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Table of Content

    16 June 2015, Volume 48 Issue 12
    CROP GENETICS & BREEDING·GERMPLASM RESOURCES·MOLECULAR GENETICS
    Fine Mapping of Rice Panicle Apical Abortion Gene qPAA3 Interacting with SP1
    ZHANG Xing-yuan, LUO Sheng, WANG Min, CONG Nan, ZHAO Zhi-chao, CHENG Zhi-jun
    Scientia Agricultura Sinica. 2015, 48(12):  2287-2295.  doi:10.3864/j.issn.0578-1752.2015.12.001
    Abstract ( 457 )   HTML ( 6 )   PDF (2260KB) ( 479 )   Save
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    【Objective】 Rice spikelet degradation reduces branch number and total grain number of single panicle, which seriously cause the yield loss per plant, is a harmful character of rice. Because of the complex genetic basis, together frequently influenced by the environment factors, up to now, there is few report about panicle apical abortion-related gene isolation. Fine mapping of panicle apical abortion mutant is meaningful in understanding of the molecular mechanism underlying panicle apical abortion formation and in the field of molecular breeding.【Method】In the present study, SP1 was mapped using the two F2 populations derived from the crosses between sp and ITA182, sp and J160, respectively. qPAA3 was finely mapped using the BC1F2 sub-population numbered 14C2017 with a pseudo-double-mutant as the non-recurrent parent originated from the cross between sp and a panicle apical abortion line 05261.【Result】 Genetic analysis showed that the sp was determinated by a single recessive nuclear gene. The candidate gene SP(t)was primarily linked on Chr.11 with the SSR markers of RM26281 and RM7391. Using the newly developed 60 markers, the SP(t) gene was further mapped between sc50 and sc66, with the genetic distance of 0.29 cM and 0.23 cM, respectively, and the physical distance 229 kb. Finally, the SP(t)gene was finely mapped between sc24 and sc66 with the physical distance of 54.3 kb. The sequencing results showed that there was 15.03 kb deletion within this region in mutant. The candidate gene was identified as a well-known gene SP1. Then, through analysis on the phenotype of double mutants combining bt and sp, it was found that there is an interaction between one of panicle apical abortion QTLs and SP1. Over consecutive 11 generation of self-crossing, the pseudo-double-mutant was further used as recurrent backcross parent to construct 81 BC1F2 sub-populations. Linkage analysis on 184 individuals from the sub-population 14C2017 by 114 polymorphic SSR primers revealed that, one QTL, within the fragment of 97.3 kb delimited by the SSR markers of RM6929 and RM1319, was corresponding to the previously documented QTL-qPAA3. 【Conclusion】The small panicle mutant sp was caused by the deletion of candidate gene SP1,interacting with one of the panicle apical abortion QTLs from bt. The later was qPAA3 and finally delimited to the physical distance of 97.3 kb by SSR marker RM6929 and RM1319 on the chromosome 3.
    Analysis of Resistance Genes of Soybean Accessions from South China to Phytophthora Root Rot
    CHENG Yan-bo, MA Qi-bin, MU Ying-hui, TAN Zhi-yuan, WU Hong, NIAN Hai
    Scientia Agricultura Sinica. 2015, 48(12):  2296-2305.  doi:10.3864/j.issn.0578-1752.2015.12.002
    Abstract ( 437 )   HTML ( 2 )   PDF (366KB) ( 510 )   Save
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    【Objective】 Phytophthora root rot caused by Phytophthora sojae is a destructive disease of soybean in most soybean-growing regions throughout the world. Development of Phytophthora-resistant varieties is the most economical and effective way to control this disease. The aim of this study was to screen accessions with resistance to strain PGD1 and multiple Phytophthora-resistant accessions, and to analyze resistance genes of soybean accessions from South China to phytophthora root rot. 【Method】The 631 soybean accessions mainly from six provinces (Guangdong, Guangxi, Fujian, Hainan, Hunan, Jiangxi and Sichuan) were evaluated with strain PGD1 using the hypocotyl inoculation method with minor modifications. And eighty-three Phytophthora-resistant accessions to strain PGD1 were evaluated with other six strains. 【Result】One hundred and one accessions were resistant to strain PGD1 with the ratio of 16.0%, 11.6% accessions had the intermediate response and 72.4% were susceptible to strain PGD1. Eighty-three Phytophthora-resistant accessions to strain PGD1 were identified with Pm14, Pm28, PNJ1, PNJ3, PNJ4, and P6497, and the infection rates were 28.9%, 34.9%, 9.6%, 66.3%, 57.8%, and 10.8%, respectively. Four of 83 soybean accessions were resistant to seven strains which were ZDD21538, ZDD21604, ZDD14286 and Mingxiadou1. Overall, 18.1% of the accessions were resistant or intermediately resistant to seven strains (virulence frequency 0). Eighty-three soybean accessions elicited 20 different reaction types with the 7 strains of pathogen. One reaction type of 8 accessions was consistent with Williams79 carrying a single gene. Nine reaction types of 45 accessions were consistent with two-gene or three-gene combinations, and they were deduced that carry two-gene or three-gene combinations. Thirty-eight accessions in 11 new reaction types probably contain new Rps genes. 【Conclusion】These results revealed the availability of strain PGD1 resistant accessions and showed an availability of multiple Phytophthora-resistant accessions in South China. These Phytophthora-resistant accessions can be used for an important parent soybean resistance breeding in tropical and subtropical regions and mapping resistant gene in soybean.
    Drought-Enduring Functional Analysis of a Natriuretic Peptide Gene GhPNP1 in Cotton
    LIU Xiao-shuang, LIU Ting-li, YUAN Hong-bo, ZHANG Bao-long, WANG Rong-fu
    Scientia Agricultura Sinica. 2015, 48(12):  2306-2316.  doi:10.3864/j.issn.0578-1752.2015.12.003
    Abstract ( 362 )   HTML ( 1 )   PDF (2403KB) ( 619 )   Save
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    【Objective】 The objectives of this research are to analyze the structural features, patterns of expression and drought tolerance functions of natriuretic peptide gene GhPNP1 in cotton, and provide a theoretical basis for future deeper study of crop drought tolerance. 【Method】 The homolog protein sequences of plant natriuretic peptides in cotton were obtained by a BLASTP search in Gossypium raimondii protein database using the query protein sequence of Verticillium dahliae plant natriuretic peptides gene Ave1 acquired from plants through horizontal gene transfer. Homologous analysis and multiple alignments were performed with MEGA 5. Expasy online tools were used for protein sequence analysis. The GhPNP1 was amplified in Gossypium hirsutum Ao3503 using the primers that were designed according to the nucleotide acid sequence of the homolog protein sequence. The isoelectric point, molecular weight, signal peptide and phylogenetic tree of the encoding protein were analyzed by related bioinformatics programs. The expression analysis of GhPNP1 gene in different organs and by PEG simulating drought stress treatment was conducted by real-time PCR. The virus induced gene silence vector was constructed and the GhPNP1 silenced cotton plants were obtained. The cDNA sequences of GhPNP1 was add to CLCrV silencing vector to construct virus-induced gene silencing vector CLCrV: GhPNP1 of GhPNP1. At 2-leaf-stage, cotton plant was infected and leaf tissues were obtained from hormone treated plant. PEG simulating drought stress treatment was used to determine the drought tolerance of GhPNP1 silenced cotton plants and test the several physiological indexes related to stress tolerance, such as water loss rate, relative water content, MDA content, T-AOC level and electrolyte leakage in GhPNP1 silenced cotton plants. 【Result】 GhPNP1 obtained in Gossypium hirsutum Ao3503 has an ORF with 396 nucleotides and encodes a protein of 131 amino acids, its isoelectric point is 9.13, the predicted molecular weight is 14.6 kD and with a signal peptide of 15 amino acids. The protein contained a conserved natriuretic peptides domain and with the highest similarity of GhPNP1 in Theobroma cacao. Quantitative real-time PCR (qRT-PCR) was used to examine the expression pattern of GhPNP1 in drought stress treatment. GhPNP1 exhibited weakly organ different expressed pattern with a little stronger expressed in stem, and moderately expressed in cotton root and leaves. In addition, PEG simulating drought stress treatment induced the up-regulated expression of GhPNP1 significantly in all the organs. The drought tolerance of GhPNP1 silenced cotton plants decreased significantly. The MDA content, electrolyte leakage and water loss rate of GhPNP1 silenced cotton plants were significantly higher than un-silenced cotton plants, wherever the T-AOC level and relative water content of silenced cotton plants were significantly lower than the un-silenced cotton plants. 【Conclusion】A plant natriuretic peptides gene (GhPNP1) was cloned from cotton, which is induced up-regulated by PEG simulating drought stress treatment and GhPNP1 silenced cotton plants significantly decreased drought tolerance. These imply that GhPNP1 may affect the drought tolerance of cotton through a cGMP dependent regulation pathway. GhPNP1 may play a positive role in drought tolerance of cotton.
