicates that, the ancestor of the genus Phortica restricted to Africa, its initial diversification was dated back to ca. 23. Mya (coinciding with the Oligocene/Miocene boundary); sympatric speciation and an Africa-to-Asia dispersal was proposed to account for the current distribution of Allophortica and the rest Phortica; most of the rest diversification of Phortica occurred in southern China, and the divergence between the African clade and its Oriental counterpart was suggested as a result of vicariance following a dispersal of their ancestral species from southern China to Africa. © 2011 Elsevier Inc.

Xu Z.,South China Agricultural University | Olmi M.,University of Tuscia | He J.,Zhejiang University
Zootaxa | Year: 2011

Seventeen Oriental species of the genus Neodryinus Perkins 1905 (Hymenoptera: Dryinidae:) are revised and a key to the species is given. N. grandis Xu, Olmi et He, sp. nov. from China (Guangdong) is described and illustrated. The status of N. malayanus (Olmi) is resurrected. Copyright © 2011.

Wang L.,National Research Council Canada | Kazachkov M.,National Research Council Canada | Shen W.,National Research Council Canada | Bai M.,South China Agricultural University | And 2 more authors.
Plant Journal | Year: 2014

Phosphatidylcholine (PC) is a key intermediate in the metabolic network of glycerolipid biosynthesis. Lysophosphatidylcholine acyltransferase (LPCAT) and phosphatidic acid phosphatase (PAH) are two key enzymes of PC homeostasis. We report that LPCAT activity is markedly induced in the Arabidopsis pah mutant. The quadruple pah lpcat mutant, with dual defects in PAH and LPCAT, had a level of lysophosphatidylcholine (LPC) that was much higher than that in the lpcat mutants and a PC content that was higher than that in the pah mutant. Comparative molecular profile analysis of monogalactosyldiacylglycerol and digalactosyldiacylglycerol revealed that both the pah and pah lpcat mutants had increased proportions of 34:6 from the prokaryotic pathway despite differing levels of LPCAT activity. We show that a decreased representation of the C16:0C18:2 diacylglycerol moiety in PC was a shared feature of pah and pah lpcat, and that this change in PC metabolic profile correlated with the increased prokaryotic contribution to chloroplast lipid synthesis. We detected increased PC deacylation in the pah lpcat mutant that was attributable at least in part to the induced phospholipases. Increased LPC generation was also evident in the pah mutant, but the phospholipases were not induced, raising the possibility that PC deacylation is mediated by the reverse reaction of LPCAT. We discuss possible roles of LPCAT and PAH in PC turnover that impacts lipid pathway coordination for chloroplast lipid synthesis. © 2014 National Research Council Canada. The Plant Journal © 2014 Society For Experimental Biology and John Wiley & Sons.

Liu F.,CAS Institute of Subtropical Agriculture | Liu F.,CAS Guangzhou Institute of Geochemistry | Wu J.,CAS Institute of Subtropical Agriculture | Ying G.-G.,CAS Guangzhou Institute of Geochemistry | And 2 more authors.
Applied Microbiology and Biotechnology | Year: 2012

Potential effects of antibiotics on agricultural soil microflora have recently become increasing concerns with antibiotic-contaminated biosolid now being used in agricultural land. However, changes of soil microbial community function caused by the antibiotic-associated disturbance are less addressed. This paper investigated the changes in microbial functional diversity by spiking sulfamethoxazole (SMX) and chlortetracycline (CTC) in a loam paddy soil and then incubating for 21 days. The dose-effect and time-dependent changes of antibiotic-associated disturbance on soil microbial community were analyzed with the soils sampled at 7 and 21 days using Biolog EcoPlate. At day 7 following treatment, SMX decreased functional diversity of soil microbial community, and the treatment of 100 mg SMX kg-1 dry soil had a significant inhibition of average well color development (AWCD) and Shannon index as compared to the control (p < 0.05). The SMX changed to improve soil microbial community function at day 21. CTC had less effect on soil microbial community function during the whole incubation period. Antibiotic dissipation and adsorption in soil, which may decrease their microbial bioavailability, led to the temporary change of antibiotic effect on functional diversity of soil microbial community. Principal component analysis clearly revealed the difference of antibiotic dose-effects on the soil microbial community function. The findings demonstrated that soil microbial community showed more sensitivity to SMX than CTC, and soil microbial community function could recover or improve due to antibiotic dissipation in soil. © 2011 Springer-Verlag.

