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Ringo E.,University of Tromso | Zhou Z.,Chinese Academy of Agricultural Sciences | Olsen R.E.,Norwegian Institute of Marine Research | Song S.K.,Handong Global University
Aquaculture Nutrition | Year: 2012

Chitin consists of β-1,4-linked N-acetylglucosamine residues and is estimated as the second most abundant biomass in the world after cellulose. However, relatively little chitin is utilized as a material for industrial, agricultural and medical applications and aquacultural purposes. Chitin may be useful as a constitutive material in formulated fish feed, and the interesting effects in fish merit further evaluation. There is evidence that fish and aquatic animals harbour a gut bacterial community that is distinctly different from that reported in the surrounding habitat or in the diet. Thus, the gut environment provides a specific niche, and bacterial activity in the gut is not merely a continuum of that observed in the environment. Today, it is well accepted that the gut microbiota in fish are modulated by dietary manipulations. But to what extent can dietary chitin and krill (chitin-rich) modulate the intestinal microbiota of fish and how do these dietary components affect the immune system? These questions will be discussed in the present review. © 2012 Blackwell Publishing Ltd.

Zhang N.,Northeast Normal University | Guo R.,Chinese Academy of Agricultural Sciences | Song P.,Northeast Normal University | Song P.,CAS Institute of Botany | And 2 more authors.
Soil Biology and Biochemistry | Year: 2013

Songnen Meadow Steppe, which is in northeast China, is increasingly affected by global warming and incremental increases in atmospheric nitrogen deposition. However, the responses of nitrogen (N) and phosphorus (P) in steppe soil, and of the coupling mechanism between them, to the dual effects of global warming and N deposition are still unknown. In this study, the effects of simulated atmospheric warming and N deposition on N and P in Songnen steppe soil, as well as on the coupling between N and P, were examined under in situ conditions. Infrared heaters were used to elevate soil temperature by approximately 1.7°C since 2006. N additions were treated once a year with aqueous ammonium nitrate at a rate of 10gm-2a-1. During the four-year study, addition of N increased the amount of total N, and available N, as well as the rate of N mineralization in the soil. Moreover, the amounts of total P and available P in the soil were considerably reduced. Thus, the N:P ratio increased, and the coupling between N and P decreased. Similar values for the N:P ratio were obtained for the addition of N by itself and for the combination of warming and addition of N, which indicates that a small amount of soil warming in Songnen Meadow Steppe would not have a substantial effect on the ratio. With the growth of China's industrialization, N deposition continues to increase. The study area of Songnen Meadow Steppe, and northeast China in general, are characterized by widespread distribution of saline alkali soil. Therefore, the finding of increased P limitation in the soil of Songnen Meadow Steppe has major implications for ecosystems in northeast China. Reasonable regulation and management of meadow soil nutrients will be of great importance in increasing soil productivity and promoting sustainable use of grassland ecosystems. © 2013 Elsevier Ltd.

Wei X.-J.,Guangxi University | Hu T.-J.,Guangxi University | Chen J.-R.,Chinese Academy of Agricultural Sciences | Wei Y.-Y.,Guangxi University
International Journal of Biological Macromolecules | Year: 2011

The aim of the present study was to investigate the immunomodulatory effect and antioxidant activity of carboxymethylpachymaran on cyclophosphamide-induced immunosuppression in mice in vivo. The results showed that carboxymethylpachymaran could be used to overcome the cyclophosphamide-induced immunosuppression in mice. Moreover, it significantly increased the thymus and spleen indices, lysozyme, catalase and superoxidase dismutase activities, and total antioxidant capacity. In contrast, it decreased xanthine oxidase activity and malondialdehyde levels. The results indicated that carboxymethylpachymaran might play an important role in the prevention of oxidative damage in the immunological system. © 2011 Elsevier B.V.

Wu T.,China Agricultural University | Zhang H.-T.,Chinese Academy of Agricultural Sciences | Wang Y.,China Agricultural University | Jia W.-S.,China Agricultural University | And 3 more authors.
Journal of Experimental Botany | Year: 2012

Iron is a critical cofactor for a number of metalloenzymes involved in respiration and photosynthesis, but plants often suffer from iron deficiency due to limited supplies of soluble iron in the soil. Iron deficiency induces a series of adaptive responses in various plant species, but the mechanisms by which they are triggered remain largely unknown. Using pH imaging and hormone localization techniques, it has been demonstrated here that root Fe(III) reductase activity and proton extrusion upon iron deficiency are up-regulated by systemic auxin signalling in a Fe-efficient woody plant, Malus xiaojinensis. Split-root experiments demonstrated that Fe-deprivation in a portion of the root system induced a dramatic increase in Fe(III) reductase activity and proton extrusion in the Fe-supplied portion, suggesting that the iron deficiency responses were mediated by a systemic signalling. Reciprocal grafting experiments of M. xiaojinensis with Malus baccata, a plant with no capability to produce the corresponding responses, indicate that the initiation of the systemic signalling is likely to be determined by roots rather than shoots. Iron deficiency induced a substantial increase in the IAA content in the shoot apex and supplying exogenous IAA analogues (NAA) to the shoot apex could mimic the iron deficiency to trigger the corresponding responses. Conversely, preventing IAA transport from shoot to roots blocked the iron deficiency responses. These results strongly indicate that the iron deficiency-induced physiological responses are mediated by systemic auxin signalling. © 2011 The Author.

Guo A.,Chinese Academy of Agricultural Sciences | Guo A.,Jiangsu Electric Power Company
PLoS ONE | Year: 2015

The cystatin superfamily is comprised of cysteine proteinase inhibitors and encompasses at least 3 subfamilies: stefins, cystatins and kininogens. In this study, the platyhelminth cystatin superfamily was identified and grouped into stefin and cystatin subfamilies. The conserved domain of stefins (G, QxVxG) was observed in all members of platyhelminth stefins. The three characteristics of cystatins, the cystatin-like domain (G, QxVxG, PW), a signal peptide, and one or two conserved disulfide bonds, were observed in platyhelminths, with the exception of cestodes, which lacked the conserved disulfide bond. However, it is noteworthy that cestode cystatins had two tandem repeated domains, although the second tandem repeated domain did not contain a cystatin-like domain, which has not been previously reported. Tertiary structure analysis of Taenia solium cystatin, one of the cestode cystatins, demonstrated that the N-terminus of T. solium cystatin formed a five turn α-helix, a five stranded β -pleated sheet and a hydrophobic edge, similar to the structure of chicken cystatin. Although no conserved disulfide bond was found in T. solium cystatin, the models of T. solium cystatin and chicken cystatin corresponded at the site of the first disulfide bridge of the chicken cystatin. However, the two models were not similar regarding the location of the second disulfide bridge of chicken cystatin. These results showed that T. solium cystatin and chicken cystatin had similarities and differences, suggesting that the biochemistry of T. solium cystatin could be similar to chicken cystatin in its inhibitory function and that it may have further functional roles. The same results were obtained for other cestode cystatins. Phylogenetic analysis showed that cestode cystatins constituted an independent clade and implied that cestode cystatins should be considered to have formed a new clade during evolution. © 2015 Aijiang Guo.

Rozenstein O.,Ben - Gurion University of the Negev | Qin Z.,Chinese Academy of Agricultural Sciences | Derimian Y.,French National Center for Scientific Research | Karnieli A.,Ben - Gurion University of the Negev
Sensors (Switzerland) | Year: 2014

Land surface temperature (LST) is one of the most important variables measured by satellite remote sensing. Public domain data are available from the newly operational Landsat-8 Thermal Infrared Sensor (TIRS). This paper presents an adjustment of the split window algorithm (SWA) for TIRS that uses atmospheric transmittance and land surface emissivity (LSE) as inputs. Various alternatives for estimating these SWA inputs are reviewed, and a sensitivity analysis of the SWA to misestimating the input parameters is performed. The accuracy of the current development was assessed using simulated Modtran data. The root mean square error (RMSE) of the simulated LST was calculated as 0.93 °C. This SWA development is leading to progress in the determination of LST by Landsat-8 TIRS. © 2014 by the authors; licensee MDPI, Basel, Switzerland.

Ji W.,Jiangsu University | Zhao D.,Jiangsu University | Cheng F.,Jiangsu University | Xu B.,Jiangsu University | And 2 more authors.
Computers and Electrical Engineering | Year: 2012

In apple harvesting robot, the first key part is the machine vision system, which is used to recognize and locate the apples. In this paper, the procedure on how to develop an automatic recognition vision system guided for apple harvesting robot, is proposed. We first use a color charge coupled device camera to capture apple images, and then utilize an industrial computer to process images for recognising fruit. Meanwhile, the vector median filter is applied to remove the color images noise of apple, and images segmentation method based on region growing and color feature is investigated. After that the color feature and shape feature of image are extract, a new classification algorithm based on support vector machine for apple recognition is introduced to improve recognition accuracy and efficiency. Finally, these procedures proposed have been tested on apple harvesting robot under natural conditions in September 2009, and showed a recognition success rate of approximately 89% and average recognition time of 352 ms. Crown Copyright © 2011 Elsevier Ltd. All rights reserved.

Peng S.,Cornell University | Derrien T.L.,Cornell University | Cui J.,Cornell University | Cui J.,Chinese Academy of Agricultural Sciences | And 3 more authors.
Materials Today | Year: 2012

Materials need to be specially engineered to interface with cells; on the other hand, cells provide great inspiration for new material designs. Here, using examples mainly from our own research, we demonstrate that DNA can be used as both a genetic and generic material for various cell-related applications, including diagnostics, drug delivery, cell culture, protein production, and immuno-modulation. We envision that other cell-based materials such as RNA, proteins, polysaccharides, and lipids can be more pervasively employed in materials science and engineering. © 2012 Elsevier Ltd.

Wang X.,Capital Normal University | Hua L.,Capital Normal University | Ma Y.,Chinese Academy of Agricultural Sciences
Chemosphere | Year: 2012

The effects of selected cations and pH on the acute toxicity of copper (Cu) to barley root elongation were investigated to develop an appropriate biotic ligand model (BLM). The results showed that increasing activities of Mg 2+ and Ca 2+, but not Na + and K +, linearly increased the EC50 (as Cu 2+ activity). Unchanged EC50 at solution pH less than 6.5 and sharply decreased EC50 with increasing of solution pH when greater than 6.5 can be explained by toxicity of the CuHCO3+, CuCO 3(aq) and CuOH + complexes. Conditional binding constants were obtained for the binding of Cu 2+, CuHCO3+, CuCO 3(aq), CuOH +, Mg 2+ and Ca 2+ with biotic ligand: logK CuBL 6.33, logKCuHCO3BL 5.71, logKCuCO3BL 5.70, logK CuOHBL 6.39, logK MgBL 2.92 and logK CaBL 1.96. Using the estimated constants, a BLM was successfully developed to predict Cu toxicity to barley root elongation as a function of solution characteristics. © 2012 Elsevier Ltd.

Zheng J.,China Agricultural University | Lang Y.,China Agricultural University | Zhang Q.,China Agricultural University | Cui D.,China Agricultural University | And 8 more authors.
Genes and Development | Year: 2015

The central region of MDM2 is critical for p53 activation and tumor suppression. Upon ribosomal stress, this region is bound by ribosomal proteins, particularly ribosomal protein L11 (RPL11), leading to MDM2 inactivation and subsequent p53 activation. Here, we solved the complex structure of human MDM2-RPL11 at 2.4 Å. MDM2 extensively interacts with RPL11 through an acidic domain and two zinc fingers. Formation of the MDM2-RPL11 complex induces substantial conformational changes in both proteins. RPL11, unable to bind MDM2 mutants, fails to induce the activation of p53 in cells. MDM2 mimics 28S rRNA binding to RPL11. The C4 zinc finger determines RPL11 binding to MDM2 but not its homolog, MDMX. Our results highlight the essential role of the RPL11-MDM2 interaction in p53 activation and tumor suppression and provide a structural basis for potential new anti-tumor drug development. © 2015 Zheng et al.

Sang Y.,Northeast Forestry University | Ma J.,Chinese Academy of Agricultural Sciences | Hou Z.,Northeast Forestry University | Zhang Y.,Northeast Forestry University
Virus Genes | Year: 2012

Aleutian mink disease parvovirus (AMDV) is a non-enveloped virus with a single-stranded DNA genome that causes a fatal, usually persistent immune complex disease in minks. In this study, a total of 18,654 serum samples were collected from minks that were farmed in China from 2009 to 2011. After testing by counter-current immunoelectrophoresis (CIE), the seroprevalence of AMDV was found to be 68.67 %. The results show that there is a serious epidemic among Chinese minks used for breeding. To gain detailed information regarding the molecular epidemiology of AMDV in China, nine strains of AMDV were isolated from mink samples that were collected from four of the primary mink farming areas in China. The fulllength capsid protein VP2 gene from each strain was sequenced after PCR amplification, and a phylogenetic analysis was performed on the VP2 gene sequence, including the VP2 genes from the other 10 AMDV strains available in the GenBank database, which were submitted from the 1970s to 2009. The phylogenetic analysis showed that the AMDV isolates were divided into five independent clades. The Chinese AMDV strains were distributed among all five groups and showed a high level of genetic diversity. Over 50 % of the Chinese AMDV strains were classified into two clades that consisted only of isolates from China and that were distinct from AMDV strains found in other countries. This finding indicated that both local and imported ADMV species are prevalent in the Chinese mink farming population. © Springer Science+Business Media, LLC 2012.

Hu L.,CAS Wuhan Botanical Garden | Hu T.,CAS Wuhan Botanical Garden | Zhang X.,Virginia Polytechnic Institute and State University | Pang H.,Chinese Academy of Agricultural Sciences | Fu J.,CAS Wuhan Botanical Garden
Journal of the American Society for Horticultural Science | Year: 2012

Salinity stress may involve the accumulation of glycine betaine (GB). The objective of this study was to examine whether exogenous GB would ameliorate the detrimental effect of salinity stress on perennial ryegrass (Lolium perenne). The grass was subjected to two salinity levels (0 and 250 mM NaCl) and three GB levels (0, 20, and 50 mM). Salinity resulted in a remarkable decrease in vertical shoot growth rate (VSGR), shoot and root fresh weight, relative water content (RWC), relative transpiration rate (Tr), and chlorophyll (Chl) content, superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) activities. Plants subjected to salt exhibited an increase in leaf electrolyte leakage (EL), lipid peroxidation (MDA), and proline content. Application of GB reduced EL, MDA, and proline content in salt-stressed plants. Perennial ryegrass subjected to salt stress plus GB had a greater level of VSGR, RWC, relative Tr, Chl content, and activities of SOD, CAT, and APX when compared with salt-stressed without GB. Salt stress increased Na + and decreased K + content, which resulted in a higher Na +/K + ratio in perennial ryegrass. Application of 20 mM GB suppressed Na + accumulation, whereas the K + content was significantly increased in shoot, which led to a higher K +/Na + ratio under saline conditions. These results suggested that GB-enhanced salt tolerance in perennial ryegrass was mainly related to the elevated SOD, CAT, and APX activity and alleviation of cell membrane damage by reducing oxidation of membrane lipid and improving the ion homeostasis under salt stress.

Chen F.,Henan Agricultural University | Zhang F.-Y.,Henan Agricultural University | Xia X.-C.,Chinese Academy of Agricultural Sciences | Dong Z.-D.,Henan Agricultural University | Cui D.-Q.,Henan Agricultural University
Molecular Breeding | Year: 2012

Kernel hardness is one of the most important factors determining the milling and processing quality of bread wheat (Triticum aestivum L.). In the present study, 267 wheat cultivars and advanced lines from the Yellow and Huai Valley of China, CIMMYT, Russia and Ukraine were used for identification of SKCS (Single Kernel Characterization System) hardness and puroindoline alleles. Results indicated that Pinb-D1b is the most popular genotype in wheat cultivars from the Yellow and Huai Valley, Russia and Ukraine, whereas PINA null is a predominant genotype in wheat cultivars and advanced lines from CIMMYT. Molecular characterization of PINA-null alleles indicated that one Chinese landrace Chiyacao had the allele Pina-D1l with a single nucleotide C deletion at position 265 in Pina coding region based on sequencing results, and 35 of 39 PINA-null alleles belonged to Pina-D1b according to PCR amplification with the sequence-tagged site (STS) marker Pina-N developed previously. The remaining three cultivars (Jiangdongmen, Heshangtou and Hongquanmang from China) with PINA-null alleles were characterized at the DNA level by a primer walking strategy, and the results showed that all three cultivars with PINA-null alleles possessed a uniform 10,415-bp deletion from -5,117 bp to +5,298 bp (ATG codon references zero), designated as Pina-D1r. Correspondingly, an STS marker Pina-N2 with an expected fragment size of 436-bp spanning the 10,415-bp deletion was developed for detection of the Pina-D1r allele. This study provided a useful molecular marker for straightforward detection of one of the PINA-null alleles and would also be helpful to further understand the molecular and genetic basis of kernel hardness in bread wheat. © 2011 Springer Science+Business Media B.V.

Zhu S.,Wageningen University | Li Y.,Chinese Academy of Agricultural Sciences | Vossen J.H.,Wageningen University | Visser R.G.F.,Wageningen University | Jacobsen E.,Wageningen University
Transgenic Research | Year: 2012

Functional stacking of broad spectrum resistance (R) genes could potentially be an effective strategy for more durable disease resistance, for example, to potato late blight caused by Phytophthora infestans (Pi). For this reason, three broad spectrum potato R genes (Rpi), Rpi-sto1 (Solanum stoloniferum), Rpi-vnt1. 1 (S. venturii) and Rpi-blb3 (S. bulbocastanum) were selected, combined into a single binary vector pBINPLUS and transformed into the susceptible cultivar Desiree. Among the 550 kanamycin resistant regenerants, 28 were further investigated by gene specific PCRs. All regenerants were positive for the nptII gene and 23 of them contained the three Rpi genes, referred to as triple Rpi gene transformants. Detached leaf assay and agro-infiltration of avirulence (Avr) genes showed that the 23 triple Rpi gene transformants were resistant to the selected isolates and showed HR with the three Avr effectors indicating functional stacking of all the three Rpi genes. It is concluded that Avr genes, corresponding to the R genes to be stacked, must be available in order to assay for functionality of each stack component. No indications were found for silencing or any other negative effects affecting the function of the inserted Rpi genes. The resistance spectrum of these 23 triple Rpi gene transformants was, as expected, a sum of the spectra from the three individual Rpi genes. This is the first example of a one-step approach for the simultaneous domestication of three natural R genes against a single disease by genetic transformation. © 2011 The Author(s).

Wang P.,Huazhong Agricultural University | Zhou G.,Huazhong Agricultural University | Cui K.,Huazhong Agricultural University | Li Z.,Huazhong Agricultural University | And 2 more authors.
Molecular Breeding | Year: 2012

Improvement of plant type plays an important role in super-high yield breeding in rice (Oryza sativa L.). In the present study, a set of backcross recombinant inbred lines derived from a cross of 9311 and Zhenshan97, both elite indica hybrid parents, were developed to identify quantitative trait loci (QTL) for flag leaf size, panicle and yield traits. Forty-seven QTL for 14 traits were detected in common in the two environmental trials, of which nine genomic regions contained clustered QTL affecting plant type traits and yield traits. Four co-localized QTL on chromosomes 1, 6, 7 and 8 involving QTL for flag leaf size (flag leaf length, width and area) contained the QTL for yield traits such as panicle weight (PW) and secondary branch number (SBN), and in all cases alleles from 9311 increased source leaf size and were associated with increased sink size and yield (SBN and PW). Using a subset of overlapping substitution lines for the QTL region on chromosome 1, the QTL were validated and narrowed into a 990 kbp interval (RM3746-RM10435) with pleiotropic effects on flag leaf size, PW, SBN and spikelet number per panicle. These QTL clusters with large effects on source leaf size and yield-related traits provide good targets for marker-assisted breeding for plant type improvement and high-yield potential in rice. © 2010 Springer Science+Business Media B.V.

Wang P.,Huazhong Agricultural University | Xing Y.,Huazhong Agricultural University | Li Z.,Chinese Academy of Agricultural Sciences | Li Z.,International Rice Research Institute | Yu S.,Huazhong Agricultural University
Molecular Breeding | Year: 2012

To facilitate marker-assisted transfer of desirable genes for improvement of yield traits, we used a set of backcross recombinant inbred lines (BRIL) derived from two elite parental lines, 'Zhenshan97' and '93-11', to resolve a quantitative trait loci (QTL) cluster for heading date and yield-related traits in rice. Four main-effect QTL (qHD6. 1, qHD6. 2, qHD7, and qHD8) and four epistatic QTL affecting heading date in the BRIL were detected in two experimental trials. The major QTL (qHD8) was confirmed in three heterogeneous inbred families (HIF) that segregated for this target region, and narrowed down to a 20-kb segment in a large HIF-derived population. qHD8 was found to interact with qHD7 and had a pleiotropic effect responsible for heading date and yield components. To test usability of the identified QTL in rice improvement, we further developed near-isogenic lines (NIL) containing one or more target genes by marker-assisted transfer of '93-11' alleles at qHD8, qHD7, and qHD6. 1, and the GS3 gene for grain size into 'Zhenshan97'. The pyramid line NIL(qHD8 + GS3) had higher yield potential, longer grains, and a more suitable heading date than 'Zhenshan97'. Comparison of the NIL showed existence of epistasis between alleles at different loci and background effect on qHD8, which are very important for pyramiding of desirable alleles at the target QTL. These results will be particularly useful not only to understand the genetic basis of yield-related traits but also to improve the efficiency of marker-assisted selection for favorable loci in rice breeding programs. © 2011 Springer Science+Business Media B.V.

Li T.,Shandong University | He S.,Shandong University | Zhao H.,Shandong University | Zhao G.,Shandong University | And 2 more authors.
Trends in Parasitology | Year: 2010

Tremendous progress has been made in the control and prevention of human parasitic diseases in mainland China in the past 30 years because of China's Reform and Opening to the Outside Policies initiated in 1978. However, parasitic diseases remain a major human health problem, with significant morbidity and mortality as well as adverse socioeconomic consequences. Although soil-transmitted parasitic diseases are in the process of being gradually controlled, food-borne parasitic diseases and emerging parasitic diseases are becoming the focus of new campaigns for control and prevention. This article reviews major trends in human parasitic diseases in mainland China, with perspectives for control. © 2010 Elsevier Ltd.

Du J.,Purdue University | Du J.,Jiangsu Academy of Agricultural Sciences | Tian Z.,Purdue University | Tian Z.,CAS Institute of Genetics and Developmental Biology | And 7 more authors.
Plant Cell | Year: 2012

The evolutionary forces that govern the divergence and retention of duplicated genes in polyploids are poorly understood. In this study, we first investigated the rates of nonsynonymous substitution (Ka) and the rates of synonymous substitution (Ks) for a nearly complete set of genes in the paleopolyploid soybean (Glycine max) by comparing the orthologs between soybean and its progenitor species Glycine soja and then compared the patterns of gene divergence and expression between pericentromeric regions and chromosomal arms in different gene categories. Our results reveal strong associations between duplication status and Ka and gene expression levels and overall low Ks and low levels of gene expression in pericentromeric regions. It is theorized that deleterious mutations can easily accumulate in recombination-suppressed regions, because of Hill-Robertson effects. Intriguingly, the genes in pericentromeric regions-the cold spots for meiotic recombination in soybean-showed significantly lower Ka and higher levels of expression than their homoeologs in chromosomal arms. This asymmetric evolution of two members of individual whole genome duplication (WGD)-derived gene pairs, echoing the biased accumulation of singletons in pericentromeric regions, suggests that distinct genomic features between the two distinct chromatin types are important determinants shaping the patterns of divergence and retention of WGD-derived genes. © 2012 American Society of Plant Biologists.

You L.,Huazhong Agricultural University | You L.,International Food Policy Research Institute | Wood S.,Bill and Melinda Gates Foundation | Wood-Sichra U.,International Food Policy Research Institute | Wu W.,Chinese Academy of Agricultural Sciences
Agricultural Systems | Year: 2014

We describe a new crop allocation model that adds further methodological and data enhancements to the available crop downscaling modeling. The model comprises the estimates of crop area, yield and production for 20 major crops under four rainfed and irrigated production systems across a global 5. arc minute grid. The new model builds on prior work by the authors (and published in this journal) in developing regional downscaled databases for Latin America and the Caribbean (LAC) and sub-Saharan Africa (SSA) and encompasses notions of comparative advantage and potential economic worth as factors influencing the geographic distribution of crop production. This is done through a downscaling approach that accounts for spatial variation in the biophysical conditions influencing the productivity of individual crops within the cropland extent, and that uses crop prices to weigh the gross revenue potential of alternate crops when considering how to prioritize the allocation of specific crops to individual grid cells. The proposed methodology also allows for the inclusion of partial, existing sources of evidence and feedback on local crop distribution patterns through the use of spatial allocation priors that are then subjected to an entropy-based optimization procedure that imposes a range of consistency and aggregation constraints. We compare the global datasets and summarize factors that give rise to systematic differences amongst them and how such differences might influence the fitness for purpose of each dataset. We conclude with some recommendations on priorities for further work in improving the reliability, utility and periodic repeatability of generating crop production distribution data. © 2014 Elsevier Ltd.

Ye L.,CAS Institute of Zoology | Ye L.,Chinese Academy of Agricultural Sciences | Fu X.,CAS Institute of Zoology | Fu X.,Heilongjiang University | Ge F.,CAS Institute of Zoology
Journal of Experimental Botany | Year: 2012

Investigations of the effects of elevated ozone (O3) on the virus-plant system were conducted to inform virus pathogen management strategies better. One susceptible cultivar of tobacco (Nicotiana tabacum L. cv. Yongding) and a resistant cultivar (Nicotiana tabacum L. cv. Vam) to Potato virus Y petiole necrosis strain (PVY N) infection were grown in open-top chambers under ambient and elevated O3 concentrations. Above-ground biomass, foliage chlorophyll, nitrogen and total non-structural carbohydrate (TNCs), soluble protein, total amino acid (TAA) and nicotine content, and peroxidase (POD) activity were measured to estimate the effects of elevated O3 on the impact of PVY N in the two cultivars. Results showed that under ambient O3, the resistant cultivar possessed greater biomass and a lower C/N ratio after infection than the susceptible cultivar; however, under elevated O3, the resistant cultivar lost its biomass advantage but maintained a lower C/N ratio. Variation of foliar POD activity could be explained as a resistance cost which was significantly correlated with biomass and C/N ratio of the tobacco cultivar. Chlorophyll content remained steady in the resistant cultivar but decreased significantly in the susceptible cultivar when stressors were applied. Foliar soluble protein and free amino acid content, which were related to resistance cost changes, are also discussed. This study indicated that a virus-resistant tobacco cultivar showed increased sensitivity to elevated O3 compared to a virus-sensitive cultivar. © 2012 The Author.

Hu L.,CAS Wuhan Botanical Garden | Li H.,CAS Wuhan Botanical Garden | Pang H.,Chinese Academy of Agricultural Sciences | Fu J.,CAS Wuhan Botanical Garden
Journal of Plant Physiology | Year: 2012

Salinity could damage cellular membranes through overproduction of reactive oxygen species (ROS), while antioxidant capacities play a vital role in protecting plants from salinity caused oxidative damages. The objective of this study was to investigate the toxic effect of salt on the antioxidant enzyme activities, isoforms and gene expressions in perennial ryegrass (Lolium perenne L.). Salt-tolerant 'Quickstart II' and salt-sensitive 'DP1' were subjected to 0 and 250mM NaCl for 12d. Salt stress increased the content of lipid peroxidation (MDA), electrolyte leakage (EL) and hydrogen peroxide (H 2O 2), to a greater extent in salt-sensitive genotype. Salt-stressed plant leaves exhibited a greater activity of superoxide dismutase (SOD, EC, peroxidase (POD, EC, ascorbate peroxidase (APX, EC at 4d after treatment (DAT), but a lower level of enzyme activity at 8 and 12d, when compared to the control. Catalase (CAT, EC activity was greater at 4 DAT and thereafter decreased in salt tolerant genotype relative to the control, whereas lower than the control during whole experiment period for salt-sensitive genotype. There were different patterns of five isoforms of SOD, POD and two isoforms of APX between two genotypes. Antioxidant gene expression was positively related to isoenzymatic and total enzymatic activities during 12-d salt-treated leaves of two genotypes, with a relatively higher level in salt-tolerant genotype. Thus, salt tolerance could be related to the constitutive/induced antioxidant gene, leading to more efficient enzyme stimulation and protection in perennial ryegrass. © 2011 Elsevier GmbH.

Gao Y.,CAS Beijing Institute of Geographic Sciences and Nature Resources Research | Gao Y.,Shanghai JiaoTong University | Yu G.,CAS Beijing Institute of Geographic Sciences and Nature Resources Research | Luo C.,Chinese Academy of Agricultural Sciences | Zhou P.,Shanghai JiaoTong University
PLoS ONE | Year: 2012

Protecting groundwater from nitrogen contamination is an important public-health concern and a major national environmental issue in China. In this study, we monitored water quality in 29 wells from 2009 to 2010 in a village in Shanghai city, whick belong to typical rural-urban continuum in China. The total N and NO 3-N exhibited seasonal changes, and there were large fluctuations in NH 4-N in residential areas, but without significant seasonal patterns. NO 2-N in the water was not stable, but was present at high levels. Total N and NO 3-N were significantly lower in residential areas than in agricultural areas. The groundwater quality in most wells belonged to Class III and IV in the Chinese water standard, which defines water that is unsuitable for human consumption. Our health risk assessments showed that NO 3-N posed the greatest carcinogenic risk, with risk values ranging from 19×10 -6 to 80×10 -6, which accounted for more than 90% of the total risk in the study area. © 2012 Gao et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Chu M.,Chinese Academy of Agricultural Sciences
BMC genomics | Year: 2014

RESULTS: A total of 483 miRNAs (including 97 known, 369 conserved and 17 predicated novel miRNAs), which belong to 183 different miRNA families, were identified in ovaries of Tan sheep and Small Tail Han (STH) sheep. Compared with the three stages of the breeding season, 25 shared significantly differentially expressed (including 19 up- and six down-regulated) miRNAs were identified in ovine anestrus. KEGG Pathway analysis revealed that the target genes for some of the differentially expressed miRNAs were involved in reproductive hormone related pathways (e.g. steroid biosynthesis, androgen and estrogen metabolism and GnRH signaling pathway) as well as follicular/luteal development related pathways. Moreover, the expression of the differentially expressed miRNAs and most of their target genes were negatively correlated in the above pathways. Furthermore, the levels of estrogen, progesterone and LH in ovine anestrus were significantly lower than those in the breeding season. Combining the results of pathway enrichment analysis, expression of target genes and hormone measurement, we suggest that these differentially expressed miRNAs in anestrus might participate in attenuation of ovarian activity by regulating the above pathways. Besides miRNAs, a large and unexpectedly diverse set of piRNAs were also identified.CONCLUSIONS: The miRNA profiles of ovine ovaries in anestrus were presented for the first time. The identification and characterization of miRNAs that are differentially expressed between ovine anestrus and the breeding season will help understanding of the role of miRNAs in the regulation of seasonal estrus, and provides candidates for determining miRNAs which could be potentially used to regulate ovine seasonal estrus.BACKGROUND: Seasonal estrus is a critical limiting factor of animal fecundity, and it involves changes in both ovarian biology and hormone secretion in different seasons. Previous studies indicate that two classes of small RNAs (miRNAs and piRNAs) play important regulatory roles in ovarian biology. To understand the roles of small RNA-mediated post-transcriptional regulation in ovine seasonal estrus, the variation in expression patterns of ovarian small RNAs during anestrus and the breeding season were analyzed using Solexa sequencing technology. In addition, reproductive hormone levels were determined during ovine anestrus and the breeding season.