    TILLAGE & CULTIVATION·PHYSIOLOGY & BIOCHEMISTRY
    Research on Variable Selection of Wheat Kernel Protein Content with Near-Infrared Spectroscopy
    LI Shuan-ming, GUO Yin-qiao, WANG Ke-ru, XIE Rui-zhi, DAI Jian-guo, XIAO Chun-hua, LI Jing, LI Shao-kun
    Scientia Agricultura Sinica. 2015, 48(12):  2317-2326.  doi:10.3864/j.issn.0578-1752.2015.12.004
    Abstract ( 371 )   HTML ( 2 )   PDF (845KB) ( 788 )   Save
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    【Objective】The objective of the study was to select the characteristic spectrum of the whole grain of wheat grain protein and set up an optimization model for the rapid and non-damage detection of protein content of the whole grain of wheat grain protein, so as to provide a basis for designing field portable wheat grain protein content determination of spectrometer.【Method】 The experiment was carried out in 2012 and 2013 with eight winter wheat varieties with obvious difference in protein content as materials. Six treatments including three nitrogen levels and two irrigation levels were designed, and rich sample types of 176 wheat grain spectral data was collected. The original reflection spectrum obtained by ASD FieldSpec Pro optical spectrum instrument were transformed as absorption spectra. Then, through the S-G smoothing, the multiplicative scatter correction and baseline correction processing, the spectra were used to create model with cross validation of partial least squares regression, uninformative variables elimination (UVE) method, successive projections algorithm (SPA), multiple linear regression (MLR) provision and stepwise multiple linear regression (SMLR) and their combination, respectively. 【Result】The results show that, the unconcerned information with wheat grain protein could be eliminated by uninformative variables elimination (UVE) method, the original spectrum wavelengths were compressed from 1621 to 717, which realized the first screening without getting rid of protein information. After that, different screening methods were used to correct the characteristics spectrum model. In this study, firstly, the grain protein content irrelevant information variables were removed by UVE. Then, using the SPA eliminated the effects of collinearity in the band spectrum matrix. Last, using SMLR contribution to the whole grain of wheat grain protein prediction model, the 15 big characteristic bands were screened out. The root mean square prediction error (RMSEP) and R2 are 0.5898 and 0.9410, respectively. 【Conclusion】To implement rapid determination of the whole grain of wheat grain protein under field conditions, the whole grain of wheat grain spectrum matrix can be effectively compressed using UVE, SPA and SMLR methods. The constructed forecasting model based on the screening protein content characteristic spectra can realize nondestructive and rapid determination of the whole grain of wheat grain protein content. The forecasting model is accuracy, reliable and cost effective, which lay a solid foundation for the design of field portable integrated wheat grain protein meter band selection and development.
    Study on Correlation Between Specific Gravity of Maize Grains and Grain Filling Characteristics
    ZHANG Li, ZHANG Ji-wang, FAN Xin, LIU Peng, DONG Shu-ting
    Scientia Agricultura Sinica. 2015, 48(12):  2327-2334.  doi:10.3864/j.issn.0578-1752.2015.12.005
    Abstract ( 659 )   HTML ( 3 )   PDF (386KB) ( 958 )   Save
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    【Objective】The specific gravity of maize grains is positively and significantly correlated with test weight. Low test weight has been one of the major problems of low grain commodity quality in maize. The aim of this experiment was to investigate the dynamic of maize specific gravity in grain filling process and the correlation between specific gravity and grain filling traits, in order to improve the specific gravity and test weight, and provide a theoretical basis for improving the grain commodity quality. 【Method】 Four maize varieties including the normal type variety Nongda 108(ND108), durum variety Feiyu4(FY4), high starch varieties Feiyu3(FY3) and Zhengdan18(ZD18) were planted in this experiment. The specific gravity of maize grains and grain filling indexes including 100-kernel dry weight, individual fresh kernel volume and percent water content were determined after pollination. Regression analysis was applied to discuss the relationship between specific gravity and grain filling characteristics.【Result】Along with the development of the grain, the fresh specific gravity showed a rising trend after pollination and tended to be stable in the mature period. However, the dry specific gravity showed a downward trend in early grain filling. A period of 20-35 days was a rapid growth period of dry specific gravity after pollination, and dry specific gravity tended to be stable at the late grain filling stage. The dry specific gravity and fresh specific gravity of FY4, FY3, and ZD18 were higher than those of ND108 at maturity. The 100-kernel dry weight and individual fresh kernel volume increased rapidly at early filling stage, and then their growth rate became slow, and finally became stable at maturity. Their dynamics could be simulated well with Logistic curve after pollination, while the correlation coefficient for each regression equation was in the range of 0.986-0.999 and reached a significant level, respectively. The 100-kernel dry weight and individual fresh kernel volume of FY4, FY3, and ZD18 were higher than those of ND108 at maturity. With dry matter accumulation after pollination, percent water content began to decline rapidly by 1.302% on the average everyday. Fresh specific gravity was positively and significantly correlated with 100- kernel dry weight (R2=0.851,P<0.01) and individual fresh kernel volume (R2=0.594,P<0.05). On the contrary, there was a negative and significant correlation between fresh specific gravity and percent water content (R2=0.803,P<0.01). Taking the 100-kernel dry weight, individual fresh kernel volume and percent water content at filling stage as the independent variable x, and the dry specific gravity as dependent variable y, a quadratic curve equation y=a+bx+cx2 was used to fit the regression relationship between them. The variance analysis showed that the regression equation coefficients were in the 0.623-0.748, and F test was significant (P0.01). It is worth mentioning that the dry specific gravity was most closely related to percent water content (r=0.731,P<0.01). Whenhundred dry kernel weight, individual fresh kernel volume and percent water content were 18.75g, 0.589cm3 and 61.5%, the dry specific gravity was at a minimum. The corresponding days after pollination of each variety were 24-28.1 d, 16.3-20.7 d and 21.1-23.6 d, which were all in the fast increasing period. So 16-28 days after pollination is a key period for the formation of the dry specific gravity. 【Conclusion】The dry specific gravity first decreased at the early stage of grain filling, then increased rapidly, and finally stabilized at the late grain filling stage. The fast increasing period of grain filling was a critical period of the formation of the dry specific gravity, at the same time, the effects of this grain filling period will significantly affect the dry specific gravity. The correlation between dry specific gravity and percent water content was the most close, and the regression coefficient is 0.731.