Zhang Z.,CAS Kunming Institute of Zoology | Geng J.,First Peoples Hospital of Yunnan Province | Tang X.,First Peoples Hospital of Yunnan Province | Fan H.,First Peoples Hospital of Yunnan Province | And 4 more authors.
ISME Journal | Year: 2014

Human gut microbiota shows high inter-subject variations, but the actual spatial distribution and co-occurrence patterns of gut mucosa microbiota that occur within a healthy human instestinal tract remain poorly understood. In this study, we illustrated a model of this mucosa bacterial communities' biogeography, based on the largest data set so far, obtained via 454-pyrosequencing of bacterial 16S rDNAs associated with 77 matched biopsy tissue samples taken from terminal ileum, ileocecal valve, ascending colon, transverse colon, descending colon, sigmoid colon and rectum of 11 healthy adult subjects. Borrowing from macro-ecology, we used both Taylor's power law analysis and phylogeny-based beta-diversity metrics to uncover a highly heterogeneous distribution pattern of mucosa microbial inhabitants along the length of the intestinal tract. We then developed a spatial dispersion model with an R-squared value greater than 0.950 to map out the gut mucosa-associated flora's non-linear spatial distribution pattern for 51.60% of the 188 most abundant gut bacterial species. Furthermore, spatial co-occurring network analysis of mucosa microbial inhabitants together with occupancy (that is habitat generalists, specialists and opportunist) analyses implies that ecological relationships (both oppositional and symbiotic) between mucosa microbial inhabitants may be important contributors to the observed spatial heterogeneity of mucosa microbiota along the human intestine and may even potentially be associated with mutual cooperation within and functional stability of the gut ecosystem. © 2014 International Society for Microbial Ecology All rights reserved 1751-7362/14.

Ying O.,U.S. Department of Agriculture | Zhang J.E.,South China Agricultural University | Cui L.,South China Agricultural University
Environmental Monitoring and Assessment | Year: 2014

Groundwater is connected to the landscape above and is thus affected by the overlaying land uses. This study evaluated the impacts of land uses upon groundwater quality using trilinear analysis. Trilinear analysis is a display of experimental data in a triangular graph. Groundwater quality data collected from agricultural, septic tank, forest, and wastewater land uses for a 6-year period were used for the analysis. Results showed that among the three nitrogen species (i.e., nitrate and nitrite (NOx), dissolved organic nitrogen (DON), and total organic nitrogen (TON)), NOx had a high percentage and was a dominant species in the groundwater beneath the septic tank lands, whereas TON was a major species in groundwater beneath the forest lands. Among the three phosphorus species, namely the particulate phosphorus (PP), dissolved ortho phosphorus (PO4 3- ) and dissolved organic phosphorus (DOP), there was a high percentage of PP in the groundwater beneath the septic tank, forest, and agricultural lands. In general, Ca was a dominant cation in the groundwater beneath the septic tank lands, whereas Na was a dominant cation in the groundwater beneath the forest lands. For the three major anions (i.e., F-, Cl-, and SO42- ), F- accounted for <1 % of the total anions in the groundwater beneath the forest, wastewater, and agricultural lands. Impacts of land uses on groundwater Cd and Cr distributions were not profound. This study suggests that trilinear analysis is a useful technique to characterize the relationship between land use and groundwater quality. © 2014 Springer International Publishing.

Wang L.,South China Agricultural University | Chen J.,U.S. Department of Agriculture
Journal of Chemical Ecology | Year: 2015

Red imported fire ants, Solenopsis invicta, are significant invasive pests. Certain native ant species can compete with S. invicta, such as the little black ant, Monomorium minimum. Defensive secretions may contribute to the competition capacity of native ants. The chemistry of ant defensive secretions in the genus Monomorium has been subjected to extensive research. The insecticidal alkaloids, 2,5-dialkyl-pyrrolidines and 2,5-dialkyl-pyrrolines have been reported to dominate the venom of M. minimum. In this study, analysis of defensive secretions of workers and queens of M. minimum revealed two primary amines, decylamine and dodecylamine. Neither amine has been reported previously from natural sources. Toxicity and digging suppression by these two amines against S. invicta were examined. Decylamine had higher toxicity to S. invicta workers than dodecylamine, a quicker knockdown effect, and suppressed the digging behavior of S. invicta workers at lower concentration. However, the amount of fatty amines in an individual ant was not enough to knockdown a fire ant or suppress its digging behavior. These amines most likely work in concert with other components in the chemical defense of M. minimum. © 2015, Springer Science+Business Media New York (outside the USA).

