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    Special Focus:Climate Change and Agriculture
    Editorial —— Climate Change and Agriculture: Impact and Adaptation
    HUANG Ji-kun
    2014, 13(4): 657-659.  DOI: 10.1016/S2095-3119(14)60752-8
    Abstract ( )   PDF in ScienceDirect  
    The Impact of Climate Change on Agriculture in Asia
    Robert Mendelsohn
    2014, 13(4): 660-665.  DOI: 10.1016/S2095-3119(13)60701-7
    Abstract ( )   PDF in ScienceDirect  
    Asian agriculture is responsible for two thirds of global agricultural GDP. There have been numerous studies exploring the impact of climate change on crops in specific locations in Asia but no study has yet analyzed crops across the entire continent. This study relies on a Ricardian study of China that estimated climate coefficients for Chinese crops. These coefficients are then used to interpolate potential climate damages across the continent. With carbon fertilization, the model predicts small aggregate effects with a 1.5°C warming but damages of about US$84 billion with 3°C warming. India is predicted to be especially vulnerable.
    Modeling Climate Change Impacts on the US Agricultural Exports
    ZHANG Yu-quan; CAI Yong-xia; Beach Robert H ; McCARL Bruce A
    2014, 13(4): 666-676.  DOI: 10.1016/S2095-3119(13)60699-1
    Abstract ( )   PDF in ScienceDirect  
    Climate change is expected to have substantial effects on agricultural productivity worldwide. However, these impacts will differ across commodities, locations and time periods. As a result, landowners will see changes in relative returns that are likely to induce modifications in production practices and land allocation. In addition, regional variations in impacts can alter relative competitiveness across countries and lead to adjustments in international trade patterns. Thus in climate change impact studies it is likely useful to account for worldwide productivity effects. In this study, we investigate the implications of considering rest of world climate impacts on projections of the US agricultural exports. We chose to focus on the US because it is one of the largest agricultural exporters. To conduct our analyses, we consider four alternative climate scenarios, both with and without rest of world climate change impacts. Our results show that considering/ignoring rest of world climate impacts causes significant changes in the US production and exports projections. Thus we feel climate change impact studies should account not only for climate impacts in the country of focus but also on productivity in the rest of the world in order to capture effects on commodity markets and trade potential.
    Crop Diversification in Coping with Extreme Weather Events in China
    HUANG Ji-kun; JIANG Jing;WANG Jin-xia ; HOU Ling-ling
    2014, 13(4): 677-686.  DOI: 10.1016/S2095-3119(13)60700-5
    Abstract ( )   PDF in ScienceDirect  
    Apart from the long-term effects of climate change, the frequency and severity of extreme weather events have been increasing. Given the risks posed by climate change, particularly the changes in extreme weather events, the question of how to adapt to these changes and mitigate their negative impacts has received great attention from policy makers. The overall goals of this study are to examine whether farmers adapt to extreme weather events through crop diversification and which factors influence farmers’ decisions on crop diversification against extreme weather events in China. To limit the scope of this study, we focus on drought and flood events only. Based on a unique large-scale household survey in nine provinces, this study finds that farmers respond to extreme weather events by increasing crop diversification. Their decision to diversify crops is significantly influenced by their experiences of extreme weather events in the previous year. Such results are understandable because farmers’ behaviors are normally based on their expectations. Moreover, household characteristics also affect farmers’ decisions on crop diversification strategy, and their effects differ by farmers’ age and gender. This paper concludes with several policy implications.
    Household and Community Assets and Farmers’ Adaptation to Extreme Weather Event: the Case of Drought in China
    WANG Yang-jie; HUANG Ji-kun ; WANG Jin-xia
    2014, 13(4): 687-697.  DOI: 10.1016/S2095-3119(13)60697-8
    Abstract ( )   PDF in ScienceDirect  
    Under climate change, rising frequency and serious extreme weather events have challenged agricultural production. Designing appropriate adaptation measures to the extreme weather events require rigorous and empirical analysis. The overall goals of this study are to understand physical adaptation measures taken by farmers and the impacts of household and community assets on farmers’ adaptation when they face drought. The analyses are based on a unique data set collected from a household survey in three provinces in China. The survey results show that though not common on annual basis, some farmers did use physical adaptation measures to fight drought. Regression analysis reveals that both household and community assets significantly affect farmers’ adaptation behaviors. Improving households’ social capital and wealth, communities’ network and access to government’s anti-drought service can facilitate farmers’ adaptation to drought. Results indicate that community’s irrigation infrastructure and physical adaptation taken by farmers can substitute each other. Further analysis shows that the households taking adaptation measures have higher crop yields than those without taking these measures. The paper concludes with several policy implications.
    Financing Sustainable Agriculture Under Climate Change
    HUANG Ji-kun ; WANG Yang-jie;
    2014, 13(4): 698-712.  DOI: 10.1016/S2095-3119(13)60698-X
    Abstract ( )   PDF in ScienceDirect  
    Agriculture is facing great challenge in meeting global food security and is expected to face even greater challenge under climate change. The overall goal of this paper is to examine how finance can be used to achieve the joint objectives of development, mitigation of and adaptation to climate change in agriculture in developing world based on literature review. The results show that agriculture is much under invested and foreign aid also has not increased appropriately to assist developing countries to maintain sustainable agriculture under climate change. There are a wide range of areas in mitigation of and adaptation to climate change that need substantial investment. Major areas and successful cases mitigation of and adaptation to climate change in agriculture that have worked in developing countries are examined. A list of areas that have worked, could work and be scaled up or transferred is identified and discussed. This study concludes that mainstreaming agricultural mitigation and adaptation into agricultural development programs, enhancing local capacity, and considering different stakeholders’ needs are major experiences for successfully financing sustainable agriculture under climate change.
