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Zhao J.,CAS Institute of Subtropical Agriculture | Zhao J.,University of Vermont | Zhao J.,Chinese Academy of Sciences | Neher D.A.,University of Vermont
Applied Soil Ecology | Year: 2013

Nematode community indices would be more cost-effective and interpretable if ambiguous genera were removed and indices reduced to only genera with known sensitivity or response to specific types of disturbance. The objective of the present study was to perform a methodical multivariate analysis of existing datasets of high quality and enumerate the genera that respond universally consistent to a specific type of disturbance, treatment, or management worldwide. We collected 20 sources of original data from land used for agricultural purposes, whether cropland, livestock grazing or fruit orchard with manipulated treatments in cultivation, inorganic or organic fertilization or contaminated by heavy metals. Canonical correspondence analysis was performed to determine the effect of disturbance type on the composition of soil nematode communities. Genera that performed consistently in a single direction and across at least two seasons were identified. Briefly, cultivation reduced abundances of Diphtherophora, Prismatolaimus and Tylenchorhynchus. Application of synthetic chemical fertilizers reduced numbers of Plectus. Application of organic fertilizers resulted in increased numbers of Cruznema, Mesorhabditus, Mesodorylaimus and Nygolaimus. No genera met the criteria for responding positively to either cultivation or inorganic fertilization or negatively to organic fertilization. The source of nutrients apparently affected nematode communities differently. Selected nematode genera were correlated positively with the heavy metals Cd, Cu and Zn, while nematode genera correlated negatively with Cr and Se. These genera need to be verified by independent data to confirm that they respond predictably and consistently to these specific types of disturbance. Once verified, this subset of genera will improve interpretation of index values and can be the initial targets for developing molecular probes that can be made accessible to non-specialists. © 2012 Elsevier B.V.

The original version of this article unfortunately contained a mistake. The affiliation of the Pedro Rocha is incorrect. The correct affiliation is given below: Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Yuan Da Er Lu, 644, Changsha 410125, People's Republic of China. © 2016, Springer-Verlag Berlin Heidelberg.

Wang M.,CAS Institute of Subtropical Agriculture | Tang S.X.,CAS Institute of Subtropical Agriculture | Tan Z.L.,CAS Institute of Subtropical Agriculture
Animal Feed Science and Technology | Year: 2011

A Logistic-Exponential (LE) model was developed by introducing a shape parameter d into the logistic function. The LE models included three mathematical forms of LEs, LE0 and LELAG, where LEs was a standard LE model, LE0 was the LEs model re-parameterized with 'V0=0', and LELAG was the LE0 model with an additional discrete LAG time. The LE models generated a wide range of curve shapes, and d revealed whether rate of gas production was or was not increased during in vitro incubation. The performances of the LE0 and LELAG models were evaluated by comparison with published models. For example, one-pool models included exponentials with and without LAG (EXPLAG and EXP0), Gompertz (GOM), Logistic (LOG), generalization of the Mitscherlich (GM) and Michaelis-Menten (MM); while two-pool models included diphase Michaelis-Menten (DGMM), diphase Exponential with LAG (DEXPLAG), diphase Gompertz (DGOM) and diphase Logistic (DLOG) models. Gas production data consisting of 23 curves, obtained from a wide range of feeds, were used to investigate the fit performance of the models. Statistical criteria used were analysis of residuals (i.e., run test and serial correlation) and goodness-of-fit (i.e., residual mean squares, root mean squared prediction error, akaike's information criterion, observed versus predicted regression). Gas production attributes of final asymptotic gas volume (VF), gas volume at 24h (V24h), half-life (t0.5) and fractional rate of gas production at half-life (μ0.5) were compared among one-pool models. The LE0 was better than EXPLAG and EXP0 models based upon overall statistical criteria, and better than GM and LOG models according to akaike's information criterion. The MM model had higher goodness-of-fit than the LE models, and had the highest VF and t0.5, and lowest V24h and μ0.5. The GOM and LOG had higher goodness-of-fit than the LE models, but positive gas volumes at 't=0' were biologically meaningless. Two-pool models could improve the fit to curve, but led to declined robustness. There were no differences of predicted gas production attributes between the LE and GM models. Results indicate that the LE models can be alternatives to describe in vitro gas production kinetics. © 2010 Elsevier B.V.