    Climatic Suitability Regionalization of Rubber Plantation in China
    LIU Shao-jun, ZHOU Guang-sheng, FANG Shi-bo
    Scientia Agricultura Sinica. 2015, 48(12):  2335-2345.  doi:10.3864/j.issn.0578-1752.2015.12.006
    Abstract ( 672 )   HTML ( 6 )   PDF (2484KB) ( 1302 )   Save
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    【Objective】 Rubber is an important and indispensable strategic material for national economy construction in China, but the range of rubber plantation in China is restricted due to the limitation of climatic factors. Thus, it is urgent to understand where is suitable for rubber plantation in China. The purpose of this paper is to differentiate climate suitability distribution of rubber tree and to clarify the climate difference of rubber tree plantation in China. 【Method】 Climatic suitability index of rubber plantation were calculated by the maximum entropy model and five main climate factors of rubber tree. (The five main climate factors are mean temperature of the coldest month, mean extremely minimum temperature, the number of month that the monthly mean temperature ≥18℃, annual mean temperature and annual mean precipitation). Typhoon disaster indexes of rubber plantation were calculated by historical typhoon data and typhoon disaster classification standard of rubber. Chilling injury indexes of rubber plantation were calculated based on meteorological industry standards of the People’s Republic of China (QX/T169-2012): Grade of rubber chilling injury. According to the natural climate characteristics and biological characteristics of rubber plantation area, the corresponding evaluation factors were used to carry out climatic suitability regionalization by the fuzzy comprehensive evaluation method, including the probability of climate suitability, probability of typhoon disaster, and probability of rubber plantation chilling injury. The climatic suitability regionalization results were divided into high suitable area, medium suitable area, low suitable area. 【Result】 A better climatic regionalization of rubber plantation in China was given in this study based on the comprehensive effects of agroclimatic resources and agrometeorological disasters. The high suitable area was about 4.99×104 km2, accounting for 20.94% of the study area. The area includs Danzhou, Chengmai, Ding’an, Ledong and Baoting of Hainan, Xuwen, leizhou, Zhanjiang and Yangjiang of Guangdong, Jinghong and Mongla of Yunnan, Zhao’An, Yunxiao of Fujian, Fangcheng of Guangxi. The regional climate condition is superior, but a part of the area are often influenced by typhoon, so it is necessary to defense typhoon influence on rubber trees. The suitable area is 8.85×104 km2, accounting for 35.86% of the study area. There are includs Qiongzhong, Dongfang, Changjiang, Wanning and Qionghai of Hainan, Lianjiang, Gaozhou, Maoming, XinYi, Huilai and Chaozhou of Guangdong, Zhangzhou and Zhangpu of Fujian, Ruili and Jiuguo of Yunnan, Beihai and Hepu of Guangxi, Chilling injury probability of rubber tree is increased compared with the high suitable area, and typhoon probability also increases in part of the area. So, it is important to strengthen the defensive to chilling injury and typhoon damage of rubber according to the characteristics of different disasters. The low suitable area is 10.3×104 km2, accounting for 43.20% of the study area. There are includes Yingjiang, Yongde and Simao of Yunnan, Yulin and Pubei of Guangxi, Yangchun, Haifeng and Luhe of Guangdong, and Hua’an of Fujian. The area is mainly affected by chilling injury of rubber.【Conclusion】The advantage area of rubber plantation climatic suitability in China is well reflected by this method, which considered the comprehensive influence of agricultural climate resources and agricultural meteorological disasters. The research result will be of benefit to the government and relevant departments for carrying out regional layout and scientific planning of rubber plantation in China.
    PLANT PROTECTION
    QTL Mapping for Adult-Plant Resistance to Leaf Rust in Chinese Wheat Cultivar Lantian9
    HAN Liu-sha, WANG Jia-zhen, SHI Ling-zhi, ZHU Lin, LI Xing, LIU Da-qun
    Scientia Agricultura Sinica. 2015, 48(12):  2346-2353.  doi:10.3864/j.issn.0578-1752.2015.12.007
    Abstract ( 442 )   HTML ( 1 )   PDF (854KB) ( 462 )   Save
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    【】Wheat leaf rust, caused by Puccinia triticina, is a devastating disease that can cause severe yield loss. The use of resistant cultivars is the most economical and effective method to reduce damages caused by wheat leaf rust. Wheat line Lantian 9 is susceptible to most of the Chinese current leaf rust pathotypes at seedling stage, but showed high resistance at adult stage. The objectives of this study are to analyze the leaf rust resistance of Chinese wheat cultivar Lantian 9 in adult-plant and locate the QTL contained in Lantian 9 by using molecular markers, and to provide a theoretical basis for molecular breeding in wheat. 【Method】Total 197 F2:3 lines derived from Lantian 9/Huixian Hong cross were used to map leaf rust QTL. The population was inoculated by three pathotypes, and then phenotyped for FDS in the field during 2011-2014 cropping seasons. A total of 1 232 SSR markers were used to detect resistant parent Lantian 9, susceptible parent Huixian Hong and F2:3 lines, to get the genotypic data. Phenotypic and genotypic data were combined to map adult plant resistance QTL in Lantian 9 and Huixian Hong using QTL software Map Manager QTXb20 and Icimapping 3.2.【Result】Five QTLs were detected in the population. The QTL located on chromosome 2B was stalely identified in two cropping seasons, tentatively designated QLr.hbau-2BS, explained 6.0% and 9.1% of the phenotypic variations in two years, respectively. QLr.hbau-2BS was located in the marker interval Xbarc55-Xgwm148 and Xgwm429-Xwmc154. The logarithm of odds (LOD) threshold was 2.6 and 3.46. The additive effect was -6.1 and -8.7. The dominate effect was 3.03 and 3.4, respectively. The QTL located on chromosome 1B was stably identified in two cropping seasons, tentatively designated QLr.hbau-1BL.2, explained 7.7% and 10.7% of the phenotypic variations in two years, respectively. QLr.hbau-1BL.2 was located in the marker interval Xwmc766-Xbarc269. The LOD threshold was 2.5 and 3.1. The additive effect was -1.0 and -1.1. The dominate effect was -13.0 and -14.9, respectively. The other three QTLs were identified in only one cropping season, including one QTL on chromosome 1B, tentatively designated QLr.hbau-1BL.1 detected in 2011-2012 crop season; one on chromosome 4B, tentatively designated QLr.hbau-4BS detected in 2011-2012 crop season; one on chromosome 3A, tentatively designated QLr.hbau-3A detected in 2011-2012 crop season, explained 11.7%, 8.5% and 5.6% of the phenotypic variation, respectively. These three QTLs were located in the marker interval Xbarc80-Xwmc728, Xgwm495-Xwmc652 and Xgwm161-Xbarc86. The LOD threshold was 5.1, 4.0 and 2.8. The additive effect was 6.5, -5.5 and -3.1. The dominate effect was -6.5, 6.2 and 6.6, respectively. QLr.hbau-1BL.1 comes from Huixian Hong, the other four QTLs come from Lantian 9. ConclusionCombining with the phenotype and genotype data, detected five leaf rust resistance QTLs on chromosomes 1B, 2B, 3A, and 4B, respectively.
    Screening of Putative Proteins in Vector Psammotettix alienus L. that are Interacted with Coat Protein of Wheat dwarf virus by a Split-ubiquitin Yeast Membrane System
    ZHAO Yi-ze, LIU Yan, WANG Xi-feng
    Scientia Agricultura Sinica. 2015, 48(12):  2354-2363.  doi:10.3864/j.issn.0578-1752.2015.12.008
    Abstract ( 525 )   HTML ( 15 )   PDF (2842KB) ( 10450 )   Save
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    【Objective】To investigate the interaction between the leafhopper (Psammotettix alienus L.) and Wheat dwarf virus (WDV), a cDNA library of leafhopper was constructed using a split-ubiquitin yeast membrane system. The protein interaction analysis was done by using WDV CP as bait protein to screen a cDNA library of P. alienus. 【Method】Total RNA of leafhopper was isolated from 2 g of insects. Poly A+ RNA was enriched from 100 ng of total RNA and double-stranded cDNA was synthesized using SMART technology. After digestion with the Sfi I enzyme, the fragmented cDNA was ligated to prey vector pPR3-N, and then also digested with Sfi I enzyme to construct the split-ubiquitin yeast membrane system cDNA library. The full-length gene, WDV CP, amplified from wheat leaves infected by WDV was ligated into bait fusion vector, pDHB1. After functional assay, pDHB1-WDV CP vector was co-transformed into NMY51 with empty library vector in order to get an optional concentration of 3-AT. Then using the split-ubiquitin yeast membrane system, proteins interact with the bait pDHB1-WDV CP were screened from the cDNA library of P.alienus. Gene ontology (GO) and pathway information of proteins were analyzed from Uniprot and KEGG websites.【Result】Detection of the cDNA library showed that the unamplified library contained 2.0×106 independent clones, the titer of the amplified library was 1.3×106 cfu. The recombination rate was above 97%. The sizes of most inserts were above 1 kb in the cDNA library. The correct ligated fusion bait vector pDHB1-WDV CP was verified by restriction enzyme digestion analysis and sequencing. Functional assay showed that the fusion protein was functionally correctly expressed in the yeast and suited to this system. In library screen test, 280 clones were got from the cDNA library of P. alienus. Twelve proteins were selected for further research based on the functional analysis in terms of GO. Finally, 9 proteins confirmed by β-galactosidase assay were interacted with WDV CP. GO annotation analysis showed 9 putative proteins were involved in 10 biological processes including protein dephosphorylation, carbohydrate metabolic process, transport, etc. Molecular functions included metal ion binding, phosphate ion carrier activity, folic acid transporter activity, protein complex binding, etc. These proteins also were involved in ubiquitin mediated proteolysis, endocytosis, arachidonic acid metabolism, cAMP signaling pathway, PPAR signaling pathway.【Conclusion】A high-quality cDNA library was constructed and 9 proteins were interacted with WDV CP, which could be used for insect vector and WDV interaction analysis.