    Crop Genetics · Breeding · Germplasm Resources
    Identification and Genetic Analysis of a Novel Rice Spotted-Leaf Mutant with Broad-Spectrum Resistance to Xanthomonas oryzae pv. oryzae
    SHEN Hai-chao; SHI Yong-feng; FENG Bao-hua; WANG Hui-mei; XU Xia; HUANG Qi-na; Lü Xiang-guang ; WU Jian-li
    2014, 13(4): 713-721.  DOI: 10.1016/S1671-2927(00)9386
    Abstract ( )   PDF in ScienceDirect  
    A spotted-leaf mutant of rice HM143 was isolated from an EMS-induced IR64 mutant bank. Brown lesions randomly distributed on leaf blades were observed about 3 wk after sowing. The symptom lasted for the whole plant growth duration. Histochemical analysis indicated that cell death occurred in and around the site of necrotic lesions accompanied with accumulation of hydrogen hyperoxide. Agronomic traits were largely similar to the wild type IR64 except seed setting rate and 1 000-grain weight which were significantly decreased in the mutant. Disease resistance of the mutant to multiple races of Xanthomonas oryzae pv. oryzae was significantly enhanced. Genetic analysis showed that the mutation was controlled by a single recessive gene, tentatively termed splHM143. In addition, using molecular markers and 1 023 mutant type individuals from an F2 segregating population derived from the cross HM143/R9308, the spotted-leaf gene was finally delimited to an interval of 149 kb between markers XX25 and ID40 on the long arm of chromosome 4. splHM143 is likely a novel rice spotted-leaf gene since no other similar genes have been identified near the chromosomal region.
    Effects of Environmental Temperature on the Regeneration Frequency of the Immature Embryos of Wheat (Triticum aestivum L.)
    WANG Xin-min; REN Xian; YIN Gui-xiang; WANG Ke; LI Jia-rui; DU Li-pu; XU Hui-jun ;
    2014, 13(4): 722-732.  DOI: 10.1016/S2095-3119(13)60361-5
    Abstract ( )   PDF in ScienceDirect  
    The immature embryos (IEs) of wheat are the most widely used tissues for in vitro culture and genetic transformation due to its high regeneration competency. However, this explant can only be maintained in 4°C daily cooler for a short period time for its use in plant tissue culture or transformation experiments. This study aimed to investigate the effects of environmental temperature, cryopreservation storage temperature, and heat shock culture (HSC) temperature on the regeneration frequency of wheat IEs. Results indicated that environmental temperature significantly affected the induction of embryonic calli. The optimum total accumulated temperature (TAT) during the time of anthesis and sampling for regeneration of these tissues was around 280°C for spring wheat type cv. CB037 and approximately 300°C for winter wheat type cv. Kenong 199. Regeneration ability obviously declined when the highest environmental temperature was over 35°C for 1 d or a high temperature between 30 and 33°C lasted for 5 d during anthesis and sampling. This finding was verified by culturing the freshly isolated IEs under different temperatures from 29 to 37°C in different controlled growth incubators for 5 d; the IEs almost completely lost regeneration ability when the temperature rose to 37°C. Cryopreservation of -20°C caused the wheat samples lost ability of producing callus or embryonic callus in a few days, and cryopreservation of -10°C more than 10 d made the regeneration potential of the tissues dramatically declined. Comparatively, the temperature that best maintained high regeneration ability was -5°C, at which the materials can be maintained for around 1 mon. In addition, the preservation of the immature samples at -5 or -10°C inhibited the direct germination of the IEs, avoiding the embryo axis removing process. Our results are useful for ensuring that field collection and cryopreservation of the wheat IEs are done correctly to enable tissue culture and genetic transformation.
    Comparison of Two MicroRNA Quantification Methods for Assaying MicroRNA Expression Profiles in Wheat (Triticum aestivum L.)
    HAN Ran, YAN Yan, ZHOU Peng , ZHAO Hui-xian
    2014, 13(4): 733-740.  DOI: 10.1016/S2095-3119(13)60362-7
    Abstract ( )   PDF in ScienceDirect  
    Two microRNA (miRNA) quantification methods, namely, poly(A) reverse transcription (RT)-quantitative real-time polymerase chain reaction (qPCR) and stem-loop RT-qPCR, have been developed for quantifying miRNA expression. In the present study, five miRNAs, including miR166, miR167, miR168, miR159, and miR396, with different sequence frequencies, were selected as targets to compare their expression profiles in five wheat tissues by applying the two methods and deep sequencing. The study aimed to determine a simple, reliable and high-throughput method for detecting miRNA expressions in wheat tissues. Results showed that the miRNA expression profiles determined by poly(A) RT-qPCR were more consistent with those obtained by deep sequencing. Further analysis indicated that the correlation coefficients of the data obtained by poly(A) RT-qPCR and deep sequencing (0.739, P 0.01) were higher than those obtained by stem-loop RT-qPCR and deep sequencing (0.535, P 0.01). The protocol used for poly(A) RT-qPCR is simpler than that for stem-loop RT-qPCR. Thus, poly(A) RT-qPCR was a more suitable high-throughput assay for detecting miRNA expression profiles. To the best of our knowledge, this study was the first to compare these two miRNA quantification methods. We also provided useful information for quantifying miRNA in wheat or other plant species.