Zhang X.,Wageningen University | Hu D.,Chinese Academy of Agricultural Sciences
China Agricultural Economic Review | Year: 2011

Purpose - The purpose of this paper is first, to develop constructs to measure three important concepts in the supply chain literature: contracts, trust and market environment, in the Chinese context and to further investigate the relationships amongst these three concepts based on the formulated hypothesis. Design/methodology/approach - The research methodology has strictly followed the recommended scale development procedures, which include specifying each constructs, item generation, data collection, reliability and validity test, and finally test hypothesis. The primary data were collected in October 2008 in Hubei Province, China. Both exploratory factor analysis and confirmatory factor analysis are applied to assess the reliability and validity of the three constructs. Findings - In total, 22 items were retained to measure six dimensions for the three core concepts: contract (marketing and production), trust (reliability and benevolence), and market environments (diversity and volatility). Second, the finding supported this argument that contracts and trust functions as complements. Furthermore, a positive relationship between environmental uncertainty and the use of contractual governance was found. Research limitations/implications - The measurement model for environmental volatility is less satisfied. More research should be carried out on the measurement of market environment in the future. Originality/value - This paper identifies and validates key constructs underlying supply chain management research: contract, trust and market environment, in a Chinese context. These measurable concepts could be applied in similar settings to further investigate small-scale farmer's position along the supply chain. Copyright © 2011 Emerald Group Publishing Limited. All rights reserved.

Zhou L.,Tsinghua University | Xu L.,Chinese Academy of Agricultural Sciences | Ye J.,PLA Fourth Military Medical University | Li D.,Tsinghua University | And 6 more authors.
Hepatology | Year: 2012

High levels of dietary saturated fat have been closely associated with the development of hepatic steatosis, but the factors that mediate this process remain elusive. Here, we observed that the level of cell death-inducing DNA fragmentation factor-alpha-like effector a (Cidea) expression was highly correlated with the severity of hepatic steatosis in humans. Overexpression of Cidea in mouse liver resulted in increased hepatic lipid accumulation and the formation of large lipid droplets (LDs). In contrast, mice with a Cidea deficiency had decreased lipid accumulation and alleviated hepatic steatosis when they received a high-fat-diet feeding or in ob/ob mice. Furthermore, the knockdown of Cidea in livers of ob/ob mice resulted in significantly reduced hepatic lipid accumulation and smaller LDs. Importantly, we observed that Cidea expression in hepatocytes was specifically induced by saturated fatty acids (FAs), and such induction was reduced when sterol response element-binding protein (SREBP)1c was knocked down. In contrast, the overexpression of SREBP1c restored the saturated FA-induced expression of Cidea. In addition, we observed that the stability of Cidea protein in hepatocytes increased significantly in response to treatment with FAs. Conclusion: Cidea plays critical roles in promoting hepatic lipid accumulation and in the development of hepatic steatosis by acting as a sensor that responds to diets that contain FAs. © 2012 American Association for the Study of Liver Diseases.

Lu Y.,CAS Nanjing Institute of Soil Science | Du C.,CAS Nanjing Institute of Soil Science | Yu C.,Chinese Academy of Agricultural Sciences | Zhou J.,CAS Nanjing Institute of Soil Science
Computers and Electronics in Agriculture | Year: 2014

This study proposed a methodology for classification of rapeseed varieties using Fourier transform infrared photoacoustic spectroscopy (FTIR-PAS). For this purpose, principal components analysis (PCA) was first used to reveal the separation of three varieties of rapeseeds, and then partial least squares-discriminant analysis (PLS-DA) and support vector machines (SVM) were employed for the classification task. The overall classification error rates (ERs) of prediction set were 7.5% and 0 for the models of PLS-DA and SVM, respectively. Furthermore, successive projections algorithm (SPA) was adopted to choose an appropriate variable subset as the inputs of PLS-DA and SVM. Both SPA-PLS-DA and SPA-SVM models gave improved predictive accuracy with significantly reduced model variables. The results of this study had showed the good performance of FTIR-PAS as a rapid, non-destructive and objective tool for classifying varieties of rapeseeds. © 2014 Elsevier B.V.

Sun C.,China Agricultural University | Sun C.,Chinese Academy of Agricultural Sciences | Ren L.,China Agricultural University
Hydrological Processes | Year: 2014

Haihe plain is an important food production area in China, facing an increasing water shortage. The water used for agriculture accounts for about 70% of total water resources. Thus, it is critical to optimize the irrigation scheduling for saving water and increasing crop water productivity (CWP). This study first simulated crop yield and CWP for winter wheat and summer maize in historical scenario during 1961-2005 for Haihe plain using previously well-established Soil and Water Assessment Tool model. Then, scenarios under historical irrigation (scenario 1) and sufficient irrigation (scenario 2) were, respectively, simulated both with sufficient fertilizer. The crop yield in scenario 2 was considered as the potential crop yield. The optimal irrigation scheduling with sufficient fertilizer (scenario 3) was explored by iteratively adjusting irrigation scheduling based on the scenario 1 and previous studies related to water stress on crop growth. Results showed that net irrigation amount was, respectively, reduced 23.1% and 18.8% in scenario 3 for winter wheat and summer maize when compared with scenario 1. The CWP was 12.1% and 8.2% higher with very slight change of crop yield. Using optimal irrigation scheduling could save 8.8×108 m3 irrigation water and reduce about 16.3% groundwater over-exploitation in winter wheat growth period. The corresponding yield was 18.5% and 12.9% less than potential yield for winter wheat and summer maize but using less irrigation water. Therefore, it could be considered that the optimal irrigation was reasonable, which provided beneficial suggestions for increasing efficiency of agricultural water use with sustainable crop yield in Haihe plain. © 2013 John Wiley & Sons, Ltd.

Li Z.,Beijing Museum of Natural History | Wang N.,Chinese Academy of Agricultural Sciences | Yang D.,China Agricultural University
Zootaxa | Year: 2014

The species of the genus Hybos Meigen from Northwest China are reviewed. The following five species are described as new to science: Hybos elongatus sp. nov., H. flavitibialis sp. nov., H. projectus sp. nov., H. qinlingensis sp. nov., and H. xii sp. nov. A key to the 17 species of the genus Hybos from Northwest China is provided. Copyright © 2014 Magnolia Press.

Sun Y.-P.,China Agricultural University | Zhao L.-J.,China Agricultural University | Sun L.,Chinese Academy of Agricultural Sciences | Zhang S.-G.,CAS Institute of Zoology | Ban L.-P.,China Agricultural University
Chemical Senses | Year: 2013

The antennal sensilla of Myzus persicae were mapped using scanning and transmission electron microscopy. Placoid sensilla and coeloconic sensilla were found on the 6th segments, whereas 2 types of trichoid sensilla were present all through the length of the antenna. A single sensillum placoideum was located on the 5th segment, whereas alate aphids also presented placoid sensilla on the 3rd antennal segment. Immunocytochemical localization of odorant-binding proteins (OBPs) was performed on ultrathin sections of antennal chemosensilla. The antiserum against OBP7 intensively labeled all placoid sensilla from both primary and secondary rhinaria, with gold granules concentrated in the lymph surrounding the dendrite. OBP6 and OBP3 could also be detected in placoid sensilla, but less strongly than OBP7. Barely significant reaction or no reaction was observed with antibodies against OBP8. © The Author 2012. Published by Oxford University Press. All rights reserved.

Ma C.,CAS Institute of Zoology | Yang P.,CAS Institute of Zoology | Jiang F.,CAS Institute of Zoology | Chapuis M.-P.,University of Sydney | And 3 more authors.
Molecular Ecology | Year: 2012

The migratory locust, Locusta migratoria, is the most widely distributed grasshopper species in the world. However, its global genetic structure and phylogeographic relationships have not been investigated. In this study, we explored the worldwide genetic structure and phylogeography of the locust populations based on the sequence information of 65 complete mitochondrial genomes and three mitochondrial genes of 263 individuals from 53 sampling sites. Although this locust can migrate over long distances, our results revealed high genetic differentiation among the geographic populations. The populations can be divided into two different lineages: the Northern lineage, which includes individuals from the temperate regions of the Eurasian continent, and the Southern lineage, which includes individuals from Africa, southern Europe, the Arabian region, India, southern China, South-east Asia and Australia. An analysis of population genetic diversity indicated that the locust species originated from Africa. Ancestral populations likely separated into Northern and Southern lineages 895 000 years ago by vicariance events associated with Pleistocene glaciations. These two lineages evolved in allopatry and occupied their current distributions in the world via distinct southern and northern dispersal routes. Genetic differences, caused by the long-term independent diversification of the two lineages, along with other factors, such as geographic barriers and temperature limitations, may play important roles in maintaining the present phylogeographic patterns. Our phylogeographic evidence challenged the long-held view of multiple subspecies in the locust species and tentatively divided it into two subspecies, L. m. migratoria and L. m. migratorioides. © 2012 Blackwell Publishing Ltd.

Peng D.-H.,Huazhong Agricultural University | Qiu D.-W.,Chinese Academy of Agricultural Sciences | Ruan L.-F.,Huazhong Agricultural University | Zhou C.-F.,Huazhong Agricultural University | Sun M.,Huazhong Agricultural University
Molecular Plant-Microbe Interactions | Year: 2011

Elicitors can stimulate defense responses in plants and have become a popular strategy in plant disease control. Previously, we isolated a novel protein elicitor, PemG1, from Magnaporthe grisea. In the present study, PemG1 protein expressed in and purified from Escherichia coli improved resistance of rice and Arabidopsis to bacterial infection, induced transient expression of pathogenesisrelated (PR) genes, and increased accumulation of hydrogen peroxide in rice. The effects of PemG1 on disease resistance and PR gene expression were mobilized systemically throughout the rice plant and persisted for more than 28 days. PemG1-induced accumulation of OsPR-1a in rice was prevented by the calcium channel blockers LaCl 3, BAPTA, EGTA, W7, and TFP. Arabidopsis mutants that are insensitive to jasmonic acid (JA) and ethylene showed increased resistance to bacterial infection after PemG1 treatment but PemG1 did not affect resistance of mutants with an impaired salicylic acid (SA) transduction pathway. In rice, PemG1 induced overexpressions of the SA signal-related genes (OsEDS1, OsPAL1, and OsNH1) but not the JA pathway-related genes (OsLOX2 and OsAOS2). Our findings reveal that PemG1 protein can function as an activator of plant disease resistance, and the PemG1-mediated systemic acquired resistance is modulated by SA-and Ca 2+-related signaling pathways. © 2011 The American Phytopathological Society.

Wang Y.,China Agricultural University | Li D.,China Agricultural University | Wang L.-J.,China Agricultural University | Li S.-J.,Chinese Academy of Agricultural Sciences | Adhikari B.,University of Ballarat
Carbohydrate Polymers | Year: 2010

The effects of different drying methods (spray drying, freeze drying, vacuum drying, oven drying at 80 and 105 °C, and ethanol precipitation) on the color and functional properties such as zeta potential, foaming, gelling, and emulsion properties of flaxseed gum were studied. Spray dried powders had the lightest color among all the powders. The powder obtained from ethanol precipitation had the lowest zeta potential and the resultant emulsion was in the most stable state. The ethanol precipitated powders had the best emulsion capacity and stability, better than even the untreated samples. The oven dried (105 °C) powders had the best foaming capacity and the foam stability, while the 80 °C oven dried powder had highest gel strength among all the dried samples. These results will be helpful in selecting suitable drying method depending on the functional properties of the flaxseed gum powders. © 2010 Elsevier Ltd. All rights reserved.

Cui J.,Chinese Academy of Agricultural Sciences
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2011

With the development of oil agriculture, the material wealth was rapidly increased, but the resources were excessively consumed and ecological environment was polluted. Along with the development of circular economy theory, agricultural circulation economy became an important form and ultimate goal of modern agricultural development. Based on discussion of theoretical source and content of circular economy, the experiences of agricultural circular economy in four typical states or regions were introduced, such as EU, US, Japan and Philippine farm. The enlightenment to China and the core of the modern agricultural planning theory were presented. Three thinking methods of modern agricultural planning on the guidance of circular economy theory were stated, which illustrated the core content of modern agricultural planning. Taking agricultural circular economy planning on Shuangcheng city in Heilongjiang province as a case study, the application and practice of modern agricultural planning theory was analyzed. The research can provide a reference for modern agricultural planning and development of agricultural circular economy.

Xie Q.,Beijing University of Chemical Technology | Wei Y.,Beijing University of Chemical Technology | Zhang G.,Chinese Academy of Agricultural Sciences
Separation and Purification Technology | Year: 2010

In order to utilize and control the invasive weed, Flaveria bidentis (L.) Kuntze, bioactive compounds mainly flavonoids from F. bidentis (L.) Kuntze were studied. High-speed counter-current chromatography (HSCCC) was successfully used for the separation of flavonol glycosides from F. bidentis (L.) Kuntze. The two-phase solvent system composed of ethyl acetate-methanol-water (10:0.4:10, v/v) was used for HSCCC. About 400 mg of the crude extract was separated by HSCCC, yielding 3.6 mg of patuletin-3-O-glucoside at a purity of over 97%; 4.4 mg of astragalin (kaempferol-3-O-glucoside) at a purity of over 98% and 4.5 mg of a mixture of hyperoside (quercetin-3-O-galactoside) and 6-methoxykaempferol-3-O-galactoside constituting over 97% of the fraction. The chemical structures were confirmed by MS and 1H, 13C, 1-D TOCSY NMR. © 2010 Elsevier B.V. All rights reserved.

Zuo Z.,Hunan University | Zuo Z.,University of California at Los Angeles | Liu H.,University of California at Los Angeles | Liu B.,Chinese Academy of Agricultural Sciences | And 3 more authors.
Current Biology | Year: 2011

Cryptochromes are blue light receptors that mediate light regulation of gene expression in all major evolution lineages, but the molecular mechanism underlying cryptochrome signal transduction remains not fully understood [1, 2]. It has been reported that cryptochromes suppress activity of the multifunctional E3 ubiquitin ligase CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1) to regulate gene expression in response to blue light [3, 4]. But how plant cryptochromes mediate light suppression of COP1 activity remains unclear. We report here that Arabidopsis CRY2 (cryptochrome 2) undergoes blue light-dependent interaction with the COP1-interacting protein SUPPRESSOR OF PHYTOCHROME A 1 (SPA1) [5, 6]. We demonstrate that SPA1 acts genetically downstream from CRY2 to mediate blue light suppression of the COP1-dependent proteolysis of the flowering-time regulator CONSTANS (CO) [7, 8]. We further show that blue light-dependent CRY2-SPA1 interaction stimulates CRY2-COP1 interaction. These results reveal for the first time a wavelength-specific mechanism by which a cryptochrome photoreceptor mediates light regulation of protein degradation to modulate developmental timing in Arabidopsis. © 2011 Elsevier Ltd.

Wang H.,Chinese Academy of Agricultural Sciences
Molecular Plant | Year: 2015

Phytochromes are red and far-red light photoreceptors that play fundamental roles in controlling many aspects of plant growth and development in response to light. The past two decades have witnessed the mechanistic elucidation of the action mode of phytochromes, including their regulation by external and endogenous factors and how they exert their function as transcriptional regulators. More importantly, recent advances have substantially deepened our understanding on the integration of the phytochrome-mediated signal into other cellular and developmental processes, such as elongation of hypocotyls, shoot branching, circadian clock, and flowering time, which often involves complex intercellular and interorgan signaling. Based on these advances, this review illustrates a blueprint of our current understanding of phytochrome signaling and its crosstalk with other signaling pathways, and also points out still open questions that need to be addressed in the future. © 2015 The Author.

Xie Z.,Chinese Academy of Forestry | An J.,Chinese Academy of Agricultural Sciences
Journal of Applied Entomology | Year: 2014

Honey bees and wild bees provide critical pollination services to agricultural ecosystems; however, the relative contributions of different bee taxa are not well understood. The natural habitats surrounding farmland support food and nesting resources for wild bees and therefore play an important role in the maintenance of crop pollination. In this study, we selected Cucurbita pepo L. (squash) as a model crop to investigate the relative importance of honey bees and bumblebees in pollinating the crop. Thirteen fields, which were surrounded by a gradient of natural habitat, were investigated on the Yunnan-Guizhou Plateau in China. We measured the visit densities of honey bees and bumblebees, the number of pollen grains deposited in a single visit by the two bee taxa, as well as the overall pollen grains deposited on stigmas during a flowering day, and then used Bayesian inference to decouple the pollen grains deposited by either the honey bees or the bumblebees. Compared with honey bees, bumblebees deposited a higher number of pollen grains on stigmas in a single visit, but had a lower visit density than honey bees. Meanwhile, the bumblebee visit density increased along the proportion of natural habitat, while the honey bee visit density was not affected by the surrounding natural habitat. Data simulations using Bayesian inference showed that on a flowering day, the number of pollen grains deposited by bumblebees increased with the proportion of natural habitat in the surrounding landscape, but the number of pollen grains deposited by honey bees did not. Moreover, the total numbers of pollen grains deposited by honey bees or bumblebees alone were all below 2000 (the critical level to satisfy the pollination requirement of this crop). Pollen calculations demonstrated that the number of pollen grains deposited by the two bee taxa was greater than 2000 in fields surrounded by more than 13% natural habitat (grasslands and forests). The results revealed that bumblebees ensured C. pepo pollination in combination with honey bees in the highland agricultural ecosystems. © 2014 Blackwell Verlag GmbH.

Lu L.,CAS Nanjing Institute of Soil Science | Lu L.,University of Chinese Academy of Sciences | Han W.,Chinese Academy of Agricultural Sciences | Zhang J.,Nanjing Normal University | And 6 more authors.
ISME Journal | Year: 2012

The hydrolysis of urea as a source of ammonia has been proposed as a mechanism for the nitrification of ammonia-oxidizing bacteria (AOB) in acidic soil. The growth of Nitrososphaera viennensis on urea suggests that the ureolysis of ammonia-oxidizing archaea (AOA) might occur in natural environments. In this study, 15 N isotope tracing indicates that ammonia oxidation occurred upon the addition of urea at a concentration similar to the in situ ammonium content of tea orchard soil (pH 3.75) and forest soil (pH 5.4) and was inhibited by acetylene. Nitrification activity was significantly stimulated by urea fertilization and coupled well with abundance changes in archaeal amoA genes in acidic soils. Pyrosequencing of 16S rRNA genes at whole microbial community level demonstrates the active growth of AOA in urea-amended soils. Molecular fingerprinting further shows that changes in denaturing gradient gel electrophoresis fingerprint patterns of archaeal amoA genes are paralleled by nitrification activity changes. However, bacterial amoA and 16S rRNA genes of AOB were not detected. The results strongly suggest that archaeal ammonia oxidation is supported by hydrolysis of urea and that AOA, from the marine Group 1.1a-associated lineage, dominate nitrification in two acidic soils tested. © 2012 International Society for Microbial Ecology. All rights reserved.

Liu Z.,Wuhan University | Wei F.,Chinese Academy of Agricultural Sciences | Feng Y.-Q.,Wuhan University
Analytical Methods | Year: 2010

In this study, a sensitive assay of cytokinins was developed using polymer monolith microextraction/hydrophilic interaction chromatography/electrospray ionization-tandem mass spectrometry (PMME/HILIC/ESI-MS/MS). The extraction was realized on a poly(2-acrylamido-2-methyl-1-propanesulfonic acid-co-ethylene dimethacrylate) (poly(AMPS-co-EDMA)) capillary monolith and the subsequent separation was carried out on a Luna silica column. Several parameters of PMME and HILIC were optimized to obtain the optimum results. After optimizing the extraction conditions, 10 mM ammonium formate of pH 2.5 was chosen as the matrix solution to obtain the highest extraction efficiency. The MS sensitivity for cytokinins investigated could be enhanced 3-fold by the use of hydrophilic interaction chromatography with the mobile phase of 85% acetonitrile with 0.01% (v/v) formic acid and 15% water with 0.01% (v/v) formic acid, when compared to the use of conventional reversed phase liquid chromatography (RPLC). Good linearities were obtained for five cytokinins with correlation coefficients (R2) > 0.9962. The LODs (S/N = 3) for the targets were found to be 0.0028-0.068 ng mL-1. Reproducibility of the method was obtained with intra-day and inter-day relative standard deviations (RSDs) less than 12.7% and the recoveries in plant samples ranged from 70.3% to 113.3%. The method was applied to the determination of cytokinins in Oryza sativa, Arabidopsis thaliana and oil seed rape tissues. © 2010 The Royal Society of Chemistry.

Xu C.,Cold Spring Harbor Laboratory | Liberatore K.L.,Cold Spring Harbor Laboratory | Liberatore K.L.,U.S. Department of Agriculture | Macalister C.A.,Cold Spring Harbor Laboratory | And 15 more authors.
Nature Genetics | Year: 2015

Shoot meristems of plants are composed of stem cells that are continuously replenished through a classical feedback circuit involving the homeobox WUSCHEL (WUS) gene and the CLAVATA (CLV) gene signaling pathway. In CLV signaling, the CLV1 receptor complex is bound by CLV3, a secreted peptide modified with sugars. However, the pathway responsible for modifying CLV3 and its relevance for CLV signaling are unknown. Here we show that tomato inflorescence branching mutants with extra flower and fruit organs due to enlarged meristems are defective in arabinosyltransferase genes. The most extreme mutant is disrupted in a hydroxyproline O-arabinosyltransferase and can be rescued with arabinosylated CLV3. Weaker mutants are defective in arabinosyltransferases that extend arabinose chains, indicating that CLV3 must be fully arabinosylated to maintain meristem size. Finally, we show that a mutation in CLV3 increased fruit size during domestication. Our findings uncover a new layer of complexity in the control of plant stem cell proliferation. © 2015 Nature America, Inc. All rights reserved.

Wang J.,Tsinghua University | Zhang Y.,Tsinghua University | Chen Y.,Nanjing University of Technology | Lin M.,Chinese Academy of Agricultural Sciences | Lin Z.,Tsinghua University
Biotechnology and Bioengineering | Year: 2012

Lignocellulosic biomass is regarded as the most viable source of feedstock for industrial biorefinery, but the harmful inhibitors generated from the indispensable pretreatments prior to fermentation remain a daunting technical hurdle. Using an exogenous regulator, irrE, from the radiation-resistant Deinococcus radiodurans, we previously showed that a novel global regulator engineering (GRE) approach significantly enhanced tolerances of Escherichia coli to alcohol and acetate stresses. In this work, an irrE library was subjected to selection under various stresses of furfural, a typical hydrolysate inhibitor. Three furfural tolerant irrE mutants including F1-37 and F2-1 were successfully obtained. The cells containing these mutants reached OD600 levels of 4- to 16-fold of that for the pMD18T cells in growth assay under 0.2% (v/v) furfural stress. The cells containing irrE F1-37 and F2-1 also showed considerably reduced intracellular oxygen species (ROS) levels under furfural stress. Moreover, these two irrE mutants were subsequently found to confer significant cross tolerances to two other most common inhibitors, 5-hydroxymethyl-2-furaldehyde (HMF), vanillin, as well as real lignocellulosic hydrolysates. When evaluated in Luria-Bertani (LB) medium supplemented with corn stover cellulosic hydrolysate (prepared with a solid loading of 30%), the cells containing the mutants exhibited lag phases markedly shortened by 24-44h in comparison with the control cells. This work thus presents a promising step forward to resolve the inhibitor problem for E. coli. From the view of synthetic biology, irrE can be considered as an evolvable "part" for various stresses. Furthermore, this GRE approach can be extended to exploit other exogenous global regulators from extremophiles, and the native counterparts in E. coli, for eliciting industrially useful phenotypes. © 2012 Wiley Periodicals, Inc.

Gao L.,Chinese Academy of Agricultural Sciences
African Journal of Microbiology Research | Year: 2011

Biomass yields and sporulation of Pochonia chlamydosporia isolate HSY-12-14 was concerned on culture conditions including culture method, nutritional requirements together with environmental factors in this study. We optimized them for biomass yields of P. chlamydosporia HSY-12-14 with the "two-step" cultivation method as well as orthogonal matrix method: firstly cultured spore suspension on the basal medium (sucrose 19.00 g, soy peptone 4.06 g, K2HPO4 1.00 g, KCl 0.50 g, MgSO4 0.50 g, FeSO4 0.01 g and 17.00 g Bactor) for the first stage culture of 4 days under room condition, then transferred them to another defined medium (sucrose 19.05 g, soypeptone 0.01 g, ZnSO4•7H2O 0.05 g/L, MnSO4•H2O 0.05 g/L, H3BO4 0.05 g/L and 17.00 g Bactor) for more 4 days cultivation, together with the environmental factors combination of water potential-3.9 MPa /pH 4 /24 h light cycle/23°C for biomass yields. We optimized the best culture conditions for sporulation of P. chlamydosporia under water potential-1.2 MPa /pH 4 /24 h light cycle/32°C wit h the same nutrition for biomass yields. These results is characterized in that it supplies the composition of media and environmental suitable for the mass production and provide important information industrialization of this great potential biocontrol fungus. © 2011 Academic Journals.

Zhang J.,Hebei Academy of Agriculture and Forestry Science | Liang S.,Tsinghua University | Duan J.,Chinese Academy of Agricultural Sciences | Wang J.,Hebei Academy of Agriculture and Forestry Science | And 5 more authors.
BMC Genomics | Year: 2012

Background: The peanut (Arachis hypogaea L.) is an important oilseed crop in tropical and subtropical regions of the world. However, little about the molecular biology of the peanut is currently known. Recently, next-generation sequencing technology, termed RNA-seq, has provided a powerful approach for analysing the transcriptome, and for shedding light on the molecular biology of peanut.Results: In this study, we employed RNA-seq to analyse the transcriptomes of the immature seeds of three different peanut varieties with different oil contents. A total of 26.1-27.2 million paired-end reads with lengths of 100 bp were generated from the three varieties and 59,077 unigenes were assembled with N50 of 823 bp. Based on sequence similarity search with known proteins, a total of 40,100 genes were identified. Among these unigenes, only 8,252 unigenes were annotated with 42 gene ontology (GO) functional categories. And 18,028 unigenes mapped to 125 pathways by searching against the Kyoto Encyclopedia of Genes and Genomes pathway database (KEGG). In addition, 3,919 microsatellite markers were developed in the unigene library, and 160 PCR primers of SSR loci were used for validation of the amplification and the polymorphism.Conclusion: We completed a successful global analysis of the peanut transcriptome using RNA-seq, a large number of unigenes were assembled, and almost four thousand SSR primers were developed. These data will facilitate gene discovery and functional genomic studies of the peanut plant. In addition, this study provides insight into the complex transcriptome of the peanut and established a biotechnological platform for future research. © 2012 Zhang et al; licensee BioMed Central Ltd.

Huang J.,Shenzhen University | Lu X.,Shenzhen University | Yan H.,Shenzhen University | Chen S.,CAS Institute of Genetics and Developmental Biology | And 3 more authors.
DNA Research | Year: 2012

Semi-mangroves form a group of transitional species between glycophytes and halophytes, and hold unique potential for learning molecular mechanisms underlying plant salt tolerance. Millettia pinnata is a semi-mangrove plant that can survive a wide range of saline conditions in the absence of specialized morphological and physiological traits. By employing the Illumina sequencing platform, we generated ∼192 million short reads from four cDNA libraries of M. pinnata and processed them into 108 598 unisequences with a high depth of coverage. The mean length and total length of these unisequences were 606 bp and 65.8 Mb, respectively. A total of 54 596 (50.3%) unisequences were assigned Nr annotations. Functional classification revealed the involvement of unisequences in various biological processes related to metabolism and environmental adaptation. We identified 23 815 candidate salt-responsive genes with significantly differential expression under seawater and freshwater treatments. Based on the reverse transcription-polymerase chain reaction (RT-PCR) and real-time PCR analyses, we verified the changes in expression levels for a number of candidate genes. The functional enrichment analyses for the candidate genes showed tissue-specific patterns of transcriptome remodelling upon salt stress in the roots and the leaves. The transcriptome of M. pinnata will provide valuable gene resources for future application in crop improvement. In addition, this study sets a good example for large-scale identification of salt-responsive genes in non-model organisms using the sequencing-based approach. © The Author 2012. Published by Oxford University Press on behalf of Kazusa DNA Research Institute.

Shao W.,CAS Shanghai Institutes for Biological Sciences | Zhao Q.-Y.,CAS Shanghai Institutes for Biological Sciences | Wang X.-Y.,CAS Shanghai Institutes for Biological Sciences | Xu X.-Y.,CAS Shanghai Institutes for Biological Sciences | And 4 more authors.
RNA | Year: 2012

Alternative splicing and trans-splicing events have not been systematically studied in the silkworm Bombyx mori. Here, the silkworm transcriptome was analyzed by RNA-seq. We identified 320 novel genes, modified 1140 gene models, and found thousands of alternative splicing and 58 trans-splicing events. Studies of three SR proteins show that both their alternative splicing patterns and mRNA products are conserved from insect to human, and one isoform of Srsf6 with a retained intron is expressed sex-specifically in silkworm gonads. Trans-splicing of mod(mdg4) in silkworm was experimentally confirmed. We identified integrations from a common 5′-gene with 46 newly identified alternative 3′-exons that are located on both DNA strands over a 500-kb region. Other trans-splicing events in B. mori were predicted by bioinformatic analysis, in which 12 events were confirmed by RT-PCR, six events were further validated by chimeric SNPs, and two events were confirmed by allele-specific RT-PCR in F 1 hybrids from distinct silkworm lines of JS and L10, indicating that trans-splicing is more widespread in insects than previously thought. Analysis of the B. mori transcriptome by RNA-seq provides valuable information of regulatory alternative splicing events. The conservation of splicing events across species and newly identified trans-splicing events suggest that B. mori is a good model for future studies. Published by Cold Spring Harbor Laboratory Press. Copyright © 2012 RNA Society.

Wu Q.S.,Yangtze University | Wu Q.S.,Chinese Academy of Agricultural Sciences
Plant, Soil and Environment | Year: 2011

Citrus plants often suffer from temperature stress, which seriously inhibits tree growth and even results in tree death. The present experiment was conducted to evaluate the effects of Glomus mosseae on growth, root morphology, superoxide dismutase (SOD) and catalase (CAT) activities, and soluble protein content of trifoliate orange (Poncirus trifoliata) seedlings at low (15°C), optimum (25°C) and high (35°C) temperatures. Sixty-eight days after temperature stresses, mycorrhizal colonization and number of both entry points and vesicles were significantly inhibited by low or high temperature. Mycorrhizal seedlings recorded significantly higher growth characteristics than non-mycorrhizal seedlings at both optimum and high temperatures, but the beneficial effects were almost lost at low temperature. Generally, mycorrhizal seedlings presented notably higher root traits (projected area, surface area, number of forks and volume) than non-mycorrhizal seedlings regardless of temperature levels. Mycorrhizal colonization significantly increased SOD and CAT activities and soluble protein content at high temperature, increased only SOD activity at optimum temperature, and decreased only soluble protein content at low temperature. It suggests that mycorrhizal alleviation of temperature stress in trifoliate orange seedlings was at high temperature, but the alleviation was obviously weakened at low temperature.