    Identification and Functional Characterization of TRPA1 in Apolygus lucorum (Meyer-Dür)
    FU Ting, YANG Ting, LIU Yang, WANG Gui-rong
    Scientia Agricultura Sinica. 2015, 48(12):  2364-2373.  doi:10.3864/j.issn.0578-1752.2015.12.009
    Abstract ( 451 )   HTML ( 3 )   PDF (2050KB) ( 711 )   Save
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    【Objective】 The objective of this study is to obtain the TRPA1 gene in Apolygus lucorum,characterize its expression profiles in different tissues of adult, illustrate its functions through heterologous expression system of Xenopus oocytes, and further to explain the molecular mechanism of thermosensation in A. lucorum.【Method】The transcriptome of A. lucorum was sequenced and analyzed, and several cDNA fragments encoding A. lucorum TRPA1 were identified. And then specific primers for RT-PCR and RACE were designed. The full-length cDNA sequence encoding AlucTRPA1 was cloned via RACE and RT-PCR techniques. The cDNA sequence encoding TRPA1 gene was analyzed by DNAMAN software and BLAST. Then ankyrin repeats and transmembrane domains were predicted with SMART and TMpred. The phylogenetic tree of TRPs in insects was constructed to analyze the evolutionary relationship between A. lucorum and other insects. RT-PCR was performed to detect the relative-expression of TRPA1 in different tissues of the adults. Two-electrode voltage clamp electrophysiological recording was introduced to demonstrate the function of TRPA1 in vitro. 【Result】 Four fragment sequences of the TRPA1gene were found according to the results of transcriptome analysis. The full-length sequence of TRPA1 gene named AlucTRPA1 was further obtained using RACE and RT-PCR techniques, which is 3 672 bp and encodes 1 223 amino acids. AlucTRPA1 contained 6 conserved transmembrane domains and 16 ankyrin repeats, which predicted by SMART and TMpred. The results of multiple alignment and phylogenetic tree analysis showed that TRPA of insects contains TRPA1, Painless, Pyrexia and Water witch, and AlucTRPA1 clustered into the branch of TRPA1. AlucTRPA1 is highly similar to the homologs from other insects, especially the pea aphids (Acyrthosiphon pisum), which also belongs to the Hemiptera, with the identity of 65.1%. Expression profiles showed that AlucTRPA1 was expressed in antennae at the highest level among different tissues. In the Xenopus-based functional study, AlucTRPA1 could be activated directly by an increasing temperature from 20 to 40 and didn’t show adaption after repeated temperature stimuli. 【Conclusion】 AlucTRPA1ors. expressed in all tested tissues, but highest in antennae. AlucTRPA1 could be activated directly by an increasing temperature from 20 to 40, indicating that AlucTRPA1 is a direct thermal sensor in A. lucorum and mediates their temperature sensing behavi
    SOIL & FERTILIZER·WATER-SAVING IRRIGATION·AGROECOLOGY & ENVIRONMENT
    Shortage of Innovative Technology for Arable Land Fertility Management Endangered Food Security and Environmental Safety in China
    ZHANG Wei-li, XU Ai-guo, ZHANG Ren-lian, JI Hong-jie
    Scientia Agricultura Sinica. 2015, 48(12):  2374-2378.  doi:10.3864/j.issn.0578-1752.2015.12.010
    Abstract ( 506 )   HTML ( 2 )   PDF (332KB) ( 634 )   Save
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    With yield increasing, the agrochemical inputs had been raised by 3.6 times since the beginning of 1980s. Over the same period, however, the crop land fertility management techniques of farmers had not been improved obviously. Blind and excessive application of fertilizers, pesticides and irrigation had been frequently involved in crop production to compensate technological shortages. Lack of technology for arable land fertility management not only caused over expending of fertilizer and water resources, but also led to soil quality degradation, production cost increase and pollution of water, soil, air and farm products. It endangered environmental safety and food security. Analyses showed that there were mainly two obstacles for improving farmers' techniques. The first one was the weakening of applied researches and applied basic researches. Over the years, the nonprofit state and provincial professional research institutions, which were formerly responsible to carry out soil and fertilization field experiments had changed their main focus into more generalized scientific questions as those from the universities. Due to such changes, the implementation of long-term studies, which were essential for developing regional technical indexes and standard for best fertilization and tillage practices had become more and more difficult., There were seldom technical indexes and standards that were understandable for farmers in different regions. The second one was missing of agricultural technology extension services. To solve the problems, improvements in following areas should be made: firstly, to restore and maintain the specialized features of state and provincial research institutes for soil and fertilizer research works; secondly, to keep a certain stability for topics of research program concerning with land fertility management techniques and to ensure the program with the necessary duration; thirdly, to try a new way for technical extension of best soil and fertilizer management practice,that may be supported by modern information, communication and intelligent techniques and more suitable for current rural conditions of the country.
    Effects of Water Stress at Different Growth Stages on the Development and Yields of Winter Wheat in Arid Region
    YAO Ning, SONG Li-bing, LIU Jian, FENG Hao, WU Shu-fang, HE Jian-qiang
    Scientia Agricultura Sinica. 2015, 48(12):  2379-2389.  doi:10.3864/j.issn.0578-1752.2015.12.011
    Abstract ( 779 )   HTML ( 75 )   PDF (544KB) ( 19223 )   Save
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    【Objective】 To investigate the influences of water stress at different growth stages on the growth and yields of winter wheat, field experiments were conducted under a rainout shelter during two seasons of 2012-2013 and 2013-2014. The dynamic changes of several eco-physical characteristics of wheat growth were measured and compared, including height, leaf area index, phenology, biomass, and yield. 【Method】 The whole growth season of wheat was divided into five growing stages (wintering, greening, jointing, heading, and grain filling). Water stress occurred at two continuous stages, while irrigations were applied at other stages, which resulted in four different levels of stress period (D1-D4). Two irrigation levels of 40 mm (I1) and 80 mm (I2) were applied. A total of eight treatments, with three replicates for each, followed a split-plot experiment design. An extra control treatment with irrigation at all five stages was arranged beside.【Result】The results showed that normal growth and development of wheat could be obviously influenced by continuous water stress given at vegetative stages. The height, LAI and biomass were the worst for all treatments, when water stress occurred at the stages of wintering and greening. However, the negative influences on wheat growth were not notable when water stress occurred after jointing stage. The average growth rate of height and LAI after jointing was about ten times as that before jointing. There were no notable differences of biomass between all of the treatments until the jointing stage. The biomass values of treatments with water stresses at wintering and greening stages were remarkably lower than other treatments. The irrigation later could not recover these serious biomass losses. Water stress could shorten the whole growth season of wheat, with a maximal 5-day advancing of maturation. At the same irrigation level, the heading and flowering stages could be delayed for 1-3 days for different levels of stress period. For the same irrigation level, relatively higher numbers of productive ears and seeds per ear could be obtained when water stress occurred at the heading and grain filling stages, but with a lower thousand-kernel weight. On the contrary, a relatively higher thousand-kernel weight could be achieved when irrigation was applied at the heading and grain filling stages, but with lower numbers of productive ears and seeds per ear. For irrigation levels of I1 and I2, yields were the lowest when water stress occurred at wintering and greening stages, which was only 42% of the control treatment. However, the treatments with the highest yield were different for different irrigation levels. For I1, it was the treatment with water stress at jointing and heading stages that had the highest yield, or about 63% of the control treatment. For I2, it was the treatment with water stress at greening and jointing stages, which had a yield of about 75% of the control treatment. 【Conclusion】There was a clear interaction between the intensity and occurring stage of water stress. In general, the greening and filling stages were the critical periods of water demand for winter wheat. Reasonable irrigation managements are needed at these two growth stages to guarantee a higher yield of winter wheat in arid region.