    Abortive Process of a Novel Rapeseed Cytoplasmic Male Sterility Line Derived from Somatic Hybrids Between Brassica napus and Sinapis alba
    WANG Juan, GAO Ya-nan, KONG Yue-qin, JIANG Jin-jin, LI Ai-min, ZHANG Yong-tai
    2014, 13(4): 741-748.  DOI: 10.1016/S2095-3119(13)60584-5
    Abstract ( )   PDF in ScienceDirect  
    Somatic hybridization is performed to obtain significant cytoplasmic male sterility (CMS) lines, whose CMS genes are derived either from the transfer of sterile genes from the mitochondrial genome of donor parent to the counterpart of receptor or production of new sterile genes caused by mitochondrial genome recombination of the biparent during protoplast fusion. In this study, a novel male sterile line, SaNa-1A, was obtained from the somatic hybridization between Brassica napus and Sinapis alba. The normal anther development of the maintainer line, SaNa-1B, and the abortive process of SaNa-1A were described through phenotypic observations and microtome sections. The floral organ of the sterile line SaNa-1A was sterile with a shortened filament and deflated anther. No detectable pollen grains were found on the surface of the sterile anthers. Semi-thin sections indicated that SaNa-1A aborted in the pollen mother cell (PMC) stage when vacuolization of the tapetum and PMCs began. The tapetum radically elongated and became highly vacuolated, occupying the entire locule together with the vacuolated microspores. Therefore, SaNa-1A is different from other CMS lines, such as ogu CMS, pol CMS and nap CMS as shown by the abortive process of the anther.
    Modeling Dynamics of Leaf Color Based on RGB Value in Rice
    ZHANG Yong-hui, TANG Liang, LIU Xiao-jun, LIU Lei-lei, CAO Wei-xing , ZHU Yan
    2014, 13(4): 749-759.  DOI: 10.1016/S2095-3119(13)60391-3
    Abstract ( )   PDF in ScienceDirect  
    This paper was to develop a model for simulating the leaf color changes in rice (Oryza sativa L.) based on RGB (red, green, and blue) values. Based on rice experiment data with different cultivars and nitrogen (N) rates, the time-course RGB values of each leaf on main stem were collected during the growth period in rice, and a model for simulating the dynamics of leaf color in rice was then developed using quantitative modeling technology. The results showed that the RGB values of leaf color gradually decreased from the initial values (light green) to the steady values (green) during the first stage, remained the steady values (green) during the second stage, then gradually increased to the final values (from green to yellow) during the third stage. The decreasing linear functions, constant functions and increasing linear functions were used to simulate the changes in RGB values of leaf color at the first, second and third stages with growing degree days (GDD), respectively; two cultivar parameters, MatRGB (leaf color matrix) and AR (a vector composed of the ratio of the cumulative GDD of each stage during color change process of leaf n to that during leaf n drawn under adequate N status), were introduced to quantify the genetic characters in RGB values of leaf color and in durations of different stages during leaf color change, respectively; FN (N impact factor) was used to quantify the effects of N levels on RGB values of leaf color and on durations of different stages during leaf color change; linear functions were applied to simulate the changes in leaf color along the leaf midvein direction during leaf development process. Validation of the models with the independent experiment dataset exhibited that the root mean square errors (RMSE) between the observed and simulated RGB values were among 8 to 13, the relative RMSE (RRMSE) were among 8 to 10%, the mean absolute differences (da) were among 3.85 to 6.90, and the ratio of da to the mean observation values (dap) were among 3.04 to 4.90%. In addition, the leaf color model was used to render the leaf color change over growth progress using the technology of visualization, with a good performance on predicting dynamic changes in rice leaf color. These results would provide a technical support for further developing virtual plant during rice growth and development.
    Detection of Internal Leaf Structure Deterioration Using a New Spectral Ratio Index in the Near-Infrared Shoulder Region
    LIU Liang-yun, HUANG Wen-jiang, PU Rui-liang , WANG Ji-hua
    2014, 13(4): 760-769.  DOI: 10.1016/S2095-3119(13)60385-8
    Abstract ( )   PDF in ScienceDirect  
    Spectral reflectance in the near-infrared (NIR) shoulder (750-900 nm) region is affected by internal leaf structure, but it has rarely been investigated. In this study, a dehydration treatment and three paraquat herbicide applications were conducted to explore how spectral reflectance and shape in the NIR shoulder region responded to various stresses. A new spectral ratio index in the NIR shoulder region (NSRI), defined by a simple ratio of reflectance at 890 nm to reflectance at 780 nm, was proposed for assessing leaf structure deterioration. Firstly, a wavelength-independent increase in spectral reflectance in the NIR shoulder region was observed from the mature leaves with slight dehydration. An increase in spectral slope in the NIR shoulder would be expected only when water stress developed sufficiently to cause severe leaf dehydration resulting in an alteration in cell structure. Secondly, the alteration of leaf cell structure caused by Paraquat herbicide applications resulted in a wavelength-dependent variation of spectral reflectance in the NIR shoulder region. The NSRI in the NIR shoulder region increased significantly under an herbicide application. Although the dehydration process also occurred with the herbicide injury, NSRI is more sensitive to herbicide injury than the water-related indices (water index and normalized difference water index) and normalized difference vegetation index. Finally, the sensitivity of NSRI to stripe rust in winter wheat was examined, yielding a determination coefficient of 0.61, which is more significant than normalized difference vegetation index (NDVI), water index (WI) and normalized difference water index (NDWI), with a determination coefficient of 0.45, 0.36 and 0.13, respectively. In this study, all experimental results demonstrated that NSRI will increase with internal leaf structure deterioration, and it is also a sensitive spectral index for herbicide injury or stripe rust in winter wheat.
