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    Crop Genetics · Breeding · Germplasm Resources
    Molecular Characterization and Functional Analysis of OsPHY1, a Purple Acid Phosphatase (PAP)-Type Phytase Gene in Rice (Oryza sativa L.)
    LI Rui-juan, LU Wen-jing, GUO Cheng-jin, LI Xiao-juan, GU Jun-tao, XIAO Kai
    2012, 12(8): 1217-1226.  DOI: 10.1016/S1671-2927(00)8650
    Abstract ( )   PDF in ScienceDirect  
    As a specific type of acid phosphatses, phytases play diverse roles in plants by catalazing the degradation of phytic acid and its derivatives. In this study, a rice phytase gene referred to OsPHY1 has been functionally characterized. OsPHY1 contains a 1 620 bp of open reading frame, encoding a 539-aa polypeptide. A conserve domain metallophosphatase (MPP) (MPP_PAPs), generally harbored in phytase and purple acid phosphatases (PAP), was identified in OsPHY1 (residue 194- 398). Phylogenetic analysis revealed that OsPHY1 shares high similarities with phytase genes and PAP-type genes that derived from diverse plant species. The OsPHY1 transcripts were detected to be abundant in germinating seeds, suggesting that this gene plays potential roles on degradation of seed phytic acid and its derivatives during the germination process. Biochemical analysis confirmed that OsPHY1 possesses strong catalytic activities on phytic acid-Na2, with optimal temperature of 57°C and suitable pH of 3.5. Based on transgene analysis, the putative role of OsPHY1 in plants on utilization of phytate was assessed. Under the condition that phytic acid-Na2 was used as sole P source, the OsPHY1- overexpressing tobacco plants behaved higher phytase activities, higher concentrations of Pi, more accumulative amount of total phosphorus, and much more improved growth traits than those of the control plants. Therefore, OsPHY1 is acted as an important component on degradation of the phytins during the seed germination process in rice. Also, OsPHY1 has a potential use on generation of elite crop germplasms with improved use efficiencies on phytate and its derivatives.
    Phylogenetic Analysis and Expression Patterns of the MAPK Gene Family in Wheat (Triticum aestivum L.)
    LIAN Wei-wei, TANG Yi-miao, GAO Shi-qing, ZHANG Zhao, ZHAO Xin, ZHAO Chang-ping
    2012, 12(8): 1227-1235.  DOI: 10.1016/S1671-2927(00)8651
    Abstract ( )   PDF in ScienceDirect  
    Mitogen activated protein kinases (MAPK) cascades based on protein phosphorylation play an important role in plant growth and development. In this study, we have identified 15 putative members of the wheat MAPK gene (TaMPK) family through an in silico search of wheat expressed sequence tags (EST) databases based on the presence of amino acid sequence of Arabidopsis and rice MAPKs. Phylogenetic analyses of MAPKs from wheat, rice and Arabidopsis genomes have classified them into seven subgroups (A, B, C, D, E, F, and G). Using the available EST information as a source of expression data, the MAPK family genes from Triticum aestivum were detected in diverse tissues. Further expression analysis of the MAPKs in NCBI EST database revealed that their transcripts were most abundant in callus (20%), followed by leaf (12%) and inflorescence (12%). Most MAPK family genes showed some tissue specificity.