    Effect of Root Layer Regulations on Soil Nitrate of the Rotation System of Sweet Corn-Cucumber in Greenhouse Vegetable Production System
    HAO Xiao-ran, PENG Ya-jing, ZHANG Li-juan, WANG Lin, JU Xiao-tang, JI Yan-zhi, REN Cui-lian
    Scientia Agricultura Sinica. 2015, 48(12):  2390-2400.  doi:10.3864/j.issn.0578-1752.2015.12.012
    Abstract ( 541 )   HTML ( 14 )   PDF (447KB) ( 9765 )   Save
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    【Objective】 Taking sweet corn as a catch crop, the accumulation of nitrate in soil profile under different root layer regulation and control measures and their influence on growth of succession cucumber were studied. 【Method】 Sweet corn was planted in the fallow season of the traditional greenhouse in the North China Plain. Using traditional cultivation as the control, a field plot experiment was conducted with 2 root layer regulation and control measures: adding soil conditioner and straw returning to field. The experiment was carried out from May 2008 to May 2011, a total of three sweet corn-cucumber crop rotation, six crops were planted. Sweet corn was planted from early June to September every year, and cucumber seedlings were reared from the early October to the end of January next year. Cucumber plants were planted in early February the same year. In the sweet corn season, three treatments were conducted and arranged at random with three replications. The plot size was about 4 m×2 m, plot interval was 0.3 m, and 1 m of guard rows were laid out between plots. 【Result】In the sweet corn planting seasons, the highest grain yields were obtained in soil conditioner treatment and the yields were 6.2, 7.4 and 7.9 t·hm-2 in 2008, 2009 and 2010. The total N uptake rate in soil conditioners and straw returning to field treatments was higher than the traditional planting. After planting sweet corn for three seasons, straw and soil conditioner treatments promoted the growth and development of root system in 20-60 cm soil layer and enhanced root to absorb nutrients from deeper soil. Both the two treatments reduced the NO3--N of soil profile, especially the subtraction of NO3--N in 100-200 cm of the crop root zone, the NO3--N subtractive trend roughly was soil conditioner>straw returning of field>the traditional planting. After cucumber harvest in three seasons, the differences in cucumber yield, the biomass and nitrogen uptake were not significant, the average soil NO3--N residue of three seasons in 0-200 cm was in the order of straw returning of field<soil conditioner<the traditional planting. After three cropping seasons, the nitrogen surplus in 0-200 cm soil layer in the traditional planting, soil conditioner and straw returning to field treatments was, respectively, 1 911.6, 1 966.83, and 1 930.2 kg·hm-2, and conditioning treatment was significantly higher than that of traditional planting. 【Conclusion】In the greenhouse soil with high nitrate accumulation, along with the increasing length of planting, adding soil conditioner to soil and appropriate straw returning to field, the subtraction of NO3--N in 100-200 cm of the crop root zone was more than traditional planting. Planting catch crops significantly decreased the effects of soil NO3--N in soil of the succession cucumber. Soil conditioners and straw returning to field can significantly improve the ability of sweet corn to decrease soil NO3--N, slow soil NO3--N leaching, and improve economic returns.
    HORTICULTURE
    The Role of MaCaM Gene in Temperature Stress and Fruit Ripening of Harvested Banana
    WANG Hai-bo, GONG Jia-jian, SU Xin-guo, ZHANG Zhao-qi
    Scientia Agricultura Sinica. 2015, 48(12):  2401-2407.  doi:10.3864/j.issn.0578-1752.2015.12.013
    Abstract ( 364 )   HTML ( 2 )   PDF (1019KB) ( 505 )   Save
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    【Objective】The objective of this experiment is to study the expression of CaM gene in temperature stress and fruit ripening of banana. Which is helpful to understand the effect of CaM gene in enhance the adaptation to temperature stress and reveal the mechanism of peel degreening during the ripening process of banana fruit.【Method】Degenerated primers were designed by comparative analysis of some species’ CaM amino acid sequence in NCBI database. The total RNA was extracted from banana peel by using hot borate method. In banana fruit, the rapid amplification of cDNA ends (RACE)-PCR techniques were used for 3’-UTR and fragment sequences cloning of the cDNA. The amino acid sequence of CaM was analyzed by using DNAMAN software and the NCBI website. Probe with DIG markers was made by using PCR DIG Probe Synthesis Kit. Northern blotting was performed to compare the expression of MaCaM gene in banana fruit under different temperature stresses and during ripening process. EGTA and calcium signal recovery treatment by using banana peels in vitro culture. The banana peel were treated by vacuum infiltration. The h values were measured by the color difference meter.【Result】A novel CaM gene, 648 bp, encoding 138 amino acids, named MaCaM (HM061077), was cloned from banana in this study. Sequence analysis showed that MaCaM gene contains 4 EF-Hand calcium binding regions. MaCaM gene has a high sequence similarity with MaCaM, OsCaM, ZmCaM, AtCaM3 and TaCaM1-2. Northern blotting results showed that the MaCaM gene expression was up-regulated rapidly at 0.5-24 h after heat shock (52℃ 3min). Banana fruits were stored at 7℃ (chilling injury temperature) for 10 days, the MaCaM gene expression increased gradually in the 7-10 d. When the banana fruits were stored at 7℃ after heat shock, MaCaM expression was higher in the 4 d and 7 d than those of at 7℃ alone. Ethylene was also observed to arouse the expression of MaCaM gradually. Furthermore, 30 mmol·L-1 calcium ion chelator EGTA treatment inhibited fruit ripening and the expression of MaCaM to the same extent, while the EGTA combined with 30 mmol·L-1 CaCl2 treatment restored the normal ripening of banana and the expression of MaCaM gene to some degree.【Conclusion】These results showed that MaCaM gene takes an important role in enhancing the adaptation to temperature stress and MaCaM gene as a regulator is involved in the peel degreening during the ripening process of banana fruit.
    The Molecular Mechanism of UV-A Induced Anthocyanin Accumulation in the Hypocotyls of Soybean Sprouts
    QI Nan-nan, ZHANG Xiao-yan, SU Na-na, WU Qi, GENG Dian-xiang, QI Xue-hui, WEI Sheng-jun, CUI Jin
    Scientia Agricultura Sinica. 2015, 48(12):  2408-2416.  doi:10.3864/j.issn.0578-1752.2015.12.014
    Abstract ( 377 )   HTML ( 1 )   PDF (929KB) ( 953 )   Save
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    【Objective】The objective of the experiment was to investigate the effect of UV-A, as well as white (W) and blue (B) lights on content of anthocyanin, activities of related enzymes, transcript levels of anthocyanin biosynthesis-related genes and light receptor genes. This study would find out the molecular mechanism about UV-A induces anthocyanin accumulation in the hypocotyls of soybean sprouts and provide a theoretical foundation for the application of light quality control technology in the industrialized production of soybean sprouts.【Method】The seedlings of soybean variety ‘Dongnong 690’ were treated with continuous UV-A, white light (W) and blue light (B). Samples were collected at 0, 12, 24 and 36 h after treatment, respectively. The anthocyanin content, the activities of PAL, CHI, and UFGT and the expression of related genes (PAL, CHS, CHI, DFR, ANS, UFGT, MYB75, CRY1, CRY2 and UVR8) were detected. The difference of anthocyanin content, related enzymes and genes expression under different light qualities in the hypocotyls of soybean sprouts was analyzed. The anthocyanin content was determined by spectrophotometric method, phenylalanine ammonia lyase (PAL) and chalcone isomerase (CHI) activities were measured by spectrophotometry, flavonoid galactosyl transferase (UFGT) activity by ultra performance liquid chromatography (UPLC) determination. Total RNA was extracted using the Trizol reagent. Gene expression was determined by qRT-PCR.【Result】Soybean sprouts grown in the dark showed yellow cotyledons while sprouts grown under white (W), blue (B) and UV-A lights existed green cotyledons. Compared with the dark and other light quality cultures, UV-A treatment significantly improved the content of anthocyanin in the hypocotyls of soybean sprouts. As the illumination time goes on, anthocyanin accumulation was increased gradually. The anthocyanin content in the hypocotyls of soybean sprouts was low at 0 h, about 2 U·g-1 FW. The content of anthocyanin reached a maximum of 43 U·g-1 FW at 36 h under UV-A, which was significantly higher than those in the other treatments. The activities of PAL and CHI were higher at 0 h. Compared to that in the dark and other light treatments, continuous UV-A light treatment for 24 h and 36 h significantly increased the activity of phenylalanine ammonia-lyase (PAL). Continuous UV-A light treatment for 12 h and 24 h significantly increased the activity of and flavonoid glycosyltransferase (UFGT). There was no difference in the expression of anthocyanin related genes among different treatments at 0 h. Continuous UV-A treatment for 36 h significantly up-regulated the expression of regulator gene MYB75 and light receptor genes (CRY1, CRY2 and UVR8) to about 12-, 30-, 6- and 2-fold, in the hypocotyls of soybean sprouts compared with those in the other treatments, respectively. Moreover, continuous UV-A treatment for 12 h significantly up-regulated the expression of anthocyanin biosynthesis-related structural genes (PAL, CHS, DFR, ANS, UFGT) to about 5, 58, 10, 6, 44 and 47 times, respectively.【Conclusion】UV-A induced anthocyanin accumulation by improving the activities of PAL and UFGT and up regulating the expression of related genes in the hypocotyls and light receptor of soybean sprouts.