Guo D.-L.,Henan University of Science and Technology | Zhang J.-Y.,Henan University of Science and Technology | Liu C.-H.,Chinese Academy of Agricultural Sciences
Molecular Biology Reports | Year: 2012

Start codon targeted (SCoT) polymorphic markers were used to assess genetic relationships among 64 grape varieties. Seventeen informative primers were selected from 36 SCoT primers based on their ability to produce clear and repeatable polymorphic and unambiguous bands among the varieties. A total of 131 bands were produced; 93.1% of them were polymorphic; the average polymorphism information content was 0.82. Cluster analysis of SCoT markers through the unweighted pairgroup method of arithmetic averages analysis and principal coordinate analysis were largely consistent. The partition of clusters in the dendrogram and PCoA plot was similar and some degree of grouping by types of grape and taxonomic status of the varieties was revealed. Four main groups were found after cluster analysis, i.e. table grape of Vitis vinifera; table grape of Euro-America hybrid; wine grape of V. vinifera and wild Vitis species. The results showed that the wild Vitis species originated from America and China could be clearly differentiated. The results also indicated that SCoT markers are informative and could be used to detect polymorphism for grape varieties. ©Springer Science+Business Media B.V. 2011.

Miao X.,Chinese Academy of Agricultural Sciences | Miao X.,Harvard University
Cellular and Molecular Life Sciences | Year: 2013

Transgenic animal technology is one of the fastest growing biotechnology areas. It is used to integrate exogenous genes into the animal genome by genetic engineering technology so that these genes can be inherited and expressed by offspring. The transgenic efficiency and precise control of gene expression are the key limiting factors in the production of transgenic animals. A variety of transgenic technologies are available. Each has its own advantages and disadvantages and needs further study because of unresolved technical and safety issues. Further studies will allow transgenic technology to explore gene function, animal genetic improvement, bioreactors, animal disease models, and organ transplantation. This article reviews the recently developed animal transgenic technologies, including the germ line stem cell-mediated method to improve efficiency, gene targeting to improve accuracy, RNA interference- mediated gene silencing technology, zinc-finger nuclease gene targeting technology and induced pluripotent stem cell technology. These new transgenic techniques can provide a better platform to develop transgenic animals for breeding new animal varieties and promote the development of medical sciences, livestock production, and other fields. © 2012 Springer Basel AG.

Wu X.-Y.,CAS Institute of Botany | Kuai B.-K.,Fudan University | Jia J.-Z.,Chinese Academy of Agricultural Sciences | Jing H.-C.,CAS Institute of Botany
Journal of Integrative Plant Biology | Year: 2012

Leaf senescence can impact crop production by either changing photosynthesis duration, or by modifying the nutrient remobilization efficiency and harvest index. The doubling of the grain yield in major cereals in the last 50 years was primarily achieved through the extension of photosynthesis duration and the increase in crop biomass partitioning, two things that are intrinsically coupled with leaf senescence. In this review, we consider the functionality of a leaf as a function of leaf age, and divide a leaf's life into three phases: the functionality increasing phase at the early growth stage, the full functionality phase, and the senescence and functionality decreasing phase. A genetic framework is proposed to describe gene actions at various checkpoints to regulate leaf development and senescence. Four categories of genes contribute to crop production: those which regulate (I) the speed and transition of early leaf growth, (II) photosynthesis rate, (III) the onset and (IV) the progression of leaf senescence. Current advances in isolating and characterizing senescence regulatory genes are discussed in the leaf aging and crop production context. We argue that the breeding of crops with leaf senescence ideotypes should be an essential part of further crop genetic improvement. © 2012 Institute of Botany, Chinese Academy of Sciences.

Qiao W.,Chinese Academy of Agricultural Sciences | Li C.,Peking University | Fan L.-M.,Peking University
Environmental and Experimental Botany | Year: 2014

Nitric oxide (NO) and hydrogen peroxide (H2O2) are two signaling molecules, which play roles in diverse organisms. In the past two decades, evidence has been accumulating to address their involvements in stress responses in plants, but how these two molecules interact with each other and how the signals are integrated in biological processes remain fragmentary and far from clear in the literature. This review brings together the knowledge obtained so far on these two molecules and their cross-talk in plant stress responses, particularly abiotic stresses including drought, salinity, extreme temperatures, UV light, and heavy metals. We tentatively discuss, in the context of abiotic stresses, how NO and H2O2 interact with each other at two levels, biosynthesis, and regulation of gene expression or protein activities. The cross-talk between NO and H2O2 with other signaling pathways in the regulation of abiotic stress responses in plants is also discussed. © 2014 Elsevier B.V.

Berg B.G.,Norwegian University of Science and Technology | Zhao X.-C.,Henan Agricultural University | Wang G.,Chinese Academy of Agricultural Sciences
Insects | Year: 2014

In heliothine moths, the male-specific olfactory system is activated by a few odor molecules, each of which is associated with an easily identifiable glomerulus in the primary olfactory center of the brain. This arrangement is linked to two well-defined behavioral responses, one ensuring attraction and mating behavior by carrying information about pheromones released by conspecific females and the other inhibition of attraction via signal information emitted from heterospecifics. The chance of comparing the characteristic properties of pheromone receptor proteins, male-specific sensory neurons and macroglomerular complex (MGC)-units in closely-related species is especially intriguing. Here, we review studies on the male-specific olfactory system of heliothine moths with particular emphasis on five closely related species, i.e., Heliothis virescens, Heliothis subflexa, Helicoverpa zea, Helicoverpa assulta and Helicoverpa armigera. © 2014 by the authors; licensee MDPI, Basel, Switzerland.

Leng-Xue,Chinese Academy of Agricultural Sciences
Bing du xue bao = Chinese journal of virology / [bian ji, Bing du xue bao bian ji wei yuan hui] | Year: 2012

To develop an attenuated vaccine against the highly pathogenic porcine reproductive and respiratory syndrome (HP-PRRS) virus, the HP-PRRS virus strain TJ was attenuated by serial passages and plaque cloned every 5 to 10 passages in Marc-145 cells. Genetic variation and pathogenicity of HP-PRRSV strain TJ in the course of attenuation were analyzed. The results showed that the strain TJ sustained various sequence changes during the course of attenuation. Fifty-eight amino acids changes and a new continuous 120 amino acids deletion after the discontinuous 30 amino acids deletion (sites 481 and 533-561) occurred in strain TJ passages 140, and the position of 120 amino acids deletion was between 628 to 747 according to VR-2332. Animal test showed that the pathogenicity of strain TJ passages 20 was attenuated obviously, so we presume that genetic variation in nonstructural protein nsp2-nsp5, nsp7 and structural protein GP5 during the attenuation provides the molecular bases for the observed attenuated phenotype.

Lu K.,Chinese Academy of Agricultural Sciences | Yu B.,International Food Policy Research Institute
Development in Practice | Year: 2011

This article first reviews the development of food prices in China since 2000. The authors find that despite tremendous price fluctuations in the international market in 2007 - 08, major staple crops (rice, wheat, and maize) in the domestic market were shielded from the volatility of the international market. This price stability can be partly attributed to Chinese government's food-security policies in stimulating grain production and smoothing domestic prices. Household data reveal that farmers' supply response is affected by prices, market access, household assets, and farmer experience. In addition, poor families are less responsive to market signals, and the impact of poverty on grain production is indirect. © 2011 Taylor & Francis.

Zhao F.,Chinese Academy of Agricultural Sciences
Virology journal | Year: 2011

The proteins of flotillin-1 and flotillin-2 were originally discovered in axon regeneration of goldfish retinal ganglion cells. They are generally used as marker proteins of lipid rafts and considered to be scaffolding proteins of lipid microdomains. Although they are ubiquitously expressed and well-conserved from fly to man, their exact functions remain controversial. In this review, we summarize the structure of flotillins and some functions of them, such as regulating axon regeneration, endocytosis, T cell activation, insulin signaling, membrane protein recruitment, roles in the progression of some diseases and so on.

Zhao J.,Chinese Academy of Agricultural Sciences
Wei sheng wu xue bao = Acta microbiologica Sinica | Year: 2012

The signaling lymphocyte activation molecule (SLAM, also known as CD150), is used as a cellular receptor by canine distemper virus (CDV). Wild-type strains of CDVs can be isolated and propagated efficiently in non-lymphoid cells expressing this protein. Our aim is to establish a Vero cells expressing raccoon dog SLAM (rSLAM) to efficiently isolate CDV from pathological samples. A eukaryotic expression plasmid, pIRES2-EGFP-rSLAMhis, containing rSLAM gene fused with six histidine-coding sequence, EGFP gene, and neomycin resistance gene was constructed. After transfection with the plasmid, a stable cell line, Vero-rSLAM, was screened from Vero cells with the identification of EGFP reporter and G418 resistance. Three CD positive specimens from infected foxes and raccoon dogs were inoculated to Vero-rSLAM cells for CDV isolation. Foxes and raccoon dogs were inoculated subcutaneously LN (10)fl strain with 4 x 10(2.39)TCID50 dose to evaluate pathogenicity of CDV isolations. The rSLAMh fused gene was shown to transcript and express stably in Vero-rSLAM cells by RT-PCR and Immunohistochemistry assay. Three CDV strains were isolated successfully in Vero-rSLAM cells 36 -48 hours after inoculation with spleen or lung specimens from foxes and raccoon dogs with distemper. By contrast, no CDV was recovered from those CD positive specimens when Vero cells were used for virus isolation. Infected foxes and raccoon dogs with LN(10)f1 strain all showed typical CD symptoms and high mortality (2/3 for foxes and 3/3 for raccoon dogs) in 22 days post challenge. Our results indicate that Vero-rSLAM cells stably expressing raccoon dog SLAM are highly sensitive to CDV in clinical specimens and the CDV isolation can maintain high virulence to its host animals.

Ali A.,Chinese Academy of Agricultural Sciences | Ahmad F.,University of Agriculture at Faisalabad | Biondi A.,University of Catania | Biondi A.,French National Institute for Agricultural Research | And 2 more authors.
Journal of Pest Science | Year: 2012

Various plants are well known for their insecticidal activity and their use was maintained for millennia throughout all the agricultural regions of the world. In a current context, the use of Botanical insecticides represents one of the best alternatives to chemicals for the development of environmental-friendly strategies for stored grain pest control. Datura alba Nees is a plant found extensively in the warmer regions of the world and it is used as a medicinal plant. This study aims to assess the contact toxicity and the trans-generational effect of D. alba leaf extract (DLE) against two important insect pests on stored rice, Trogodermagranarium and Sitophilus oryzae, under laboratory conditions. Filter papers were soaked in three DLE concentration solutions and in two control treatments: water and acetone. The survivor specimens (F 0) were transferred to a new untreated feeding substrate and the population build up of the two following generations (F 1 and F 2) were counted after 30 and 60 days, respectively. The highest DLE concentration (2. 5 %) induced the significantly highest mortality with 33. 5 and 45 % mortality in T. granarium and S. oryzae after 7 days of exposure, respectively. The DLE long-term effect toward both tested species was also proved by the high demographic decrease in the F 2 generations, when compared to control groups. This study is the first step toward establishing a scientific basis for the effective application of D. alba plant materials as biorational tools to control stored grain pests. © 2012 Springer-Verlag.

Huang S.,Jiangxi Agricultural University | Huang S.,Nanjing Agricultural University | Sun Y.,Jiangxi Agricultural University | Sun Y.,Nanjing Agricultural University | And 2 more authors.
Climatic Change | Year: 2012

Great uncertainties remain in the impact of cropping systems on soil organic carbon (SOC) stocks in paddy fields that hold a large potential for carbon (C) sequestration. In this study, a meta-analysis was performed to examine trends on SOC stocks in unfertilized and fertilized fields from three of the most common rice cropping systems in China. Results showed that rice cropping without any nutrient application (Control) significantly increased SOC stocks by 9% compared to the initial level in double rice cropping systems (DR), whereas no significant effects were observed in single rice cropping systems (SR) and rice-upland crop rotation systems (RU). Paddy soils sequestered C in all the three cropping systems under inorganic NPK fertilization, and the magnitude of the increase in SOC stocks was in the order DR & RU & SR. Soil C stocks increased with the increasing cropping duration. Continuous rice cropping for more than 20 years led to average SOC gains of 15% and 23% in the control and NPK treatments, respectively. Furthermore, it seems that C sequestration was still occurring in the longest fields from the included studies. Thus, no SOC saturation trend was found over the investigated cropping duration. However, the negative relationship between SOC changes and their initial C stocks suggests indirectly the possibility of SOC saturation in paddy fields. © 2011 Springer Science+Business Media B.V.

Teng C.,China Agricultural University | Yan Q.,China Agricultural University | Jiang Z.,China Agricultural University | Fan G.,China Agricultural University | Shi B.,Chinese Academy of Agricultural Sciences
Bioresource Technology | Year: 2010

The production of xylooligosaccharides (XOs) from corncobs was studied using a two-stage process based on a steam explosion pretreatment followed by enzymatic hydrolysis. Corncobs with different chip sizes were subjected to steam explosion under different experimental conditions of temperature and time, namely 188-204 °C for 2.5-7.5 min. The results indicate that corncobs were optimally steam exploded at 196 °C for 5 min, resulting in hemicellulose recovery of 22.8%. Especially, corncobs with large chip sizes (~100 mm) during steam explosion pretreatment were suitable to produce XOs. Furthermore, a thermostable xylanase from Paecilomyces themophila J18 was used to hydrolyze steam explosion liquor of corncobs (SELC) for the production of XOs. A maximum XOs yield of 28.6 g XOs/100 g xylan in corncobs was achieved and XOs syrup contained more than 90% of xylobiose and xylotriose when the hydrolysis was carried out under the optimized conditions (pH 7.0, 70 °C, 7.5 U mL -1 and 2.5 h). These results suggest that the process might be effective in production of XOs for industrial applications. © 2010 Elsevier Ltd. All rights reserved.

Guo Y.,Chinese Academy of Agricultural Sciences | Guo Y.,Key Laboratory of Tobacco Biology and Processing
Plant Molecular Biology | Year: 2013

The application of systems biology approaches has greatly facilitated the process of deciphering the molecular mechanisms underlying leaf senescence. Analyses of the leaf senescence transcriptome have identified some of the major biochemical events during senescence including protein degradation and nutrient remobilization. Proteomic studies have confirmed these findings and have suggested up-regulated energy metabolism during leaf senescence which might be important for cell viability maintenance. As a critical part of systems biology, studies involving transcription regulation networking and senescence-inducing signaling have deepened our understanding on the molecular regulation of leaf senescence. The important next steps towards a systems biological understanding of leaf senescence will be discussed. © 2012 Springer Science+Business Media Dordrecht.

Lam S.K.,University of Melbourne | Lin E.,Chinese Academy of Agricultural Sciences | Norton R.,University of Melbourne | Norton R.,International Plant Nutrition Institute | Chen D.,University of Melbourne
Soil Biology and Biochemistry | Year: 2011

There are no reports on the effects of elevated carbon dioxide [CO2] on the fluxes of N2O, CO2 and CH4 from semi-arid wheat cropping systems. These three soil gas fluxes were measured using closed chambers under ambient (420 ± 18 μmol mol-1) and elevated (565 ± 37 μmol mol-1) at the Free-Air Carbon dioxide Enrichment experimental facility in northern China. Measurements were made over five weeks on a wheat crop (Triticum aestivum L. cv. Zhongmai 175). Elevated [CO2] increased N2O and CO2 emission from soil by 60% and 15%, respectively, but had no significant effect on CH4 flux. There was no significant interaction between [CO2] and N application rate on these gas fluxes, probably because soil N was not limiting. At least 22% increase in C storage is required to offset the observed increase in greenhouse gas emissions under elevated [CO2]. © 2010 Elsevier Ltd.

Huang W.-Y.,Jiangsu Academy of Agricultural Sciences | Zhang H.-C.,Chinese Academy of Agricultural Sciences | Liu W.-X.,Nanjing Agricultural University | Li C.-Y.,Jiangsu Academy of Agricultural Sciences
Journal of Zhejiang University: Science B | Year: 2012

Berries are a good source of natural antioxidants. In the present study, the total antioxidant capacity and phenolic composition of three berry fruits (blueberry, blackberry, and strawberry) cultivated in Nanjing were investigated. Blueberry, with a Trolox equivalent antioxidant capacity (TEAC) value of 14.98 mmol Trolox/100 g dry weight (DW), exhibited the strongest total antioxidant capacity using both the 2,2-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) and the 2,2-diphenyl-1-picrylhydrazyl (DPPH) methods. Blueberry also had the highest total phenolic content (TPC., 9.44 mg gallic acid/g DW), total flavonoid content (TFC., 36.08 mg rutin/g DW), and total anthocyanidin content (TAC., 24.38 mg catechin/g DW). A preliminary analysis using high performance liquid chromatography (HPLC) showed that the blueberry, blackberry, and strawberry samples tested contained a range of phenolic acids (including gallic acid, protocatechuic acid, p-hydroxybenzoic acid, vanillic acid, caffeic acid, p-coumaric acid, ferulic acid, ellagic acid, and cinnamic acid) and various types of flavonoids (flavone: luteolin; flavonols: rutin, myricetin, quercetrin, and quercetin; flavanols: gallocatechin, epigallocatechin, catechin, and catechin gallate; anthocyanidins: malvidin-3-galactoside, malvidin-3-glucoside, and cyanidin). In particular, the blueberries had high levels of proanthocyanidins and anthocyanidins, which might be responsible for their strong antioxidant activities. These results indicate a potential market role for berries (especially blueberries) as a functional food ingredient or nutraceutical. © Zhejiang University and Springer-Verlag Berlin Heidelberg 2012.

Liu T.,Huazhong Agricultural University | Liu T.,Chinese Academy of Agricultural Sciences | Liu H.,Huazhong Agricultural University | Zhang H.,Huazhong Agricultural University | Xing Y.,Huazhong Agricultural University
Journal of Integrative Plant Biology | Year: 2013

A quantitative trait locus (QTL) that affects heading date (HD) and the number of spikelets per panicle (SPP) was previously identified in a small region on chromosome 7 in rice (Oryza sativa L.). In order to further characterize the QTL region, near isogenic lines (NILs) were quickly obtained by self-crossing recombinant inbred line 189, which is heterozygous in the vicinity of the target region. The pleiotropic effects of QTL Ghd7.1 on plant height (PH), SPP, and HD, were validated using an NIL-F2 population. Ghd7.1 explained 50.2%, 45.3%, and 76.9% of phenotypic variation in PH, SPP, and HD, respectively. Ghd7.1 was precisely mapped to a 357-kb region on the basis of analysis of the progeny of the NIL-F2 population. Day-length treatment confirmed that Ghd7.1 is sensitive to photoperiod, with long days delaying heading up to 12.5 d. Identification of panicle initiation and development for the pair of NILs showed that Ghd7.1 elongated the photoperiod-sensitive phase more than 10 d, but did not change the basic vegetative phase and the reproductive growth phase. These findings indicated that Ghd7.1 regulates SPP by controlling the rate of panicle differentiation rather than the duration of panicle development. © 2013 Institute of Botany, Chinese Academy of Sciences.

Yao S.-H.,CAS Nanjing Institute of Soil Science | Yao S.-H.,Nanjing Agricultural University | Zhang B.,CAS Nanjing Institute of Soil Science | Zhang B.,Chinese Academy of Agricultural Sciences | Hu F.,Nanjing Agricultural University
Soil Biology and Biochemistry | Year: 2011

Although it is well known that fluctuations in soil moisture affect the decomposition of organic matter, few studies have provided direct evidence of the underlying biophysical mechanisms. Cycles of wetting and drying (W/D) may not only alter soil pore structure, but also stimulate a proliferation of fungi, since these organisms are typically less affected by drought stress than bacteria, and hence the development of fungal-induced soil water repellency. The biophysical interaction between these processes is likely to influence the decomposition of organic matter amendments to soil and carbon sequestration. By using soil cores amended with rice straw, the objectives of this study were to determine the effects of drying intensity and frequency of W/D cycles on decomposition rate after rewetting, soil pore-size distribution, soil microbial biomass (SMB) and soil water repellency, and to assess their biophysical interaction. One W/D cycle consisted of wetting a soil core from the bottom for 1.5-days at -0.03 kPa followed by 1.5, 3.5 or 6.5 days of drying in open air at 25 ± 2.5 °C. This resulted in different intensities of drying and frequencies of W/D cycles over a 120-d incubation period. The decomposition rate decreased with repeated W/D cycles and increasing drying intensity, particularly between the 3rd and 9th W/D cycles. The SMB-C concentration and soil water repellency peaked at the 3rd W/D cycle. The peak size of the SMB-C concentration was larger in the drier soils and soil water repellency was significantly related to SMB-C concentration (R = 0.57, P = 0.025). The soil with the strongest drying treatment had a greater concentration of particulate organic carbon (POC) and the lowest C:N ratio in POC. Although the decomposition rate was significantly correlated to the concentration of soil organic carbon (SOC) (P < 0.01), POC (P < 0.01) and SMB-C (P < 0.05), stepwise regression analysis further identified that it was largely correlated to soil pore characteristics. The decrease in the decomposition rate in the drier soil was largely explained by the increase in macropores >300 μm in diameter (R = 0.98). The results suggest that an increased drying intensity or a longer duration of drying after rainfall or irrigation may favour SOC sequestration through inhibiting decomposition of amended residue. This may be due to the formation of macropores and their subsequent stabilization via fungal growth and fungal-induced soil water repellency. © 2010 Elsevier Ltd.

Guo Y.,Chinese Academy of Agricultural Sciences | Gan S.-S.,Cornell University
Journal of Experimental Botany | Year: 2014

Leaf senescence is a very important trait that limits yield and biomass accumulation of agronomic crops and reduces post-harvest performance and the nutritional value of horticultural crops. Significant advance in physiological and molecular understanding of leaf senescence has made it possible to devise ways of manipulating leaf senescence for agricultural improvement. There are three major strategies in this regard: (i) plant hormone biology-based leaf senescence manipulation technology, the senescence-specific gene promoter-directed IPT system in particular; (ii) leaf senescence-specific transcription factor biology-based technology; and (iii) translation initiation factor biology-based technology. Among the first strategy, the P SAG12-IPT autoregulatory senescence inhibition system has been widely explored and successfully used in a variety of plant species for manipulating senescence. The vast majority of the related research articles (more than 2000) showed that crops harbouring the autoregulatory system displayed a significant delay in leaf senescence without any abnormalities in growth and development, a marked increase in grain yield and biomass, dramatic improvement in horticultural performance, and/or enhanced tolerance to drought stress. This technology is approaching commercialization. The transcription factor biology-based and translation initiation factor biology-based technologies have also been shown to be very promising and have great potentials for manipulating leaf senescence in crops. Finally, it is speculated that technologies based on the molecular understanding of nutrient recycling during leaf senescence are highly desirable and are expected to be developed in future translational leaf senescence research. © 2014 The Author.

Fan F.,China Agricultural University | Fan F.,Chinese Academy of Agricultural Sciences | Zhang F.,China Agricultural University | Lu Y.,China Agricultural University
Soil Biology and Biochemistry | Year: 2011

Both plants and microbes influence soil nutrient cycling. However, the links between plants, microbes and nutrient cycling are poorly understood. In this study, we investigated how plant identity and interspecific competition influence soil nitrogen cycling and attempted to link plant identity and interspecific competition to community structures of bacterial and archaeal ammonia oxidizers based on terminal restriction fragment length polymorphism analysis (T-RFLP) of bacterial and archaeal ammonia monooxygenase (amoA) genes. Faba bean and maize monocultures and a faba bean/maize mixture were planted with two nitrogen levels (0 and 100mg Nkg -1 soil as urea). Soil mineral nitrogen, ammonia oxidizer function (potential nitrification activity, PNA) and community structures were measured 28 and 54 days after plant emergence. Faba bean and maize substantially differed in their influences on mineral nitrogen concentrations and PNA in rhizosphere soils. Soil mineral nitrogen and PNA in the rhizosphere soils of the faba bean/maize mixture were closer to those of the maize monoculture than to those of the faba bean monoculture. T-RFLP with restriction enzymes BsaJI and Hpy8I distinguished variations in bacterial and archaeal ammonia oxidizers community structure, respectively, and detected both between-cluster and within-cluster variations in bacterial ammonia oxidizers. T-RFLP data showed that nitrogen addition favored part of a Nitrosospira cluster 3b sequence type and suppressed part of a cluster Nitrosospira 3a sequence type of bacterial ammonia oxidizers, while it had no influence on the archaeal ammonia oxidizer community structure. Although multivariate analysis showed that the function and community structure of bacterial ammonia oxidizers were significantly correlated, plant species and interspecific competition did not significantly change the community structure of bacterial and archaeal ammonia oxidizers. These results indicate that plant species and interspecific competition regulate soil nitrogen cycling via a mechanism of other than alteration in the community structure of ammonia oxidizers as investigated by DNA based methods. © 2010 Elsevier Ltd.

Yang A.,CAS Institute of Botany | Li Y.,Chinese Academy of Agricultural Sciences | Xu Y.,CAS Institute of Botany | Zhang W.-H.,CAS Institute of Botany | Zhang W.-H.,Chinese Academy of Sciences
Journal of Experimental Botany | Year: 2013

Iron (Fe) is one of the essential mineral elements for plant growth and development. Acquisition of Fe by plants is mediated by a complex network involving Fe mobilization, uptake by root cells, and transport within plants. Here, we evaluated the role of a previously clarified gene encoding a receptor-like protein from rice, OsRMC, in the regulation of Fe acquisition by comparing Fe concentration, biomass, and expression patterns of genes associated with Fe mobilization and transport in wild-type (WT) rice with those in OsRMC overexpression and RNA interference (RNAi) knockdown transgenic rice plants. Expression of OsRMC was upregulated in both shoots and roots upon exposure of WT to Fe-deficient medium. Expression levels of OsRMC were positively correlated with Fe concentration in rice plants under both Fe-sufficient and Fe-deficient conditions such that overexpression and RNAi lines had higher and lower Fe concentration in both roots and shoots than WT plants, respectively. Moreover, overexpression of OsRMC conferred greater accumulation of Fe in mature seeds under Fe-sufficient conditions. OsRMC may also play a role in regulation of Fe deficiency-induced changes in root growth, as evidenced by greater and smaller root systems of OsRMC overexpression lines and RNAi lines than WT under Fe-deficient conditions, respectively. Several Fe deficiency-responsive genes including OsDMAS1, OsNAS1, OsNAS2, OsNAAT1, OsIRT1, OsYSL15, and OsIRO2 were up- and downregulated in OsRMC-overexpressing and RNAi plants compared with WT rice plants. These novel findings highlight an important role of OsRMC played in mediation of Fe acquisition and root growth in rice, particularly under Fe-deficient conditions. © The Author 2013. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Xie Y.,Nanjing Agricultural University | Mao Y.,Nanjing Agricultural University | Lai D.,Nanjing Agricultural University | Zhang W.,Nanjing Agricultural University | And 2 more authors.
Journal of Experimental Botany | Year: 2013

Despite substantial evidence on the separate roles of Arabidopsis nitric oxide-associated 1 (NOA1)-associated nitric oxide (NO) production and haem oxygenase 1 (HY1) expression in salt tolerance, their integrative signalling pathway remains largely unknown. To fill this knowledge gap, the interaction network among nitrate reductase (NIA/NR)- and NOA1-dependent NO production and HY1 expression was studied at the genetic and molecular levels. Upon salinity stress, the majority of NO production was attributed to NIA/NR/NOA1. Further evidence confirmed that HY1 mutant hy1-100, nia1/2/noa1, and nia1/2/noa1/hy1-100 mutants exhibited progressive salt hypersensitivity, all of which were significantly rescued by three NO-releasing compounds. The salinity-tolerant phenotype and the stronger NO production in gain-of-function mutant of HY1 were also blocked by the NO synthetic inhibitor and scavenger. Although NO- or HY1-deficient mutants showed a compensatory mode of upregulation of HY1 or slightly increased NO production, respectively, during 2 d of salt treatment, downregulation of ZAT10/12-mediated antioxidant gene expression (cAPX1/2 and FSD1) was observed after 7 d of treatment. The hypersensitive phenotypes and stress-related genes expression profiles were differentially rescued or blocked by the application of NO- (in particular) or carbon monoxide (CO)-releasing compounds, showing a synergistic mode. Similar reciprocal responses were observed in the nia1/2/noa1/hy1-100 quadruple mutant, with the NO-releasing compounds exhibit the maximal rescuing responses. Overall, the findings present the combination of compensatory and synergistic modes, linking NIA/NR/NOA1-dependent NO production and HY1 expression in the modulation of plant salt tolerance. © The Author(2) [2013].

Gao Y.,Chinese Academy of Agricultural Sciences
European journal of histochemistry : EJH | Year: 2012

Amniotic epithelial cells (AECs) express Oct4, Nanog and Sox-2, which are necessary for maintaining the undifferentiated state of pluripotent stem cells. AECs additionally express CK19, which is a specific marker of epithelial cells, both in vivo and in vitro. In this research, we investigated the biological characteristics and potential for cell therapy of AECs from 6-day-old chicken embryos. We induced the AECs to differentiate into pancreatic islet-like cells (endoderm), adipocytes and osteoblasts (mesoderm) and neural-like cells (ectoderm), and used immunofluorescence and RT-PCR to detect the expression of AECs specific markers. To assess the differentiation capacity of AECs, passage 3 cells were induced to differentiate into adipocytes, osteoblasts, pancreatic islet-like cells and neural-like cells. The AEC markers, Oct4, Nanog, Sox-2 and CK19, were all positively expressed. Cloning efficiency decreased with increasing passage number. Passage 3 AECs were successfully induced to differentiate into pancreatic islet-like cells, osteoblasts, adipocytes, and neural-like cells. These results suggested that AECs isolated from chicken embryos exhibited the characteristics of the multipotent stem cells. AECs may therefore be ideal candidates for cellular transplantation therapy and tissue engineering.

Guo F.J.,Chinese Academy of Agricultural Sciences
Zhongguo ji sheng chong xue yu ji sheng chong bing za zhi = Chinese journal of parasitology & parasitic diseases | Year: 2010

To construct and express the recombinant plasmid pET32a-SjPGAM-SjEnol and evaluate its immuno-protective efficacy against the infection of Schistosoma japonicum in mice. The peptides of SjPGAM and SjEnol containing the multivalent epitopes with higher binding capacity of human MHC II and mouse H2-dII but low homology with the host were analyzed and screened through bioinformatics. The corresponding nucleotide sequence of selected epitopes was spliced and the recombinant plasmid pET32a-SjPGAM-SjEnol was constructed and expressed in Escherichia coli BL21 cells. The antigenicity of the recombinant protein was detected by Western blotting and the protective effect induced with the recombinant was evaluated in mice. 55 BALB/c mice were randomly divided into 5 groups each with 11. Mice from groups A, B and C were injected with a mixture of recombinant protein (27 microg) pET32a-SjPGAM-SjEnol (A), pETL28a-SjPGAM (B) and pET28a-SjEnol (C) respectively together with 206 adjuvant, mice from groups D and E received adjuvant or PBS only, all injected for three times at two-week intervals. Mice were then challenged with 40 +/- 2 cercariae of S. japonicum at two weeks after the last vaccination, and sacrificed for perfusion by 6 weeks post infection. Adult worms were collected, the number of eggs in a gram of liver tissue was counted, and the rates of worm reduction and egg reduction were calculated. Serum samples were collected before vaccination, every one week after each inoculation and before sacrifice, and specific IgG was detected by ELISA. The sequences encoding the 96-147 aa of SjPGAM and 233-312 aa of SjEonl were chosen for constructing the recombinant plasmid, a cDNA fragment with the length of 447 bp was amplified by PCR. The recombinant plasmid was expressed in E. coli with a molecular weight of Mr 33,000. Western blotting revealed that the fusion protein was recognized by the rabbit serum specific to SjSWAP, and showed an adequate antigenicity. Vaccination experiment showed that when compared with those of the blank control, the worm reduction rate in group A was 39.7%, significantly higher than that of groups B (18.5%) and C (14.7%) (P < 0.05). The liver egg reduction rate in group A was 64.9%, also higher than that of groups B (47.5%, P < 0.05) and C (30.5%, P < 0.01). ELISA showed that the serum specific IgG in group A (2.372 +/- 0.268) was much higher than that of groups D (0.490 +/- 0.138) (P < 0.01 and E (0.220 +/- 0.088) (P < 0.01). The recombinant plasmid pET32a-SjPGAM-SjEnol has been constructed, and recombinant protein pET32a-SjPGAM-SjEnol induces higher immune-protection against S. japonicum than that of SjPGAM and SjEonl.