    Foci of Future Studies on Abiotic Stress Tolerance of Maize in the Era of Post-Genomics
    LI You-zhi, FAN Xian-wei, LIAO Jiang-xiong
    2012, 12(8): 1236-1244.  DOI: 10.1016/S1671-2927(00)8652
    Abstract ( )   PDF in ScienceDirect  
    Genetic and metabolic engineering approaches are powerful tools for improving the tolerance of maize to abiotic stresses because they are faster and can afford greater control over agronomically useful traits. However, in-depth understanding of the molecular mechanisms controlling response to abiotic stresses is the prerequisite for successful implementation of these strategies. A great flaw to dissect the biological mechanisms by genome sequencing is that genome sequencing approach could not reflect real-time molecular actions of plants especially under the stresses because the living organisms rarely live in unchanging environments. Post-genomics such as transcriptomics, metabolomics, and proteomics can generate knowledge that is closer to the biological processes. With the development of post-genomics, it can be expected that voluminous data will be generated. This paper proposes that future research on maize stress tolerance in the era of post-genomics should focus on metabolomics and proteomics; stress tolerance of whole plant rather than individual tissues or organs; coordination of expression of genes among tissues; characterization of promoters of stress-responsive genes; interrelation between mechanisms for tolerance to, and growth recovery from the stress; hexose metabolism as well as the glycolysis pathway; and foundation genotypes.
    Genome-Wide Transcriptional Analysis of Yield and Heterosis-Associated Genes in Maize (Zea mays L.)
    ZHANG Ti-fu, LI Bo, ZHANG Deng-feng, JIA Guan-qing, LI Zhi-yong, WANG Shou-cai
    2012, 12(8): 1245-1256.  DOI: 10.1016/S1671-2927(00)8653
    Abstract ( )   PDF in ScienceDirect  
    Heterosis has contributed greatly to yield in maize, but the nature of its contribution is not completely clear. In this study, two strategies using whole-genome oligonucleotide microarrays were employed to identify differentially expressed genes (DEGs) associated with heterosis and yield. The analysis revealed 1 838 heterosis-associated genes (HAGs), 265 yieldassociated genes (YAGs), and 85 yield heterosis-associated genes (YHAGs). 37.1% of HAGs and 22.4% of YHAGs expressed additively. The remaining genes expressed non-additively, including those with high/low-parent dominance and over/under dominance, which were prevalent in this research. Pathway enrichment analysis and quantitative trait locus (QTL) co-mapping demonstrated that the metabolic pathways for energy and carbohydrates were the two main enriched pathways influencing heterosis and yield. Therefore, the DEGs participating in energy and carbohydrate metabolism were considered to contribute to heterosis and yield significantly. The investigation of potential groups of HAGs, YAGs, and YHAGs might provide valuable information for exploiting heterosis to improve yield in maize breeding. In addition, our results support the view that heterosis is contributed by multiple, complex molecular mechanisms.
    Characterization of Tomato Transcription Factor WUSCHEL and Functional Study in Arabidopsis
    WANG Xiang, WANG Xin-guo, REN Jiang-ping, MA Ying, YIN Jun
    2012, 12(8): 1257-1265.  DOI: 10.1016/S1671-2927(00)8654
    Abstract ( )   PDF in ScienceDirect  
    The homeobox transcription factor WUSCHEL (WUS) plays a critical role in keeping the balance between the maintenance and differentiation of stem cell population in shoot and floral meristems of Arabidopsis thaliana. The corresponding gene SlWUS is yet to be characterized in tomato. In order to characterize SlWUS gene and its biological function, we cloned it from tomato and analyzed its structure. Tissue expression showed that the SlWUS highly expressed in tomato flower abscission zone. The overexpression of SlWUS in Arabidopsis could trigger undifferentiation of plant flower organ and indeterminacy of flower identity, suggesting that SlWUS maybe involved in flower structure development as well as flower organ identity. Taken together, our results indicated that the SlWUS plays an important role in flower abscission zone and plant organ shedding.