Xu D.-L.,U.S. Department of Agriculture | Zhou G.-H.,U.S. Department of Agriculture | Xie Y.-J.,South China Agricultural University | Mock R.,U.S. Department of Agriculture | Li R.,U.S. Department of Agriculture
Virus Genes | Year: 2010

The complete genomic sequence of a Pakistani isolate of Sugarcane streak mosaic virus (SCSMV-PAK) is determined to be 9782 nucleotides in length, excluding the 3′ poly(A) tail, and it comprises a large open reading frame encoding a polyprotein of 3130 amino acid residues. The deduced polyprotein is likely to be cleaved at nine putative protease sites by three viral proteases to ten mature proteins. Conserved motifs of orthologous proteins of other potyviruses are identified in corresponding positions of SCSMV-PAK. The genomic organization is virtually identical to the genera Ipomovirus, Potyvirus, Rymovirus, and Tritimovirus in the family Potyviridae. Sequence analyses indicate that the SCSMV-PAK genomic sequence is different from those of Sugarcane mosaic virus and Sorghum mosaic virus, two viruses with very similar symptoms and host range to SCSMV-PAK. SCSMV-PAK shares 52.7% identity with Triticum mosaic virus (TriMV) and 26.4-31.5% identities with species of the existing genera and unassigned viruses in the Potyviridae at the polyprotein sequence level. Phylogenetic analyses of the polyprotein and deduced mature protein amino acid sequences reveal that SCSMV, together with TriMV, forms a distinct group in the family at the genus level. Therefore, SCSMV should represent a new genus, Susmovirus, in the Potyviridae. © Springer Science+Business Media, LLC 2010.

Gong L.,South China Agricultural University | Yang X.,Guangzhou RiboBio Co. | Zhang B.,Guangzhou RiboBio Co. | Zhong G.,South China Agricultural University | Hu M.,South China Agricultural University
Pest Management Science | Year: 2011

BACKGROUND: Extensive applications and frequent long-term use of pesticides can affect behavioural mechanisms and physiological and biochemical aspects of insects, leading to resistance. However, insect control strategies involving a different mode of action would be valuable for managing the emergence of insect resistance. In this context, the development of RNA interference technology has brought a turning point in the creation of new biopesticides. RESULTS: Full-length cDNA of Rieske iron-sulfur protein (RISP) was cloned and characterised from Plutella xylostella L. Three siRNAs specific to RISP sequences were designed and chemically synthesised, and fed to P. xylostella larvae by coating cabbage leaves. This resulted in specific gene silencing of RISP, and consequently brought significant mortality of P. xylostella larvae compared with the control treatment. Silencing of RISP leads to significantly lower transcript levels of RISP compared with the control. In addition, the amount of ATP in the surviving larvae was lower than in the control. However, surviving larvae gradually recovered to normal transcript and protein levels. CONCLUSION: This is the first demonstration of the potential use of chemically synthesised siRNA in the development of new biopesticides as a mitochondrial electron transport inhibitor. © 2011 Society of Chemical Industry.

Zang S.,South China Agricultural University | Liu Y.,South China Agricultural University | Lin M.,South China Agricultural University | Kang J.,Tianjin Polytechnic University | And 2 more authors.
Electrochimica Acta | Year: 2013

In this work, an electrochemical immunosensor, basing on a dual signal amplified strategy by employing a biocompatible polypyrrole film-Au nanocluster matrix as a sensor platform and multi-enzyme-antibody functionalized gold nanorod as an electrochemical detection label, is established for sensitive detection of ofloxacin (OFL). Firstly, polypyrrole film and Au nanoclusters were progressively fabricated onto the surface of a glassy carbon electrode via electropolymerization and electrochemical deposition, respectively. Such PPy-Au nanocomposite modified electrode was used to immobilize OFL-OVA, blocked with the blocking reagent, and then associated with the corresponding antibody. Secondly, gold nanorod (GNR) was synthesized to load horseradish peroxidase (HRP) and horseradish peroxidase-secondary antibody (HRP-Ab2), and the resulting nanostructure (multi-HRP-GNR-Ab2) was applied as the detection label. The fabrication process of the ordered multilayer structure and immunosensor were characterized by scanning electron microscopy (SEM) and electrochemical measurements, respectively. Finally, based on a competitive immunoassay, i.e., the association ability with the corresponding antibody between the captured antigen and free OFL in the solution, the fabricated immunosensor exhibited a sensitive response to OFL in the range from 0.08 to 410 ng/mL with a detection limit of 0.03 ng/mL. The current immunosensor exhibited good sensitivity, selectivity and long-term stability. This amplification strategy shows excellent promise for food safety monitoring of other antibiotics and a potential application in other immunosensors. © 2012 Elsevier Ltd.