Liu J.,Rockefeller University | Liu J.,Chinese Academy of Agricultural Sciences | Wang H.,Rockefeller University | Chua N.-H.,Rockefeller University
Plant Biotechnology Journal | Year: 2015

Summary: Since their discovery more than two decades ago, animal long noncoding RNAs (lncRNAs) have emerged as important regulators of many biological processes. Recently, a large number of lncRNAs have also been identified in higher plants, and here, we review their identification, classification and known regulatory functions in various developmental events and stress responses. Knowledge gained from a deeper understanding of this special group of noncoding RNAs may lead to biotechnological improvement of crops. Some possible examples in this direction are discussed. © 2015 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

Jin D.P.,Chinese Academy of Agricultural Sciences
Cell biology international | Year: 2011

Apoptosis research has been focused on several model species in the past decades, whereas studies concerned with non-mammalian vertebrate, particularly birds, have rarely been involved. In accord with requirements to expand the biodiversity of apoptotic research, a chicken embryonic fibroblasts model involving UVB (ultraviolet B) as the death stimulus was established through primary explantation and serial passage. Myriads of antioxidants can inhibit UVB-induced apoptosis by virtue of scavenging reactive oxygen species. To improve our understanding of the possible anti-apoptotic effects and mechanisms of Vitamin E against UVB-induced apoptosis in chicken embryonic fibroblasts, cells treated with Vitamin E after UVB irradiation were stained with AO/EB and Fluo-3/AM to visualize chromatin distribution and calcium homoeostasis, respectively. They were also analysed by flow cytometry to detect mitochondrial transmembrane potential, and cell cycle progression and apoptotic rates were recorded. RT-PCR was used to analyse the expression of some apoptosis-related genes. Typical apoptotic events, including cell shrinkage, blebbing and nuclear condensation, occurred after radiation. In the presence of Vitamin E following irradiation, apoptotic cells were reduced. Ca2+ release was temporarily prevented, and cell cycle arrest at S/G2 checkpoint had almost completely reverted to normal. fas decreased, while procaspase-3 remained nearly unchanged with and without Vitamin E, and bcl2/bax ratio was up-regulated, indicating possible anti-apoptotic mechanisms through the mitochondrial pathway. This new investigation of an apoptosis model involving chicken embryonic fibroblasts expands the database of knowledge across a wider spectrum of vertebrate species.

Neumann G.,University of Wisconsin - Madison | Chen H.,Chinese Academy of Agricultural Sciences | Gao G.F.,CAS Institute of Microbiology | Shu Y.,Chinese National Institute for Viral Disease Control and Prevention | And 2 more authors.
Cell Research | Year: 2010

All known subtypes of influenza A viruses are maintained in wild waterfowl, the natural reservoir of these viruses. Influenza A viruses are isolated from a variety of animal species with varying morbidity and mortality rates. More importantly, influenza A viruses cause respiratory disease in humans with potentially fatal outcome. Local or global outbreaks in humans are typically characterized by excess hospitalizations and deaths. In 1997, highly pathogenic avian influenza viruses of the H5N1 subtype emerged in Hong Kong that transmitted to humans, resulting in the first documented cases of human death by avian influenza virus infection. A new outbreak started in July 2003 in poultry in Vietnam, Indonesia, and Thailand, and highly pathogenic avian H5N1 influenza viruses have since spread throughout Asia and into Europe and Africa. These viruses continue to infect humans with a high mortality rate and cause worldwide concern of a looming pandemic. Moreover, H5N1 virus outbreaks have had devastating effects on the poultry industries throughout Asia. Since H5N1 virus outbreaks appear to originate from Southern China, we here examine H5N1 influenza viruses in China, with an emphasis on their biological properties. © 2010 IBCB, SIBS, CAS All rights reserved.

Wang Y.,Chinese Academy of Agricultural Sciences
Wei sheng wu xue bao = Acta microbiologica Sinica | Year: 2010

The role of Quroum Sensing response regulator nprR on the expression of Cry protein in B. thuringiensis HD-73 was studied. The nprR gene deletion mutant HD73 (delta nprR) was constructed by using of homologous recombination. Beta-galactosidase assay of cry1Ac'-lacZ gene fusion and SDS-PAGE in both HD-73 and HD73 (delta nprR) strains were performed to analyze the effect of nprR gene deletion on expression of cry1lAc gene. Beta-galactosidase assay of nprR'-lacZ in both LB and Schaeffer' s sporulation medium showed nprR gene in B. thuringiensis was initially transcripted at TO (end of Logarithmic growth phase) and keeping expression in stationary phase. Beta-galactosidase assay of cry1Ac'-lacZ and SDS-PAGE indicated that expression of cry1Ac gene in HD73 (delta nprR) was stronger than that in HD-73 during transition phase and early stationary phase. However, Cry expressed product between HD-73 and HD73 (delta nprR) in LB medium has no significant difference when crystal and spore were released. The deletion of nprR increased expression and transcription activity of cry1Ac during transition and early stationary phase in rich media.

Wang H.,Chinese Academy of Agricultural Sciences
Wei sheng wu xue bao = Acta microbiologica Sinica | Year: 2010

OBJECTIVE: The aim of this study was to screen straw-cellulose degrading microorganisms and to investigate their degradation ability of straw-cellulose. METHODS: The methods used to screen the high effect straw-cellulose degrading microorganism included the traditional isolation methods of straw-cellulose degrading microorganism such as holes observation method on filter paper sheet, disintegration test of filter paper scrip, hydrolysis spot diameter measurement method of CMC-Na, weight lose assay method of straw, measurement method of cellulose decomposition rate, measurement method of extracellular enzyme activity. RESULTS: We isolated 3 fungi with cellulose degrading ability, of which 98MJ was identified as Penicillium oxalicum, W3 as Trichoderma sp., and W4 as Penicillium expansum. Strain W4 possessed high straw-cellulose degrading ability with straw-cellulose degrading rate of 56.3%, cellulose 59.06%, hemicellulose 78.75% and lignin 33.79% in 10 days. CONCLUSION: Strain W4 was a cellulase-producing strain with broad development potential.

OBJECTIVE: To better elucidate the functions of RpfFxoo, RpfCxoo and RpfGxoo, 3 proteins of diffusible signal factor (DSF)-dependent cell-cell signaling system in regulation of virulence expression of Xanthomonas oryzae pv. oryzae (Xoo). METHOD: Deltarpfxoo, the gene deletion mutants were generated from PXO99(A), the wild-type strain of Xoo via marker-exchanging and DSF biosynthesis and extracellular polysaccharide production and virulence to rice of the mutants were assayed. RESULT: rpfFxoo,rpfCxoo and rpfGxoo were cloned from the genomic DNA of PXO99(A) and the relative single or double mutants were constructed. Compared to PXO99(A), DSF production was deficient in deltarpfFxoo, deltarpfFCxoo and deltarpfFGxoo, while DSF was overproduced in deltarpfCxoo and reduced in deltarpfGxoo. DSF production of deltarpfFxcc, deltarpfCxcc and deltarpfGxcc, the mutants of X. campestris pv. campestris can be restored as XC1, the wild-type strain by in trans complementation of rpfFxoo, rpfCxoo and rpfGxoo. All the mutants except deltarpfFxoo were remarkably deficient in production All the mutants significantly exhibited the reduced bacterial virulence to rice. of extracellular polysaccharide. CONCLUSION: DSF signaling proteins RpfFxoo, RpfCxoo and RpfGxoo might function in regulation of DSF biogenesis and EPS production and bacterial virulence.

Zhang H.,Chinese Academy of Agricultural Sciences
Wei sheng wu xue bao = Acta microbiologica Sinica | Year: 2010

We investigated the genetic diversity and phylogeny of soybean rhizobia isolated from the regions of Loess Plateau in China. We analyzed 130 soybean rhizobia isolated from 15 regions in 4 provinces of Loess Plateau through BOX-PCR, 16S rDNA PCR- RFLP, 16S-23S IGS PCR-RFLP and 16S rRNA gene sequencing. BOX-PCR, 16S rDNA PCR- RFLP and 16S-23S IGS PCR-RFLP were in good agreement with the results which showed that all strains tested ascribed to two groups: the genus of Sinorhizobium and Bradyrhizobium phylogenetically. The analysis of 16S rRNA gene of 5 representative strains indicated that they were related to type strains S. fredii, B. japonicum and B. liaoningense, homology coefficient with type strains was 100% respectively. Soybean rhizobia isolated from the regions of Loess Plateau in China showed rich genetic diversity. S. fredii was the dominant species. Bradyrhizobium accounted for 10% of the strains tested only, of which, two strains were B. liaoningense.

Zhao X.,Chinese Academy of Agricultural Sciences
International Agricultural Engineering Journal | Year: 2015

As China being a populous emerging country with a large demand on the food, China's firms' OFDI in agriculture was always criticized for "land grabbing" or "new colonialism". Drawing on second-hand materials and in-depth interviews with China's firms and officials in charge of agriculture both domestically and abroad, this article investigates the dimensions of China's agricultural OFDI. The impetuses for driving China's enterprises to invest in agriculture overseas are diverse and exploiting the lands is just one. Until now, only a very small part of the agricultural products growing abroad was sold back to China, and a large part was sold in the local market or exported to the third market, and therefore China's firms' agricultural OFDI has little direct but a little indirect help to guaranteeing China's food security. China's firms maybe compete with the local growers, but the growing presence of China's firms with advanced technology will yield the benefits of competition: an expansion of local supplies while providing cheaper technologies that can be copied by local farmers.

Zhao Q.,Wuhan University | Wei F.,Chinese Academy of Agricultural Sciences | Luo Y.-B.,Wuhan University | Ding J.,Wuhan University | And 2 more authors.
Journal of Agricultural and Food Chemistry | Year: 2011

In this study, magnetic multiwalled carbon nanotubes were fabricated by a simple method and applied to magnetic solid-phase extraction (MSPE) of eight heavy molecular weight polycyclic aromatic hydrocarbons (PAHs) including chrysene, benzo[a]anthracene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, indeno[1,2,3-cd]pyrene, dibenzo[a,h]anthracene and benzo[g,h,i]perylene from edible oil samples. Several parameters affecting the extraction efficiency were investigated, including the type and volume of desorption solvent, extraction and desorption time, washing solution and the amount of sorbent. Under the optimized conditions, a simple and effective method for the determination of PAHs in edible oils was developed by coupling with gas chromatography-mass spectrometry (GC-MS). The whole pretreatment process was rapid, and it can be accomplished within 10 min. The limits of quantitation for the target PAHs were found to be 0.34-2.9 ng/g. The recoveries in oil sample were in the range 87.8-122.3% with the RSDs less than 6.8% (intraday) and 9.6% (interday). This method was successfully applied to the analysis of PAHs in seven kinds of edible oils from local markets. © 2011 American Chemical Society.

Liu Y.,CAS Beijing Institute of Geographic Sciences and Nature Resources Research | Liu Y.,Chinese Academy of Sciences | Guo L.,Chinese Academy of Agricultural Sciences
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2011

In order to instruct new countryside construction, to remain the basic arable land at a safe level and to coordinate land use allocation between urban and rural areas, taking the 327 counties in the area around Bohai gulf as research units, a zoning model for the rural residential land was proposed based on the index discrimination method. First, according to the potential of land consolidation, the ability to adopt consolidation projects and the urgency for consolidation, 15 factors were selected to construct the evaluation index system and the conceptual model for zoning the rural residential land. Then, the entropy method and the index discrimination model were employed to attach the weights to the factors and to delineate the rural residential land respectively. Finally, five type zones, including the prior consolidation area, the key consolidation area, the optimal consolidation area, the moderate consolidation area and the preferred area were divided for "pothook project" based on the comprehensive assessment values and the division standards. For prior consolidation area with the highest urgency, its suitable consolidation model was the urbanization leading model. Population concentration, industrial agglomeration and scale land use was the suitable consolidation model for the key consolidation area, and intra-village intensification model was the main consolidation model for the optimal consolidation area. In the preferred area for the pilot project of linking urban and rural construction land change, agriculture was the top priority for consolidated land, and the main object for this type of area was to establish a new city-countryside relationship by restructuring rural space. In the moderate consolidation area, it was necessary to pay attention to ecological environment and ecological function. The study results revealed the current situation of rural residential land use. The optimization strategy is feasible to carry out consolidation projects, for it can contribute to protecting arable land, developing land consolidation plans, and implementing the pilot project of linking urban and rural construction land change.

Wang H.,Hong Kong Baptist University | Wang H.,Fudan University | Lu Y.,Hong Kong Baptist University | Lu Y.,Chinese Academy of Agricultural Sciences | And 5 more authors.
Plant Journal | Year: 2013

AtNUDT7 was reported to be a negative regulator of EDS1-mediated immunity in Arabidopsis. However, the underlying molecular and genetic mechanism of the AtNUDT7-regulated defense pathway remains elusive. Here we report that AtNUDT7 and its closest paralog AtNUDT6 function as novel negative regulators of SNC1, a TIR-NB-LRR-type R gene. SNC1 is upregulated at transcriptional and possibly post-transcriptional levels in nudt6-2 nudt7. The nudt6-2 nudt7 double mutant exhibits autoimmune phenotypes that are modulated by temperature and fully dependent on EDS1. The nudt6-2 nudt7 mutation causes EDS1 nuclear accumulation shortly after the establishment of autoimmunity caused by the temperature shift. We found that a low ammonium/nitrate ratio in growth media leads to a higher level of nitrite-dependent nitric oxide (NO) production in nudt6-2 nudt7, and NO acts in a positive feedback loop with EDS1 to promote the autoimmunity. The low ammonium/nitrate ratio also enhances autoimmunity in snc1-1 and cpr1, two other autoimmune mutants in Arabidopsis. Our study indicates that Arabidopsis senses the ammonium/nitrate ratio as an input signal to determine the amplitude of the EDS1-mediated defense response, probably through the modulation of NO production. © 2012 The Authors. The Plant Journal © 2012 Blackwell Publishing Ltd.

Hou J.C.,Northeast Agricultural University | Jiang C.G.,Chinese Academy of Agricultural Sciences | Long Z.C.,Husbandry and Veterinary Bureau of Yichun City
Food Control | Year: 2013

Nitrite is commonly present in pickled vegetables. Nitrite has been proven to have adverse effects on health, including changing the normal form of hemoglobin and the formation of carcinogenic nitrosamines. The aim of our study was to determine the levels of nitrite in pickled vegetable samples consumed in Harbin, China. In this study, 218 samples of pickled turnip (PT) (n = 42, packaged (PK) = 19; unpackaged (UPK) = 23), pickled tuber mustard (PTM) (n = 44, PK = 23; UPK = 21), pickled cucumber (PCC) (n = 48, PK = 25; UPK = 23), and pickled cabbage (PCB) (n = 84, PK = 39; UPK = 45) were analyzed between October 2011 and December 2011, using colorimetric nitrite assay based on the Griess reaction. A nitrite level of <5 mg/kg was normally predominant in 147 (67%) samples of the investigated pickled vegetables, ranging from 0.01 mg/kg to 42.03 mg/kg, while a nitrite level of >20 mg/kg was detected in 9 (4%) samples. The overall nitrite content was 4.02 ± 0.62 mg/kg for PT, 4.52 ± 1.07 mg/kg for PTM, 3.91 ± 0.69 mg/kg for PCC, and 4.86 ± 0.80 mg/kg for PCB. The content of nitrite in unpackaged pickled vegetables (PT, 5.47 ± 0.89; PTM, 6.84 ± 2.02; PCC, 5.32 ± 1.27; PCB, 6.41 ± 1.28; and total, 6.08 ± 0.71 mg/kg) was significantly higher than those in packaged products (PT, 2.68 ± 0.72; PTM, 2.30 ± 0.55; PCC, 2.62 ± 0.54; PCB, 3.08 ± 0.81; and total, 2.73 ± 0.36 mg/kg) (P < 0.05). The variance in the concentration of nitrite in the pickled vegetables probably resulted from differences in quality, processing technique, and storage condition of the pickled vegetables. Our results indicated that, in China, low level nitrite is widely present in pickled vegetables. It is therefore important to assess the content of nitrite in pickled vegetables in China. © 2012 Elsevier Ltd.

Gu X.,Key Laboratory of Feed Biotechnology | Yao T.,Chinese Academy of Agricultural Sciences
Journal of Environmental Science and Health - Part B Pesticides, Food Contaminants, and Agricultural Wastes | Year: 2013

The bioconcentration and elimination of racemic benalaxyl (BX) in trout liver microsomes and in juvenile rainbow trout (Oncorhynchus mykiss) were investigated to determine whether the fish can bioconcentrate and degrade this fungicide enantioselectively. Both enantiomers of BX were extracted with organic solvents and evaluated using high-performance liquid chromatography. In the microsomes, BX degradation followed first-order kinetics, and the S-(+) enantiomer of BX was eliminated twice as rapidly as the R-(-) enantiomer, resulting in residues enriched for R-(-)-BX. In vivo experiment, chiral analysis showed an obvious selective bioconcentration of BX based on statistically altered enantiomer fractions (EFs) in the fish compared with the values in the water. The R-(-)-BX was initially preferentially bioconcentrated by rainbow trout and then dissipated more slowly than its antipode. The mean half-lives for individual enantiomers were calculated as 31.6 h for R-(-)-BX and 20.3 h for the S-(+)-form. The results of the study showed that the degradation of BX enantiomers was stereoselective in rainbow trout. © 2013 Copyright Taylor and Francis Group, LLC.

Zhang Z.,Renmin University of China | Zhao W.,Chinese Academy of Agricultural Sciences
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2011

It is instructive for instructing practical activities after land consolidation to evaluate quantitatively resource and economic profits of land consolidation and analyze its effects on economic and social development. Based on survey of land consolidation, resource and economic profits of land consolidation were explained. Several indices were selected to evaluate resource and economic profits, including the annual increase of crop production, net increase production value and the output-input ratio per unit area. Moreover, quantitative method was used for each indicator according to its connotation. Furthermore, based on the statistical and surveyed data, the resource and economic profits of land consolidation were evaluated according to the farmer inquiry in Daxing district of Beijing.

Wang J.,Jiangsu University of Science and Technology | Zhang J.-L.,Jiangsu University of Science and Technology | Wu F.-A.,Jiangsu University of Science and Technology | Wu F.-A.,Chinese Academy of Agricultural Sciences
European Journal of Lipid Science and Technology | Year: 2013

The desilked silkworm (Bombyx mori L.) pupae oil is a good source of α-linolenic acid (ALA), but selectively enriching ALA is a great technical challenge due to the presence of multiple analogues such as linoleic acid and oleic acid. To set up a simple, highly selective and low-cost combinative inclusion process for obtaining ALA concentrate from silkworm pupae oil, the effects of β-cyclodextrin (β-CD) inclusion parameters on the purity and recovery of polyunsaturated fatty acid (PUFA) were investigated; then, four types of combinative processes using β-CD and/or urea were compared. The results indicated that a two-stage combinative inclusion process was established. In the first stage, when the volume ratio of β-CD-saturated solution to free fatty acids ethanol solution was 9 v/v, the dispersion temperature and time were 60°C and 1.5h, the freezing temperature and time were -10°C and 15h, and the purity of ALA was raised from 15.0 to 47.6% with a recovery of 39.4%. Then, the purity of ALA was further increased to 67.4% in the second-stage operation with a corresponding recovery of 34.8% using urea complexation. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Li D.,Liaocheng University | Chen L.,Liaocheng University | Zhang X.,Chinese Academy of Fishery Sciences | Ye N.,Chinese Academy of Fishery Sciences | Xing F.,Chinese Academy of Agricultural Sciences
Biomass and Bioenergy | Year: 2011

Marine algae have great potential as a third generation biofuel feedstock. The pyrolytic and kinetic characteristics of three kinds of red algae (Pophyra yezoensis, Plocamium telfairiae Harv and Corallina pilulifera) were studied at heating rates of 10, 30 and 50°Cmin-1 under an inert atmosphere. The most probable mechanism function and activation energy pre-exponential factors were calculated by the Popescu, FWO and KAS methods. Three stages appeared during pyrolysis: moisture evaporation, primary devolatilization and residual decomposition. Significant differences in the average activation energy, thermal stability, final residuals and reaction rates of the algae samples were observed. Stage II of the samples could be described by the Avramic-Erofeev equation. The average activation energy of all samples was similar when calculated by different methods. Kinetic compensation effects of the pre-exponential factors and activation energy were also observed. © 2011 Elsevier Ltd.

Li X.,CAS Institute of Microbiology | Wu P.,Chinese Academy of Agricultural Sciences | Gao G.F.,CAS Institute of Microbiology | Cheng S.,CAS Institute of Microbiology
Biomacromolecules | Year: 2011

The high transmissibility and genetic variability of the influenza virus have made the design of effective approaches to control the infection particularly challenging. The virus surface hemagglutinin (HA) protein is responsible for the viral attachment to the host cell surface via the binding with its glycoligands, such as sialyllactose (SL), and thereby is an attractive target for antiviral designs. Herein we present the facile construction and development of two SL-incorporated chitosan-based materials, either as a water-soluble polymer or as a functional fiber, to demonstrate their abilities for viral adhesion inhibition and decontamination. The syntheses were accomplished by grafting a lactoside bearing an aldehyde-functionalized aglycone to the amino groups of chitosan or chitosan fiber followed by the enzymatic sialylation with sialyltransferase. The obtained water-soluble SL-chitosan conjugate bound HA with high affinity and inhibited effectively the viral attachment to host erythrocytes. Moreover, the SL-functionalized chitosan fiber efficiently removed the virus from an aqueous medium. The results collectively demonstrate that these potential new materials may function as the virus adsorbents for prevention and control of influenza. Importantly, these materials represent an appealing approach for presenting a protein ligand on a chitosan backbone, which is a versatile molecular platform for biofunctionalization and, thereby, can be used for not only antiviral designs, but also extensive medical development such as diagnosis and drug delivery. © 2011 American Chemical Society.

Guo J.-J.,Soochow University of China | Guo J.-J.,Qiqihaer Medical College | Zheng H.-J.,Chinese National Human Genome Center at Shanghai | Xu J.,Soochow University of China | And 3 more authors.
PLoS Neglected Tropical Diseases | Year: 2012

Background: Schistosomiasis japonica is a serious debilitating and sometimes fatal disease. Accurate diagnostic tests play a key role in patient management and control of the disease. However, currently available diagnostic methods are not ideal, and the detection of the parasite DNA in blood samples has turned out to be one of the most promising tools for the diagnosis of schistosomiasis. In our previous investigations, a 230-bp sequence from the highly repetitive retrotransposon SjR2 was identified and it showed high sensitivity and specificity for detecting Schistosoma japonicum DNA in the sera of rabbit model and patients. Recently, 29 retrotransposons were found in S. japonicum genome by our group. The present study highlighted the key factors for selecting a new perspective sensitive target DNA sequence for the diagnosis of schistosomiasis, which can serve as example for other parasitic pathogens. Methodology/Principal Findings: In this study, we demonstrated that the key factors based on the bioinformatic analysis for selecting target sequence are the higher genome proportion, repetitive complete copies and partial copies, and active ESTs than the others in the chromosome genome. New primers based on 25 novel retrotransposons and SjR2 were designed and their sensitivity and specificity for detecting S. japonicum DNA were compared. The results showed that a new 303-bp sequence from non-long terminal repeat (LTR) retrotransposon (SjCHGCS19) had high sensitivity and specificity. The 303-bp target sequence was amplified from the sera of rabbit model at 3 d post-infection by nested-PCR and it became negative at 17 weeks post-treatment. Furthermore, the percentage sensitivity of the nested-PCR was 97.67% in 43 serum samples of S. japonicum-infected patients. Conclusions/Significance: Our findings highlighted the key factors based on the bioinformatic analysis for selecting target sequence from S. japonicum genome, which provide basis for establishing powerful molecular diagnostic techniques that can be used for monitoring early infection and therapy efficacy to support schistosomiasis control programs. © 2012 Guo et al.

Yang A.,Chinese Academy of Agricultural Sciences
Genetika | Year: 2010

A novel 407 bp nucleotide sequence NTPp13 was isolated from tobacco (Nicotiana tabacum L.) by PCR, its structure and function were characterized. The NTPp13 sequence was highly homologous with the pollen-specific expression promoter Zm13 from maize (Zea mays L.) and contained some key motifs which controlled pollen-specific expression. The NTPp13 was fused to the beta-glucuronidase (GUS) reporter gene and transferred into tobacco. Analysis of the transgenic plants revealed that this putative promoter fragment was sufficient to direct GUS expression specifically in the anther, exactly in the pollen and pollen tube, and that GUS activity reached the maximum at the stage of pollen grain began to separate. Further study showed that the expression of NTPp13 sequence at pollen was stable at the range of temperature measured. These data suggested that the NTPp13 sequence was likely the essential element of promoter region of an unknown pollen-specific gene from tobacco.

Xu Y.,Zhejiang University | Huang L.,Zhejiang University | Fu S.,Zhejiang University | Wu J.,Zhejiang University | And 2 more authors.
PLoS ONE | Year: 2012

Background: Small RNA-mediated gene silencing plays evolutionarily conserved roles in gene regulation and defense against invasive nucleic acids. Virus-derived small interfering RNAs (vsiRNAs) are one of the key elements involved in RNA silencing-based antiviral activities in plant and insect. vsiRNAs produced after viruses infecting hosts from a single kingdom (i.e., plant or animal) are well described. In contrast, vsiRNAs derived from viruses capable of infecting both plants and their insect vectors have not been characterized. Methodology/Principal Findings: We examined Rice stripe virus (RSV)-derived small interfering RNAs in three different hosts, Oryza sativa, Nicotiana benthamiana and a natural RSV transmitting vector Laodelphgax striatellus, through deep sequencing. Our results show that large amounts of vsiRNAs generated in these hosts after RSV infection. The vsiRNAs from N. benthamiana and L. striatellus mapped equally to the genomic- and antigenomic-strand of RSV RNAs. They showed, however, a significant bias in those from O. sativa. Furthermore, our results demonstrate that the number and size distributions of vsiRNAs in the three hosts were very different. In O. sativa and N. benthamiana, most vsiRNAs were mapped to the discrete regions in the RSV genome sequence, and most of the vsiRNAs from these two hosts were generated from RSV genomic RNAs 3 and 4. In contrast, the vsiRNAs identified in L. striatellus distributed uniformly along the whole genome of RSV. We have also shown that silencing Agronaute 2 in L. striatellus enhanced RSV accumulation in this host. Conclusions/Significance: Our study demonstrates that the core RNA-induced gene silencing (RNAi) machinery is present in L. striatellus. We also provide evidence that the RNAi-mediated immunity against RSV is present in L. striatellus. We propose that a common small RNA-mediated virus defense mechanism exists in both helipterum insects and plants, but the vsiRNAs are generated differentially in different hosts. © 2012 Xu et al.

Wang H.-S.,Zhejiang Agriculture And forestry University | Yu C.,Zhejiang Agriculture And forestry University | Zhu Z.-J.,Zhejiang Agriculture And forestry University | Yu X.-C.,Chinese Academy of Agricultural Sciences
Plant Cell Reports | Year: 2011

GDP-mannose pyrophosphorylase (GMPase: EC plays a crucial role in the synthesis of l-ascorbate (AsA) and the consequent detoxification of reactive oxygen species (ROS). Herein, a GMPase (accession ID DQ449030) was identified and cloned from tomato. The full-length cDNA sequence of this gene contains 1,498bp nucleotides encoding a putative protein with 361 amino acid residues of approximate molecular weight 43kDa. Northern blot analysis revealed that the GMPase was expressed in all examined tomato tissues, but its expression level was up-regulated in tomato plants subjected to abnormal temperatures. We then overexpressed this tomato GMPase in tobacco plants and observed that the activity of GMPase and the content of AsA were significantly increased by two- to fourfold in the leaves of transgenic tobacco plants. The effect of this gene overexpression was superimposed by the treatments of high or low temperature in tobacco, since the activities of both chloroplastic SOD (superoxide dismutase EC, APX (ascorbate peroxidase EC and the content of AsA in leaves were significantly higher in transgenic plants than those of WT, while the contents of H2O2 and O2 -· were reduced. Meanwhile, relative electric conductivity increased less in transgenic plants than that in WT, and the net photosynthetic rate (Pn) and the maximal photochemical efficiency of PSII (Fv/Fm) of transgenic plants were notably higher than those of WT under temperature stresses. In conclusion, the overexpression of GMPase increased the content of AsA, thereby leading to the increase in tolerance to temperature stress in transgenic plants. © 2011 Springer-Verlag.

Wei J.,China Agricultural University | Hu X.,Chinese Academy of Agricultural Sciences | Yang J.,China Agricultural University | Yang W.,China Agricultural University
PLoS ONE | Year: 2012

The genus Physalis includes a number of commercially important edible and ornamental species. Its high nutritional value and potential medicinal properties leads to the increased commercial interest in the products of this genus worldwide. However, lack of molecular markers prevents the detailed study of genetics and phylogeny in Physalis, which limits the progress of breeding. In the present study, we compared the DNA sequences between Physalis and tomato, and attempted to analyze genetic diversity in Physalis using tomato markers. Blasting 23180 DNA sequences derived from Physalis against the International Tomato Annotation Group (ITAG) Release2.3 Predicted CDS (SL2.40) discovered 3356 single-copy orthologous genes between them. A total of 38 accessions from at least six species of Physalis were subjected to genetic diversity analysis using 97 tomato markers and 25 SSR markers derived from P. peruviana. Majority (73.2%) of tomato markers could amplify DNA fragments from at least one accession of Physalis. Diversity in Physalis at molecular level was also detected. The average Nei's genetic distance between accessions was 0.3806 with a range of 0.2865 to 0.7091. These results indicated Physalis and tomato had similarity at both molecular marker and DNA sequence levels. Therefore, the molecular markers developed in tomato can be used in genetic study in Physalis. © 2012 Wei et al.