    Functional Analysis of the ZAG2 Promoter from Maize in Transgenic Tobaccos
    LU Min-hui, WANG Guo-ying, MENG Zheng, WANG Jian-hua
    2012, 12(8): 1266-1273.  DOI: 10.1016/S1671-2927(00)8655
    Abstract ( )   PDF in ScienceDirect  
    The function of the 3 040 bp sequence at the upstream translation starting site (ATG) of the ZAG2 gene, isolated from the maize genome, was studied. The sequence analysis showed that the sequence contained a typical class C MADS-box gene regulatory element. The 5´ UTR region of the gene contains a 1 299-bp intron that might have important regulatory functions. To study the sequence function, deletion derivatives of promoter-reporter (uidA) gene fusions were generated and transformed into tobaccos. The GUS staining and fluorescence quantification results showed that the GUS activity was detected only in the third and fourth whorl floral organs of the transgenic tobaccos under driving the promoter including the first intron, while detected in all the organs and was stronger under driving the promoter without the first intron. However, the GUS activity was just detected in one whorl of the fourth or third floral organs under driving of the 35S promoter. These results suggested that the first intron of the ZAG2 gene contains functional regulatory elements, which turned out to be important for gene expression in the heterologous systems. Moreover, the GUS activity was decreased when the reporter gene driven by the promoters with 5´-deletions, respectively, from -1 606 to -951 and -951 to -426 nts, which indicates that positive regulatory elements are present in these two sequence stretches.
    Comparison of Crop Model Validation Methods
    CAO Hong-xin, Jim Scott Hanan, LIUYan , LIU Yong-xia, YUE Yan-bin, ZHU Da-wei, LU Jian-fei, SUN
    2012, 12(8): 1274-1285.  DOI: 10.1016/S1671-2927(00)8656
    Abstract ( )   PDF in ScienceDirect  
    In this paper, the many indices used in validation of crop models, such as RMSE (root mean square errors), Sd (standard error of absolute difference), da (mean absolute difference), dap (ratio of da to the mean observation), r (correlation), and R2 (determination coefficient), are compared for the same rice architectural parameter model, and their advantages and disadvantages are analyzed. A new index for validation of crop models, dap between the observed and the simulated values, is proposed, with dap<5% as the suggested standard for precision of crop models. The different kinds of validation methods in crop models should be combined in the following aspects: (1) calculating da and dap; (2) calculating the RMSE or Sd; (3) calculating r and R2, at the same time, plotting 1:1 diagram.
    Effects of Different Tillage Systems on Soil Properties, Root Growth, Grain Yield, and Water Use Efficiency of Winter Wheat (Triticum aestivum L.) in Arid Northwest China
    HUANG Gao-bao, CHAI Qiang, FENG Fu-xue, YU Ai-zhong
    2012, 12(8): 1286-1296.  DOI: 10.1016/S1671-2927(00)8657
    Abstract ( )   PDF in ScienceDirect  
    Studies on root development, soil physical properties, grain yield, and water-use efficiency are important for identifying suitable soil management practices for sustainable crop production. A field experiment was conducted from 2006 through 2008 in arid northwestern China to determine the effects of four tillage systems on soil properties, root development, water-use efficiency, and grain yield of winter wheat (Triticum aestivum L.). The cultivar Fan 13 was grown under four tillage systems: conventional tillage (CT) without wheat stubble, no-tillage without wheat stubble mulching (NT), notillage with wheat stubble standing (NTSS), and no-tillage with wheat stubble mulching (NTS). The soil bulk density (BD) under CT system increased gradually from sowing to harvest, but that in NT, NTSS, and NTS systems had little change. Compared to the CT system, the NTSS and NTS systems improved total soil water storage (0-150 cm) by 6.1-9.6 and 10.5- 15.3% before sowing, and by 2.2-8.9 and 13.0-15.1% after harvest, respectively. The NTSS and NTS systems also increased mean dry root weight density (DRWD) as compared to CT system. The NTS system significantly improved water-use efficiency by 17.2-17.5% and crop yield by 15.6-16.8%, and the NTSS system improved that by 7.8-9.6 and 7.0- 12.8%, respectively, compared with the CT system. Our results suggested that Chinese farmers should consider adopting conservation tillage practices in arid northwestern China because of benefits to soil bulk density, water storage, root system, and winter wheat yield.
    Mechanical Harvesting Effects on Seed Yield Loss, Quality Traits and Profitability of Winter Oilseed Rape (Brassica napus L.)