Wu J.,CAS Institute of Subtropical Agriculture
European Journal of Soil Science | Year: 2011

Carbon (C) sequestration in terrestrial ecosystems can play a role in counteracting the rapid increase in CO2 concentration in the atmosphere. In this study, soils were sampled from some 2700 sites under contrasting land uses in four selected landscape units as representatives of the lowland (LL), low hill (LH), high hill (HH) and karst mountain (KM) areas in subtropical China. The aim was to quantify the potential for C sequestration in paddy ecosystems in the region. The mean values of organic C stocks in paddy soils (0-20 cm) in the landscape units varied from 37.8 to 60.4 t ha-1, and were considerably larger than those for soils under arable cropping and orchard managements, and even under woodland except in the KM landscape unit. In the LH unit, the mean organic C concentration in paddy soils increased by 1.67 times (P < 0.05) during the period between 1979 and 2003. This increase was consistent with the prolonged increase (since the 1950s) in rice productivity in the region. It is concluded that paddy ecosystems in subtropical China have the ability to accumulate organic C faster than other ecosystems. Because these landscape units represent the real situation in paddy ecosystems under farmers' practices for rice production, the data confirm that prolonged organic C accumulation in paddy soils has occurred in subtropical China. © 2010 The Author. Journal compilation © 2010 British Society of Soil Science.

Rocha P.S.C.F.,CAS Institute of Subtropical Agriculture
Planta | Year: 2015

Main conclusion: RCI2/PMP3s participate in abiotic stress responses and impact the expression of other genes. Their multifunctionality is determined by differential expression and by distinct activities of their structurally different proteins.In plants, RCI2/PMP3 genes, which encode small membrane proteins of the PMP3 family, are closely associated with abiotic stress responses. Their involvement in mediating stress tolerance is supported by genetic evidence and overexpression studies. RCI2/PMP3s occur as multigenes in plant genomes and their encoded proteins belong to distinct and conserved structural groups. In addition, different isoforms appear to be targeted to the plasma membrane or to distinct endomembrane compartments in cells. Several studies have revealed that RCI2/PMP3 proteins participate in cell ion homeostasis, and in regulation of membrane stability and polarization. They also appear to potentiate plant transcriptional responses to abiotic stresses. However, their mechanisms of action remain unknown. This paper reviews the current knowledge of the multiple roles of plant RCI2/PMP3 genes resulting from their differential expression under normal and stress conditions. The structural diversity of RCI2/PMP3 proteins is analyzed and evidence supporting their functional specialization and possible activity mechanisms is examined. Finally, strategies are discussed for exploiting new and established technologies to overcome the difficulties posed by the multigene status of RCI2s and the integral membrane character of their proteins, enabling the probing of their individual functions and collective significance. © 2015 Springer-Verlag Berlin Heidelberg

Mao D.,CAS Institute of Subtropical Agriculture | Chen C.,CAS Institute of Subtropical Agriculture
PLoS ONE | Year: 2012

The clustered genes C-repeat (CRT) binding factor (CBF)1/dehydration-responsive element binding protein (DREB)1B, CBF2/DREB1C, and CBF3/DREB1A play a central role in cold acclimation and facilitate plant resistance to freezing in Arabidopsis thaliana. Rice (Oryza sativa L.) is very sensitive to low temperatures; enhancing the cold stress tolerance of rice is a key challenge to increasing its yield. In this study, we demonstrate chilling acclimation, a phenomenon similar to Arabidopsis cold acclimation, in rice. To determine whether rice CBF/DREB1 genes participate in this cold-responsive pathway, all putative homologs of Arabidopsis DREB1 genes were filtered from the complete rice genome through a BLASTP search, followed by phylogenetic, colinearity and expression analysis. We thereby identified 10 rice genes as putative DREB1 homologs: nine of these were located in rice genomic regions with some colinearity to the Arabidopsis CBF1-CBF4 region. Expression profiling revealed that six of these genes (Os01g73770, Os02g45450, Os04g48350, Os06g03670, Os09g35010, and Os09g35030) were similarly expressed in response to chilling acclimation and cold stress and were co-expressed with genes involved in cold signalling, suggesting that these DREB1 homologs may be involved in the cold response in rice. The results presented here serve as a prelude towards understanding the function of rice homologs of DREB1 genes in cold-sensitive crops. © 2012 Mao, Chen.

The objective of this study was to determine developmental changes in mRNA and protein levels for N-acetylglutamate synthase (NAGS; a key enzyme in synthesis of citrulline and arginine from glutamine/glutamate and proline) in the small intestine of suckling piglets. The porcine NAGS gene was cloned using the real-time polymerase-chain reaction (RT-PCR) method. The porcine NAGS gene encoded 368 amino acid residues and had a high degree of sequence similarity to the "conserved domain" of human and mouse NAGS genes. The porcine NAGS gene was expressed in E. coli BL21 and a polyclonal antibody against the porcine NAGS protein was developed. Real-time RT-PCR and western-blot analyses were performed to quantify NAGS mRNA and protein, respectively, in the jejunum and ileum of 1- to 28-day-old pigs. Results indicated that intestinal NAGS mRNA levels were lower in 7- to 28-day-old than in 1-day-old pigs. Immunochemical analysis revealed that NAGS protein was localized in enterocytes of the gut. Notably, intestinal NAGS protein abundance declined progressively during the 28-day suckling period. The postnatal decrease in NAGS protein levels was consistent with the previous report of reduced NAGS enzymatic activity as well as reduced synthesis of citrulline and arginine in the small intestine of 7- to 28-day-old pigs. Collectively, these results suggest that intestinal NAGS expression is regulated primarily at the post-transcriptional level. The findings also provide a new molecular basis to explain that endogenous synthesis of arginine is impaired in sow-reared piglets and arginine is a nutritionally essential amino acid for the neonates.