Darmency H.,French National Institute for Agricultural Research | Picard J.C.,French National Institute for Agricultural Research | Wang T.,French National Institute for Agricultural Research | Wang T.,Chinese Academy of Agricultural Sciences
Heredity | Year: 2011

A mutant Thr-239-Ileu at the α2-tubulin gene was found to confer resistance to dinitroanilines, a family of mitosis-disrupting herbicides. However, mutations affecting microtubule polymerization and cell division are expected to impact growth and reproduction, that is, the fitness of a resistant weed or the yield of a tolerant crop, although it has not been demonstrated yet. This study was designed to test this hypothesis for the growth and reproduction of near-isogenic resistant and susceptible materials that were created in F 2 and F 3 generations after a Setaria viridis x S. italica cross. Differential growth was noticeable at the very onset of seedling growth. The homozygous resistant plants, grown both in a greenhouse cabinet and in the field, were smaller and had lower 1000-grain weight and therefore a lower yield. This fitness penalty is certainly due to modified cell division kinetics. Although the presence of the mutant allele accounted for 20% yield losses, there were also measurable benefits of dinitroaniline resistance, and these benefits are discussed. © 2011 Macmillan Publishers Limited All rights reserved 0018-067X/11.

Gao L.,Chinese Academy of Agricultural Sciences | Gao L.,Stanford University | Kelliher T.,Stanford University | Nguyen L.,Stanford University | Walbot V.,Stanford University
Plant Journal | Year: 2013

The basidiomycete Ustilago maydis is a ubiquitous pathogen of maize (Zea mays), one of the world's most important cereal crops. Infection by this smut fungus triggers tumor formation in aerial plant parts within which the fungus sporulates. Using confocal microscopy to track U. maydis infection on corn anthers for 7 days post-injection, we found that U. maydis is located on the epidermis during the first 2 days, and has reached all anther lobe cell types by 3 days post-injection. Fungal infection alters cell-fate specification events, cell division patterns, host cell expansion and host cell senescence, depending on the developmental stage and cell type. Fungal effects on tassel and plant growth were also quantified. Transcriptome profiling using a dual organism microarray identified thousands of anther genes affected by fungal infection at 3 days post-injection during the cell-fate specification and rapid cell proliferation phases of anther development. In total, 4147 (17%) of anther-expressed genes were altered by infection, 2018 fungal genes were expressed in anthers, and 206 fungal secretome genes may be anther-specific. The results confirm that U. maydis deploys distinct genes to cause disease in specific maize organs, and suggest mechanisms by which the host plant is manipulated to generate a tumor. © 2013 The Authors The Plant Journal © 2013 John Wiley & Sons Ltd.

Elsheikha H.M.,University of Nottingham | Zhu X.-Q.,Chinese Academy of Agricultural Sciences
Current Opinion in Infectious Diseases | Year: 2016

Purpose of review The apicomplexan protozoan Toxoplasma gondii has a striking predilection for infecting the central nervous system and has been suggested as a risk factor for schizophrenia. Here, we address some of the mechanisms by which T. gondii achieves this by manipulating signaling pathways of the host brain cells. Recent findings Recent years have brought notable progress in the understanding of how the opportunistic parasite T. gondii establishes a successful infection in mammalian brain by secreting effector molecules that manipulate multiple cell functions. Many pathways involved in this inter-kingdom signaling, such as dopaminergic, GABAergic and kynurenine pathways, also have key roles in the development of schizophrenia. More understanding of T. gondii-brain cell interaction holds the key to unlocking the mystery of T. gondii-mediated schizophrenia pathogenesis. Summary T. gondii usurps a variety of host signaling pathways to ensure physiological adaptation, evasion of host immune defense systems, and efficient replication. A detailed knowledge of T. gondii signaling molecules involved in this cross-kingdom communication with host brain cells will probably provide novel means of pharmacologically manipulating host cellular pathways to promote efficient elimination of the parasite and may permit the development of new schizophrenia-modifying therapeutics. © 2016 Wolters Kluwer Health, Inc. All rights reserved.

Fu J.,Chinese Academy of Agricultural Sciences
Acta Physiologiae Plantarum | Year: 2013

A putative gene encoding germacrene D synthase (GenBank Accession No. JQ247185) from tea plant (Camellia sinensis) was isolated by rapid amplification of cDNA ends for the first time, which was designated as tea plant gene terpene synthase 1 (Cstps1). This full-length cDNA was 2,090 nucleotides, and the open reading frame was 1,704 bp encoding polypeptides of 568 amino acids. The deduced amino acid sequence contained two characteristic conserved motifs of RRx8W and DDxxD, which showed high homology with sesquiterpene synthases of angiosperms, and the highest level of similarity was 73 % to germacrene D synthase from Actinidia deliciosa (Accession NO. AAX16121. 1). Phylogenetic analysis indicated that Cstps1 belonged to the terpene synthase-a subfamily of plant, which was the largest clade of terpene synthases and mainly composed of sesquiterpene synthases. The Cstps1 expression was detected in different organs, with high expression levels in leaf and flower, weak expression in stem and root. Real-time qRT-PCR indicated that Cstps1 could be induced by insect damage, this result suggested Cstps1 might have potential ecological function during tea plant defense response. © 2012 The Author(s).

Tang X.-Z.,Beijing University of Chemical Technology | Tang X.-Z.,Nanyang Technological University | Li X.,Beijing University of Chemical Technology | Cao Z.,Chinese Academy of Agricultural Sciences | And 4 more authors.
Carbon | Year: 2013

A green and efficient approach for the synthesis of graphene decorated with silver nanoparticles is demonstrated by simultaneously reducing both graphene oxide (GO) sheets and silver ions with glucose as the reducing agent and poly(N-vinyl-2-pyrrolidone) (PVP) as the surface modifier. Different silver-containing materials are obtained by changing the synthesis temperature. The oxygen-containing groups of the substrate influence its decoration with the in situ formed silver nanoparticles. The combination of glucose and a silver-ammonia solution, as well as maintaining a good dispersion of GO by using PVP are crucial for the decoration of graphene with silver nanoparticles. The materials exhibit a distinct surface-enhanced Raman scattering effect. © 2013 Elsevier Ltd.

Wu B.,CAS Institute of Microbiology | Wu B.,University of Chinese Academy of Sciences | Tian J.,CAS Institute of Microbiology | Bai C.,Chinese Academy of Agricultural Sciences | And 3 more authors.
ISME Journal | Year: 2013

Whether fungal community structure depends more on historical factors or on contemporary factors is controversial. This study used culture-dependent and -independent (polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE)) methods to assess the influence of historical and contemporary factors on the distributions of fungi in the wetland sediments at 10 locations along the Changjiang River and at 10 other locations in China. The culture-dependent approach detected greater species diversity (177 operational taxonomic units (OTUs)) than PCR-DGGE analysis (145 OTUs), and the species in the genera of Penicillium (relative frequency=16.8%), Fusarium (15.4%), Aspergillus (7.6%), Trichoderma (5.8%) and Talaromyces (4.2%) were dominant. On the basis of DGGE data, fungal diversity along the Changjiang River increased from upstream to downstream; altitude explained 44.8% of this variation in diversity. And based on the data from all 20 locations, the fungal communities were geographically clustered into three groups: Southern China, Northern China and the Qinghai-Tibetan Plateau. Multivariate regression tree analysis for data from the 20 locations indicated that the fungal community was influenced primarily by location (which explained 61.8% of the variation at a large scale), followed by total potassium (9.4%) and total nitrogen (3.5%) at a local scale. These results are consistent with the concept that geographic distance is the dominant factor driving variation in fungal diversity at a regional scale (1000-4000 km), whereas environmental factors (total potassium and total nitrogen) explain variation in fungal diversity at a local scale (<1000 km). © 2013 International Society for Microbial Ecology All rights reserved.

Brunius C.,Swedish University of Agricultural Sciences | Zamaratskaia G.,Swedish University of Agricultural Sciences | Andersson K.,Swedish University of Agricultural Sciences | Chen G.,Chinese Academy of Agricultural Sciences | And 3 more authors.
Vaccine | Year: 2011

The aim of this study was to investigate the effect of a vaccine against gonadotropin-releasing hormone (GnRH), Improvac ® (Pfizer Ltd), administered at a pre- or early pubertal stage on boar taint, hormonal status and reproductive organs. Crossbred male pigs (Swedish Yorkshire dams×Swedish Landrace sires or Swedish Yorkshire sires, n=192) were at birth randomly allocated to four groups: one group of pigs surgically castrated without anaesthesia before age 1 week, a second group of early vaccinated pigs given Improvac at ages 10 and 14 weeks, a third group of standard vaccinated pigs given Improvac at ages 16 and 20 weeks, and a fourth group of entire male pigs. Following the second vaccine injection, antibody titres increased rapidly, accompanied by a rapid decrease in testosterone and a slower decrease of skatole in plasma to the same low levels as for surgically castrated pigs. At slaughter, the levels of androstenone and skatole in adipose tissue were low in surgically castrated and vaccinated pigs, whereas entire male pigs had elevated levels (p<0.001). Similarly, oestradiol was at low levels for surgically castrated and vaccinated pigs, whereas entire male pigs had elevated levels (p<0.001). IGF-1 was lowest for surgically castrated pigs and highest for entire male pigs, with vaccinated pigs at an intermediate level (p<0.001). At slaughter, reproductive organs were small in pigs vaccinated with Improvac, and smaller in pigs vaccinated early (p<0.001). Under our experimental conditions, early vaccination with Improvac can be used as an alternative to the recommended schedule with maintained control of boar taint and testicular secretory activity. © 2011 Elsevier Ltd.

Kirby J.K.,CSIRO | McLaughlin M.J.,CSIRO | Ma Y.,CSIRO | Ma Y.,Chinese Academy of Agricultural Sciences | Ajiboye B.,University of Adelaide
Chemosphere | Year: 2012

Aging reactions in soils can influence the lability and hence bioavailability of added metals in soils through their removal from labile pools into pools from which desorption is slow (non-labile pools). The aims of this study were to examine the effect of aging reactions on the lability of soluble molybdate (MoO42-) added into soils with varying physical and chemical properties and develop models to predict changes in the labile pool of MoO42- in soils with incubation time. Soils were spiked with soluble MoO42- at quantities sufficient to inhibit barley root growth by 10% (EC10) or 90% (EC90) and incubated for up to 18months. The labile pool of MoO42- (E value) was observed to decrease in soils with incubation time, particularly in soils with high clay content. A strong relationship was observed between measures of MoO42- lability in soils determined using E and L value techniques (R2=0.98) suggesting E values provided a good measure of the potential plant available pool of MoO42- in soils. A regression model was developed that indicates clay content and incubation time were the most important factors affecting the labile pool of MoO42- in soils with time after addition (R2=0.70-0.75). The aging model developed suggests soluble MoO42- will be removed into non-labile pools more rapidly with time in neutral to alkaline clay soils than in acidic sandy soils. Labile MoO42- concentrations in molybdenum (Mo) contaminated soils was found to be <10% of the total Mo concentrations in soils. © 2012 .

Zhu X.F.,Zhejiang University | Lei G.J.,Zhejiang University | Wang Z.W.,Zhejiang University | Shi Y.Z.,Chinese Academy of Agricultural Sciences | And 3 more authors.
Plant Physiology | Year: 2013

Whether aluminum toxicity is an apoplastic or symplastic phenomenon is still a matter of debate. Here, we found that three auxin overproducing mutants, yucca, the recessive mutant superroot2, and superroot1 had increased aluminum sensitivity, while a transfer DNA insertion mutant, xyloglucan endotransglucosylase/hydrolases15 (xth15), showed enhanced aluminum resistance, accompanied by low endogenous indole-3-acetic acid levels, implying that auxin may be involved in plant responses to aluminum stress. We used yucca and xth15 mutants for further study. The two mutants accumulated similar total aluminum in roots and had significantly reduced cell wall aluminum and increased symplastic aluminum content relative to the wild-type ecotype Columbia, indicating that altered aluminum levels in the symplast or cell wall cannot fully explain the differential aluminum resistance of these two mutants. The expression of Al sensitive1 (ALS1), a gene that functions in aluminum redistribution between the cytoplasm and vacuole and contributes to symplastic aluminum detoxification, was less abundant in yucca and more abundant in xth15 than the wild type, consistent with possible ALS1 function conferring altered aluminum sensitivity in the two mutants. Consistent with the idea that xth15 can tolerate more symplastic aluminum because of possible ALS1 targeting to the vacuole, morin staining of yucca root tip sections showed more aluminum accumulation in the cytosol than in the wild type, and xth15 showed reduced morin staining of cytosolic aluminum, even though yucca and xth15 had similar overall symplastic aluminum content. Exogenous application of an active auxin analog, naphthylacetic acid, to the wild type mimicked the aluminum sensitivity and distribution phenotypes of yucca, verifying that auxin may regulate aluminum distribution in cells. Together, these data demonstrate that auxin negatively regulates aluminum tolerance through altering ALS1 expression and aluminum distribution within plant cells, and plants must coordinate exclusion and internal detoxification to reduce aluminum toxicity effectively. © 2013 American Society of Plant Biologists. All Rights Reserved.

Zhao X.,Beijing Institute of Technology | Niu Z.,Beijing Institute of Technology | Chen W.,Beijing Institute of Technology | Chen W.,Chinese Academy of Agricultural Sciences
Knowledge-Based Systems | Year: 2013

Recommender systems become increasingly significant in solving the information explosion problem. Existing techniques focus on minimizing predicted rating errors and recommend items with high predicted values to people. They consider high and low rating values as liking and disliking, respectively, and tend to recommend items that users will like in the future. However, especially in the information overloaded age, we consider whether a user rates an item as a measure of interest no matter whether the value is high or low, and the rating values themselves represent the attitude to the quality of the target item. In this paper, we propose two-step recommendation approaches that recommend items matching users' interests first, and then try to find high quality items that users will like. Experiments using MovieLens dataset are carried out to evaluate the proposed methods with precision, recall, NDCG, preference-ratio and precision-like as evaluation metrics. The results show that our proposed approaches outperform the seven existing ones, i.e., UserCF, ItemCF, ALS-WR, Slope-one, SVD++, iExpand and LICF. © 2013 Elsevier B.V. All rights reserved.

Wang J.,CAS Beijing Institute of Geographic Sciences and Nature Resources Research | Rothausen S.G.S.A.,University of East Anglia | Conway D.,University of East Anglia | Zhang L.,CAS Beijing Institute of Geographic Sciences and Nature Resources Research | And 3 more authors.
Environmental Research Letters | Year: 2012

China is the worlds largest emitter of greenhouse gases (GHGs) and the agricultural sector in China is responsible for 1720% of annual emissions and 62% of total freshwater use. Groundwater abstraction in China has increased rapidly from 10km3yr1 in the 1950s to more than 100km 3yr1 in the 2000s, such that roughly 70% of the irrigated area in northern China is now groundwater-fed. Pumping of water for irrigation is one of the most energy consuming on-farm processes; however, to date this source of GHG emissions in China and elsewhere has been relatively neglected. We derive the first detailed estimate of GHG emissions from groundwater pumping for irrigation in China, using extensive village survey data from 11 provinces, broadly representative of the situation during the mid-2000s. The 11 provinces cover roughly half of Chinas irrigated cropland and we upscale to the national level using government statistics for the remaining 20 provinces. Our results show emissions of 33.1MtCO2e, just over half a per cent of the national total. Groundwater abstraction represents an important source of GHG emissions that has been rapidly increasing and which at present is largely unregulated. Water scarcity in China is already driving policies to improve water conservation. These results suggest that significant potential exists to promote the co-benefits of water and energy saving in order to meet national planning targets. © 2012 IOP Publishing Ltd.

Cheng G.,Chinese Academy of Agricultural Sciences
Advanced Drug Delivery Reviews | Year: 2015

MicroRNAs (miRNAs) belong to a class of small non-coding RNAs that regulate numerous biological processes by targeting a broad set of messenger RNAs. Recently, miRNAs have been detected in remarkably stable forms in many types of body fluids. A comparison between cancer patients and healthy individuals has clearly shown that certain types of circulating miRNAs are associated with cancer initiation and progression. Research on miRNA-based biomarkers has witnessed phenomenal growth, owing to the non-invasive nature of miRNA-based screening assays and their sensitivity and specificity in detecting cancers. Consequently, a considerable effort has been devoted to identify suitable miRNAs for cancer diagnosis and also decode the information carried by circulating miRNAs. This review highlights the current studies that focus on the identification of circulating miRNA-based diagnostic and prognostic markers, for the most prevalent types of cancer. Additionally, the review also provides an insight into the putative functions of miRNAs, and attempts to delineate the mechanisms through which they are released into the bloodstream. Moreover, methodologies and strategies for identification of circulating miRNAs in cancers are summarized. Finally, potential strategies for circulating miRNA-based cancer therapies are proposed. © 2014 Elsevier B.V.

Han P.,Huazhong Agricultural University | Niu C.-Y.,Huazhong Agricultural University | Lei C.-L.,Huazhong Agricultural University | Cui J.-J.,Chinese Academy of Agricultural Sciences | Desneux N.,French National Institute for Agricultural Research
Ecotoxicology | Year: 2010

Transgenic Cry1Ac ? CpTI cotton (CCRI41) is increasingly planted throughout China. However, negative effects of this cultivar on the honey bee Apis mellifera L., the most important pollinator for cultivated ecosystem, remained poorly investigated. The objective of our study was to evaluate the potential side effects of transgenic Cry1Ac ? CpTI pollen from cotton on young adult honey bees A. mellifera L. Two points emphasized the significance of our study: (1) A higher expression level of insecticidal protein Cry1Ac in pollen tissues was detected (when compared with previous reports). In particular, Cry1Ac protein was detected at 300 ± 4.52 ng g -1 [part per billion (ppb)] in pollen collected in July, (2) Effects on chronic mortality and feeding behaviour in honey bees were evaluated using a no-choice dietary feeding protocol with treated pollen, which guarantee the highest exposure level to bees potentially occurring in natural conditions (worst case scenario). Tests were also conducted using imidacloprid-treated pollen at a concentration of 48 ppb as positive control for sublethal effect on feeding behaviour. Our results suggested that Cry1Ac ? CpTI pollen carried no lethal risk for honey bees. However, during a 7-day oral exposure to the various treatments (transgenic, imidacloprid- treated and control), honey bee feeding behaviour was disturbed and bees consumed significantly less CCRI41 cotton pollen than in the control group in which bees were exposed to conventional cotton pollen. It may indicate an antifeedant effect of CCRI41 pollen on honey bees and thus bees may be at risk because of large areas are planted with transgenic Bt cotton in China. This is the first report suggesting a potential sublethal effect of CCRI41 cotton pollen on honey bees. The implications of the results are discussed in terms of risk assessment for bees as well as for directions of future work involving risk assessment of CCRI41 cotton. © The Author(s) 2010.

Periyannan S.,CSIRO | Moore J.,CSIRO | Ayliffe M.,CSIRO | Bansal U.,University of Sydney | And 12 more authors.
Science | Year: 2013

Wheat stem rust, caused by the fungus Puccinia graminis f. sp. tritici, afflicts bread wheat (Triticum aestivum). New virulent races collectively referred to as "Ug99" have emerged, which threaten global wheat production. The wheat gene Sr33, introgressed from the wild relative Aegilops tauschii into bread wheat, confers resistance to diverse stem rust races, including the Ug99 race group. We cloned Sr33, which encodes a coiled-coil, nucleotide-binding, leucine-rich repeat protein. Sr33 is orthologous to the barley (Hordeum vulgare) Mla mildew resistance genes that confer resistance to Blumeria graminis f. sp. hordei. The wheat Sr33 gene functions independently of RAR1, SGT1, and HSP90 chaperones. Haplotype analysis from diverse collections of Ae. tauschii placed the origin of Sr33 resistance near the southern coast of the Caspian Sea.

Chen L.,China Agricultural University | Xing L.,Chinese Academy of Agricultural Sciences | Han L.,China Agricultural University
Waste Management | Year: 2010

Agro-residue is one of the important biomass resources in China and its efficient utilization is crucial for providing bio-energy, releasing risk of environmental pollution, and enhancing rural incomes. Densification is one of the important utilization routes of agro-residues. The objective of this paper is to explore the development of agro-residue densified fuel in China based on energetics analysis. The energetical property and energy potential of main agro-residues in China were firstly analyzed and then the development of agro-residue densified fuel in every region was evaluated based on energetics analysis. The results show that the main agro-residues in China are good feedstocks as densified fuel and they constitute enormous energy potential for developing densified fuel. However, the situation of every region should be considered for the development of agro-residue densified fuel. The primary energy embodied per unit of useful energy indicates that most of the regions in China are suitable for developing agro-residue densified fuel as it is energetically advantageous compared with coal, whereas only about 25% of regions near coal production locations are not suitable as they are less energetically advantageous. © 2009 Elsevier Ltd.

Wang C.,Nanjing Agricultural University | Han J.,Nanjing Agricultural University | Liu C.,Chinese Academy of Agricultural Sciences | Kibet K.N.,Nanjing Agricultural University | And 4 more authors.
BMC Genomics | Year: 2012

Background: MicroRNA (miRNA) is a class of functional non-coding small RNA with 19-25 nucleotides in length while Amur grape (Vitis amurensis Rupr.) is an important wild fruit crop with the strongest cold resistance among the Vitis species, is used as an excellent breeding parent for grapevine, and has elicited growing interest in wine production. To date, there is a relatively large number of grapevine miRNAs (vv-miRNAs) from cultivated grapevine varieties such as Vitis vinifera L. and hybrids of V. vinifera and V. labrusca, but there is no report on miRNAs from Vitis amurensis Rupr, a wild grapevine species.Results: A small RNA library from Amur grape was constructed and Solexa technology used to perform deep sequencing of the library followed by subsequent bioinformatics analysis to identify new miRNAs. In total, 126 conserved miRNAs belonging to 27 miRNA families were identified, and 34 known but non-conserved miRNAs were also found. Significantly, 72 new potential Amur grape-specific miRNAs were discovered. The sequences of these new potential va-miRNAs were further validated through miR-RACE, and accumulation of 18 new va-miRNAs in seven tissues of grapevines confirmed by real time RT-PCR (qRT-PCR) analysis. The expression levels of va-miRNAs in flowers and berries were found to be basically consistent in identity to those from deep sequenced sRNAs libraries of combined corresponding tissues. We also describe the conservation and variation of va-miRNAs using miR-SNPs and miR-LDs during plant evolution based on comparison of orthologous sequences, and further reveal that the number and sites of miR-SNP in diverse miRNA families exhibit distinct divergence. Finally, 346 target genes for the new miRNAs were predicted and they include a number of Amur grape stress tolerance genes and many genes regulating anthocyanin synthesis and sugar metabolism.Conclusions: Deep sequencing of short RNAs from Amur grape flowers and berries identified 72 new potential miRNAs and 34 known but non-conserved miRNAs, indicating that specific miRNAs exist in Amur grape. These results show that a number of regulatory miRNAs exist in Amur grape and play an important role in Amur grape growth, development, and response to abiotic or biotic stress. © 2012 Wang et al; licensee BioMed Central Ltd.

Ma B.,CAS Institute of Genetics and Developmental Biology | Yin C.-C.,CAS Institute of Genetics and Developmental Biology | He S.-J.,CAS Institute of Genetics and Developmental Biology | Lu X.,CAS Institute of Genetics and Developmental Biology | And 4 more authors.
PLoS Genetics | Year: 2014

Ethylene and abscisic acid (ABA) have a complicated interplay in many developmental processes. Their interaction in rice is largely unclear. Here, we characterized a rice ethylene-response mutant mhz4, which exhibited reduced ethylene-response in roots but enhanced ethylene-response in coleoptiles of etiolated seedlings. MHZ4 was identified through map-based cloning and encoded a chloroplast-localized membrane protein homologous to Arabidopsis thaliana (Arabidopsis) ABA4, which is responsible for a branch of ABA biosynthesis. MHZ4 mutation reduced ABA level, but promoted ethylene production. Ethylene induced MHZ4 expression and promoted ABA accumulation in roots. MHZ4 overexpression resulted in enhanced and reduced ethylene response in roots and coleoptiles, respectively. In root, MHZ4-dependent ABA pathway acts at or downstream of ethylene receptors and positively regulates root ethylene response. This ethylene-ABA interaction mode is different from that reported in Arabidopsis, where ethylene-mediated root inhibition is independent of ABA function. In coleoptile, MHZ4-dependent ABA pathway acts at or upstream of OsEIN2 to negatively regulate coleoptile ethylene response, possibly by affecting OsEIN2 expression. At mature stage, mhz4 mutation affects branching and adventitious root formation on stem nodes of higher positions, as well as yield-related traits. Together, our findings reveal a novel mode of interplay between ethylene and ABA in control of rice growth and development. © 2014 Ma et al.

Liu K.,Nanjing Agricultural University | Han M.,Nanjing Agricultural University | Zhang C.,Chinese Academy of Agricultural Sciences | Yao L.,Nanjing Agricultural University | And 2 more authors.
Journal of Proteomics | Year: 2012

Cotton fibers are single-celled seed trichomes and provide an ideal model for studying plant cell patterning. At present, the molecular mechanisms of fiber differentiation and initiation are unclear. To determine the proteins involved in these processes, a comparative proteomic analysis based on 2-DE and MS/MS technology was conducted between the fuzzless-lintless mutant (fl) and its parental wild type (WT). Forty-six differentially expressed proteins were identified in ovules at - 3 and 0. days post-anthesis (DPA), at the times of cotton fiber differentiation and initiation, respectively. Most of the proteins (72%) were expressed at lower levels in the fl mutant than in the WT, suggesting deleterious effects of the mutant genes on ovule development. The consistency between protein levels and transcript levels was examined using quantitative PCR. The differentially expressed proteins had diverse putative functions related to redox homeostasis, stress responses, post-transcriptional and post-translational regulation, and carbohydrate, energy, protein, amino acid, and sterol metabolism. A strong burst of ROS was detected on the surface of - 3 and - 2 DPA fl ovules, and the concentrations of several carbohydrates at 0 DPA were lower in the fl mutant than in the WT ovules. These findings suggest that ROS homeostasis may be a central regulatory mechanism for cotton fiber morphogenesis and that post-transcriptional and post-translational regulation may be pivotal in this process. © 2011 Elsevier B.V.

Zheng M.-M.,Wuhan University | Zheng M.-M.,Chinese Academy of Agricultural Sciences | Wang S.-T.,Wuhan University | Hu W.-K.,Wuhan University | Feng Y.-Q.,Wuhan University
Journal of Chromatography A | Year: 2010

A rapid, sensitive and automated in-tube solid-phase microextraction-liquid chromatography-mass spectrometry (in-tube SPME/LC-MS) method was developed for the analysis of ten antidepressants in urine and plasma. A hybrid organic-inorganic silica monolith with cyanoethyl functional groups was prepared and used as a sorbent for in-tube SPME. Integration of the sample extraction, LC separation and MS detection into a single system permitted direct injection of the diluted urine or plasma after filtration. Under the optimized conditions, good extraction efficiencies for the targets were obtained with no matrix interference in the subsequent LC-MS. Automation of the sampling, extraction and separation procedures was realized under the control of a program in this study. The total process time was 30. min and only 30 μL of urine or plasma was required in one analysis cycle. Good linearities were obtained for ten antidepressants with the correlation coefficients (R) above 0.9933. The limits of detection (S/. N= 3) for ten antidepressants were found to be 0.06-2.84. ng/mL in urine and 0.07-2.95. ng/mL in plasma. The recoveries of antidepressants spiked in urine and plasma were from 75.2% to 113.0%, with relative standard deviations less than 16.5%. The developed method was successfully used to analyze urine sample from ageing patients undergoing therapy with antidepressants. © 2010 Elsevier B.V.

Dong X.,China Agricultural University | Zhang Y.-J.,Chinese Academy of Agricultural Sciences | Zhang Z.,China Agricultural University
PLoS ONE | Year: 2013

Background: As one of the most important virulence factor types in gram-negative pathogenic bacteria, type-III effectors (TTEs) play a crucial role in pathogen-host interactions by directly influencing immune signaling pathways within host cells. Based on the hypothesis that type-III secretion signals may be comprised of some weakly conserved sequence motifs, here we used profile-based amino acid pair information to develop an accurate TTE predictor. Results: For a TTE or non-TTE, we first used a hidden Markov model-based sequence searching method (i.e., HHblits) to detect its weakly homologous sequences and extracted the profile-based k-spaced amino acid pair composition (HH-CKSAAP) from the N-terminal sequences. In the next step, the feature vector HH-CKSAAP was used to train a linear support vector machine model, which we designate as BEAN (Bacterial Effector ANalyzer). We compared our method with four existing TTE predictors through an independent test set, and our method revealed improved performance. Furthermore, we listed the most predictive amino acid pairs according to their weights in the established classification model. Evolutionary analysis shows that predictive amino acid pairs tend to be more conserved. Some predictive amino acid pairs also show significantly different position distributions between TTEs and non-TTEs. These analyses confirmed that some weakly conserved sequence motifs may play important roles in type-III secretion signals. Finally, we also used BEAN to scan one plant pathogen genome and showed that BEAN can be used for genome-wide TTE identification. The webserver and stand-alone version of BEAN are available at http://protein.cau.edu.cn:8080/bean/. © 2013 Dong et al.

Peng P.,University of Michigan | Zhao J.,University of Michigan | Zhao J.,Chinese Academy of Agricultural Sciences | Zhu Y.,University of Michigan | And 2 more authors.
Journal of Biological Chemistry | Year: 2010

Glycogen synthase kinase 3 (GSK3) is a highly conserved serine/threonine protein kinase that plays important roles in a variety of physiological and developmental processes in animals. It is well known that the GSK3 kinase-catalyzed protein phosphorylation often requires a stable kinase-substrate docking interaction, which is achieved mainly by two mechanisms as follows: priming phosphorylation of a substrate by a distinct kinase to create a docking phosphate group and scaffold protein-mediated protein complex formation. Brassinosteroid-INsensitive 2 (BIN2) is an Arabidopsis GSK3-like kinase that negatively regulates brassinosteroid (BR) signaling by phosphorylating BES1 (bri1 EMS suppressor 1) and BZR1 (brassinazole-resistant 1), two highly similar transcription factors critical for bringing about characteristic BR responses. However, little is known about the biochemical mechanism by which BIN2 phosphorylates its substrates. Here, we show that BIN2 interacts directly with BZR1 through a 12-amino acid BIN2-docking motif adjacent to the C terminus of BZR1. Interestingly, this 12-amino acid motif is sufficient to allow a Drosophila GSK3 substrate Armadillo to be phosphorylated by BIN2 in vitro. Deletion of this motif inhibits the phosphorylation and subsequent degradation of BZR1 in vivo, resulting in phenotypic suppression of a hypermorphic bin2 mutation and enhanced resistance to a BR biosynthesis inhibitor. We thus concluded that BIN2 utilizes a direct kinase-substrate docking mechanism to phosphorylate BZR1 and regulate its protein stability. © 2010 by The American Society for Biochemistry and Molecular Biology, Inc.

Wendlandt S.,Institute of Farm Animal Genetics | Shen J.,China Agricultural University | Kadlec K.,Institute of Farm Animal Genetics | Wang Y.,China Agricultural University | And 5 more authors.
Trends in Microbiology | Year: 2015

Most antimicrobial resistance genes known so far to occur in staphylococci of animal origin confer resistance to a specific class of antimicrobial agents or to selected members within such a class. However, there are also a few examples of multidrug resistance (MDR) genes that confer resistance to antimicrobial agents of different classes by either target site methylation or active efflux via ATP-binding cassette (ABC) transporters. The present review provides an overview of these MDR genes with particular reference to those genes involved in resistance to critically or highly important antimicrobial agents used in human and veterinary medicine. Moreover, their location on mobile genetic elements and colocated resistance genes, which may play a role in coselection and persistence of the MDR genes, are addressed. © 2014 Elsevier Ltd.