    MA Ni, ZHANG Chun-lei, LI Jun, ZHANG Ming-hai, CHENG Yu-gui, LI Guang-ming, ZHANG Shujie
    2012, 12(8): 1297-1304.  DOI: 10.1016/S1671-2927(00)8658
    Abstract ( )   PDF in ScienceDirect  
    China is one of the most important rapeseed producing countries in the world. Effective mechanical harvesting time for decreasing harvesting loss of winter oilseed rape has been becoming a critical factor. An elite cultivar Zhongshuang 11 (Brassica napus L.) was employed in two rounds of field experiments from 2009 to 2011. Seeds were sown with machine, three combine harvesting times namely combine harvesting A, B, and C (CHA, CHB, and CHC) were designed and manual harvesting (MH) as control was performed at maturity. The harvesting treatments were determined according to color of pod and seed in the field. Seed yield loss and quality in different treatments were evaluated. Results showed that both seed yields and harvesting losses in 2009-2010 were higher than that in 2010-2011, whereas seed oil contents in 2010-2011 were higher than that in 2009-2010. The highest yield appeared in CHB, which was significantly higher than that in MH. Furthermore, harvesting loss in CHB were 50% that in MH. Seed oil content and chlorophyll exhibited no obvious difference between CHB and MH. Economic profit analysis demonstrated that mechanical sowing/combine harvesting (MS/CH) showed an input/output ratio of 1:1.6, and it was 1:1.2 in mechanical sowing/manual harvesting (MS/MH). Labor-cost accounted for more than 70% of the total cost in MS/MH, which led to low profitability to a great extent. Our results suggested that CHB was the optimum harvesting time for winter oilseed rape along the Yangtze River.
    The Role of Radical Burst in Plant Defense Responses to Necrotrophic Fungi
    Mahesh S Kulye, LIU Hua, QIU De-wen
    2012, 12(8): 1305-1312.  DOI: 10.1016/S1671-2927(00)8659
    Abstract ( )   PDF in ScienceDirect  
    Necrotrophic fungi, being the largest class of fungal plant pathogens, pose a serious economic problem to crop production. Nitric oxide (NO) is an essential regulatory molecule in plant immunity in synergy with reactive oxygen species (ROS). Most experimental data available on the roles of NO and ROS during plant-pathogen interactions are from studies of infections by potential biotrophic pathogens, including bacteria and viruses. However, there are several arguments about the role of ROS in defense responses during plants and necrotrophic pathogens interaction and little is known about the role of NO as a counterpart of ROS in disease resistance to necrotrophic pathogens. This review focuses on the recent knowledge about the role of oxidative burst in plant defense response to necrotrophic fungi.
    Effects of Temperature on Functional Response of Anagrus nilaparvatae Pang et Wang (Hymenoptera: Mymaridae) on the Eggs of Whitebacked Planthopper, Sogatella furcifera Horváth and Brown Planthopper, Nilaparvata lugens Stål
    MA Ming-yong, PENG Zhao-pu, HE Yuan
    2012, 12(8): 1313-1320.  DOI: 10.1016/S1671-2927(00)8660
    Abstract ( )   PDF in ScienceDirect  
    Understanding the temperature affecting parasitic efficiency is critical to succeed in utilizing parasitoid as natural enemy in pest management. Laboratory studies were carried out to determine the effects of temperature on parasitoid preference of female Anagrus nilaparvatae Pang et Wang (Hymenoptera: Mymaridae) to the eggs of whitebacked planthopper (WBPH), Sogatella furcifera Horváth and brown planthopper (BPH), Nilaparvata lugens Stål to build a composite model describing changes in parasitic response along a temperature gradient (18, 22, 26, 30, 34°C). The results showed that attack responses of A. nilaparvatae on WBPH and BPH were the best described by a Type II functional response. The two parameters, attack rates (a) and handling times (Th), of A. nilaparvatae to both eggs were influenced by the temperature. The maximum attack rates to WBPH (1.235) and BPH (1.049) were at 26 and 34°C, respectively, and the shortest handling times to WBPH (0.063) and BPH (0.057) were at 30 and 26°C, respectively. However, the optimal temperature for parasitic efficiency of A. nilaparvatae to WBPH and BPH eggs was both at 26°C, which showed that the present microclimate temperature of the habitat in the paddyfield was beneficial to A. nilaparvatae and indicated that parasitic efficiency of A. nilaparvatae would be impaired by global warming.