Sun G.M.,CAS Institute of Subtropical Agriculture
Acta Horticulturae | Year: 2011

Pineapple, next to banana and mango, is the third most important tropical fruit in the mainland of China. The cultivation areas range from 52,000 to 65,000 ha with a total production 780,000 to 920,000 ton within this decade. Guangdong, Hainan, Guangxi and Yunnan provinces are the main pineapple cultivation areas. Guangdong province produces 50-60% of the pineapple grown in China. Nearly 80% of the pineapple produced in China goes to the domestic market as fresh fruit. 'Comte de Paris', which occupies more than 80% of the planted area, is the most important pineapple cultivar in mainland China. But 'Yuecui', 'Tainung No.16' and 'Tainung No.17' are promising cultivars and the area devoted to these cultivars continues to increase. Although the pineapple industry takes an important role in the tropical agriculture economy in China, there were few researches carried out on pineapple before 2005. Crop management is mostly based on farmer's experience. To promote the development of the pineapple industry and increase its competitive ability, The Ministry of Agriculture of China started a research program on pineapple in 2006. It includes genetic improvement, studies into high yield and good quality fruit production techniques, integrated management of pests and diseases, postharvest handling, utilization of by-products and marketing strategy. Some progress has been made from this program, including a better understanding of the role of nutrient requirements and uptake by 'Comte de Paris' and 'Smooth Cayenne' and of sugar metabolism and accumulation during fruit development. Also, it has been found that pineapple leaf fibres have the ability to kill and/or inhibit bacteria and eliminate unpleasant smells. Techniques have also been developed in leaf fibre extraction and processing.

Li Y.,CAS Institute of Subtropical Agriculture | Li Y.,University of Melbourne
Geoderma | Year: 2010

The data quality of soil properties, such as the soil organic matter (SOM) content, can be improved and the spatial sampling intensities may be reduced by incorporating secondary information, such as those derived from topographic (TOPO) and remote sensing (RS) data to enhance their spatial estimates. This study adopted a generic framework for spatial interpolation using regression kriging (RK) developed by Hengl et al. (2004) to evaluate RK's capability in improving SOM spatial interpolation using internal secondary variables (sampling coordinates) and external auxiliary information, such as soil map (SOIL), vegetation indices (VIs) derived from a Landsat 5 TM image, and several terrain attributes (elevation, slope, convergence and wetness indices, and plan and profile curvatures). Meanwhile, the SOM spatial distribution was also interpolated by using ordinary kriging (OK) and universal kriging (UK) methods for comparison purposes. The results of this study showed that the prediction accuracy of SOM by using RK was unimproved with the inclusion of more auxiliary information in the regression models, but in contrast it significantly declined when TOPO, VI and SOIL information were combined, particularly the last one. It was also observed that with the increase of the minimum sampling distances from 25 to 500m or with the decrease of the sampling densities from 0.42 to 0.26 # km-2, the RK techniques did not outperform OK and UK in improving the SOM prediction accuracy at coarse sampling resolutions. Interestingly, the highest accuracy of the SOM prediction by all these interpolation methods was achieved at the minimum sampling distance of 250m. The suitability of RK implementation in the spatial interpolation was therefore discussed by considering the minimum sampling distance, the sampling density and the compatibility of spatial resolutions of target variables and auxiliary information or the spatial scales. © 2010 Elsevier B.V.

Huang Y.,Appraisal Center for Environment and Engineering | Li D.,CAS Institute of Subtropical Agriculture
Scientific Reports | Year: 2014

Soils are among the major sources of atmospheric nitric oxide (NO), which play a crucial role in atmospheric chemistry. Here we systematically synthesized the modeling studies and field measurements and presented a novel soil NO emission inventory of terrestrial ecosystems in China. The previously modeled inventories ranged from 480 to 1375 and from 242.8 to 550 Gg N yr-1 for all lands and croplands, respectively. Nevertheless, all the previous modeling studies were conducted based on very few measurements from China. According to the current synthesis of field measurements, most soil NO emission measurements were conducted at croplands, while the measurements were only conducted at two sites for forest and grassland. The medianNOflux was 3.2 ngNm-2 s-1 with a fertilizer induced emission factor (FIE) of 0.04% for rice fields, and was 7.1 ngNm-2 s-1 with an FIE of 0.67% for uplands. A novelNOemission inventory of 1226.33 (ranging from 588.24 to 2132.05) Gg N yr-1 was estimated for China's terrestrial ecosystems, which was about 18% of anthropogenic emissions. More field measurements should be conducted to cover more biomes and obtain more representative data in order to well constrain soil NO emission inventory of China.

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