Huang S.,Nanjing Agricultural University | Peng X.,Nanjing Agricultural University | Huang Q.,Nanjing Agricultural University | Zhang W.,Nanjing Agricultural University | Zhang W.,Chinese Academy of Agricultural Sciences
Geoderma | Year: 2010

We examined the long-term effects of inorganic fertilizer (N and NPK) and manure application on soil aggregation and carbon (C) fractions under a double corn (Zea mays L.) cropping system in a subtropical red soil. Results showed that application of manure combined with NPK (NPK + M) gained the highest yield and increased the stability of crop production. Application of inorganic fertilizer could sustain soil organic carbon (SOC) concentrations, whereas long-term application of manure alone or combined with NPK (M and NPK + M) significantly increased SOC contents compared with the unfertilized control. Manure application significantly increased the proportion of large macroaggregates (> 2000 μm) compared with the control, while leading to a corresponding decline in the percentage of microaggregates (53-250 μm). Carbon storage in the intra-aggregate particulate organic matter within microaggregates (iPOM_m) was enhanced from 9.8% of the total SOC stock in the control to 19.7% and 18.6% in the M and NPK + M treatments, respectively. The shift in SOC stocks towards microaggregates is beneficial for long-term soil C sequestration. Moreover, the differences in the microaggregate protected C (i.e., iPOM_m) accounted, on average, for 39.8% of the differences in total SOC stocks between the control and the manure-applied treatments. Thus, we suggest that the microaggregate protected C is promising for assessing the impact of long-term fertilization management on SOC storage in the red soil. Crown Copyright © 2009.

Hughes D.T.,University of Miami | Wang G.,Chinese Academy of Agricultural Sciences | Zwiebel L.J.,Vanderbilt University | Luetje C.W.,University of Miami
Chemical senses | Year: 2014

To explore the structural basis for odorant specificity in odorant receptors of the human malaria vector mosquito, Anopheles gambiae, odorant-binding subunits (Agam\Ors) expressed in Xenopus oocytes in combination with Agam\Orco (coreceptor subunit) were assayed by 2-electrode voltage clamp against 25 structurally related odorants. Agam\Or13 and Agam\Or15 display 82% amino acid identity and had similar, but somewhat distinct odorant response profiles. The ratio of acetophenone to 4-methylphenol responses was used in a mutation-based analysis of Agam\Or15, interchanging 37 disparate residues between Agam\Or15 and Agam\Or13. Eleven mutations caused significant changes in odorant responsiveness. Mutation of alanine 195 resulted in the largest shift in response ratio from Agam\Or15 toward Agam\Or13. Concentration-response analysis for a series of mutations of residue 195 revealed a large effect on acetophenone sensitivity, with EC50 values varying by >1800-fold and correlating with residue side chain length. Similar results were obtained for propiophenone and benzaldehyde. But, for other odorants, such as 4-methylphenol, 4-methylbenzaldehyde, and 4-methylpropiophenone, the effect of mutation was much smaller (EC50 values varied by ≤16-fold). These results show that alanine 195, putatively located at the second extracellular loop/fourth transmembrane domain interface, plays a critical role in determining the odorant response specificity of Agam\Or15. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

He F.,China Agricultural University | He F.,Chinese Academy of Agricultural Sciences | Ma C.,China Agricultural University
Computers and Electronics in Agriculture | Year: 2010

A back propagation neural network (BPNN) based on principal component analysis (PCA) was proposed for modeling the internal greenhouse humidity in winter of North China. The environment factors influencing the inside humidity include outside air temperature and humidity, wind speed, solar radiation, inside air temperature, open angle of top vent and side vent, and open ration of sunshade curtain, which were all collected as data samples. Through PCA of these data samples, 4 main factors were extracted, and the relationship between the main factors and the original data was discussed. Taking the principal component values as the input of BPNN, the model showed a good performance. A comparison was made between the performances of the BPNN based on PCA and the stepwise regression method with 20 data samples which had not been used to establish the NN model, and the prediction of stepwise regression method was less accurate than the BPNN based on PCA. © 2009 Elsevier B.V. All rights reserved.

Gou M.,Cornell University | Shi Z.,Cornell University | Shi Z.,CAS Institute of Plant Physiology and Ecology | Zhu Y.,Cornell University | And 4 more authors.
Plant Journal | Year: 2012

Disease resistance (R) proteins, as central regulators of plant immunity, are tightly regulated for effective defense responses and to prevent constitutive defense activation under non-pathogenic conditions. Here we report the identification of an F-box protein CPR1/CPR30 as a negative regulator of an R protein SNC1 likely through SCF (Skp1-cullin-F-box) mediated protein degradation. The cpr1-2 (cpr30-1) loss-of-function mutant has constitutive defense responses, and it interacts synergistically with a gain-of function mutant snc1-1 and a bon1-1 mutant where SNC1 is upregulated. The loss of SNC1 function suppresses the mutant phenotypes of cpr1-2 and cpr1-2 bon1-1, while overexpression of CPR1 rescues mutant phenotypes of both bon1-1 and snc1-1. Furthermore, the amount of SNC1 protein is upregulated in the cpr1-2 mutant and down-regulated when CPR1 is overexpressed. The regulation of SNC1 by CPR1 is dependent on the 26S proteosome as a protease inhibitor MG132 stabilizes SNC1 and reverses the effect of CPR1 on SNC1. Interestingly, CPR1 is induced after infection of both virulent and avirulent pathogens similarly to the other negative defense regulator BON1. Thus, this study reveals a new mechanism in R protein regulation likely through protein degradation and suggests negative regulation as a critical component in fine control of plant immunity. © 2011 The Authors. The Plant Journal © 2011 Blackwell Publishing Ltd.

Chen B.,Agricultural Environment and Resources Research Center | Chen B.,Chinese Academy of Forestry | Liu S.,Chinese Academy of Forestry | Ge J.,Beijing Normal University | Chu J.,Chinese Academy of Agricultural Sciences
Soil Biology and Biochemistry | Year: 2010

The annual and seasonal variations in the temperature sensitivity of soil respiration (Rs) were assessed through continuous measurements during the 2004-2006 growing seasons using chamber-based techniques in two sub-alpine forest ecosystems in the Eastern Qinghai-Tibet Plateau, China. The study sites were 40-year-old spruce plantations (Picea asperata) (FSPF) and Faxon Fir Primary Forest (FPF). Our results showed that Q10, regardless of site origin, exhibited a strong seasonal and annual variation pattern, and decreased with soil temperature increase. Estimated Q10 values ranged between 1.16 and 24.3. The maximum, annual, mean Q10 values remained consistent over 3 years, while the highest Q10 values (7.01 in FSPF and 6.39 in FPF) occurred in 2005 (for all sites). There was no significant difference observed among Q10 values between the two forest types in each year (2004-2006) (p=0.07). Q10 values were fitted well with data of soil temperature using linear regression models, while the correlation between Q10 and soil moisture was not significant (p>0.1). This study suggested that soil temperature was the dominant factor influencing Q10 values, while soil moisture was a potential contributor to the annual and seasonal variations of Q10 in a sub-alpine forest. Due to the complexity of correlation between Rs and soil moisture, Q10 values derived from annual and seasonal patterns of RS should be used with caution when predicting future soil CO2 emissions under conditions of global warming. © 2010.

Yang T.,Auburn University | Yang T.,Chinese Academy of Agricultural Sciences | Liu N.,Auburn University
Insect Science | Year: 2014

This study examines the genetic variations and mechanisms involved in the development of permethrin resistance in individual mosquitoes from a field population of Culex quinquefasciatus, HAmCqG0, and characterizes susceptible reference lines of mosquitoes with a similar genetic background to the field HAmCqG0 strain. Six upregulated cytochrome P450 genes, CYP9M10, CYP9J34, CYP6P14, CYP9J40, CYP6AA7, and CYP4C52v1, previously identified as being upregulated in the larvae of resistant HAmCqG8 mosquitoes were examined in the larvae of 3 strains (susceptible S-Lab, parental HAmCqG0 and permethrin-selected highly resistant HAmCqG8) and 8 HAmCqG0 single-egg raft colonies, covering a range of levels of susceptibility/resistance to permethrin and exhibiting different variations in the expression of A and/or T alleles at the L-to-F kdr locus of the sodium channel. The 2 lines with the lowest tolerance to permethrin and bearing solely the susceptible A allele at the L-to-F kdr locus of the sodium channels, from colonies Cx_SERC5 and Cx_SERC8, showed lower or similar levels of all 6 of the P450 genes tested compared with the S-Lab strain, suggesting that these 2 lines could be used as the reference mosquitoes in future studies characterizing insecticide resistance in HAmCq mosquitoes. This study also provides a detailed investigation of the mechanisms involved in insecticide resistance in individuals within a population: individuals with elevated levels of resistance to permethrin all displayed one or more potential resistance mechanisms-either elevated levels of P450 gene expression, or L-to-F mutations in the sodium channel, or both. © 2014 Institute of Zoology, Chinese Academy of Sciences.

Wang W.,Southwest University | Liu G.,Chinese Academy of Agricultural Sciences | Niu H.,Southwest University | Timko M.P.,University of Virginia | Zhang H.,Southwest University
Journal of Experimental Botany | Year: 2014

Jasmonate (JA) plays an important role in regulating plant male fertility and secondary metabolism, but its role in regulating primary metabolism remains unclear. The F-box protein CORONATINE INSENSITIVE 1 (COI1) is a critical component of the JA receptor, and mediates JA-signalling by targeting JASMONATE ZIM-domain (JAZ) proteins for proteasomal degradation in response to JA perception. Here, we found that RNA interference-mediated knockdown of NtCOI1 in tobacco (Nicotiana tabacum L. cv. TN90) recapitulated many previously observed phenotypes in coi1 mutants, including male sterility, JA insensitivity, and loss of floral anthocyanin production. It also affected starch metabolism in the pollen, anther wall, and floral nectary, leading to pollen abortion and loss of floral nectar. Transcript levels of genes encoding starch metabolism enzymes were significantly altered in the pollen, anther wall, and floral nectary of NtCOI1-silenced tobacco. Changes in leaf primary metabolism were also observed in the NtCOI1-silenced tobacco. The expression of NtMYB305, an orthologue of MYB305 previously identified as a flavonoid metabolic regulator in Antirrhinum majus flowers and as a floral-nectar regulator mediating starch synthesis in ornamental tobacco, was extremely downregulated in NtCOI1-silenced tobacco. These findings suggest that NtCOI1 functions upstream of NtMYB305 and plays a fundamental role in coordinating plant primary carbohydrate metabolism and correlative physiological processes. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Sarwar M.,Nuclear Institute of Agriculture | Sarwar M.,Chinese Academy of Agricultural Sciences
New Zealand Journal of Crop and Horticultural Science | Year: 2014

The two-spotted spider mite, Tetranychus urticae Koch (Tetranychidae), is a pest of agricultural crops that could potentially be controlled by the predatory mite Neoseiulus pseudolongispinosus (Xin, Liang and Ke) (Phytoseiidae). This study investigated the development, fecundity and population density of these two mite species on three different species of bean (Phaseolus lunatus L., Lablab purpureus [L.] and Phaseolus vulgaris L. [Papilionaceae: Leguminosae]). The morphological characteristics of the host plants, including leaf area, thickness and hairiness, main stem diameter and plant height affected development rate, fecundity and population density of T. urticae and also the searching success and abundance of the predatory species, N. pseudolongispinosus. L. purpureus was found to be a superior host plant for both predator and prey species. These findings emphasize the importance of host plant characteristics on the performance of species used for biological control. © 2013 The Royal Society of New Zealand.

Zegeye H.,Ethiopian Institute of Agricultural Research | Rasheed A.,Chinese Academy of Agricultural Sciences | Rasheed A.,Quaid-i-Azam University | Makdis F.,University of Aleppo | And 2 more authors.
PLoS ONE | Year: 2014

Use of genetic diversity from related wild and domesticated species has made a significant contribution to improving wheat productivity. Synthetic hexaploid wheats (SHWs) exhibit natural genetic variation for resistance and/or tolerance to biotic and abiotic stresses. Stripe rust caused by (Puccinia striiformis f. sp. tritici; Pst), is an important disease of wheat worldwide. To characterise loci conferring resistance to stripe rust in SHWs, we conducted a genome-wide association study (GWAS) with a panel of 181 SHWs using the wheat 9K SNP iSelect array. The SHWs were evaluated for their response to the prevailing races of Pst at the seedling and adult plant stages, the latter in replicated field trials at two sites in Ethiopia in 2011. About 28% of the SHWs exhibited immunity at the seedling stage while 56% and 83% were resistant to Pst at the adult plant stage at Meraro and Arsi Robe, respectively. A total of 27 SNPs in nine genomic regions (1BS, 2AS, 2BL, 3BL, 3DL, 5A, 5BL, 6DS and 7A) were linked with resistance to Pst at the seedling stage, while 38 SNPs on 18 genomic regions were associated with resistance at the adult plant stage. Six genomic regions were commonly detected at both locations using a mixed linear model corrected for population structure, kinship relatedness and adjusted for false discovery rate (FDR). The loci on chromosome regions 1AS, 3DL, 6DS and 7AL appeared to be novel QTL; our results confirm that resynthesized wheat involving its progenitor species is a rich source of new stripe (yellow) rust resistance that may be useful in choosing SHWs and incorporating diverse yellow rust (YR) resistance loci into locally adapted wheat cultivars. © 2014 Zegeye et al.

Xu X.,Chinese Academy of Agricultural Sciences | Xu X.,University of Aarhus | Enkegaard A.,University of Aarhus
Journal of Insect Science | Year: 2010

The prey preference of polyphagous predators plays an important role in suppressing different species of pest insects. In this study the prey preference of the predatory mite, Amblyseius swirskii (Athias-Henriot) (Acari: Phytoseiidae) was examined between nymphs of the twospotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae) and first instar larvae of the western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), as well as between active and chrysalis spider mite protonymphs and active and chrysalis spider mite deutonymphs. The study was done in the laboratory on bean leaf discs at 25 ± 1° C and 70 ± 5% RH. Amblyseius swirskii had a clear preference for thrips compared to both spider mite protonymphs and deutonymphs. About twice as many thrips as spider mites were consumed. Amblyseius swirskii did not show a preference between active and chrysalis stages of spider mites.

Qi J.,Zhejiang University | Zhou G.,Zhejiang University | Yang L.,Zhejiang University | Erb M.,Max Planck Institute for Chemical Ecology | And 4 more authors.
Plant Physiology | Year: 2011

The oxylipin pathway is of central importance for plant defensive responses. Yet, the first step of the pathway, the liberation of linolenic acid following induction, is poorly understood. Phospholipases D (PLDs) have been hypothesized to mediate this process, but data from Arabidopsis (Arabidopsis thaliana) regarding the role of PLDs in plant resistance have remained controversial. Here, we cloned two chloroplast-localized PLD genes from rice (Oryza sativa), OsPLDα4 and OsPLDα5, both of which were up-regulated in response to feeding by the rice striped stem borer (SSB) Chilo suppressalis, mechanical wounding, and treatment with jasmonic acid (JA). Antisense expression of α and -α5 (as-pld), which resulted in a 50% reduction of the expression of the two genes, reduced elicited levels of linolenic acid, JA, green leaf volatiles, and ethylene and attenuated the SSB-induced expression of a mitogen-activated protein kinase (OsMPK3), a lipoxygenase (OsHI-LOX), a hydroperoxide lyase (OsHPL3), as well as a 1-aminocyclopropane-1-carboxylic acid synthase (OsACS2). The impaired oxylipin and ethylene signaling in as-pld plants decreased the levels of herbivore-induced trypsin protease inhibitors and volatiles, improved the performance of SSB and the rice brown planthopper Nilaparvata lugens, and reduced the attractiveness of plants to a larval parasitoid of SSB, Apanteles chilonis. The production of trypsin protease inhibitors in as-pld plants could be partially restored by JA, while the resistance to rice brown planthopper and SSB was restored by green leaf volatile application. Our results show that phospholipases function as important components of herbivore-induced direct and indirect defenses in rice. © 2011 American Society of Plant Biologists. All Rights Reserved.

Chen L.,China Agricultural University | Xing L.,Chinese Academy of Agricultural Sciences | Han L.,China Agricultural University
Journal of Environmental Quality | Year: 2013

Animal manure contains a variety of chemical constituents that are highly valuable to agriculture, including nitrogen, phosphorus, potassium, and metal micronutrients. Although appropriately applied manure has numerous positive attributes, the excessive application of manure may lead to pollution of the atmosphere, water, or soil. To reconcile precision agriculture and the potential negative environmental influences of animal manure, it is necessary to develop rapid and robust methods to evaluate the chemical composition of animal manure. This paper summarizes recent advances in nearinfrared reflectance spectroscopy (NIRS) in predicting moisture, dry matter, organic matter, nitrogen, phosphorus, carbon, and metal content in animal manure. The results indicate the high potential of NIRS as an efficient tool for monitoring the chemical composition of animal manure. Future prospects and needs related to increasing the feasibility of the industrial application of NIRS and improving NIRS prediction precision in determining the chemical composition of animal manure are discussed. ©American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America.

Rea M.,Saint Louis University | Zheng W.,Saint Louis University | Chen M.,Saint Louis University | Chen M.,Chinese Academy of Agricultural Sciences | And 4 more authors.
Plant Journal | Year: 2012

Imprinting, i.e. parent-of-origin expression of alleles, plays an important role in regulating development in mammals and plants. DNA methylation catalyzed by DNA methyltransferases plays a pivotal role in regulating imprinting by silencing parental alleles. DEMETER (DME), a DNA glycosylase functioning in the base-excision DNA repair pathway, can excise 5-methylcytosine from DNA and regulate genomic imprinting in Arabidopsis. DME demethylates the maternal MEDEA (MEA) promoter in endosperm, resulting in expression of the maternal MEA allele. However, it is not known whether DME interacts with other proteins in regulating gene imprinting. Here we report the identification of histone H1.2 as a DME-interacting protein in a yeast two-hybrid screen, and confirmation of their interaction by the in vitro pull-down assay. Genetic analysis of the loss-of-function histone h1 mutant showed that the maternal histone H1 allele is required for DME regulation of MEA, FWA and FIS2 imprinting in Arabidopsis endosperm but the paternal allele is dispensable. Furthermore, we show that mutations in histone H1 result in an increase of DNA methylation in the maternal MEA and FWA promoter in endosperm. Our results suggest that histone H1 is involved in DME-mediated DNA methylation and gene regulation at imprinted loci. © 2012 Blackwell Publishing Ltd.

Song J.B.,Nanjing Agricultural University | Huang S.Q.,Nanjing Agricultural University | Huang S.Q.,Chinese Academy of Agricultural Sciences | Dalmay T.,University of East Anglia | Yang Z.M.,Nanjing Agricultural University
Plant and Cell Physiology | Year: 2012

The present study identified Arabidopsis miR394 and its target, an F-box (SKP1-Cullin/CDC53-F-box) gene At1g27340 (here referred to as LEAF CURLING RESPONSIVENESS, LCR), for regulation of leaf curling-related morphology. The loss-of-function lcr mutants exhibit pleiotropic defects with semi-dwarfism, altered leaf shape and a shorter stem. Overexpression of an miR394-resistant version of LCR under the 35S promoter (35S:m5LCR) and target mimicry MIM394 resulted in a curled-down leaf defect. Conversely, transgenic plants overexpressing 35S:MIR394a/b display a curled-up leaf phenotype. Detailed analyses show that there is a certain level of LCR that is optimal for leaf morphology, but lower or higher levels lead to abnormal leaf development, indicating that expression of miR394 in the leaf lamina is necessary for proper leaf morphology. Because the phytohormone auxin plays a crucial role in leaf morphogenesis and patterning, the DR5-GUS reporter gene was used to monitor the auxin response. We show that DR5 expression patterns in lcr and 35S::m5LCR plants were significantly different from those in the wild type. Also, overexpression of LCR in 35S::m5LCR plants drastically decreased the expression of the auxin-responsive genes IAA3, AXR3 and IAMT1, whereas increased expression of the genes was found in 35S::MIR394a plants. These results indicate that miR394 and its target LCR are involved in the regulation of leaf development. © 2012 The Author.

He Y.,Fujian Academy of Agricultural science | Zhao J.,Fujian Academy of Agricultural science | Zheng Y.,Fujian Academy of Agricultural science | Desneux N.,French National Institute for Agricultural Research | Wu K.,Chinese Academy of Agricultural Sciences
Ecotoxicology | Year: 2012

Neonicotinoid insecticides are widely used for controlling sucking pests, and sublethal effects can be expected in beneficial arthropods like natural enemies. Serangium japonicum is an important predator in many agricultural systems in China, and a potential biological control agent against Bemisia tabaci. We evaluated the toxicity of imidacloprid to S. japonicum and its impact on the functional response to B. tabaci eggs. S. japonicum adults exposed through contact to dried residues of imidacloprid at the recommended field rate on cotton against B. tabaci (4 g active ingredient per 100 l, i.e. 40 ppm [part per million]), and reduced rates (25, 20, 15 and 10 ppm) for 24 h showed high mortality rates. The mortality induced by a lowest rate, 5 ppm, was not significantly different than the control group and thus it was considered as a sublethal rate. The lethal rate 50 and hazard quotient (HQ) were estimated to be 11.54 ppm and 3.47 respectively, indicating a risk for S. japonicum in treated fields (HQ > 2). When exposed to dried residues of imidacloprid at the sublethal rate (5 ppm) on cotton leaves, functional response of S. japonicum to B. tabaci eggs was affected with an increase in handling time and a reduction in peak consumption of eggs. Imidacloprid residues also disturbed predator voracity, the number of B. tabaci eggs consumed on treated leaves being significantly lower than on untreated leaves. All effects disappeared within a few hours after transfer to untreated cotton leaves. Imidacloprid systemically applied at the recommended field rate (for cotton) showed no toxicity to S. japonicum, nor affected the functional response of the predator. Sublethal effects of imidacloprid on S. japonicum observed in our study likely negatively affect S. japonicum development and reproductive capacity and may ultimately reduce predator population growth. These results hint at the importance of assessing potential effects of imidacloprid on S. japonicum for developing effective integrated pest management programs of B. tabaci in China. © Springer Science+Business Media, LLC 2012.

Zhang B.,CAS Institute of Botany | Zhang B.,Chinese Academy of Agricultural Sciences
Plant Gene | Year: 2015

Glycolysis is an indispensable biochemical pathway in both animals and plants and is required for almost all physiological processes. Previous studies have shown that glycolysis plays an important role in cotton fiber development process. However, the detailed mechanism by which glycolysis is regulated is still unclear. In this study, a total of 163 genes encoding different isoforms of 20 enzymes involved in the catalysis of glycolysis and fermentation were identified in diploid Asian cotton (Gossypium arboreum). These enzymes have unique subcellular localizations and phylogenies. Among these 163 genes, 125 were expressed in Asian cotton plants, but only 51 were highly expressed in elongating Asian cotton fibers. Cis-regulatory elements involved in phytohormone responses were identified in these 51 genes, suggesting that glycolysis might be regulated by phytohormones. Furthermore, the expression of fermentation-related genes and the wide distribution of cis-regulatory elements that promote anaerobic induction strongly suggested the involvement of anaerobic glycolysis in cotton fiber development, especially during the elongation process. © 2015 The Author. Published by Elsevier Inc.

Wei F.,Chinese Academy of Agricultural Sciences | Feng Y.-Q.,Wuhan University
Analytical Methods | Year: 2011

Veterinary medicines are extensively applied in food producing animals for the treatment of various bacterial infections, so the risk of occurrence of unwanted residues in edible products exists. This review is focused on the methods of sample preparation for determination of veterinary residues in food matrices by porous monolith microextraction-based techniques. Microextraction techniques using porous monoliths offer several advantages, including miniaturization, automation, high-throughput performance, and on-line coupling with analytical instruments, as well as being solvent-free and portable. In this review the focus is on application of porous monolith microextraction techniques for veterinary drug residues analysis. The general approaches used to synthesize organic polymer and silica monolithic materials are briefly described. Several porous monolith microextraction formats, including in-tube solid-phase microextraction (in-tube SPME), stir bar sorptive extraction (SBSE) and stir rod sorptive extraction (SRSE) modes based on porous monoliths are critically evaluated and the applications of these techniques in veterinary drug residues analysis are summarized. © 2011 The Royal Society of Chemistry.

Xing L.,Chinese Academy of Agricultural Sciences | Chen L.,China Agricultural University
Spectroscopy Letters | Year: 2013

Data preprocessing and multivariate regression methods are two key factors influencing the model prediction ability of near-infrared (NIR) spectroscopy. The present paper evaluated the application of the combined stationary wavelet transform-support vector machine method for developing juice NIR models. The performance of this method has been compared with other methods, such as stand normal variate-partial least squares, stationary wavelet transform-partial least squares, and stand normal variate-stationary wavelet transform methods. The result showed that compared with other methods, the stationary wavelet transform-support vector machine method can provide good quantitative analysis on saccharose concentration in juice. © 2013 Copyright Taylor and Francis Group, LLC.

Tang W.,China Agricultural University | Ding Z.,China Agricultural University | Zhou Z.Q.,Chinese Academy of Agricultural Sciences | Wang Y.Z.,China Institute of Technology | Guo L.Y.,China Agricultural University
Plant Disease | Year: 2012

Apple ring rot and Botryosphaeria canker are severe diseases affecting apple production in China, but there is confusion regarding which pathogens cause these diseases and their similarity to other diseases, such as white rot of apple, and ring rot and Botryosphaeria canker of pear. In this study, the pathogen of apple ring rot in China was compared with the pathogen of apple ring rot in Japan and Korea, the pathogen of Botryosphaeria canker of apple and pear in China, the pathogen of pear ring rot in China, and the pathogen of white rot of apple in the United States. Comparisons were based on morphology, pathogenicity on branches and fruit, and sequences of rDNA in the internal transcribed spacer region and of the β-tubulin and actin genes. Results showed that the causal agent of apple ring rot and Botryosphaeria canker of apple in China was Botryosphaeria dothidea, which has also been reported to be the pathogen of apple ring rot in Korea and Japan. Pathogenicity tests showed that B. dothidea infection on apple and pear branches may induce wart or canker symptoms depending on the conditions. These results are consistent with the hypothesis that the same pathogen causes the wart symptom of apple ring rot and the Botryosphaeria canker symptom on apple branches in China. The results also suggest that apple ring rot and white rot are the same disease and are caused by B. dothidea. Finally, B. dothidea isolates from pear and other fruit or forest trees may serve as inoculum for apple ring rot. © 2012 The American Phytopathological Society.

Qiao W.,Chinese Academy of Agricultural Sciences | Fan L.,Peking University
Frontiers in Biology | Year: 2011

Epigenetics has been becoming a hot topic in recent years. It can be mechanisms that regulate gene expression without changing DNA base sequence. In plants epigenetic regulation has been implicated to be a very important phenomenon and mechanism for the regulation of responses to environmental stresses. Environmental signals induce various epigenetic modifications in the genome, and these epigenetic modifications might likely be inherited to the next generation that behaves with enhanced ability to tolerate stresses. This review highlights recent advances in the study of epigenetics in plant stress responses. © 2011 Higher Education Press and Springer-Verlag Berlin Heidelberg.

Gu Y.X.,Chinese Academy of Agricultural Sciences
DNA and cell biology | Year: 2012

Ovine adenovirus 287 (OAdV287) emerges as one of the most promising gene vectors resulting from its unique biological characteristics. To obtain a more detailed knowledge about the codon usage of OAdV287, a comparative study based on the codon usage of OAdV287 and the prototypes of human adenovirus serotypes 2 and 5 (HAdV2/5) was carried out. Some commonly used indices measuring the codon usage patterns, including effective number of codons, relative synonymous codon usage, and statistical methods, were adopted. Overall, OAdV287 had a more biased and conservative codon usage pattern than that of HAdV2/5. Both mutation pressure and natural selection played important roles in shaping the codon usage patterns of these three adenoviruses. All the preference codons of OAdV287 had A/U ends and were totally different from those of sheep and humans; however, the preference codons of HAdV2/5 mostly had G/C ends and were mostly coincident with those of sheep and humans. The codon usage analysis in this study supplies some clues for further comprehending the unique biological characteristics of OAdV287 as gene vectors.

Tian R.-Y.,Chinese Academy of Agricultural Sciences | Liu Y.-J.,CAS Institute of Policy and Management
Decision Support Systems | Year: 2014

Online public opinion has become an important issue affecting national benefit and security. Based on system modeling and simulation, combining quantitative model methods and network topology analysis, this article establishes an Opinion SuperNetwork model to investigate different strategies of online public opinion intervention. We analyzed the effects of online opinion environments, opinion agents, psychologies, and viewpoints on the online public opinion formation and evolution. We further used these factors to investigate isolation, insertion, and reconstruction strategies. The results show that all the three intervention strategies produce good results, while insertion strategy is the best. And the mutual influence among superedges has the greatest impact on the result of intervention. Therefore, inserting positive superedges, meanwhile strengthening the mutual influence among superedges, is the optimal intervention strategy. This investigation will help quantify the research of online public opinion intervention, while provides a new method for rumor intervention. © 2014 Elsevier B.V. All rights reserved.

Hu X.,Chinese Academy of Agricultural Sciences | Wang H.,China Agricultural University | Chen J.,China Agricultural University | Yang A.W.,China Agricultural University
Pakistan Journal of Botany | Year: 2012

Twenty-six morphological traits as well as 47 single nucleotide polymorphism and simple sequence repeat markers were used to investigate genetic variation in 67 tomato (Solanum lycopersicum L.) varieties collected from Argentina between 1932 and 1974. Approximately 65.0% of the morphological traits and 55.3% of the molecular markers showed polymorphisms in the 67 varieties. Average taxonomic distance between any two varieties ranged from 0.6643 to 1.1776, while Nei's genetic distance varied from 0 to 0.2022. Cluster analysis indicated that 67 varieties could be grouped into three clusters at both morphological and molecular levels. The varieties collected before 1960 had larger genetic variation than those collected after 1960.

Geng H.,Washington State University | Geng H.,Xinjiang Agricultural University | Beecher B.S.,Washington State University | He Z.,Chinese Academy of Agricultural Sciences | And 3 more authors.
Theoretical and Applied Genetics | Year: 2012

Kernel texture is a major factor influencing the classification and end use properties of wheat (Triticum aestivum L.), and is mainly controlled by the Puroindoline a (Pina) and Puroindoline b (Pinb) genes. Recently, a new puroindoline gene, Puroindoline b-2 (Pin b-2), was identified. In this study, 388 wheat cultivars and advanced breeding lines from the U. S. Pacific Northwest were investigated for frequencies of Puroindoline D1 alleles and Pinb-2 variants 2 and 3. Results indicated that Pinb-D1b (74.0%) was the predominant genotype among hard wheats (N = 196), the only other hard allele encountered was Pina-D1b (26. 0%). Across all varieties, Pinb-2v3 was the predominant genotype (84.5%) compared with Pinb-2v2 (15.5%). However, among 240 winter wheat varieties (124 soft white, 15 club, 68 hard red and 33 hard white varieties), all carried Pinb-2v3. Among spring wheats, Pinb-2v2 and Pinb-2v3 frequencies were more variable (soft white 25.0:75.0, hard red 58.2:41.8 and hard white 40.0:60.0, respectively). Kernel texture variation was analyzed using 247 of the 388 wheat varieties grown in multi-location factorial trials in up to 7 crop years. The range of variety means among the four groups, soft winter, soft spring, hard winter and hard spring, was on the order of 15-25 single kernel characterization system (SKCS) Hardness Index. The least significant difference for each of these trials ranged from 2. 8 to 5.6 SKCS Hardness Index. Observations lead to the conclusion that Pinb-2 variants do not exert a prominent effect on kernel texture, however, Pinb-2 variants do identify features of wheat germ plasm structure in the U. S. Pacific Northwest. © 2012 Springer-Verlag (outside the USA).