    STORAGE·FRESH-KEEPING·PROCESSING
    Rheologic Properties of ‘Huahong’ Apple Pulp and Their Principal Component Analysis
    YANG Ling, ZHANG Cai-xia, KANG Guo-dong, TIAN Yi, CONG Pei-hua
    Scientia Agricultura Sinica. 2015, 48(12):  2417-2427.  doi:10.3864/j.issn.0578-1752.2015.12.015
    Abstract ( 382 )   HTML ( 1 )   PDF (440KB) ( 589 )   Save
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    【Objective】 An experiment was carried out to study the changes of rheological properties (including stress relaxation property and creep property) of ‘Huahong’ apple pulp during storage, analyze the correlation among rheological parameters, aiming to predict and evaluate ‘Huahong’ apple fruit quality by rheological method, and also improve the fruit quality evaluation system.【Method】 Through an experiment on ‘Huahong’ apple pulp’s creep and relaxation properties, creep models including the four components Burger’s model and the three components Maxwell stress relaxation model were established. The changes of stress relaxation and creep parameters during storage were acquired, and the correlation among these parameters were analyzed. The main stress relaxation and creep parameters were analyzed by Principal Component Analysis (PCA) using SPSS software.Result The creep parameters of initial elastic coefficient E1, delayed elasticity coefficient E2, and viscosity coefficient η1 and η2 decreased constantly, and there was a significant positive correlation between each two parameters among these ones. The creep value increased slowly, and the creep was significantly and negatively correlated with the above four creep parameters. The delay time τ increased slowly, the maximum hardness of work increased first and then decreased, the values of the two parameters had a poor correlation with the other five creep parameters. The variation of relaxation parameters of the elastic modulus E0, balance elastic modulus Ee, the decay modulus E1, viscosity factor η, hardness, stress and total work decreased first, and than increased slight and finally decreased, there was a significant positive correlation among these seven parameters. The relaxation time was not consistent with the above seven relaxation parameters and had a poor correlation with them. The creep and relaxation parameters were analyzed by Principal Components Analysis, extract the first principal component of 10 variables was sufficient, and the contribution rate was 88.828%. The first principal component ‘rheological factors’ F1 decreased with the fruit texture soft and edible quality decreased during storage. 【Conclusion】 The ‘Huahong’ apple pulp has compression visco elastic mechanical properties. The four elements Burger’s model and Maxwell model could be well fitted the creep and relaxation model of ‘Huahong’ apple. They could be used as a method to characterize the rheological changes of ‘Huahong’ apple during storage, and could reflect the change of flesh texture.
    The Variations in μ-Calpain and Physico-Chemical Characteristics of Myofibrillar Proteins in Postmortem Porcine Muscle
    WEI Xiu-li, XIE Xiao-lei, ZHANG Chun-hui, LI Xia, WANG Chun-qing
    Scientia Agricultura Sinica. 2015, 48(12):  2428-2438.  doi:10.3864/j.issn.0578-1752.2015.12.016
    Abstract ( 377 )   HTML ( 3 )   PDF (673KB) ( 726 )   Save
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    【Objective】Variations in μ-calpain and physico-chemical characteristics of myofibrillar proteins in relation to the water-holding capacity in postmortem porcine muscle (1-168 h) were investigated. The study was expected to provide theoretical supports to regulate the unacceptable high drip loss of muscle and meat postmortem.【Method】Samples of porcine M. longissimus dorsi was collected for μ-calpain activity by casein zymography, myofibril fragmentation index, SDS-PAGE, myofibrillar protein surface hydrophobicity and solubility, water-holding capacity analysis. And low-field nuclear magnetic resonance relaxation T2 (LF-NMR T2) analysis of water mobility and distribution was also carried out.【Result】During the 1 h to 24 h postmortem, μ-calpain activity increased, while no significant changes of myofibrillar proteins degradation and MFI values were observed. Significant decreases of μ-calpain activity, with the increases in MFI occurred at 24 h postmortem, which revealed the conversion of muscle into meat. Proteolysis of muscle proteins by μ-calpain, on the one hand gave a rise in protein solubility because of more low molecular proteins emerged, on the other hand led to higher surface hydrophobicity and lower solubility due to hydrophobic groups in protein exposure to its surface and protein aggregation. Both contributed to the protein hydration characteristics. Changes of protein hydration capacity affected the attributes of muscle water populations. During the 24 h to 120 h postmortem, proteolysis degradation of myofibrillar proteins by μ-calpain occurred. The improvements of protein solubility led to the decreased population of free water P23 (r=-0.246, P<0.05)and increased population of immobilized water P22(r=0.286, P<0.01). Meanwhile, the exposure of hydrophobic residues resulted in increases of surface hydrophobicity, which was accompanied with decreases of the population of free water P23 (r=0.319, P<0.01). T2 relaxation patterns data indicated that protein-associated water was released into the intra-myofibrillar spaces, which was supported by a high correlation between bound water P21 and immobilized water P22 (r=-0.890, P<0.01). Free water and bound water converted to immobilized water. Therefore, porcine muscle water-holding capacity improved during this stage. During the 120 h to 168 h postmortem, ongoing degradation of myofibrillar proteins gave a rise in MFI values. Decreases of surface hydrophobicity and solubility caused the increased population of free water, and the decreased population of immobilized water. Immobilized water converted to free water. Thereby a flow of water from intra- to extra-myofibrillar water spaces occurred, and it can be lost as drip and water-holding capacity decreased.【Conclusion】The obtained data strongly supported that the postmortem μ-calpain was essential to changes of myofibrillar proteins hydration capacity, which moreover was found to affect the muscle 3 water populations distribution and mobility. During the 24-120 h, μ-calpain contributed to proteolysis of muscle proteins, increased proteins hydration capacity. Bound water and free water converted to immobilized water and porcine water-holding capacity improved. During the 120-168 h, low molecular proteins aggregated because of ongoing degradation, which led to the decreases of proteins hydration capacity. Immobilized water converted to free water, leading to the increases of drip loss.