     YANG Xu-yuan, MA Huai-yu, LIU Guo-cheng, LÜ De-guo, QIN Si-jun , DU Guo-dong
    YANG Xu-yuan, MA Huai-yu, LIU Guo-cheng, Lü De-guo, QIN Si-jun , DU Guo-dong
    2014, 13(4): 770-777.  DOI: 10.1016/S2095-3119(13)60409-8
    Abstract ( )   PDF in ScienceDirect  
    The terminal flower buds of 6-yr-old Hanfu apple were used to study the ovule development, ovular characteristics, cell death of abortive ovules, and dynamic change of starch grain quantity in the embryo sac with paraffin slices and terminal deoxynucleotidyl transferase-mediated fluorescein deoxyuridine triphosphate nick-end labeling (TUNEL) system. Four anatropous ovules in each ventricle could be observed before flowering. With the developing of floral organ, the bulk of normal ovules enlarged in each ventricle, the mature embryo sac differentiated into nucellus, and the egg cell developed into zygote by double fertilization. A large number of starch grains were observed during pollen tube growth and double fertilization, which guaranteed basic nutrient supply in the normal development of ovules. Moreover, abortion phenomenon of runtish ovules emerged at the stages of mature embryo sac, double fertilization and zygote development. The abortion characteristics included deformity of ovule development, degradation of nucellus tissue, separation between funiculus and ovule, abnormality of four-nucleate embryo sac, as well as development interruption of mature embryo sac. TUNEL analysis proved that ovule abortion was programmed cell death.
    Metabolic Response of Pakchoi Leaves to Amino Acid Nitrogen
    WANG Xiao-li, YU Wen-juan, ZHOU Qian, HAN Rui-feng , HUANG Dan-feng
    2014, 13(4): 778-788.  DOI: 10.1016/S2095-3119(13)60622-X
    Abstract ( )   PDF in ScienceDirect  
    Different nitrogen (N) forms may cause changes in the metabolic profiles of plants. However, few studies have been conducted on the effects of amino acid-N on plant metabolic profiles. The main objective of this study was to identify primary metabolites associated with amino acid-N (Gly, Gln and Ala) through metabolic profile analysis using gas chromatography- mass spectrometry (GC-MS). Plants of pakchoi (Brassica campestris L. ssp. chinensis L.), Huawang and Wuyueman cultivars, were grown with different nitrogen forms (i.e., Gly, Gln, Ala, NO3 --N, and N starvation) applied under sterile hydroponic conditions. The fresh weight and plant N accumulation of Huawang were greater than those of Wuyueman, which indicates that the former exhibited better N-use efficiency than the latter. The physiological performances of the applied N forms were generally in the order of NO3 --N>Gln>Gly>Ala. The metabolic analysis of leaf polar extracts revealed 30 amino acid N-responsive metabolites in the two pakchoi cultivars, mainly consisting of sugars, amino acids, and organic acids. Changes in the carbon metabolism of pakchoi leaves under amino acid treatments occurred via the accumulation of fructose, glucose, xylose, and arabinose. Disruption of amino acid metabolism resulted in accumulation of endogenous Gly in Gly treatment, Pro in Ala treatment, and Asn in three amino acid (Gly, Gln and Ala) treatments. By contrast, the levels of endogenous Gln and Leu decreased. However, this reduction varied among cultivars and amino acid types. Amino acid-N supply also affected the citric acid cycle, namely, the second stage of respiration, where leaves in Gly, Gln and Ala treatments contained low levels of malic, citric and succinic acids compared with leaves in NO3 --N treatments. No significant difference in the metabolic responses was observed between the two cultivars which differed in their capability to use N. The response of primary metabolites in pakchoi leaves to amino acid-N supply may serve an important function in pakchoi adaptation to amino acid-N sources.
    Plant Protection
    Proteomics Identification of Differentially Expressed Leaf Proteins in Response to Setosphaeria turcica Infection in Resistant Maize
    ZHANG Xiao-li, SI Bing-wen, FAN Cheng-ming, LI Hong-jie , WANG Xiao-ming
    2014, 13(4): 789-803.  DOI: 10.1016/S2095-3119(13)60513-4
    Abstract ( )   PDF in ScienceDirect  
    Northern corn leaf blight (NCLB), caused by the heterothallic ascomycete fungus Setosphaeria turcica, is a destructive foliar disease of maize and represents a serious threat to maize production worldwide. A comparative proteomic study was conducted to explore the molecular mechanisms underlying the defense responses of the maize resistant line A619 Ht2 to S. turcica race 13. Leaf proteins were extracted from mock and S. turcica-infected leaves after inoculated for 72 h and analyzed for differentially expressed proteins using two-dimensional electrophoresis and mass spectrometry identification. 137 proteins showed reproducible differences in abundance by more than 2-fold at least, including 50 up-regulated proteins and 87 down-regulated proteins. 48 protein spots were successfully identified by MS analysis, which included 10 unique, 6 up-regulated, 20 down-regulated and 12 disappeared protein spots. These identified proteins were classified into 9 functional groups and involved in multiple functions, particularly in energy metabolism (46%), protein destination and storage (12%), and disease defense (18%). Some defense-related proteins were upregulated such as β-glucosidase, SOD, polyamines oxidase, HSC 70 and PPIases; while the expressions of photosynthesis- and metabolism-related proteins were down-regulated, by inoculation with S. turcica. The results indicated that a complex regulatory network was functioned in interaction between the resistant line A619 Ht2 and S. turcica. The resistance processes of A619 Ht2 mainly resided on directly releasing defense proteins, modulation of primary metabolism, affecting photosyntesis and carbohydrate metabolism.