Fu X.-Z.,Huazhong Agricultural University | Fu X.-Z.,Chinese Academy of Agricultural Sciences | Gong X.-Q.,Huazhong Agricultural University | Zhang Y.-X.,Huazhong Agricultural University | And 2 more authors.
PLoS ONE | Year: 2012

Citrus canker disease caused by Xanthomonas citri subsp. citri (Xcc) is one of the most devastating biotic stresses affecting the citrus industry. Meiwa kumquat (Fortunella crassifolia) is canker-resistant, while Newhall navel orange (Citrus sinensis Osbeck) is canker-sensitive. To understand the molecular mechanisms underlying the differences in responses to Xcc, transcriptomic profiles of these two genotypes following Xcc attack were compared by using the Affymetrix citrus genome GeneChip. A total of 794 and 1324 differentially expressed genes (DEGs) were identified as canker-responsive genes in Meiwa and Newhall, respectively. Of these, 230 genes were expressed in common between both genotypes, while 564 and 1094 genes were only significantly expressed in either Meiwa or Newhall. Gene ontology (GO) annotation and Singular Enrichment Analysis (SEA) of the DEGs showed that genes related to the cell wall and polysaccharide metabolism were induced for basic defense in both Meiwa and Newhall, such as chitinase, glucanase and thaumatin-like protein. Moreover, apart from inducing basic defense, Meiwa showed specially upregulated expression of several genes involved in the response to biotic stimulus, defense response, and cation binding as comparing with Newhall. And in Newhall, abundant photosynthesis-related genes were significantly down-regulated, which may be in order to ensure the basic defense. This study revealed different molecular responses to canker disease in Meiwa and Newhall, affording insight into the response to canker and providing valuable information for the identification of potential genes for engineering canker tolerance in the future. © 2012 Fu et al.

Du J.,London School of Hygiene and Tropical Medicine | Du J.,Chinese Academy of Agricultural Sciences | Bhattacharya B.,London School of Hygiene and Tropical Medicine | Ward T.H.,London School of Hygiene and Tropical Medicine | Roy P.,London School of Hygiene and Tropical Medicine
Journal of Virology | Year: 2014

Bluetongue virus (BTV), a member of the Orbivirus genus in the Reoviridae family, is a double-capsid insect-borne virus enclosing a genome of 10 double-stranded RNA segments. Like those of other members of the family, BTV virions are nonenveloped particles containing two architecturally complex capsids. The two proteins of the outer capsid, VP2 and VP5, are involved in BTV entry and in the delivery of the transcriptionally active core to the cell cytoplasm. Although the importance of the endocytic pathway in BTV entry has been reported, detailed analyses of entry and the role of each protein in virus trafficking have not been possible due to the lack of availability of a tagged virus. Here, for the first time, we report on the successful manipulation of a segmented genome of a nonenveloped capsid virus by the introduction of tags that were subsequently fluorescently visualized in infected cells. The genetically engineered fluorescent BTV particles were observed to enter live cells immediately after virus adsorption. Further, we showed the separation of VP2 from VP5 during virus entry and confirmed that while VP2 is shed from virions in early endosomes, virus particles still consisting of VP5 were trafficked sequentially from early to late endosomes. Since BTV infects both mammalian and insect cells, the generation of tagged viruses will allow visualization of the trafficking of BTV farther downstream in different host cells. In addition, the tagging technology has potential for transferable application to other nonenveloped complex viruses. © 2014, American Society for Microbiology.

Chen M.,Chinese Academy of Agricultural Sciences | Chen M.,Tsinghua University | Chen J.,Tsinghua University | Sun F.,Tsinghua University
Science of the Total Environment | Year: 2010

Agriculture related pollution has attracted the attention of policy makers as well as scientists in China as its contribution to water impairment has increased, and quantitative information at the national and regional levels is being sought to support decision making. However, traditional approaches are either time-consuming, expensive (e.g. national surveys) or oversimplified and crude (e.g. coefficient methods). Therefore, this study proposed an extended substance flow analysis (SFA) framework to estimate nutrient releases from agricultural and rural activities in China by depicting the nutrient flows in Chinese agro-ecosystems. The six-step process proposed herein includes: (a) system definition; (b) model development; (c) database development; (d) model validation; (e) results interpretation; and (f) uncertainty analysis. The developed Eubolism (Elementary Unit based nutrient Balance m. Ode. LIng in agro-eco. Syste. M) model combined a nutrient balance module with an emission inventory module to quantify the nutrient flows in the agro-ecosystem. The model was validated and then applied to estimate the total agricultural nutrient loads, identify the contribution of different agricultural and rural activities and different land use types to the total loads, and analyze the spatial pattern of agricultural nutrient emissions in China. These results could provide an entire picture of agricultural pollution at the national level and be used to support policy making. Furthermore, uncertainties associated with the structure of the elementary units, spatial resolution, and inputs/parameters were also analyzed to evaluate the robustness of the model results. © 2010 Elsevier B.V.

Ye G.,International Rice Research Institute | Liang S.,International Rice Research Institute | Wan J.,Chinese Academy of Agricultural Sciences
Theoretical and Applied Genetics | Year: 2010

Protein content (PC) is an important component of rice nutritional quality. In order to better understand the genetic basis of this trait and increase related breeding efficiency, 21 single chromosome segment substitution (SCSS) lines grown in four sites over two growing seasons (regarded as eight environments) were used to associate PC with particular chromosome segments. Segments from 15 chromosomes were found to contain quantitative trait loci (QTLs) for PC in at least one environment. These included segments from chromosome 3 and 8, in which QTLs for PC had not previously been identified. The segment of chromosome 8 in CSSL-48 had the largest positive effect across all environments. The interaction between substitution and environment was highly significant. Some substitutions had large effects in one environment, but no effect in another (i.e. CSSL-08 and CSSL-17), while some substitutions significantly increased PC in one environment but decreased it in another (i.e. CSSL-41 and CSSL-43). By biplot and clustering analysis, the eight environments were grouped into two contrasting environment types, that is, Hainan and Jiangsu. The segment of chromosome 8 in CSSL-48 had PC-enhancing QTLs in both of the environment types. The segments in CSSL-34 had QTLs which increase PC in the Jiangsu environment but have no effect in the Hainan environment. For enhancing PC, CSSL-48 could be explored in breeding for wide adaptation across all environments, while CSSL-12, CSSL-14, CSSL-17, CSSL-41 and CSSL-43, and that in CSSL-34 could be explored in breeding for specific adaptation to the Hainan and Jiangsu environments, respectively. Near isogenic lines are under development to validate the QTLs with large effects in a range of genetic backgrounds relevant to Jiangsu and Hainan breeding programs. Secondary mapping populations are also being developed for further localising the responsible QTLs in CSSL-14, CSSL-34 and CSSL-48. © 2010 Springer-Verlag.

Lv M.,Chinese Academy of Agricultural Sciences
Wei sheng wu xue bao = Acta microbiologica Sinica | Year: 2011

To elucidate the co-localization characteristic between porcine epidemic diarrhea virus (PEDV) N protein and B23.1 phosphoprotein. Two pairs of primers used to amplify N gene and B23.1 gene were designed and synthesized according to CV777 N gene sequence (AF353511) and human nucleolar phosphoprotein B23.1 gene sequence (BC050628.1), respectively. The PEDV N gene and B23.1 gene were amplified by RT-PCR from PEDV strain CV777 and Vero E6 cells, respectively; then cloned into eukaryotic expression vector pAcGFP1-C1 and pDsRed2-N1, to generate the recombinant plasmids pAcGFP1-C1/N and pDsRed2-N1/B23.1, respectively. Vero E6 cells were transfected with plasmids pAcGFP1-C1/N and pDsRed2-N1/B23.1. The fusion proteins successfully expressed in transfected Vero E6 cells by western blot analysis, and the PEDV N protein and the B23.1 phosphoprotein showed co-localization features in co-transfected cells through confocal microscopy analysis. The results will help to identify the nucleolar localization signals in PEDV N protein and to elucidate the mechanism of N protein located in nucleus.

Liu Y.,Jilin University | Liu Y.,Academy of Military Medical Science | Zheng J.,Chinese Academy of Agricultural Sciences | Li J.,Jilin University | And 2 more authors.
Parasitology Research | Year: 2013

Rhomboid protein in Apicomplexa was associated with the process of host cell invasion. To evaluate the potential of the protein in eliciting protective immunity against challenge, a DNA vaccine pVAX1-Rho encoding Eimeria tenella rhomboid was constructed. Recombinant protein was expressed in Hela cells and verified by indirect immunofluorescence and western blotting analysis. In vivo experiments, 1-week-old chickens were randomly divided into three groups. Experimental group of chickens were immunized with DNA vaccines while control group of chickens were injected with pVAX1 plasmid alone or sterile water. Two weeks following the booster dose, all chickens were inoculated orally with 5 × 104 sporulated oocysts of E. tenella. The host immunity and protective efficacy of this vaccine against E. tenella challenge in broilers were evaluated. Results showed that specific antibody, the levels of interleukin-2 (IL-2), interferon-γ (IFN-γ), and the percentages of CD4+ and CD8+ T lymphocyte cells were significantly increased in the pVAX1-Rho group. Challenge experiments demonstrated that pVAX1-Rho vaccination could reduce oocyst excretion, decrease cecal lesion, increase bodyweight gains and provide chickens with oocysts decrease ratio around 75.8 %. These results suggest that the pVAX1-Rho was able to induce humoral and cellular responses and generate protective immunity against E. tenella infection. © 2012 Springer-Verlag Berlin Heidelberg.

Yan W.J.,Chinese Academy of Agricultural Sciences
Bing du xue bao = Chinese journal of virology / [bian ji, Bing du xue bao bian ji wei yuan hui] | Year: 2012

Tumor suppressor p53, known as 'the guardian of the genome', has the ability to prevent the emergence of transformed cells by the induction of cell cycle arrest and apoptosis. Otherwise, there were researches about the function of p53, such as NDA repair, regulating metabolism and maternal reproduction in recent years. Furthermore, there was a new function for p53 in antiviral apoptosis mentioned in the research, Integration of interferon-alpha/beta signaling to p53 responses in tumour suppression and antiviral defense. In order to define the antiviral function of p53, many target genes has been defined, such as IRF9, IRF5, ISG15 and TLR3. All of these implied there must be a complex mechanism for role of p53 in antiviral innate immunity, adaptive immunity and inflammation.

Jin J.,Chinese Academy of Agricultural Sciences
Journal of the Science of Food and Agriculture | Year: 2012

Results of three nationwide fertiliser efficiency studies in recent history in China are reviewed. The results indicate that after a long history using organic recycling to maintain soil fertility in China, nitrogen (N) became the first yield-limiting nutrient in the first national fertiliser efficiency study in 1935-1940. With N fertilisation being used, phosphorus (P) and potassium (K) deficiencies were gradually revealed and developed in the following national fertiliser efficiency studies in 1958-1962 and 1981-1983. Research conducted through the International Plant Nutrition (IPNI) cooperative network in China in 2000-2006 indicates that agronomic efficiencies of N fertiliser (yield increase per kilogram from the application of 1 kg N) for rice, wheat and maize are 11.7 kg, 10.8 kg and 12.2 kg grain per kilogram of N, respectively, while crop recovery efficiency of N (percentage of N taken up by plant in total N applied) with rice, wheat and maize were 24.8%, 35.7% and 30.5%, respectively. Both agronomic efficiency and crop recovery efficiency of N are significantly lower than the average N use efficiency reported in international literature for other countries. Current agronomic efficiency of P and K are also discussed. Measures to improve fertiliser use in China are discussed. © 2012 Society of Chemical Industry.

Huang G.,China Agricultural University | Wang X.,Chinese Academy of Agricultural Sciences | Han L.,China Agricultural University
Bioresource Technology | Year: 2011

Regression equations which relate livestock and poultry manure nutrient content to its several physicochemical properties have been reported by previous researchers. This study explores the feasibility and efficiency to determine the nutrients (TN; TP; TK; Cu and Zn) in chicken manure during composting using physicochemical properties (pH, EC and DM), and compares the performances of regression equations in this study with those in the literature. The results show that DM is the best predictor to construct the single linear regressions for all the nutrients (R2≥0.84, p<0.001). In addition, the multiple linear regression equations based on DM and pH are all notable. These findings show the potential of physicochemical models for TN, TP, TK, Cu and Zn with more convenience and rapidness, but further research is needed to develop better models with higher accuracy for the above and other more nutrients. © 2010 Elsevier Ltd.

Yu D.W.,Chinese Academy of Agricultural Sciences
Yi chuan = Hereditas / Zhongguo yi chuan xue hui bian ji | Year: 2011

Transgenic technology represents a revolutionary way to produce elite livestock breeds, allowing introduction of alien gene into livestock genome. Currently, pronuclear microinjection of DNA and somatic cell nuclear transfer are two popular methods used to make transgenic farm animals. Transgenic technology can be used in livestock breeding for improving disease resistance, carcass composition, lactational performance, wool production, growth rate, and reproductive performance, as well as reducing negative environmental impact. In addition to introduction of animal transgenic technologies, this review described the status and the future perspective of transgenic breeding in livestock.

Ye X.G.,Chinese Academy of Agricultural Sciences
Yi chuan = Hereditas / Zhongguo yi chuan xue hui bian ji | Year: 2011

Genetic transformation is a valuable tool for direct crop improvement and functional genomics study. Unfortunately, wheat is considered as a recalcitrant plant to genetic transformation due to its low efficiency and genotype dependency. To overcome these problems, various transformation methods such as biolistic bombardment, Agrobacterium tumefaciens, pollen-tube pathway, ion implantation, laser microbeams puncture, treatment with polyethylene glycol and ultrasonic wave, and electroporation have been reported in wheat using various types of explants including immature embryos, mature embryos, anthers derived calluses, inflorescences, apical meristems, and other floral organs. In this review, several major transformation approaches and their applications in wheat are reviewed, and potential strategies for the development of safe transgenic wheat plants are discussed. The objective of this review is to provide an update on current status of wheat trans-formation, and to stimulate further research for improving transformation efficiency in wheat.

Huang D.W.,Chinese Academy of Agricultural Sciences
Yi chuan = Hereditas / Zhongguo yi chuan xue hui bian ji | Year: 2011

Animal seasonal reproduction involves complicated neuroendocrine processes of the hypothalamo-pituitary-gonadal axis. It is dominantly regulated by photoperiod, a crucial environmental cue. Melatonin, as internal photoperiod signal, regulates seasonal reproduction of animals. In recent years, it has been found that Kiss1/GPR54 system, which may influence GnRH secretion evidently, is regulated by both melatonin and feedback action of gonadal steroid hormones. Consequently, Kiss1/GPR54 system may play a key role in seasonal reproduction. Additionally, there exists another potential retrograde control pathway of seasonal breeding, which involves TSH-DIO2/DIO3 system. TSH-DIO2/ DIO3 system affects synthesis and secretion of GnRH and is regulated by melatonin, as well as Kiss1/GPR54 system. In this article, melatonin signal, especially the research advances of Kissl/GPR54 system and TSH-DIO2/DIO3 system were reviewed.

Yuan Y.,Chinese Academy of Sciences | Wu C.,Chinese Academy of Sciences | Liu Y.,Chinese Academy of Agricultural Sciences | Yang J.,Chinese Academy of Sciences | Huang L.,Chinese Academy of Sciences
PLoS ONE | Year: 2013

R2R3-MYB proteins play role in plant development, response to biotic and abiotic stress, and regulation of primary and secondary metabolism. Little is known about the R2R3-MYB proteins in Scutellaria baicalensis which is an important Chinese medical plant. In this paper, nineteen putative SbMYB genes were identified from a S. baicalensis cDNA library, and eleven R2R3-MYBs were clustered into 5 subgroups according to phylogenetic reconstruction. In the S. baicalensis leaves which were sprayed with GA3, SbMYB2 and SbMYB7 had similar expression pattern with SbPALs, indicating that SbMYB2 and SbMYB7 might be involved in the flavonoid metabolism. Transactivation assay results showed that SbMYB2 and SbMYB7 can function as transcriptional activator. The expression of several flavonoid biosynthesis-related genes were induced or suppressed by overexpression of SbMYB2 or SbMYB7 in transgenic tobacco plants. Consistent with the change of the expression of NtDH29 and NtCHI, the contents of dicaffeoylspermidine and quercetin-3,7-O-diglucoside in SbMYB2-overexpressing or SbMYB7-overexpressing transgenic tobacco plants were decreased. The transcriptional level of NtUFGT in transgenic tobacco overexpressing SbMYB7 and the transcriptional level of NtHCT in SbMYB2-overexpressing tobacco plants were increased; however the application of GA3 inhibited the transcriptional level of these two genes. These results suggest that SbMYB2 and SbMYB7 might regulate the flavonoid biosynthesis through GA metabolism. © 2013 Yuan et al.

Wulff J.A.,University of Kentucky | Buckman K.A.,U.S. Department of Agriculture | Buckman K.A.,University of Minnesota | Wu K.,Chinese Academy of Agricultural Sciences | And 2 more authors.
PLoS ONE | Year: 2013

Aphids commonly harbor bacterial facultative symbionts that have a variety of effects upon their aphid hosts, including defense against hymenopteran parasitoids and fungal pathogens. The soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), is infected with the symbiont Arsenophonus sp., which has an unknown role in its aphid host. Our research goals were to document the infection frequency and diversity of the symbiont in field-collected soybean aphids, and to determine whether Arsenophonus is defending soybean aphid against natural enemies. We performed diagnostic PCR and sequenced four Arsenophonus genes in soybean aphids from their native and introduced range to estimate infection frequency and genetic diversity, and found that Arsenophonus infection is highly prevalent and genetically uniform. To evaluate the defensive role of Arsenophonus, we cured two aphid genotypes of their natural Arsenophonus infection through ampicillin microinjection, resulting in infected and uninfected isolines within the same genetic background. These isolines were subjected to parasitoid assays using a recently introduced biological control agent, Binodoxys communis [Braconidae], a naturally recruited parasitoid, Aphelinus certus [Aphelinidae], and a commercially available biological control agent, Aphidius colemani [Braconidae]. We also assayed the effect of the common aphid fungal pathogen, Pandora neoaphidis (Remaudiere & Hennebert) Humber (Entomophthorales: Entomophthoraceae), on the same aphid isolines. We did not find differences in successful parasitism for any of the parasitoid species, nor did we find differences in P. neoaphidis infection between our treatments. Our conclusion is that Arsenophonus does not defend its soybean aphid host against these major parasitoid and fungal natural enemies.

This study reports the effects of various nutritional and environmental factors on sporulation and biomass of Paecilomyces lilacinus IPC-P. These factors included carbon and nitrogen sources, carbon-to-nitrogen ratios, mineral elements and vitamins together with water potentials, temperatures, dark/light cycles and pH. On the basis of these results, together with a 'two-step' cultivation and orthogonal method, the culture conditions for sporulation of this fungus were optimized. The spore suspension was inoculated on a basal medium (sucrose 19.00 g/l, soy peptone 4.06 g/l, K2HPO4 1.00 g/l, KCl 0.50 g/l, MgSO4 0.50 g/l, FeSO4 0.01 g/l, agar 13.00 g/l) for 4 days, before being transferred to a sporulation medium (dextrin 2.27 g/l, urea 2.13 g/l, CaCl2 3.00 g/l, ZnSO4·7H2O 0.01 g/l, agar 13.00 g/l) for a further 4 days under the following environmental conditions: -3.9 MPa/pH 7/light 24 h/temperature 29°C; these conditions were altered to -0.3 MPa/pH 6/light 24 h/temperature 23°C in order to obtain better biomass yields. The data presented provide information on the nutrient and environmental requirements of this fungus, which will be essential for its commercial production. © 2014 Blackwell Verlag GmbH.

Li X.,Samuel Roberts Noble Foundation | Wei Y.,Samuel Roberts Noble Foundation | Acharya A.,Samuel Roberts Noble Foundation | Jiang Q.,Samuel Roberts Noble Foundation | And 2 more authors.
G3: Genes, Genomes, Genetics | Year: 2014

A genetic linkage map is a valuable tool for quantitative trait locus mapping, map-based gene cloning, comparative mapping, and whole-genome assembly. Alfalfa, one of the most important forage crops in the world, is autotetraploid, allogamous, and highly heterozygous, characteristics that have impeded the construction of a high-density linkage map using traditional genetic marker systems. Using genotyping-by-sequencing (GBS), we constructed low-cost, reasonably high-density linkage maps for both maternal and paternal parental genomes of an autotetraploid alfalfa F1 population. The resulting maps contain 3591 single-nucleotide polymorphism markers on 64 linkage groups across both parents, with an average density of one marker per 1.5 and 1.0 cM for the maternal and paternal haplotype maps, respectively. Chromosome assignments were made based on homology of markers to the M. truncatula genome. Four linkage groups representing the four haplotypes of each alfalfa chromosome were assigned to each of the eight Medicago chromosomes in both the maternal and paternal parents. The alfalfa linkage groups were highly syntenous with M. truncatula, and clearly identified the known translocation between Chromosomes 4 and 8. In addition, a small inversion on Chromosome 1 was identified between M. truncatula and M. sativa. GBS enabled us to develop a saturated linkage map for alfalfa that greatly improved genome coverage relative to previous maps and that will facilitate investigation of genome structure. GBS could be used in breeding populations to accelerate molecular breeding in alfalfa. © 2014 Li et al.

Zhang H.,Chinese Academy of Agricultural Sciences
Plant signaling & behavior | Year: 2011

Drought, salinity and low temperature are major environmental factors that influence plant growth and development, and eventually limit crop yield and quality. To survive adverse stresses, plants have developed complex signaling networks to perceive external stimuli, and then manifest adaptive responses at molecular and physiological levels. Sucrose non-fermenting1-related protein kinase 2 (SnRK2) plays a critical role in plant sugar signaling via phosphorylation, while knowledge of specific functions of SnRK2s in wheat is still undiscovered. In this paper, we reviewed our recent studies on wheat SnRK2 members, TaSnRK2.4, TaSnRK2.7 and TaSnRK2.8, involved in abiotic stress responses. The results suggest that the three wheat kinases participate in sugar metabolic and stress signaling in wheat. Furthermore, we compare their distinct transcript levels in various tissues, expression patterns under diverse stress conditions, and functions in transgenic Arabidopsis.

Wang J.Q.,Chinese Academy of Agricultural Sciences
Yi chuan = Hereditas / Zhongguo yi chuan xue hui bian ji | Year: 2011

Fecundity trait in sheep is regulated by some major genes. Among them, BMPR-IB, BMP-15, and GDF-9 are most distinguishing. The mutant FecB of BMPR-IB has multiplicative effects on ovulation. GDF-9's mutants FecGH, FecI, and BMP-15's mutants FecXI, FecXH, FecXG, FecXB, FecXL, and FecXR increase ovulation rate in the heterozygote but result in sterile phenotypes in the homozygote, while GDF-9's mutant, FecGE, only increases ovulation rate in the homozygote. In addition, Woodlands and Lacaune are known as inheritable major genes. Woodlands gene is an X-linked maternally imprinted gene, and Lacaune is similar to FecB with a multiplicative effect on ovulation rate. The size of the effect of one copy of a mutation on ovulation rate ranges from an extra 0.4 ovulations for the woodlands mutation to an extra 1.5 ovulations for the BMPR-IB and Lacaune mutation. Investigation into these genes will not only help to select breeds with high fertility, but also give a chance to further elucidate the mechanism involved in the phenomenon. This review summaries the source, location, phenotype, and mechanism of the major genes in all breeds of sheep.

Zhao J.,Chinese Academy of Agricultural Sciences
Wei sheng wu xue bao = Acta microbiologica Sinica | Year: 2011

Canine parvovirus (CPV-2), first recognized in 1978 as a new pathogen of dogs, was probably derived from a very closely related virus in cats, feline panleukopaenia virus (FPLV) or a closely related carnivore parvovirus (FPLV-like virus). CPV-2 is responsible for either myocarditis or fatal gastroenteritis in pups with high morbidity and mortality. Shortly after its emergence, CPV-2 has become endemic in the global dog population. The original CPV-2 continued to evolve, and was subsequently replaced by three different but closely related antigenic variants, designated CPV-2a, CPV-2b and CPV-2c, which now coexist in dog populations worldwide. The genetic and antigenic variation in CPV-2 also correlated with changes in the host range and tissue tropisms of the virus. Here, we reviewed variation and evolution of CPV-2 in past 30 years and discussed CPV-2 as an important model to study virus evolution.

Xu Y.,Chinese Academy of Agricultural Sciences | Xu Y.,University of Arizona | Zhou T.,Utah State University | Espinosa-Artiles P.,University of Arizona | And 4 more authors.
ACS Chemical Biology | Year: 2014

The phytotoxic fungal polyketides lasiodiplodin and resorcylide inhibit human blood coagulation factor XIIIa, mineralocorticoid receptors, and prostaglandin biosynthesis. These secondary metabolites belong to the 12-membered resorcylic acid lactone (RAL12) subclass of the benzenediol lactone (BDL) family. Identification of genomic loci for the biosynthesis of lasiodiplodin from Lasiodiplodia theobromae and resorcylide from Acremonium zeae revealed collaborating iterative polyketide synthase (iPKS) pairs whose efficient heterologous expression in Saccharomyces cerevisiae provided a convenient access to the RAL12 scaffolds desmethyl-lasiodiplodin and trans-resorcylide, respectively. Lasiodiplodin production was reconstituted in the heterologous host by co-expressing an O-methyltransferase also encoded in the lasiodiplodin cluster, while a glutathione-S-transferase was found not to be necessary for heterologous production. Clarification of the biogenesis of known resorcylide congeners in the heterologous host helped to disentangle the roles that biosynthetic irregularities and chemical interconversions play in generating chemical diversity. Observation of 14-membered RAL homologues during in vivo heterologous biosynthesis of RAL12 metabolites revealed stuttering by fungal iPKSs. The close global and domain-level sequence similarities of the orthologous BDL synthases across different structural subclasses implicate repeated horizontal gene transfers and/or cluster losses in different fungal lineages. The absence of straightforward correlations between enzyme sequences and product structural features (the size of the macrocycle, the conformation of the exocyclic methyl group, or the extent of reduction by the hrPKS) suggest that BDL structural variety is the result of a select few mutations in key active site cavity positions. © 2014 American Chemical Society.

Zhang C.,China Agricultural University | Wang S.,Tsinghua University | Yan Y.,Chinese Academy of Agricultural Sciences
Bioresource Technology | Year: 2011

Pseudomonas aeruginosa CH7, isolated from activated sludge, was able not only to isomerize and degrade beta-cypermethrin but also to utilize it as the sole source of carbon and energy for growth and produce biosurfactant. The strain effectively degraded beta-cypermethrin with inocula biomass of 0.1-0.2gL-1 at 25-35°C, pH 6-9, and a final concentration of beta-cypermethrin 25-900mgL-1. Via response surface methodology analysis, we found the optimal condition was 29.4°C, pH 7.0, and inocula biomass of 0.15gL-1; under these conditions, about 90% of the beta-cypermethrin could be degraded within 12days. Noticeably, biosurfactant was detected in the MSM culture of strain CH7, suggesting that the biosurfactant (rhamnolipid) could potentially enhance the degradation of beta-cypermethrin by promoting the dissolution, adsorption, and absorption of the hydrophobic compounds. Therefore, CH7 may serve as a promising strain in the bioremediation of wastewater and soil polluted by beta-cypermethrin. © 2011 Elsevier Ltd.

Liu K.J.,Rice University | Dai J.,Rice University | Truong K.,Rice University | Song Y.,Chinese Academy of Agricultural Sciences | And 2 more authors.
PLoS Computational Biology | Year: 2014

One outcome of interspecific hybridization and subsequent effects of evolutionary forces is introgression, which is the integration of genetic material from one species into the genome of an individual in another species. The evolution of several groups of eukaryotic species has involved hybridization, and cases of adaptation through introgression have been already established. In this work, we report on PhyloNet-HMM-a new comparative genomic framework for detecting introgression in genomes. PhyloNet-HMM combines phylogenetic networks with hidden Markov models (HMMs) to simultaneously capture the (potentially reticulate) evolutionary history of the genomes and dependencies within genomes. A novel aspect of our work is that it also accounts for incomplete lineage sorting and dependence across loci. Application of our model to variation data from chromosome 7 in the mouse (Mus musculus domesticus) genome detected a recently reported adaptive introgression event involving the rodent poison resistance gene Vkorc1, in addition to other newly detected introgressed genomic regions. Based on our analysis, it is estimated that about 9% of all sites within chromosome 7 are of introgressive origin (these cover about 13 Mbp of chromosome 7, and over 300 genes). Further, our model detected no introgression in a negative control data set. We also found that our model accurately detected introgression and other evolutionary processes from synthetic data sets simulated under the coalescent model with recombination, isolation, and migration. Our work provides a powerful framework for systematic analysis of introgression while simultaneously accounting for dependence across sites, point mutations, recombination, and ancestral polymorphism. © 2014 Liu et al.

Abdel Latef A.A.H.,South Valley University | Chaoxing H.,Chinese Academy of Agricultural Sciences
Journal of Plant Growth Regulation | Year: 2014

A pot experiment was conducted to determine the effects of Glomus mosseae inoculation on growth and some biochemical activities in roots and shoots of pepper (Capsicum annuum L. cv. Zhongjiao 105) plants subjected to four levels of NaCl [0 (control), 25 (low), 50 (medium), and 100 (high) mM] for 30 days, after 30 days of establishment under non-saline conditions. In mycorrhizal (M) plants, root colonization varied from 48 to 16 %. M plants had higher root and shoot dry weight and leaf area compared with non-mycorrhizal (NM) plants. Under salinity stress, M plants accumulated higher amounts of leaf photosynthetic pigments as well as soluble sugar, soluble protein, and total free amino acids in roots and shoots than those of NM plants. In contrast, the accumulation of proline was less intense in M plants than NM plants. Salt stress induced oxidative stress by increasing malondialdehyde (MDA) content; however, the extent of oxidative damage in M plants was less compared with NM plants due to G. mosseae-enhanced activity of superoxide dismutase (SOD) and peroxidase (POD). We concluded that inoculation with G. mosseae improved growth performance and enhanced salt tolerance of pepper plants via improving photosynthetic pigments and the accumulation of organic solutes (except proline), reducing oxidative stress, and enhancing antioxidant activities of the SOD-POD system. © 2014 Springer Science+Business Media New York.