    Phagocytic Uptake of Nosema bombycis (Microsporidia) Spores by Insect Cell Lines
    CAI Shun-feng, LU Xing-meng, QIU Hai-hong, LI Ming-qian, FENG Zhen-zhen
    2012, 12(8): 1321-1326.  DOI: 10.1016/S1671-2927(00)8661
    Abstract ( )   PDF in ScienceDirect  
    Microsporidia are highly specialized obligate intracellular parasites that can infect a wide variety of animals ranging from protists to mammals. The classical concept of the parasite invasion into a host cell involves its polar tube acting as a needle-syringe system. However, recent studies show microsporidian spores can also gain access to host cells by phagocytosis. The present study investigated the phagocytic uptake process of causative agent of the pebrine disease, Nosema bombycis, in several insect cell lines. We observed KOH-treated spores and cold-storaged spores can be easily uptaken by all the studied cell types 4 h post inoculation. In contrast, large numbers of freshly recovered spores remained in the culture medium. To further investigate the intracellular fates of KOH-treated spores and cold-storaged spores, electron and fluorescence microscopy were performed. No intracellular germination or subsequent parasite development were observed. Intracellular spores can be detected in host cells by polyclonal antibody 7 d post inoculation, suggesting phagocytized N. bombycis could not be digested by these non-professional phagocytes. Our results suggest that, phagocytic uptake of N. bombycis spores might represent a defense mechanism of the host cells and the intact spore wall barrier enable freshly recovered spores to keep resistance to this mechanism.
    Novel 6-bp Deletion Mutation in visfatin Gene and Its Associations with Birth Weight and Bodyweight in Chinese Cattle
    WANG Mou, ZHANG Ya, YU Hui, LAI Xin-sheng, ZHU Jin-long, JIAO Jin-zhen, LAN Xian-yong, LEI Chuzhao, ZHANG Liang-zhi, CHEN Hong
    2012, 12(8): 1327-1332.  DOI: 10.1016/S1671-2927(00)8662
    Abstract ( )   PDF in ScienceDirect  
    Visfatin, like insulin, induces phosphorylation of signal transduction proteins that operatate downstream of the insulin receptor. The present study is focused on detecting deletion of visfatin gene and analyzing its effect on growth traits in six Chinese cattle breeds (Nangyang, Luxi, Qinchuan, Jiaxian Red, Grassland Red, and Chinese Holstein) using DNA sequencing, PCR-SSCP and PCR-RFLP methods. For the first time, a 6-bp deletion of visfatin was described and two alleles were revealed: W and D. The χ2-test analysis demonstrated that all breeds were in agreement with Hardy-Weinberg equilibrium (P>0.05). The associations of the novel 6-bp deletion of visfatin gene with growth traits of Nanyang cattle at 6-, 12-, 18-, and 24-mon-old were analyzed. Birth weight, 12- and 24-mon-old cattle with genotype WW had greater birth weight and average daily gain than genotype WD (P<0.01 or P<0.05). These results suggest that the deletion may influence the birth weight and bodyweight in 12 mon-old cattle.