    Isolation and Structural Identification of Herbicidal Active Substance from Root of Flaveria bident (L.) Kuntze
    HUO Jing-qian, XING Ji-hong, ZHANG Li-hui, KANG Zhan-hai , ZHANG Jin-lin
    2014, 13(4): 804-810.  DOI: 10.1016/S2095-3119(13)60360-3
    Abstract ( )   PDF in ScienceDirect  
    In order to understand the composition and structure of herbicidal active substance from the root of Flaveria bidentis (L.) Kuntze, the isolation and structural identification were researched in this paper. The crude extract from the root of F. bidentis (L.) Kuntze was extracted by petroleum ether, ethyl acetate, and water saturation of n-butyl alcohol, respectively, and the extraction fluid was separated by using the method of TLC, then the main fraction was separated by HPLC, and the structure of the herbicidal active substance was analyzed by LC-MS, elemental analysis and 1H-NMR. The results showed that the petroleum extraction had the strongest herbicidal activity, and the purple blue stripe separated by TLC had the strongest effect on Digitaria sanguinalis. The herbicidal active substance was identified as α-terthienyl according to the data of LC-MS, elemental analysis and 1H-NMR.
    Validation of Reference Genes for Quantitative Real-Time PCR in Laodelphax striatellus
    HE Xiu-ting, LIU Cheng-cheng, LI Zhao-qun, ZHANG Zan, LI Guo-qing, LI Fei , DONG Shuang
    2014, 13(4): 811-818.  DOI: 10.1016/S2095-3119(13)60515-8
    Abstract ( )   PDF in ScienceDirect  
    The normalization of quantitative real-time PCR (qPCR) is important to obtain accurate gene expression data, and the most common method for qPCR normalization is to use reference genes. However, reference genes can be regulated under different conditions. qPCR has recently been used for gene expression study in Laodelphax striatellus, but there is no study on validation of the reference genes. In this study, five new housekeeping genes (LstrTUB1, LstrTUB2, LstrTUB3, LstrARF and LstrRPL9) in L. striatellus were cloned and deposited in the GenBank with accession numbers of JF728809, JF728810, JF728811, JF728807 and JF728806, respectively. Furthermore, mRNA expressions of the five genes and β-actin were measured by qPCR with insect samples of different instar at nymph stage, and the expression stabilities were determined by the software geNorm and NormFinder. As a result, ARF and RPL9 were consistently more stable than β-actin, while three TUB genes were less stable than β-actin. To determine the optimal number of reference genes used in qPCR, a pairwise variations analysis by geNorm indicated that two references ARF and RPL9 were required to obtain the accurate quantification. These results were further confirmed by the validation qPCR experiment with chitinase gene as the target gene, in which the standard error of the mRNA quantification by using binary reference ARF-RPL9 was much lower than those by ARF, RPL9 or β-actin alone. Taken together, our study suggested that the combination of ARF-RPL9 could replace β-actin as the reference genes for qPCR in L. striatellus.
    Effects of Glutamate and Na+ on the Development and Enzyme Activity of the Oriental Migratory Locust, Locusta migratoria manilensis (Meyen) in Successive Generations
    ZHAO Xia, JIA Miao, WANG Lei, CAO Guang-chun , ZHANG Ze-hua
    2014, 13(4): 819-826.  DOI: 10.1016/S2095-3119(13)60516-X
    Abstract ( )   PDF in ScienceDirect  
    Rapid and mass rearing of Locusta migratoria manilensis is an urgent need to meet the increasing demand for food of people. In this study, the effects of four artificial feeds on the development, reproduction and the activities of detoxification and protective enzymes of L. migratoria manilensis in three successive generations were investigated. The results showed that sucrose and monosodium glutamate (MSG) significantly increased the net reproductive rate (R0) and the intrinsic growth rate (rm) of L. migratoria manilensis, but sodium chloride (0.17%) suppressed this increase. Furthermore, the artificial feed with sucrose and monosodium glutamate increased the activities of esterase (EST), acetylcholinesterase (AChE), glutathione-Stransferase (GST), multi-function oxidase (MFO), phenol oxidase (PO), catalase (CAT) and peroxidase (POD), but inhibited the activity of superoxide dismutase (SOD). However, sodium chloride (0.17%) increased the activities of EST, AChE, CAT and SOD, and inhibited the activities of MFO, GST, PO and POD. Correlation analysis found that the increasing of PO activity and the decreasing of SOD activities were significantly related with the increasing of the intrinsic growth rate (rm). The above results indicated that sucrose and monosodium glutamate could promote the development and reproduction of L. migratoria manilensis, but Na+ inhibit such promotion with the concentration above 0.2%. The activities of PO and SOD can be used as biochemical standard to assess the effect of artificial feed.
    Animal Science · Veterinary Science
    17β-Estradiol Regulates SKP2 Expression in Cultured Immature Boar Sertoli Cells Mainly via Estrogen Receptor β, cAMP-PKA and ERK1/2
    WANG Xian-zhong, ZHU Feng-wei, WANG Yong, WANG Yi, ZHANG Jiao-jiao , ZHANG Jia-hua
    2014, 13(4): 827-836.  DOI: 10.1016/S2095-3119(13)60430-X
    Abstract ( )   PDF in ScienceDirect  
    Estrogen plays an important role in regulating testicular Sertoli cell number. Furthermore, S-phase kinase-associated protein 2 (SKP2) plays a central role in mammalian cell cycle progression. The objective of this study was to determine whether 17β-estradiol can regulate the expression of SKP2, and the Sertoli cell cycle, via estrogen receptor β (ERβ), the cyclic adenosine monophosphate (cAMP)-protein kinase A (PKA) and extracellular signal-regulated kinase (ERK1/2) pathway. When cultured immature boar Sertoli cells were treated with 17β-estradiol, a time-dependent increase in SKP2 mRNA and protein level was observed by real-time PCR and Western blot, and 17β-estradiol activity peaked at 30 min. Treatment with ICI182780 and ERβ antagonist reduced 17β-estradiol-induced expression of SKP2 and proliferating cell nuclear antigen (PCNA), while increasing the protein concentration of p27kip1. However, the effect of ERa antagonist on these parameters was lower than that of ICI182780 and ERβ. Forskolin had a similar effect as 17β-estradiol on the expression of SKP2, PCNA and p27kip1. Rp-cAMP, H-89 and U0126 treatment reduced 17β-estradiol-induced changes, while H-89 also inhibited ERK1/2 activation. Therefore, 17β-estradiol mainly regulates SKP2 mRNA and protein expression via ERβ-cAMP-PKA and ERK1/2 activation. SKP2 and PCNA expression were positively correlated, while increased SKP2 expression likely resulted in p27kip1 degradation.