    ANIMAL SCIENCE·VETERINARY SCIENCERE·SOURCE INSECT
    The Expression of EGF and EGFR in Yak Oocyte and Its Function on Development Competence of Embryo
    PAN Yang-yang, LI Qin, CUI Yan, FAN Jiang-feng, YANG Kun, HE Jun-feng, YU Si-jiu
    Scientia Agricultura Sinica. 2015, 48(12):  2439-2448.  doi:10.3864/j.issn.0578-1752.2015.12.017
    Abstract ( 371 )   HTML ( 2 )   PDF (1704KB) ( 570 )   Save
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    【Objective】The aim of this study was to verify the expression of epidermal growth factor (EGF) and its receptor (EGFR) on cumulus-oocyte complexes (COCs) during in vitro maturation, and the effect of EGF on development of COCs and possible molecular mechanisms were also investigated. 【Method】Yak ovaries were collected and COCs were aspirated, the COCs with multilayered compact cumulus and uniformly dark, evenly granulated cytoplasm were selected and cultured in vitro; The expression of EGF and EGFR in immaturate and mature COCs was detected by the methods of Real-time PCR and immunofluorescence at mRNA and protein levels. The 0, 50, 100 and 200 ng·mL-1 EGF and the optimal concentration of EGFR inhibitor (Gefitinib) were supplemented to the basic medium during in vitro maturation, the rate of maturation, cleavage and blastocyst of oocyte were compared among different groups. Moreover, the genes related to apoptosis (Bax and Baxi) in COCs treated with EGF and Gefitinib were determined by the method of Real-time PCR. 【Result】 Both levels of EGF and EGFR gene were higher in maturation COCs than in immaturate COCs, The relative quantitative expression of EGF in maturation COCs was 2.17±0.36 fold when compared with the levels in immaturate COCs, and the relative quantitative expression of EGFR in maturation COCs was 6.82±0.21 fold compared with the levels in immaturate COCs. Both in immaturate COCs and maturation COCs, the level of EGFR gene was higher than EGF. The results of immunofluorescence showed that EGF and EGFR proteins could be detected on immaturate COCs and maturation COCs, they was mainly in cumulus granulosa cells (CGCs), and the expression of EGF and EGFR protein was lower in oocyte. The rates of maturation (73.45±2.09)%, cleavage (59.46±1.41)% and blastocyst (26.23±1.08)% were significantly higher in the groups with 100 ng·mL-1 EGF, the rates of maturation, cleavage and blastocyst were (54.16±3.25)%, (48.33±1.93)% and (15.34±0.43)% in control group (0 EGF). In the groups with 50 ng·mL-1 EGF, the rates of maturation, cleavage and blastocyst were (61.79±1.04)%, (51.76±0.61)% and (18.62±1.13)%, and in 200 ng·mL-1 EGF groups the rates of maturation, cleavage and blastocyst were (71.26±4.18)%, (57.13±2.06)% and (23.96±0.53)%. However the rates of maturation, cleavage and blastocyst were lower in the groups with EGFR inhibitor (Gefitinib), they were (43.63±1.46)%, (41.79±2.81)% and (12.65±0.67)%, respectively. The expression of Bax gene in maturation COCs could be inhibited by EGF, the levels of Bax gene were 0.83±0.12, 0.21±0.02 and 0.27±0.03 fold in maturation COCs treated with 50 ng·mL-1, 100 ng·mL-1 and 200 ng·mL-1 EGF druring in vitro maturation when compared with control group (0 ng·mL- 1 EGF), it was the lowest in the group with 200 ng·mL-1 EGF, however, the expression of Bax gene was enhanced by Gefitinib, which was 4.24±0.10 fold of levels in control group. The expression of Baxi gene in maturation COCs could be enhanced by EGF, the levels of Baxi gene were 2.18±0.12, 7.06±0.59 and 6.73±0.31 fold in groups with 50 ng·mL-1, 100 ng·mL-1 and 200 ng·mL-1 EGF when compared with control group (0 EGF), however the expression of Bax gene was inhibited by Gefitinib, which was 0.32±0.04 fold of levels in control group.【Conclusion】 EGF and EGF were important autocrine growth factors during yak COCs in vitro maturation, and the rates of maturation, cleavage and blastocyst could be enhanced by exogenous EGF, the optimal concentration was 100 ng·mL-1, and the functional mechanism might be related to the expression of Bax and Baxi genes was regulated by EGF.
    1H NMR-Based Plasma Metabolic Profiling of Dairy Cows with Type I and Type II Ketosis
    LI Ying, XU Chuang, XIA Cheng, ZHANG Hong-you, SUN Ling-wei, XU Chu-chu
    Scientia Agricultura Sinica. 2015, 48(12):  2449-2459.  doi:10.3864/j.issn.0578-1752.2015.12.018
    Abstract ( 419 )   HTML ( 3 )   PDF (1267KB) ( 449 )   Save
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    【Objective】To identify the differential metabolites in plasma among the cows of type I ketosis, type II ketosis and normal controls, the plasma metabolic profiles from all experimental cows were analyzed using 1H nuclear magnetic resonance technology (1H NMR).【Method】A total of 50 cows with 2 to 3 parities were selected at 7-28 days postpartum and divided into type I ketosis (K1, 20 cows), type II ketosis (K2, 20 cows) and normal control (C, 10 cows) according to glucose (Glc), 3-hydroxybutyrate acid (BHBA), non-esterified fatty acid (NEFA) level and clinical signs of the disease. Type I ketosis was defined as having plasma BHBA>1.20 mmol·L-1, plasma Glc<2.50 mmol·L-1, and plasma NEFA>0.50 mmol·L-1. Type II ketosis was defined as having plasma BHBA>1.20 mmol·L-1, Glc>2.80 mmol·L-1, and plasma NEFA>0.50 mmol·L-1. Healthy controls were those with plasma BHBA<1.00 mmol·L-1, plasma Glc>3.75 mmol·L-1, and plasma NEFA<0.40 mmol·L-1. The plasma metabolic profiles from all experimental cows were analyzed using 1H NMR. The data were processed by principal component analysis (PCA), and orthogonal partial least-squares discriminant analysis (OPLS-DA) was performed to identify the differential metabolites in plasma among the three groups.【Result】The results showed that OPLS-DA model was better to distinguish the three plasma samples. Compared with healthy controls, 7 differential metabolites were obtained from type II ketosis and healthy controls, such as alanine, lysine, 3-hydroxybutyrate, acetone, lactate, and so on, type II ketosis had higher plasma levels of BHBA, acetone, and lactate and lower levels of alanine, lysine, tyrosine, and creatine. Nineteen differential metabolites were obtained from type I ketosis and healthy controls, for example tyrosine, phenylalanine, creatine, 3-hydroxybutyrate, acetoneet, and so on. Type I had higher levels of BHBA and acetone and lower levels of tyrosine, phenylalanine, lysine, histidine, alanine, creatine, myo-inositol, β-Glc, glutamine, glutamate, citrate, α-Glc, formate, glycine, O-acetyl glycoprotein (OAG), and phosphocholine. Twenty-four differential metabolites were obtained from type I ketosis and type II ketosis, for instance citrate, histidine, β-glcose, isoleucine, VLDL/LDL, and so on. Compared with type II ketosis, type I ketosis had higher levels of BHBA, low density lipoprotein (LDL), very low density lipoprotein (VLDL), isoleucine, valine, acetone, leucine, and acetate and lower levels of citrate, tyrosine, histidine, creatine, glutamine, β-Glc, phenylalanine, glutamate, α-Glc, lysine, formate, glycine, phosphocholine, and OAG . 【Conclusion】The combination of 1H NMR and multivariate statistical analysis techniques could effectively distinguish different metabolites among type I, type II ketosis and the healthy control group, It is an important basis for further studying the clinical pathology, early detection, diagnosis and detailed pathogenesis of type I and type II ketosis in dairy cows in the future, which lays a foundation for preventing type I and type II ketosis in dairy cows effectively.