    Expression of Interleukin-6 and Interleukin-6 Receptor in Ovine Oocytes During In vitro Maturation
    ZHAO Xi-an, CANG Ming, GAO Xiao-yu, YANG Mei-ling, YUAN Jian-long, ZHU Bing, WANG Zhi-gang
    2012, 12(8): 1333-1339.  DOI: 10.1016/S1671-2927(00)8663
    Abstract ( )   PDF in ScienceDirect  
    To study the effects of interleukin-6 (IL-6) and its receptor (IL-6R) during in vitro maturation of ovine oocytes, the mRNA and protein expression levels of IL-6 and IL-6R, along with their localization, were examined during ovine oocytes maturation in vitro through real-time PCR, Western blotting, and immunohistochemistry. Specific patterns of expression of IL-6 and IL-6R were observed at both mRNA and protein levels at each stage of ovine oocytes maturation. IL-6 and IL-6R were distributed primarily on the surface of the cell membrane, with little expression in the cytoplasm or nucleus. IL-6 and IL- 6R were expressed significantly at higher levels in the maturation around 4 h, and then decreased dramatically. However the level slightly elevated at 20-24 h. The role of IL-6 and IL-6R on oocytes maturation was studied through in vitro addition of recombinant human IL-6 in different concentrations. The addition of 10 ng mL-1 IL-6 significantly increased the rates of oocytes maturation (P<0.05), but did not affect the rates of development of the subsequence IVF ovine embryos. In summary, IL-6 is likely to play an important role in the early ovine oocytes maturation. The expression patterns of the IL-6 and IL-6R on the ovine oocytes maturation open up the possibility of regulatory role of the cytokine in ovine oocytes maturation.
    Cardiopulmonary, Biochemical and Haematological Effects of the Tiletamine/ Zolazepam-Xylazine-Tramadol Combination to Provide Anaesthesia in Miniature Pigs
    LU De-zhang, FAN Hong-gang, JIANG Sheng, ZHANG Luan-song, MA Kun, YU Shi-ming, TAN Lijuan, WANG Hong-bin
    2012, 12(8): 1340-1346.  DOI: 10.1016/S1671-2927(00)8664
    Abstract ( )   PDF in ScienceDirect  
    The objective of this study was to investigate the suitability of tiletamine/zolazepam-xylazine-tramadol combination for miniature pigs. Fourteen Chinese experimental miniature pigs subjected to this study received 3.5 mg tiletamine/zolazepam kg-1 bw, 1.32 mg xylazine kg-1 bw and 1.8 mg tramadol kg-1 bw intramuscularly, as a mixture of the drugs. Cardiopulmonary, biochemical and haematological parameters were recorded before drug administration and after anaesthesia. The combination of the compounds resulted in anaesthesia lasting about 87 min and a satisfactory immobilization for handling. Cardiopulmonary parameters were changed after administration, but there were within biologically acceptable limits. Biochemical and haematological values decreased after drug administration, however, they returned to the baseline at 24 h. At the doses described, tiletamine/zolazepam-xylazine-tramadol combination produced good immobilization in miniature pigs with minimal changes over time in cardiopulmonary, biochemical and haematological parameters.
    Isolation and Molecular Characterization of Toxoplasma gondii from Chickens in China
    ZHAO Guang-wei, SHEN Bo, XIE Qing, XU Li-xin, YAN Ruo-feng, SONG Xiao-kai, Hassan Ibrahim Adam, LI Xiang-rui
    2012, 12(8): 1347-1353.  DOI: 10.1016/S1671-2927(00)8665
    Abstract ( )   PDF in ScienceDirect  
    One strain of Toxoplasma gondii was successfully isolated from chickens in China by bioassay in mice. Antibodies and circulating antigens of T. gondii were assayed by the ELISA kits in 100 free range chickens from a rural area surrounding Funing, China. Fifty-three chickens were antibody-positive and 21 chickens were antigen positive. Hearts, brains, spleens, lungs, livers, and kidneys of 21 antibody or antigen-positive chickens were bioassayed in mice. One strain of T. gondii was isolated from 1 of 21 (4.76%) chickens. The isolated T. gondii killed all of the inoculated mice. Genotyping of this isolate using polymorphisms at the loci 5´-SAG2, 3´-SAG2, SAG3, cB21-4, L358, BTUB, and GRA6 revealed that it was Type I. These indicated that it was virulent for mice. This is the first report of isolation of T. gondii from chickens in China.