Wang S.,South China Agricultural University | Wang S.,CAS Guangzhou Institute of Geochemistry | Li H.,South China Agricultural University | Lin C.,University of Southern Queensland
Pesticide Biochemistry and Physiology | Year: 2013

A dose-response experiment was conducted to examine the effects of butachlor on the growth, physiology and biochemistry of Italian ryegrass. The plant suffered a >50% reduction in fresh biomass when exposed to a butachlor dose of 5mgL-1. However, a significant further biomass reduction only occurred when the dosage level of butachlor was increased to 40mgL-1. The root was more sensitive than the shoot to butachlor toxicity. It appears that the inhibition of fine root development under butachlor stress was the upstream cause for the retarded plant growth. A butachlor dose of 5mgL-1 was sufficiently high to cause significant H2O2-induced oxidative damage in the plant cells, as indicated by the increased MDA and the lower production rate relative to consumption rate of CAT. The plants tended to maintain sufficiently high levels of root activity and photosynthesis, and possibly relied on these mechanisms for survival in such a stressed environment. Butachlor had a stimulatory effect on the release of dissolved organic carbon but not amino acids from the plant roots. There were 5 types of organic acids in the root exudates, which all exhibited a trend to decrease with increasing level of butachlor. © 2013 Elsevier Inc.

Sealey W.M.,University of Idaho | Hardy R.W.,University of Idaho | Barrows F.T.,U.S. Department of Agriculture | Pan Q.,South China Agricultural University | Stone D.A.J.,South Australian Research And Development Institute
Journal of the World Aquaculture Society | Year: 2011

The ability of poultry products to replace fish meal in diets for rainbow trout, Oncorhynchus mykiss, depends on their nutrient composition, cost, and consistency. The aim of this study was to assess the ability of three commercially available poultry products (chicken concentrate, CC, poultry by-product blend, PBB; or chicken and egg concentrate, CE) to maintain growth and disease resistance when substituted for fish meal in a rainbow trout starter diet. A control diet was formulated to contain 48% crude protein and 18% crude lipid; 100% of the fish meal in test diets was replaced with CC, PBB, or CE. At stocking, fry were counted into groups (50 fish/tank) with six replicate tanks for each diet and fed their respective diets four times daily for 8 wk. All the poultry-based diets supported growth (over 1600% increase over initial weight), nutrient retention, and feed conversion ratios of rainbow trout fry equal to or greater than those observed for fry fed with the fish meal-based diet. No effect of diet on survival was observed following subcutaneous injection challenge with Flavobacterium psychrophilum. These data suggest that the examined products can be used in place of fish meal for rainbow trout fry without lowering growth and disease resistance. © by the World Aquaculture Society 2011.

Wang W.,South China Agricultural University | Luo X.,South China Agricultural University | Sun D.,South China Agricultural University | Jiang S.,South China Agricultural University | Xiao G.,Samsung
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2011

A wireless sensor network (WSN) node was developed for information collection in a tea plantation, aimed at boosting wireless penetrating power through communication barriers. The node uses the ATmega128 as the core, a nRF905 RF chip and its periphery circuits as the wireless communication module, SHT11 temperature and humidity sensors and TDR-3 soil moisture sensor as its sensor module. Communication protocol, application program and background management software were compiled and embedded into the node. Communication distance and energy consumption of the node were tested and analyzed. The effective communication distance was measured up to 150m in broad smooth areas. By comparison with Micaz node of Crossbow, the indoor and outdoor distances of the node increase by 200% and 150% respectively. A WSN of 7 nodes was established for measuring temperature, humidity and soil water content in a tea plantation. Experimental results show that the average packet loss rate is 0.84% and the measurement precision is not less than 98.2%. The node is suitable for and could meet the needs of data acquisition in a tea plantation.

Tian M.,South China Agricultural University | Clarke A.,University of Tasmania
Cave and Karst Science | Year: 2012

Qianaphaenops emersoni n. sp. is described from Gan Dong, a limestone cave in Yanhe Xian, northeastern Guizhou Province, China. Likely to be a narrow range endemic species, Q. emersoni is only known from two almost adjacent type locality sites in Gan Dong cave. Q. emersoni is the fifth species to be described in this genus of eyeless troglobitic trechine beetles, known only from caves in northeastern Guizhou; a distributional map of the genus Qianaphaenops Ueno is provided. Q. emersoni belongs to the Qianaphaenops tenuis species group which contains two described species: Q. tenuis and Q. rotundicollis (Ueno, 2000). Q. emersoni is very similar to Q. rotundicollis Uéno, but easily distinguished from the latter by its broader head and elytra, narrower pronotum and its more elongate and slender aedeagus. Some explanation of the exploration of Gan Dong is provided, along with habitat details of the trechine beetle Type Locality sites located approximately 950 metres into the cave. The subsequent discovery of an efflux cave, presumed to be the Gan Dong Resurgence, is also discussed. © British Cave Research Association 2012.