    Characterization and Differentiation into Adipocytes and Myocytes of Porcine Bone Marrow Mesenchymal Stem Cells
    DU Min-qing, HUANG Yue-qin, LU Nai-Sheng, SHU Gang, ZHU Xiao-tong, WANG Li-na, GAO Ping
    2014, 13(4): 837-848.  DOI: 10.1016/S2095-3119(13)60497-9
    Abstract ( )   PDF in ScienceDirect  
    Bone marrow mesenchymal stem cells (BMSCs) could differentiate into various cell types including adipocytes and myocytes, which had important scientific significance not only in the field of tissue regeneration, but also in the field of agricultural science. In an attempt to exhibit the characterization and differentiation into adipocytes and myocytes of porcine BMSCs, we isolated and purified porcine BMSCs by red blood cell lysis method and percoll gradient centrifugation. The purified cells presented a stretched fibroblast-like phenotype when adhered to the culture plate. The results of flow cytometry analysis and immunofluorescence staining demonstrated that the isolated cells were positive for mesenchymal surface markers CD29, CD44 and negative for hematopoietic markers CD45 and the adhesion molecules CD31. Cells were induced to differentiate into adipocytes with adipogenic medium containing insulin, dexamethasone, oleate and octanoate. Oil Red O staining demonstrated that the porcine BMSCs successfully differentiated to adipocytes. Moreover, the findings of real-time PCR and Western blotting indicated that the induced cells expressed adipogenic marker genes (PPAR-γ, C/EBP-α, perilipin, aP2) mRNA or proteins (PPAR-γ, perilipin, aP2). On the other hand, porcine BMSCs were induced into myoctyes with myogenic medium supplemented with 5-azacytidine, basic fibroblast growth factor, chick embryo extract and horse serum. Morphological observation by hochest 33342 staining showed that the induced cells presented as multi-nucleus muscular tube structure. And myogenic marker genes (Myf5, desmin) mRNA or proteins (Myf5, MyoD, myogenin, desmin) were found in the induced cells. In addition, the results of immunofluorescence staining revealed that myogenic marker (Myf5, MyoD, myogenin, desmin, S-MyHC) proteins was positive in the induced cells. Above all, these results suggested that the isolated porcine BMSCs were not only consistent with the characterization of mesenchymal stem cells, but also exhibited the multipotential capacity to form adipocytes and myocytes, which provided the basis to investigate the regulation mechanism involved in the selective differentiation of porcine BMSCs.
    Analysis of the Genetic Diversity and Origin of Some Chinese Domestic Duck Breeds
    ZHANG Yang, CHEN Yang, ZHEN Ting, HUANG Zheng-yang, CHEN Chang-yi, LI Xin-yu
    2014, 13(4): 849-857.  DOI: 10.1016/S2095-3119(13)60447-5
    Abstract ( )   PDF in ScienceDirect  
    Twelve fluorescence-labeled microsatellite markers were used to analyze the genetic diversity of 12 domestic duck breeds and 2 wild duck breeds to determine the relationship and origin of Chinese domestic duck breeds. Gene frequency, effective number of alleles (Ne), expected heterozygosity (He), polymorphism information contents (PIC), inbreeding coefficient in population (Fis), standard genetic distance (DS), and genetic distance (DA) were calculated by FSTAT and distance and phylogenetic analysis after the dates which were output from the Microsatellite-Toolkit software. Genetic distances between 12 domestic duck breeds and 2 wild duck breeds were analyzed by variance analysis. Unweighted pair group method with arithmetic mean (UPGMA) and phylogenetic trees used for cluster analysis were structured. The results indicated that 11 loci had medium- or high-level genetic diversity among the 12 loci, which could be efficiently used in the detection of the genetic parameters of each population. The values of He were 0.5414 to 0.7343, those of PIC proved similar, and those of Fis were 0.1101 to 0.3381 among all populations. All breeds were clustered into three groups by UPGMA phylogenetic trees. Banzui duck was clustered into a separate group. Differences of the DA were analysed by t-test. The results showed that difference in DA between the 12 domestic duck breeds and Lvtou duck and the Banzui duck were very significant (P<0.01), indicating that these 12 domestic duck breeds originated from Lvtou wild duck, but not Banzui duck.