    Characteristics and Driven Factors of Nitrous Oxide and Carbon Dioxide Emissions in Soil Irrigated with Treated Wastewater
    XUE Yan-dong, YANG Pei-ling, LUO Yuan-pei, LI Yun-kai, REN Shu-mei, SU Yan-ping, NIU Yongtao
    2012, 12(8): 1354-1364.  DOI: 10.1016/S1671-2927(00)8666
    Abstract ( )   PDF in ScienceDirect  
    The reuse of treated wastewater in agricultural systems could partially help alleviate water resource shortages in developing countries. Treated wastewater differs from fresh water in that it has higher concentrations of salts, Escherichia coli and presence of dissolved organic matter, and inorganic N after secondary treatment, among others. Its application could thus cause environmental consequences such as soil salinization, ammonia volatilization, and greenhouse gas emissions. In an incubation experiment, we evaluated the characteristics and effects of water-filled pore space (WFPS) and N input on the emissions of nitrous oxide (N2O) and carbon dioxide (CO2) from silt loam soil receiving treated wastewater. Irrigation with treated wastewater (vs. distilled water) significantly increased cumulative N2O emission in soil (117.97 μg N kg-1). Cumulative N2O emissions showed an exponentially increase with the increasing WFPS in unamended soil, but the maximum occurred in the added urea soil incubated at 60% WFPS. N2O emissions caused by irrigation with treated wastewater combined with urea-N fertilization did not simply add linearly, but significant interaction (P<0.05) caused lower emissions than the production of N2O from the cumulative effects of treated wastewater and fertilizer N. Moreover, a significant impact on cumulative CO2 emission was measured in soil irrigated with treated wastewater. When treated wastewater was applied, there was significant interaction between WFPS and N input on N2O emission. Hence, our results indicated that irrigation with treated wastewater should cause great concern for increasing global warming potential due to enhanced emission of N2O and CO2.
    Spatio-Temporal Changes of Soil Salinity in Arid Areas of South Xinjiang Using Electromagnetic Induction
    LI Xiao-ming, YANG Jing-song, LIU Mei-xian, LIU Guang-ming, YU Mei
    2012, 12(8): 1365-1376.  DOI: 10.1016/S1671-2927(00)8667
    Abstract ( )   PDF in ScienceDirect  
    The aim of this paper was to research the spatio-temporal changes in total soluble salt content (TS) in a typical arid region of South Xinjiang, China, where the climate is arid and soil salinization happens easily. The total soluble salt content was interpreted by measurements made in the horizontal mode with EM38 and EM31. The electromagnetic induction (EM) surveys were made three times with the apparent soil electrical conductivity (ECa) measurements taken at 3 873 locations in Nov. 2008, 4807 locations in Apr. 2009 and 6 324 locations in Nov. 2009, respectively. For interpreting the ECa measurements into total soluble salt content, calibtion sites were needed for EM survey of each time, e.g., 66 sites were selected in Nov. 2008 to measure ECa, and soils-core samples were taken by different depth layers of 0-10, 10-20 and 20-40 cm at the same time. On every time duplicate samples were taken at five sites to allevaite the local-scale variability, and soil temperatures in different layers through the profiles were also measured. Factors including TS, pH, water content, bulk density were analyzed by lab experiments. ECa calibration equations were obtained by linear regression analysis, which indicated that soil salinity was one primary concern to ECa with a determination coefficient of 0.792 in 0-10 cm layer, 0.711 in 10-20 cm layer and 0.544 in 20-40 cm layer, respectively. The maps of spatial distribution were predicted by Kriging interpolation, which showed that the high soil salinity was located near the drainage canal, which validated the trend effect caused by the irrigation canal and the drainage canal. And by comparing the soil salinity in different layers, the soluble salt accumulated to the top soil surface only in the area where the soil salinization was serious, and in the other areas, the soil salinity trended to increase from the top soil surface to 40 cm depth. Temporal changes showed that the soil salinity in November was higher than that in April, and the soil salinization trended to aggravate, especially in the top soil layer of 0- 10 cm.