Chen M.,South China Agricultural University | Liu H.,South China Agricultural University | Kong J.,South China Agricultural University | Kong J.,University of Tübingen | And 8 more authors.
Plant Cell | Year: 2011

The root stem cell niche defines the area that specifies and maintains the stem cells and is essential for the maintenance of root growth. Here, we characterize and examine the functional role of a quiescent center (QC)-expressed RAC/ROP GTPase activator, RopGEF7, in Arabidopsis thaliana. We show that RopGEF7 interacts with At RAC1 and overexpression of a C-terminally truncated constitutively active RopGEF7 (RopGEF7ΔC) activates RAC/ROP GTPases. Knockdown of RopGEF7 by RNA interference causes defects in embryo patterning and maintenance of the QC and leads to postembryonic loss of root stem cell population. Gene expression studies indicate that RopGEF7 is required for root meristem maintenance as it regulates the expression of PLETHORA1 (PLT1) and PLT2, which are key transcription factors that mediate the patterning of the root stem cell niche. Genetic analyses show that RopGEF7 interacts with PLT genes to regulate QC maintenance. Moreover, RopGEF7 is induced transcriptionally by auxin while its function is required for the expression of the auxin efflux protein PIN1 and maintenance of normal auxin maxima in embryos and seedling roots. These results suggest that RopGEF7 may integrate auxin-derived positional information in a feed-forward mechanism, regulating PLT transcription factors and thereby controlling the maintenance of root stem cell niches. © 2011 American Society of Plant Biologists. All rights reserved.

Pan S.-H.,South China Agricultural University | Pan S.-H.,CAS Guangzhou Institute of Geochemistry | Li J.,CAS Guangzhou Institute of Geochemistry | Lin T.,CAS Guangzhou Institute of Geochemistry | And 3 more authors.
Environmental Pollution | Year: 2012

Organic films were collected from indoor and outdoor window surfaces in two large cities in southern China, Guangzhou and Hong Kong, and analyzed to quantify the polycyclic aromatic hydrocarbons (PAHs). In the glass films, the highest concentration of total PAHs, predominantly phenanthrene, fluorene, fluoranthene, and pyrene, was found to be l400 ng/m 2. The concentrations of PAHs in Guangzhou were usually higher than those in Hong Kong. In general, higher concentrations of PAHs on exterior window films in comparison with interior window films in both cities indicated that the outdoor air acted as a major source of pollution to the indoor environment. However, indoor air was a major source of some light-weight PAHs. Measurements made over time indicated that the growth rates of light-weight PAHs on window surfaces were fast at the beginning and then gradually reached a consistent level, whereas heavy-weight PAHs exhibited near-linear accumulation during the 40 days sampling period. © 2012 Elsevier Ltd. All rights reserved.

Nibau C.,University of Massachusetts Amherst | Nibau C.,Aberystwyth University | Tao L.,University of Massachusetts Amherst | Tao L.,South China Agricultural University | And 4 more authors.
Journal of Experimental Botany | Year: 2013

Rac-like GTPases or Rho-related GTPases from plants (RAC/ROPs) are important components of hormone signalling pathways in plants. Based on phylogeny, several groups can be distinguished, and the underlying premise is that members of different groups perform distinct functions in the plant. AtRAC7/ROP9 is phylogenetically unique among 11 Arabidopsis RAC/ROPs, and here it was shown that it functions as a modulator of auxin and abscisic acid (ABA) signalling, a dual role not previously assigned to these small GTPases. Plants with reduced levels of AtRAC7/ROP9 had increased sensitivity to auxin and were less sensitive to ABA. On the other hand, overexpressing AtRAC7/ROP9 activated ABA-induced gene expression but repressed auxin-induced gene expression. In addition, both hormones regulated the activity of the AtRAC7/ROP9 promoter, suggesting a feedback mechanism to modulate the signalling output from the AtRAC7/ROP9-controlled molecular switch. High levels of AtRAC7/ROP9 were detected specifically in embryos and lateral roots, underscoring the important role of this protein during embryo development and lateral root formation. These results place AtRAC7/ROP9 as an important signal transducer in recently described pathways that integrate auxin and ABA signalling in the plant. © The Author [2013].