    Dramatic Changes of Matrix Metalloproteinases-7 and Lysozyme in the Ulcerative Colitis of Mice Induced by Dextran Sulfate Sodium
    KANG Jing-jing, ZHAO De-ming, TENG Ke-dao, JIAO Xi-lan, WANG Ping-li, SUN Zhe, NI Peipei, WANG Zhi-feng, ZHANG Rui, YANG Yu-rong , LIANG Hong-de
    2014, 13(4): 858-859.  DOI: 10.1016/S2095-3119(13)60416-5
    Abstract ( )   PDF in ScienceDirect  
    Ulcerative colitis (UC) is a lifelong illness with profound emotional and social impacts, and could cause serious damage to large intestine, especially in colon. However, the pathogenesis of UC remained unclear. The present study attempts to find out the role of matrix metalloproteinases-7 (MMP-7) and lysozyme in the pathogenesis of UC through a mice model induced by dextran sulfate sodium (DSS). The UC model was evaluated both by disease activity index (DAI) and the intestinal histopathology. The results show that there is a high correlation between the DAI score and the pathological changes of colon. Interleukin-6 (IL-6) serum levels and large intestinal fluids levels in UC mice are always higher than that of the control groups, which might be associated with the degree of the inflammation damage in the colon. The change tendency of the MMP-7 mRNA and protein expressions are both up-regulated firstly and then down-regulated from 1 to 5 d in the colon, but only the MMP-7 protein is up-regulated at 7 d again. The up-regulated MMP-7 levels in the early stage of UC may play a protective role through the activated defensins, while the down-regulated levels in the mid-later stage of UC may be connected with the severe lesions in the colon. However, the up-regulated MMP-7 levels in the later stage of UC in the colon may also contribute to the tissue repair or be served as a marker to CRC (colorectal cancer). The distribution of lysozyme protein indicates that there may be Paneth-like cells in the colon. Both the changes of MMP-7 and lysozyme in the small intestine may play a protective role for the safe environment of the whole gut, especially to the colon of UC.
    Soil & Fertilization · Irrigation · Agro-Ecology & Environment
    Abundance and Community Composition of Ammonia-Oxidizers in Paddy Soil at Different Nitrogen Fertilizer Rates
    SONG Ya-na , LIN Zhi-min
    2014, 13(4): 870-880.  DOI: 10.1016/S2095-3119(13)60426-8
    Abstract ( )   PDF in ScienceDirect  
    Ammonia oxidation, the first and rate-limiting step of nitrification, is carried out by both ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA). However, the relative importance of AOB and AOA to nitrification in terrestrial ecosystems is not well understood. The aim of this study was to investigate the effect of the nitrogen input amount on abundance and community composition of AOB and AOA in red paddy soil. Soil samples of 10-20 cm (root layer soil) and 0-5 cm (surface soil) depths were taken from a red paddy. Rice in the paddy was fertilized with different rates of N as urea of N1 (75 kg N ha-1 yr-1), N2 (150 kg N ha-1 yr-1), N3 (225 kg N ha-1 yr-1) and CK (without fertilizers) in 2009, 2010 and 2011. Abundance and community composition of ammonia oxidizers was analyzed by real-time PCR and denaturing gradient gel electrophoresis (DGGE) based on amoA (the unit A of ammonia monooxygenase) gene. Archaeal amoA copies in N3 and N2 were significantly (P<0.05) higher than those in CK and N1 in root layer soil or in surface soil under tillering and heading stages of rice, while the enhancement in bacterial amoA gene copies with increasing of N fertilizer rates only took on in root layer soil. N availability and soil NO3 --N content increased but soil NH4 +-N content didn’t change with increasing of N fertilizer rates. Otherwise, the copy numbers of archaeal amoA gene were higher (P<0.05) than those of bacterial amoA gene in root lary soil or in surface soil. Redundancy discriminate analysis based on DGGE bands showed that there were no obvious differs in composition of AOA or AOB communities in the field among different N fertilizer rates. Results of this study suggested that the abundance of ammonia-oxidizers had active response to N fertilizer rates and the response of AOA was more obvious than that of AOB. Similarity in the community composition of AOA or AOB among different N fertilizer rates indicate that the community composition of ammonia-oxidizers was relatively stable in the paddy soil at least in short term for three years.
    Impacts of Fertilization Alternatives and Crop Straw Incorporation on N2O Emissions from a Spring Maize Field in Northeastern China
    YANG Li , WANG Li-gang, LI Hu, QIU Jian-jun , LIU Hui-ying
    2014, 13(4): 881-892.  DOI: 10.1016/S2095-3119(13)60496-7
    Abstract ( )   PDF in ScienceDirect  
    Spring maize is one of the most popular crops planted in northeastern China. The cropping systems involving spring maize have been maintaining high production through intensive management practices. However, the high rates of nitrogen (N) fertilizers application could have introduced a great amount of nitrous oxide (N2O) into the atmosphere. It is crucial for sustaining the maize production systems to reduce N2O emissions meanwhile maintaining the optimum yields by adopting alternative farming management practices. The goal of this study was to evaluate effects of alternative fertilization and crop residue management practices on N2O emission as well as crop yield for a typical maize field in northeastern China. Field experiments were conducted during the 2010-2011 maize growing seasons (from early May to late September) in Liaoning Province, northeastern China. N2O fluxes were measured at the field plots with six different treatments including no N fertilizer use (CK), farmers’ conventional N fertilizer application rate (FP), reduced N fertilizer rate (OPT), reduced N fertilizer rate combined with crop straw amendment (OPTS), slow-release N fertilizer (CRF), and reduced N fertilizer rate combined with nitrification inhibitor (OPT+DCD). The static chamber method combined with gas chromatography technique was employed to conduct the measurements of N2O fluxes. The field data showed that N2O emissions varied across the treatments. During the maize growing season in 2010, the total N2O emissions under the treatments of CK, FP, OPT, OPTS, and CRF were 0.63, 1.11, 1.03, 1.26, and 0.98 kg N ha-1, respectively. The seasonal cumulative N2O emissions were 0.54, 1.07, 0.96, 1.12, and 0.84 kg N ha-1, respectively, under CK, FP, OPT, OPTS, and OPT+DCD in 2011. In comparison with FP, CRF or OPT+DCD reduced the N2O emissions by 12 or 21%, respectively, while the crop yields remained unchanged. The results indicate that the reduction of N-fertilizer application rate in combination with the slow-release fertilizer type or nitrification inhibitor could effectively mitigate N2O emissions from the tested field. The incorporation of crop residue didn’t show positive effect on mitigating N2O emissions from the tested cropping system. The field study can provide useful information for the on-going debate on alternative N fertilization strategies and crop straw management in China. However, further studies would be needed to explore the long-term impacts of the alternative management practices on a wide range of environmental services.