Wei H.,Zhejiang University | Wei H.,Chinese Academy of Agricultural Sciences | Li W.,Zhejiang University | Sun X.,Zhejiang University | And 2 more authors.
PLoS ONE | Year: 2013

Plant disease resistance genes are a key component of defending plants from a range of pathogens. The majority of these resistance genes belong to the super-family that harbors a Nucleotide-binding site (NBS). A number of studies have focused on NBS-encoding genes in disease resistant breeding programs for diverse plants. However, little information has been reported with an emphasis on systematic analysis and comparison of NBS-encoding genes in cotton. To fill this gap of knowledge, in this study, we identified and investigated the NBS-encoding resistance genes in cotton using the whole genome sequence information of Gossypium raimondii. Totally, 355 NBS-encoding resistance genes were identified. Analyses of the conserved motifs and structural diversity showed that the most two distinct features for these genes are the high proportion of non-regular NBS genes and the high diversity of N-termini domains. Analyses of the physical locations and duplications of NBS-encoding genes showed that gene duplication of disease resistance genes could play an important role in cotton by leading to an increase in the functional diversity of the cotton NBS-encoding genes. Analyses of phylogenetic comparisons indicated that, in cotton, the NBS-encoding genes with TIR domain not only have their own evolution pattern different from those of genes without TIR domain, but also have their own species-specific pattern that differs from those of TIR genes in other plants. Analyses of the correlation between disease resistance QTL and NBS-encoding resistance genes showed that there could be more than half of the disease resistance QTL associated to the NBS-encoding genes in cotton, which agrees with previous studies establishing that more than half of plant resistance genes are NBS-encoding genes. © 2013 Wei et al.

Li K.,China Agricultural University | Yang X.,China Agricultural University | Liu Z.,China Agricultural University | Zhang T.,CAS Institute of Atmospheric Physics | And 2 more authors.
European Journal of Agronomy | Year: 2014

The yield gap (YG) between the potential yields (Yp) and the average on-farm yields (Ya) is an indicator of the potential improvement for crop production. Understanding how large the current gap is and how this gap has changed over the past few decades is essential for increasing wheat production to meet increased food demand in China. This paper describes a study conducted using an APSIM-Wheat model and farm-level crop yield to analyze the spatio-temporal distribution of the yield gap of winter wheat from 1981 to 2010 in the North China Plain. Nine varieties were calibrated and evaluated based on the data from 16 agro-meteorological experimental sites and then potential yields were estimated considering cultivar replacement. In addition, a trend pattern analysis of on-farm yields for the period 1981-2010 was conducted. Results revealed an estimated yield gap across the entire North China Plain region of 1140-6810kgha-1, with a weight average of 3630kgha-1 in 1981-2010. Expressed as a relative yield (yield gap % of potential yields), the range was 15-80%, and the weight average was 45%. Despite the negative effects of increasing temperature and decreasing radiation, the potential yields significantly increased by 45kgha-1 per year due to cultivar improvement. On-farm yields increased even more notably because of new cultivar selection, increased fertilizer application and other management improvements, but were stagnating in 32.3% of wheat areas, located mainly in Hebei province, Shandong province, Beijing and Tianjin. The improvement of on-farm yields have substantially contributed to yield gap spatio-temporal variation. As a result, the yield gap decreased from 4200kgha-1 (56%) in 1981-1990 to 3000kgha-1 (35%) in 2001-2010 at a rate of -69kgha-1 per year. However, yields stagnation will expand to the northern Henan province without cultivar potential productivity improving, where yield gap was close to or less than 20% of the potential yields and proved difficult to reduce. To further improve the total production of winter wheat in the coming decades, efforts should be paid to break the potential ceiling and reduce the yield gap by breeding higher yield variety and introduction of new agricultural technology. © 2014 Elsevier B.V.

Wang Z.,Huazhong University of Science and Technology | Zhang Y.,Huazhong University of Science and Technology | Zhang J.,Huazhong University of Science and Technology | Huang L.,Huazhong University of Science and Technology | And 5 more authors.
Scientific Reports | Year: 2014

Sericin, a major component of silk, has a long history of being discarded as a waste during silk processing. The value of sericin for tissue engineering is underestimated and its potential application in regenerative medicine has just begun to be explored. Here we report the successful fabrication and characterization of a covalently-crosslinked 3D pure sericin hydrogel for delivery of cells and drugs. This hydrogel is injectable, permitting its implantation through minimally invasive approaches. Notably, this hydrogel is found to exhibit photoluminescence, enabling bioimaging and in vivo tracking. Moreover, this hydrogel system possesses excellent cell-adhesive capability, effectively promoting cell attachment, proliferation and long-term survival of various types of cells. Further, the sericin hydrogel releases bioactive reagents in a sustained manner. Additionally, this hydrogel demonstrates good elasticity, high porosity, and pH-dependent degradation dynamics, which are advantageous for this sericin hydrogel to serve as a delivery vehicle for cells and therapeutic drugs. With all these unique features, it is expected that this sericin hydrogel will have wide utility in the areas of tissue engineering and regenerative medicine.

Shen M.,Nanjing Agricultural University | Liu Z.,Nanjing Agricultural University | Teng Y.,Nanjing Agricultural University | Zhang J.,Nanjing Agricultural University | And 3 more authors.
Cell Death and Disease | Year: 2014

In mammalian ovaries, follicular atresia occurs periodically and destroys almost all the follicles in the ovary. Follicle-stimulating hormone (FSH) acts as the primary survival factor during follicular atresia by preventing apoptosis in granulosa cells. FoxO1 is a critical factor in promoting follicular atresia and granulosa cell apoptosis. FSH inhibits the induction of FoxO1. In this report, we investigated the role of FSH-FoxO1 pathway in mouse follicular atresia. FSH dampened stress-induced apoptosis and the expression of FoxO1 and pro-apoptosis genes in mouse granulosa cells (MGCs). In contrast, overexpression of FoxO1 inhibited the viability of MGCs and induced the expression of endogenous FoxO1. The signaling cascades involved in regulating FoxO1 activity upon FSH treatment were identified using FSH signaling antagonists. Blocking protein kinase A (PKA), phosphatidylinositol-3 kinase (PI3K) or protein kinase B (AKT) restored the upregulation of FoxO1 and apoptotic signals, which was suppressed by FSH. Moreover, inhibition of PKA or PI3K impaired FSH-induced AKT activity, but inactivation of PI3K or AKT had little effect on PKA activity in the presence of FSH. Correspondingly, constitutive activation of FoxO1 (all three AKT sites were replaced by alanines) also promoted MGC apoptosis despite FSH administration. Furthermore, both luciferase reporter assays and chromatin immunoprecipitation assays showed that FoxO1 directly bound to a FoxO-recognized element site within the FoxO1 promoter and contributed to the regulation of FoxO1 expression in response to FSH. Taken together, we propose a novel model in which FSH downregulates FoxO1-dependent apoptosis in MGCs by coordinating the PKA-PI3K-AKT-FoxO1 axis and FoxO1-FoxO1 positive feedback. © 2014 Macmillan Publishers Limited. All rights reserved.

Zhang Z.,Beijing Forestry University | Zhang Z.,Chinese Academy of Agricultural Sciences | Kang X.,Beijing Forestry University
Euphytica | Year: 2010

Natural triploids of Populus tomentosa (2n = 3x = 57) are presumably the result of sexual polyploidization through the union of normal n female gametes and numerically unreduced (2n) male gametes. In our microscopic study of microspore mother cells (MMCs) of diploid P. tomentosa (2n = 2x = 38), we observed that the first meiotic division was normal but that the second division was characterized by frequent abnormal spindle orientation (parallel, tripolar, and fused spindles) and premature cytokinesis. The parallel, fused spindles and premature cytokinesis were considered to be leading dyad formation, and tripolar spindles seemed to be leading triad formation at the tetrad stage. There was a higher frequency of parallel spindles than other spindle forms, but there were no significant correlations between parallel spindles and dyads. An indirect immunofluorescence examination of meiosis II revealed that four tetragonally arranged nuclei were formed in MMCs with parallel spindles and that there were radial microtubules systems (RMSs) among these four nuclei, leading to the tetragonal tetrad. In some MMCs, however, the parallel spindles led to the gathering of one or two non-sister groups of chromosomes, causing an incorporation of RMSs from two daughter nuclei. Thus, the incorporated RMSs established three or two nuclear cytoplasmic domains for the control of division plane, resulting in either triad or dyad formation. These results provide new insights on the mechanism of parallel spindles leading to numerically unreduced pollen formation and on the selection and utilization of this type of pollen in polyploid breeding of P. tomentosa. © 2009 Springer Science+Business Media B.V.

Gong Z.L.,Chinese Academy of Agricultural Sciences
Zhongguo ji sheng chong xue yu ji sheng chong bing za zhi = Chinese journal of parasitology & parasitic diseases | Year: 2010

To clone and express BC48 gene of Babesia caballi, and to establish an indirect ELISA for the diagnosis of B. caballi in equine animals. The genomic DNA of B. caballi was extracted from the infected donkey blood. BC48 gene was amplified by PCR. The PCR product was cloned into expression plasmid pET28a, and expressed in E. coli BL21 with IPTG induction. The recombinant protein was purified by Ni-NTA affinity chro-matography and was used as a diagnostic antigen to establish an indirect ELISA. The reaction conditions of the indirect ELISA were optimized. Specificity and sensitivity of this method were evaluated. BC48 gene of B. caballi was 1 272 bp. The recombinant protein was expressed in E. coli BL21 as a soluble protein with a molecular weight of about M, 46 000 under induction of IPTG. The concentration of purified protein was 12.98 mg/ml. The best conditions were obtained for the ELISA when the antigen concentration was 65 microg/ml with the serum dilution of 1:80. The protein specifically reacted with serum from donkey infected by B. caballi, but did not react with serum from donkey infected by Theileria equi (B. equi). Both ELISA and microscopy were applied to examine 17 donkeys in the field, 3 were positive by ELISA and 2 were found parasite-positive, respectively. The indirect ELISA method may be used to detect B. caballi infection in equine animals.

Cao X.Z.,Chinese Academy of Agricultural Sciences
Bing du xue bao = Chinese journal of virology / [bian ji, Bing du xue bao bian ji wei yuan hui] | Year: 2010

The threshold hypothesis of attenuated lentiviral vaccine considers that the type of host response to infections of lentiviruses depends on the viral load. To evaluate the correlation between viral loads of the attenuated vaccine strain of equine infectious anemia virus (EIAV) and their effects to induce protective immunity, longitudinal plasma viral loads in groups of horses inoculated with either an attenuated EIAV vaccine strain (EIAV(DLV125)) or sub-lethal dose of an EIAV virulent strain (EIAV(LN40)) were compared. Similar levels of plasma viral loads ranging from 10(3)-10(5) copies/mL were detected from samples of these two groups of animals (P > 0.05) during 23 weeks post the inoculation. However, different responses to the challenge performed thereafter with lethal dose of the EIAV virulent strain were observed from the groups of horses inoculated with either EIAV(DLV125) or sub-lethal dose of EIAV(LN40). The protective efficiency was 67% (3 of 4 cases) and 0 (none of 2 cases), respectively. Our results implicate that the viral load of EIAV attenuated vaccine is not the primary factor, or at least not the solo primary factor, to determine the establishment of immune protection.

Hu Z.,Hefei University of Technology | Chen H.,Hefei University of Technology | Ji F.,Chinese Academy of Agricultural Sciences | Yuan S.,Hefei University of Technology
Journal of Hazardous Materials | Year: 2010

In this study, cattail root was used to remove Congo Red (CR) from aqueous solution. The effects of operation variables, such as cattail root dosage, contact time, initial pH, ionic strength and temperature on the removal of CR were investigated using batch adsorption technique. Removal efficiency increased with increase of cattail root dosage and ionic strength, but decreased with increase of temperature. The equilibrium data fitted well to the Langmuir model (R2 > 0.98) and the adsorption kinetic followed the pseudo-second-order equation (R2 > 0.99). Thermodynamics parameters such as standard free energy change (ΔG°), standard enthalpy change (ΔH°), and standard entropy change (ΔS°) were analyzed. The values of ΔG° were between -7.871 and -4.702 kJ mol-1, of ΔH° was -54.116 kJ mol-1, and of ΔS° was -0.157 kJ mol-1 K-1, revealing that the removal of CR from aqueous solution by cattail root was a spontaneous and exothermic adsorption process. The maximum adsorption capacities of CR on cattail root were 38.79, 34.59 and 30.61 mg g-1 at 20, 30 and 40 °C, respectively. These results suggest that cattail root is a potential low-cost adsorbent for the dye removal from industrial wastewater. © 2009 Elsevier B.V. All rights reserved.

Verburg P.H.,VU University Amsterdam | Mertz O.,Copenhagen University | Erb K.-H.,University of Vienna | Haberl H.,University of Vienna | Wu W.,Chinese Academy of Agricultural Sciences
Current Opinion in Environmental Sustainability | Year: 2013

Land system science can contribute to sustainable solutions by an integrated analysis of land availability and the assessment of the tradeoffs associated with agricultural expansion and land use intensification. A land system perspective requires local studies of production systems to be contextualised in a regional and global context, while global assessments should be confronted with local realities. Understanding of land governance structures will help to support the development of land use policies and tenure systems that assist in designing more sustainable ways of intensification. Novel land systems should be designed that are adapted to the local context and framed within the global socio-ecological system. Such land systems should explicitly account for the role of land governance as a primary driver of land system change and food production. © 2013 The Authors.

Zhang B.,CAS Institute of Geographical Sciences and Natural Resources Research | Xie G.,CAS Institute of Geographical Sciences and Natural Resources Research | Zhang C.,CAS Institute of Geographical Sciences and Natural Resources Research | Zhang J.,Chinese Academy of Agricultural Sciences
Journal of Environmental Management | Year: 2012

Urbanization involves the replacement of vegetated surfaces with impervious built surfaces, and it often results in an increase in the rate and volume of rainwater surface runoff. Urban green spaces play a positive role in rainwater-runoff reduction. However, few studies have explored the benefits of rainwater-runoff reduction by urban green spaces. Based on inventory data of urban green spaces in Beijing, the paper evaluated the economic benefits of rainwater-runoff reduction by urban green spaces, using the rainwater-runoff-coefficient method as well as the economic valuation methods. The results showed that, 2494 cubic meters of potential runoff was reduced per hectare of green area and a total volume of 154 million cubic meters rainwater was stored in these urban green spaces, which almost corresponds to the annual water needs of the urban ecological landscape in Beijing. The total economic benefit was 1.34 billion RMB in 2009 (RMB: Chinese currency, US$1 = RMB6.83), which is equivalent to three-quarters of the maintenance cost of Beijing's green spaces; the value of rainwater-runoff reduction was 21.77 thousand RMB per hectare. In addition, the benefits in different districts and counties were ranked in the same order as urban green areas, and the average benefits per hectare of green space showed different trends, which may be related to the impervious surface index in different regions. This research will contribute to an understanding of the role that Beijing's green spaces play in rainwater regulation and in the creation and scientific management of urban green spaces. © 2012 Elsevier Ltd.

Yang Z.,Chinese Academy of Agricultural Sciences
Molecular genetics and genomics : MGG | Year: 2014

Somatic embryogenesis is a useful tool for gene transfer and propagation of plants. AGAMOUS-LIKE15 (AGL15) promotes somatic embryogenesis in many plant species. In this study, three homologous AGL15 genes were isolated from Gossypium hirsutum L., namely GhAGL15-1, GhAGL15-3, and GhAGL15-4. Their putative proteins contained a highly conserved MADS-box DNA-binding domain and a less conserved K domain. Phylogenetic analysis suggested that the three GhAGL15s clustered most closely with AGL15 proteins in other plants. Subcellular location analyses revealed that three GhAGL15s were localized in the nucleus. Furthermore, their expression levels increased following embryogenic callus induction, but sharply decreased during the embryoid stage. GhAGL15-1 and GhAGL15-3 were significantly induced by 2,4-D and kinetin, whereas GhAGL15-4 was only responsive to 2,4-D treatment. Over-expression of the three GhAGL15s in cotton callus improved callus quality and significantly increased the embryogenic callus formation rate, while GhAGL15-4 had the highest positive effect on the embryogenic callus formation rate (an increase from 38.1 to 65.2%). These results suggest that over-expression of GhAGL15s enhances embryogenic potential of transgenic calli. Therefore, spatiotemporal manipulation of GhAGL15s expression may prove valuable in improving cotton transformation efficiency.

Duan Y.,Chinese Academy of Sciences | Duan Y.,Chinese Academy of Agricultural Sciences | Li F.,Chinese Academy of Sciences | Li L.,Chinese Academy of Sciences | And 4 more authors.
British Journal of Nutrition | Year: 2014

The objective of the present study was to investigate the optimal dietary n-6:n-3 PUFA ratios that regulate lipid metabolism and inflammation in pigs. A total of ninety-six cross-bred (Large White × Landrace) growing-finishing pigs (73·8 (sem 1·6) kg) were chosen and fed one of the four isoenergetic diets with n-6:n-3 PUFA ratios of 1:1, 2·5:1, 5:1 and 10:1. The growth performance of pigs fed the diet with an n-6:n-3 PUFA ratio of 5:1 was the best, but the group fed the diet with an n-6:n-3 PUFA ratio of 1:1 had the highest muscle mass and the lowest adipose tissue mass (P< 0·05). The concentrations of IL-6 and IL-1β of pigs fed the diet with an n-6:n-3 PUFA ratio of 1:1 were decreased compared with those of the other groups (P< 0·05). The concentration of adiponectin of pigs fed the diet with an n-6:n-3 PUFA ratio of 1:1 was also markedly decreased, but the concentration of leptin was increased compared with that of the groups fed the diets with n-6:n-3 PUFA ratios of 5:1 and 10:1 (P< 0·05). Additionally, the optimal dietary ratios of n-6:n-3 PUFA of 1:1 and 5:1 markedly suppressed the expression levels of lipid metabolism-related genes and proteins such as phosphoinositide-3-kinase-α, fatty acid transport protein-1 and PPARγ. They also significantly suppressed the expression levels of the inflammatory cytokines IL-1β, TNF-α and IL-6. The results indicated that the optimal n-6:n-3 PUFA ratios of 1:1 and 5:1 exerted beneficial effects on lipid metabolism and inflammatory system, leading to the availability of more energy and nutrients for high performance and homeostatic pathways. © 2013 The Authors.

Sun Y.L.,Chinese Academy of Agricultural Sciences
Yi chuan = Hereditas / Zhongguo yi chuan xue hui bian ji | Year: 2012

The present study was conducted to evaluate genetic analysis of fuzzless seed trait in cotton. One hundred and two upland cotton (G. hirsutum) and eighty-five island cotton (G. barbadense) were used to cross with the same lines, TM-1 (G. hirsutum) and Xinhai 13 (G. barbadense), respectively. Two different F1 populations obtained were assessed to specify the dominant and recessive inheritance of fiber fuzziness in these lines. Three F1 populations (Kuguangzi × TM-1, Luwuxu × TM-1, and SA65 × TM-1) displaying recessive fiber fuzziness inheritance were selected to construct the F2 population for a further genetic study of fuzzless seed trait. The results of this study indicated that (1) the same materials showed different quantities of fuzzy fiber in different environments. Less fuzzy fiber was found in Xinjian and Hainan compared to Anyang. Thus, the quantity of fuzzy cotton seed depends on ecological environment. (2) In upland cotton, the inheritance of fiber fuzziness was dominant for 26 accessions (25.49%), incompletely dominant for 8 accessions (7.84%), and recessive for 22 accessions (21.57%). The inheritance of fiber fuzziness in island cotton was dominant for 5 accessions (5.88%), incompletely dominant for 16 accessions (18.82%), and recessive for 9 accessions (10.59%). Analysis of F2 population indicated that the fiber fuzziness of Kuguangzi was controlled by two recessive complementary effect alleles. The fiber fuzziness of Luwuxu was controlled by two recessive additive effect alleles, and a single recessive gene controlled the same trait for SA65. Fiber fuzziness evaluation in cotton germplasm provides the genetic and basic information for cotton fiber development study and breeding.

Wang C.,Chinese Academy of Agricultural Sciences
G3 (Bethesda, Md.) | Year: 2012

As an ancient cereal of great importance for dryland agriculture even today, foxtail millet (Setaria italica) is fast becoming a new plant genomic model crop. A genotypic analysis of 250 foxtail millet landraces, which represent 1% of foxtail millet germplasm kept in the Chinese National Gene Bank (CNGB), was conducted with 77 SSRs covering the foxtail millet genome. A high degree of molecular diversity among the landraces was found, with an average of 20.9 alleles per locus detected. STRUCTURE, neighbor-jointing, and principal components analyses classify the accessions into three clusters (topmost hierarchy) and, ultimately, four conservative subgroups (substructuring within the topmost clusters) in total, which are in good accordance with eco-geographical distribution in China. The highest subpopulation diversity was identified in the accessions of Pop3 from the middle regions of the Yellow River, followed by accessions in Pop1 from the downstream regions of the Yellow River, suggesting that foxtail millet was domesticated in the Yellow River drainage area first and then spread to other parts of the country. Linkage disequilibrium (LD) decay of less than 20 cM of genetic distance in the foxtail millet landrace genome was observed, which suggests that it could be possible to achieve resolution down to the 20 cM level for association mapping.

Luo Q.M.,Chinese Academy of Agricultural Sciences
Yi chuan = Hereditas / Zhongguo yi chuan xue hui bian ji | Year: 2011

The animal transgenic technology has increasingly turned mature over several decades and promoted the research of transgenic technology to a new developmental phase. In this review, various kinds of transgenic technologies, including somatic cell nuclear transfer, gene transfer mediated by transposon, gene knockout mediated by RNA interference, and zinc-finger nucleases-gene targeting technology, are summarized. Recently, the success of induced pluripotent stem cells (iPS cells), which has provided an alternative way to derive pluripotent stem cells of large animals, will extend the field of transgenic animal studies. Here, we summarized the latest trends on the basis of previous studies. In addition, the characteristics of different kinds of transgenic methods in detail are discussed.

Li Y.K.,Chinese Academy of Agricultural Sciences
Yi chuan = Hereditas / Zhongguo yi chuan xue hui bian ji | Year: 2012

SOD is an important enzyme which exists in eukaryote extensively and plays an essential role in stress-tolerance of higher plants. A cDNA of Cu/ZnSOD gene was cloned from Galega orientalis L. using rapid amplification of cDNA ends (RACE) method. The full-length of cDNA sequence is 935 bp, included a 600 bp open reading frame which encoded a 199-amino-acid polypeptide. The molecular weight of this protein was 20.35 kDa. The results of Real-Time PCR indicated that the expression level of Cu/ZnSOD gene was the highest in leaves, moderate in stems, and the least in roots. The expression of Cu/ZnSOD gene under stress of NaCl and PEG was up-regulated firstly and then declined. The expression level was significantly lower than the control after 24 h treated with NaCl. Abscisic acid downregulated the expression of Cu/ZnSOD gene. The result of subcellular localization indicated that Cu/ZnSOD was located in chloroplast. Gene Cu/ZnSOD mainly expressed in the green organs of G. orientalis and played a certain role in resisting osmotic stress.

Yang L.,Chinese Academy of Agricultural Sciences
Wei sheng wu xue bao = Acta microbiologica Sinica | Year: 2012

We studied the physiological, biochemical properties and metabolism of Enterococcus strain CJ-1 from high-altitude soil in Namtso, Tibet. Strain CJ-1(T) was isolated from the soil of Namtso alpine meadow soil by Hungate anaerobic technique. Through physiological, biochemical and phylogenetic analysis, we identified the strain CJ-1. Strain CJ-1 was Gram-positive and facultative anaerobe, 1 -1.5 microm in diameter. CJ-1(T) was atrichia nonmotile cocci, and always occurred in pairs. CJ-1(T) occurred in the presence of 0% -7% NaCl (optimum at 5%), pH 5.0 - 8.5 (optimum 7.0) and temperature between 10 degrees C and 50 degrees C (optimum at 25 degrees C). CJ-1 could metabolize many carbon sources including cellobiose, melezitose and ribose. Metabolites of cellobiose were lactic acid, acetic acid, propionic acid, butyrate, CO2, and little H2. The mol% G + C content of the genomic DNA was 39.2 mol%. 16S rRNA gene sequence analysis of the above strain showed the highest similarity of 95.9% with its closest phylogenetic neighbor Enterococcus aquimarinus. The strain can degrade cellobiose which act as intermediate metabolites in the methane fermentation process. CJ-1(T) can degrade cellobiose. CJ-1(T) represents a novel species in the genus fermentation process. Enterococcus.

Zhou C.,Chinese Academy of Agricultural Sciences
Methods in molecular biology (Clifton, N.J.) | Year: 2012

Viral cross protection in plants is known as an acquired immunity phenomenon, where a mild virus isolate/strain can protect plants against economic damage caused by a severe challenge strain/isolate of the same virus. Mild strain cross protection (MSCP) has been used extensively to control losses caused by a few major virus diseases in some parts of the world. So far, none of the many proposed mechanisms can fully explain the intact process of MSCP. In fact, it may be that different mechanisms are involved in MSCP against different viruses, even when different research approaches are used for the same virus, different mechanisms could be proposed. The molecular detail of MSCP still remains unclear, although several lines of evidence imply that the resistance is protein and/or RNA mediated. Some data to date have shown that a minimum time (a few days to less than a month) is required for the mild virus strain to establish MSCP. To investigate interference among virus strains and the plant host at an early stage of MSCP at a subcellular level, we developed a rapid micro-extraction method for the preparation of total nucleic acid (TNA), combined with other molecular methods, to monitor the interaction of virus strains at short time intervals in young plants. This method was initially developed to further study the mechanism of MSCP against Citrus tristeza virus, but has potentially widespread application to other viruses after having been efficiently used to extract over 50,000 TNA samples of citrus viruses, viroids, and bacteria.

For a comprehensive survey of the structure and dynamics of the Dutch Phytophthora infestans population, 652 P. infestans isolates were collected from commercial potato fields in the Netherlands during the 10-year period 2000-2009. Genotyping was performed using 12 highly informative microsatellite markers and mitochondrial haplotypes. In addition, for each isolate, the mating type was determined. STRUCTURE analysis grouped the 322 identified genotypes in three clusters. Cluster 1 consists of a single clonal lineage NL-001, known as "Blue_13"; all isolates in this cluster have the A2 mating type and the Ia mitochondrial haplotype. Clusters 2 and 3 display a more elaborate substructure containing many unique genotypes. In Cluster 3, several distinct clonal lineages were also identified. This survey witnesses that the Dutch population underwent dramatic changes in the 10 years under study. The most notable change was the emergence and spread of A2 mating type strain NL-001 (or "Blue_13"). The results emphasize the importance of the sexual cycle in generating genetic diversity and the importance of the asexual cycle as the propagation and dispersal mechanism for successful genotypes. Isolates were also screened for absence of the Avrblb1/ipiO class I gene, which is indicative for virulence on Rpi-blb1. This is also the first report of Rpi-blb1 breakers in the Netherlands. Superimposing the virulence screening on the SSR genetic backbone indicates that lack the Avrblb1/ipiO class I gene only occurred in sexual progeny. So far, the asexual spread of the virulent isolates identified has been limited.

Wang J.,Chinese Academy of Agricultural Sciences
Wei sheng wu xue bao = Acta microbiologica Sinica | Year: 2012

To identify preliminarily the specific fragment SCF73's function in Verticillium dahlia virulence. The specific fragment SCF73 exposed to be existed in the high-virulent V. dahliae strain VDG1 and not in the mild one VDG2. The SCF73 fragment was obtained from comparatively aligned genome sequences of the two strains and its existence was confirmed using PCR method. According to SCF73's DNA sequence, a homologous recombination plasmid was constructed to knock out the fragment. The Agrobacterium tumefaciens-mediated transformation technique was used to initiate the mutant deltaSCF73, followed by antibiotic resistance screening, and PCR verification. The mutant's ability to secrete carbohydrate hydrolase was analyzed using pectin, cellulose and starch media and its virulence to the susceptible cotton cultivar Gossypium hirsutum cv. Junmian1 was assessed. SCF73 (27.1 kb) contains 5 genes, two of them have glycosyl hydrolase activity. Although the, mutant deltaSCF73's carbohydrate hydrolase secretion was not significantly different from the control VDG1, virulence of the mutant to cotton plants decreased significantly accompanied with disease outburst delay. The specific fragment SCF73 plays an important role in the virulence of V. dahlia towards its cotton host plants.

Wang Y.,Chinese Academy of Agricultural Sciences
Genetics and molecular research : GMR | Year: 2012

To identify amplified fragment length polymorphism (AFLP) markers associated with resistance or susceptibility of alfalfa to common leafspot (CLS) caused by the fungus Pseudopeziza medicaginis (Dermateaceae), bulked segregant analysis was conducted based on an F(1(M × M)) population of 93 plants and a BC(1)S population of 91 plants. Three AFLP markers, ACTCAA(R206), TAGCAC(R185), and GGACTA(S264), were found to be associated with CLS resistance or susceptibility. All three markers were found at significantly different frequencies (71.9, 80.3 and 91.8%) compared to resistant or susceptible plants in the original population. Subsequently, these three AFLP markers were converted into three SCAR markers, ACTCAA(R136), TAGCAC(R128) and GGACTA(S254), which are easier to employ in breeding programs. The three SCAR markers were used in a randomly selected population with 50% resistance; the probability of finding one resistant plant was increased to 67.3, 66.7 and 90.0% with markers ACTCAA(R136), TAGCAC(R128) and GGACTA(S254), independently. If two of the SCAR markers were used simultaneously, the probability would be higher than 89%. The three SCAR markers identified in this study would be applicable for selection for CLS resistance in alfalfa breeding programs. Moreover, the genetic analysis indicated that CLS resistance in alfalfa is conferred by a single dominant gene.

Chen T.,Tsinghua University | Wang J.,Tsinghua University | Yang R.,Tsinghua University | Yang R.,Massachusetts Institute of Technology | And 3 more authors.
PLoS ONE | Year: 2011

Background: The tolerance of cells toward different stresses is very important for industrial strains of microbes, but difficult to improve by the manipulation of single genes. Traditional methods for enhancing cellular tolerances are inefficient and time-consuming. Recently, approaches employing global transcriptional or translational engineering methods have been increasingly explored. We found that an exogenous global regulator, irrE from an extremely radiation-resistant bacterium, Deinococcus radiodurans, has the potential to act as a global regulator in Escherichia coli, and that laboratory-evolution might be applied to alter this regulator to elicit different phenotypes for E. coli. Methodology/Principal Findings: To extend the methodology for strain improvement and to obtain higher tolerances toward different stresses, we here describe an approach of engineering irrE gene in E. coli. An irrE library was constructed by randomly mutating the gene, and this library was then selected for tolerance to ethanol, butanol and acetate stresses. Several mutants showing significant tolerances were obtained and characterized. The tolerances of E. coli cells containing these mutants were enhanced 2 to 50-fold, based on cell growth tests using different concentrations of alcohols or acetate, and enhanced 10 to 100-fold based on ethanol or butanol shock experiments. Intracellular reactive oxygen species (ROS) assays showed that intracellular ROS levels were sharply reduced for cells containing the irrE mutants. Sequence analysis of the mutants revealed that the mutations distribute cross all three domains of the protein. Conclusions: To our knowledge, this is the first time that an exogenous global regulator has been artificially evolved to suit its new host. The successes suggest the possibility of improving tolerances of industrial strains by introducing and engineering exogenous global regulators, such as those from extremophiles. This new approach can be applied alone or in combination with other global methods, such as global transcriptional machinery engineering (gTME) for strain improvements. Copyright: © 2011 Chen et al.