    The Regulated Mechanism of Follistatin on the Proliferation Process of Duck Skeletal Muscle Satellite Cell Involved in TGF-β / Smad Signaling Pathway
    LIN Kai, YU De-bing, XIE Xiao-dong, YU Min-li, LI Dong-feng, DU Wen-xing
    Scientia Agricultura Sinica. 2015, 48(12):  2460-2468.  doi:10.3864/j.issn.0578-1752.2015.12.019
    Abstract ( 378 )   HTML ( 1 )   PDF (2620KB) ( 510 )   Save
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    【Objective】Follistatin can regulate skeletal muscle hypertrophy and fat deposition, and promote proliferation of the skeletal muscle satellite cell. The study intends to use in vitro recombination follistatin to treat the duck skeletal muscle satellite cell, which can be proved that the functional mechanism of TGF-β/smad signaling pathway is playing a role in its proliferation process.【Method】 Based on differential centrifugation technology, skeletal muscle satellite cells isolated from embryonic 14-day ducks were treated by proliferation medium containing 0,1,10 and 100 ng·mL-1 follistatin, respectively, after the cells density reached 70%-80% confluence. After incubation for 36 h, the degree of skeletal muscle satellite cells proliferation were tested by CCK-8. The cells were identified by immunofluorescence staining with pax7 antibody. Real-time qPCR was performed to measure the genes of expression differntiation including proliferation marker gene PCNA, and myogenic MyoD, smad2/3, TGF-βcaused by follistatin supplement.【Result】Under the inverted microscope, ti was found that a part of duck skeletal muscle cells did not adhere to round, a of cells part of cells adhered to fusiform 12 hours of culture. Adherent cell number increased and cells slightly longer after 24 h. Cells completely adherent, and fusiform, on day 2. The cell number increased, some cells differentiated, after 3 days. The number of cells further was increased, the cells thicker, some cells started to fuse after 4 days. A small amount of cells began differentiation, and further fusion of the cell on day five. The result of immunofluorescence staining showed that pax7 in more than 95% of the skeletal muscle satellite cells was positive, and the population of cells stained with Pax7 was suggested that the group of 10 ng·mL-1 follistatin was significantly higher than the control group (P<0.01). The gene expression analysis showed that compared with the control group, the expression level of MyoD in 10 ng·mL-1 follistatin treated group was significantly decreased (P<0.05), whereas, the expression levels of PCNA, TGF-β and Smad2 in follistatin treated groups were significantly increased (P<0.05). The expression of Smad3 gene ultimately significantly increased (P<0.01). Results of detection of protein expression by Western blotting showed that compared with the control group, TGF-β protein and Smad2/3 phosphorylat ion protein levels were also significantly increased.【Conclusion】Results of study suggested that follistatin promoted the expression of PCNA gene and reduced MyoD gene expression in duck skeletal muscle satellite cell. Furthermore, follistatin raised the expression of TGF-β, Smad2/3. Generally, 10 ng·mL-1 concentration of follistatin could significantly promote proliferation of the duck skeletal muscle satellite cell, the same that TGF-β / Smad signaling pathway maybe play a important role in it.
    RESEARCH NOTES
    Correlation Analysis Between Heterosis and Genetic Distance Evaluated by Genome-Wide SNP Chip in Brassica napus
    SANG Shi-fei, WANG Hui, MEI De-sheng, LIU Jia, FU Li, WANG Jun, WANG Wen-xiang, HU Qiong
    Scientia Agricultura Sinica. 2015, 48(12):  2469-2478.  doi:10.3864/j.issn.0578-1752.2015.12.020
    Abstract ( 620 )   HTML ( 2 )   PDF (381KB) ( 948 )   Save
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    【Objective】 To investigate the feasibility of heterosis prediction by single nucleotide polymorphism (SNP) markers in rapeseed, the 60K SNP chip covering the whole genome of Brassica napus was used to estimate the genetic distance (GD) of elite parental lines of B. napus, and the correlation between GD and heterosis was analyzed for the guidance of hybrid development of rapeseed. 【Method】 Forty-six F1 hybrids were produced using six maintainer lines (1019B, 1055B, 6098B, 8908B, 6019B and ZS11B) and eight restorer lines (R1, R2, R3, R6, R9, R10, R11 and OR1) of Polima cytoplasmic male sterility (CMS) in an incomplete diallel cross design. All the parents and F1s were grown in three different ecological conditions which are located in Wuhan, Guiyang, and Chaohu. Ten yield-related traits including plant height (PH), branch height (BH), number of effective primary branches (NEPB), silique density (SD), effective length of main inflorescence (ELMI), number of effective siliques on main inflorescence (ESMI), number of effective siliques per plant (ESPP), seed per silique (SPS), 1 000-seed weight (TSW) and yield per plant (YPP) were investigated for mid-parent heterosis and high-parent heterosis. The 14 parental lines were genotyped by 60K SNP chip of Brassicas. GD based on SNP genotyping was estimated with MEGA5.0 software, and cluster analysis was carried out using unweighted pair group method arithmetic averages (UPGMA) method. Correlation analysis between GD and heterosis was conducted by SAS9.1 statistical analysis software.【Result】There were 40 201 loci selected from 52 157 SNP loci as being effective for genetic distance calculation and cluster analysis after quality determination. GDs of the 14 parental lines ranged from 0.1883 to 0.8811, with an average of 0.5217. The GD between 6098B and 6019B was the smallest and that between ZS11B and R6 was the largest. The parental lines were divided into four groups, with six maintainers in one big group, four restorer lines R2, R6, R9 and R10 in a second group, three restorer lines R1, R3 and R11 in the third group, and the remaining one restorer OR1 in the fourth group. This cluster results indicate that the genetic variation in the restorers is greater than that in the maintainers, which is in accordance with their pedigree relationships. The average mid-parent heterosis of the 10 traits ranged from -0.07%-38.78%, and the average high-parent heterosis ranged from -7.74%-20.78%. Except for NEPB, all other nine yield-related traits showed significant heterosis in F1 hybrids. Especially for PH, SPS, BH and YPP, the average mid-parent heterosis was 6.83%, 15.31%, 16.13% and 38.78%, respectively, with the number of F1s having positive mid-parent heterosis was 45, 41, 46 and 46; and the average high-parent heterosis reached 3.18%, 5.19%, 7.85% and 20.78%, respectively, with the number of F1s having positive high-parent heterosis was 41, 31, 42 and 44. A significant positive correlation between heterosis and SNP estimated GD was detected for PH, BH and YPP, with the correlation coefficients between SNP estimated GD and mid-parent heterosis were 0.3884, 0.4051 and 0.4038, respectively. The correlation between heterosis and SNP estimated GD for other traits was not significant.【Conclusion】The genome-wide 60K SNP chip of Brassicas has significant advantages for genotyping, genetic distance estimation and cluster analysis. The GD estimated by genome-wide SNP makers has a very significantly positive correlation with heterosis for traits with high and universal heterosis, including plant yield. Thus, the genome-wide 60K SNP chip of Brassicas can be used to well predict heterosis in rapeseed.
    Establishment of TRV-mediated Transient Gene-Silencing System in Soybean
    LIU Xiao-bin, LIU Na, LI Fu-kuan, WU Li-zhu, ZHANG Jie, WANG Dong-mei
    Scientia Agricultura Sinica. 2015, 48(12):  2479-2486.  doi:10.3864/j.issn.0578-1752.2015.12.021
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    【Objective】Virus-induced gene silencing (VIGS) technology has been widely applied in the field of functional gene research in plants. Tobacco rattle virus-mediated gene silencing technology was used in the interaction between soybean and soybean mosaic virus (SMV) for gene function evaluation, and a TRV-mediated gene transient silence system in soybean was established.【Method】Soybean cv. Jidou 7 (J7) was used as material, and specifically amplified part of the GmPDS gene fragment from J7 leaves, and then was inserted into the plasmid pTRV: RNA2; The Agrobacterium carried with TRV or TRV:GmPDS were injected into the first true leaves of J7. After that, the upper non-inoculated leaves were observed and GmPDS gene’s expression level was confirmed by semi-quantitative RT-PCR analysis. In order to investigate the effect of inoculation with TRV on the resistance of soybean to SMV infection, the first true leaves of soybean inoculated with TRV for 10 days , then were inoculated with SMV strain N3 or SC-8. The control treatments were conducted by inoculating N3 or SC-8 alone. At 5 days after inoculating SMV, the phenotypes of upper uninoculated leaves were observed and SMV coat protein CP was detected. 【Result】At 25 days after injected with Agrobacterium suspension carrying TRV: GmPDS intothe first true leaves, the upper uninoculated leaves showed whitening phenotype and expression level of GmPDS was decreased significantly by semi-quantitative RT-PCR analysis. Based on this, soybean leaves injected with Agrobacterium suspension (carrying TRV) were then inoculated with SMV. J7 and SMV strains N3 and SC-8 were used to constitute incompatible and compatible combinations. Inoculated with TRV and then with SMV strains N3 or SC-8, the phenotype of upper uninoculated leaves were consistent with the upper leaves after inoculated with SMV alone. Leaves were taken for viral coat protein CP test. It was found that when inoculated with N3 alone, or pre-inoculated with TRV and then inoculated with N3, the coat protein CP was not detected on the upper leaves. If inoculated with SC-8 alone, or pre-inoculated with TRV and then inoculated with SC-8, the viral coat protein CP was detected on the uninoculated upper leaves. These results showed that the TRV had no influence on the performance of soybean resistance to SMV. The similar results were got on susceptible cv. Nannong 1138-2. 【Conclusion】The TRV-VIGS system in soybean was established in this experiment. The TRV has no influence on the performance of soybean resistance to SMV.