    Classification and Net Primary Productivity of the Southern China’s Grasslands Ecosystem Based on Improved Comprehensive and Sequential Classification System (CSCS) Approach
    SUN Zheng-guo, SUN Cheng-ming, ZHOU Wei, JU Wei-min , LI Jian-long
    2014, 13(4): 893-903.  DOI: 10.1016/S2095-3119(13)60415-3
    Abstract ( )   PDF in ScienceDirect  
    This research classified vegetation types and evaluated net primary productivity (NPP) of southern China’s grasslands based on the improved comprehensive and sequential classification system (CSCS), and proposed 5 thermal grades and 6 humidity grades. Four classes of grasslands vegetation were recognized by improved CSCS, namely, tundra grassland class, typical grassland class, mixed grassland class and alpine grassland class. At the type level, 14 types of vegetations (9 grasslands and 5 forests) were classified. The NPP had a trend to decrease from east to west and south to north, and the annual mean NPP was estimated to be 656.3 g C m-2 yr-1. The NPP value of alpine grassland class was relatively high, generally more than 1 200 g C m-2 yr-1. The NPP value of mixed grassland class was in a range from 1 000 to 1 200 g C m-2 yr-1. Tundra grassland class was located in southeastern Tibet with high elevation, and its NPP value was the lowest (<600 g C m-2 yr-1). The typical grassland class distributed in most of the area, and its NPP value was generally from 600 to 1 000 g C m-2 yr-1. The total NPP value in the study area was 68.46 Tg C. The NPP value of typical grassland class was the highest (48.44 Tg C), and mixed grassland class was the second (16.54 Tg C), followed by alpine grassland class (3.22 Tg C), with tundra grassland class being the lowest (0.25 Tg C). For all the grasslands types, the total NPP of forest meadow was the highest (34.81 Tg C), followed by sparse forest brush (16.54 Tg C), and montane meadow was the lowest (0.01 Tg C).
    Short Communication
    Expression of Chicken Toll-Like Receptors and Signal Adaptors in Spleen and Cecum of Young Chickens Infected with Eimeria tenella
    ZHOU Zuo-yong, HU Shi-jun, WANG Zhi-ying, GUO Zhi-li, QIN Bo , NIE Kui
    2014, 13(4): 904-910.  DOI: 10.1016/S2095-3119(13)60384-6
    Abstract ( )   PDF in ScienceDirect  
    Toll-like receptors (TLRs) are a group of highly conserved molecules which initiate the innate immune response to pathogens by recognizing structural motifs of microbes. Understanding the changes in chicken Toll-like receptors (ChTLRs) and signal adaptors expression that occur with Eimeria tenella infection will help to elucidate the molecular basis of immune control of coccidiosis caused by Eimeria. The present study detected the dynamic changes in the expression of ChTLRs and associated signal adaptors in the spleen and cecum of E. tenella-infected chickens during the early stage of infection. The results showed that the expression peak for ChTLRs, MyD88 and TRIF occurred at 12 h post-infection (hpi), ChTLR3, ChTLR15 and MyD88 mRNA expression in the spleen of E. tenella infected chickens were significantly higher (P<0.05) than that of negative control chickens, and there were similar tendencies of these molecules expression in the cecum and spleen of E. tenella-infected chickens. The expression of MyD88 was upregulated at four time points in the cecum of E. tenella-infected chickens. The results of this study indicate that ChTLR3, ChTLR15 and MyD88 play a role in young chickens infected with E. tenella.
    Antimicrobial Susceptibility and Characterization of Outer Membrane Proteins of Aeromonas hydrophila Isolated in China
    GUO Peng, WANG Na, LIU Yong-jie , LU Cheng-ping
    2014, 13(4): 911-917.  DOI: 10.1016/S2095-3119(13)60312-3
    Abstract ( )   PDF in ScienceDirect  
    Aeromonas hydrophila isolates from clinical cases (n=43) were tested against 8 antimicrobial agents and typed by outer membrane protein (OMP) pattern by using sodium dodecyl sulfate gel electrophoresis. All isolates were resistant to ampicillin (MICs, 16 mg mL-1) and sulfamonomethoxine (MICs, 64 mg mL-1), but susceptible to norfloxacin (MICs, 0.5 mg mL-1). There was a high incidence of resistance to erythromycin (90.70%) and tylosin (93.02%), while a low incidences of resistance to ciprofloxacin (2.33%), enrofloxacin (2.33%) and florfenicol (4.65%). Six different outer membrane protein patterns were found among 34 isolates by analyzing proteins in the range of 22 to 50 kDa, other than 9 isolates with their respective profiles. The strains with the similar OMP profiles had similar resistances. Compared with the other strains from the same OMP patterns, NB-1, A.Pun and MR-1 had lacked the proteins in the range of 30 to 45 kDa and their resistance to florfenicol substantially increased. It is speculated that the outer membrane protein changes might correlate with decreased susceptibility to florfenicol in the three strains. Some strains which showed completely identical OMP types had a little difference in their resistance to fluoroquinolones, indicating that there might be other factors that were involved in the antimicrobial resistance of A. hydrophila.