    Analysis of Two Bradyrhizobium japonicum Strains with Different Symbiotic Matching for Nodulation by Primary Proteomic
    GUAN Da-wei, MA Ming-chao, MA Zhong-yu, JIANG Xin, LI Li, CAO Feng-ming, SHEN De-long, CHEN Hui-jun, LI Jun
    2012, 12(8): 1377-1383.  DOI: 10.1016/S1671-2927(00)8668
    Abstract ( )   PDF in ScienceDirect  
    The symbiotic matching for nodulation of Bradyrhizobium japonicum strains is a synergy of multi-proteins and plays a key role in symbiotic nitrogen fixation in nature. Studies on mechanism of symbiotic matching are significant in both theory and practice. In this paper, B. japonicum USDA110-A with high symbiotic matching with high-oil content soybean cultivar Suinong 20 and B. japonicum 2178 with low symbiotic matching were selected for proteomic to reveal mechanism of different symbiotic nodulation. The results showed that the amount and categories of proteins identified in this test were different when the two strains were treated by symbiotic nodulation. There were 10 up-regulated proteins and 5 down-regulated proteins with significant difference for B. japonicum USDA110-A. Proteins associated with nodulation and metabolism of energy and material, which were propitious to symbiotic nodulation, were all up-regulated, such as PHDPS synthase, metal-dependent phosphohydrolase, glycosyl transferase family. In contrast, only 5 up-regulated and 7 down-regulated differential proteins were detected in B. japonicum 2178. Molecular chaperones and defensive proteins, which influence the folding of nascent polypeptide chains and the active of azotase were down-regulated. To a certain extent, the different responses of B. japonicum to daidzein were one of the most important reasons that cause varieties in symbiotic matching ability.
    Occurrence and Characterization of Pale, Soft, Exudative-Like Broiler Muscle Commercially Produced in China
    ZHU Xue-shen, XU Xing-lian, MIN Hui-hui, ZHOU Guang-hong
    2012, 12(8): 1384-1390.  DOI: 10.1016/S1671-2927(00)8669
    Abstract ( )   PDF in ScienceDirect  
    Pale, soft, exudative-like (PSE-like) broiler muscle is a growing problem for meat industry all over the world. However, limited studies have been made to assess broiler meat quality in China. The aim of this study was to investigate the characteristics and incidence of PSE-like broiler muscle commercially produced in China. A total of 1 274 Pectoralis muscles of Arbor Acre broiler were randomly obtained from the processing line to determine the commercial incidence of PSE-like muscle based on color. Furthermore, broiler Pectoralis muscles selected from the 1 274 muscle samples were classified as PSE-like muscle (L*>53, n=33) and normal muscle (L*>48 and L*=53, n=33) to assess meat quality. It was determined that PSE-like muscle had lower muscle pH values, lower water-holding capacity (WHC), lower sarcoplasmic protein solubility, and lower total protein solubility than the normal muscle did. SDS-PAGE profile also showed that bands of approximate 96 and 24 kDa in sarcoplasmic protein and myofibrillar protein varied between these two groups, suggesting partial denaturation of sarcoplasmic proteins and precipitation on myofillarments. Correlation analysis showed that L* values have significant correlation with WHC and protein solubility. Furthermore, the distribution of L* values exhibited a normal curve with range varying from 42.70 to 58.37. It was considered that approximately 23.39% of the population was PSE-like muscle. These results suggest that PSE-like meat can represent a significant portion of commercially processed broiler breast meat in China and that the L* value measurement could be used to sort broiler meat quality using a cut-off point.