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    2018 Vol. 17 No. 05 Previous Issue    Next Issue

    Review
    Special Focus: Agricultural products processing characteristics and quality evaluation
    Special Focus: Insect heat shock proteins and their underlying functions
    Crop Science
    Horticulture
    Animal Science · Veterinary Medicine
    Agro-ecosystem & Environment
    Short Communication


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    Review
    Molecular mechanisms controlling seed set in cereal crop species under stress and non-stress conditions
    LI Hui-yong, Thomas Lübberstedt
    2018, 17(05): 965-974.  DOI: 10.1016/S2095-3119(17)61719-2
    Abstract ( )   PDF (826KB) ( )  
    Maximizing seed yield is the ultimate breeding goal in important cereal crop species.  Seed set is a key developmental stage in the process of seed formation, which determines grain number, seed mass, and realized yield potential, and can be severely affected by abiotic and biotic stresses.  However, seed set can also be substantially reduced by genetic factors even under optimal fertilization conditions.  The underlying molecular genetic mechanisms are still obscure.  In this review, we elucidate the process of seed set of cereal crop species in detail, including development of floral structures, formation of viable gametes, double fertilization, seed development, and abortion.  We discuss how genetic and non-genetic factors affect seed set in different development stages.  Finally, we will propose novel strategies to study genetic mechanisms controlling seed set and exploit genetic resources to improve seed set in cereal crop species.
    Special Focus: Agricultural products processing characteristics and quality evaluation
    Editorial- Agricultural products processing characteristics and quality evaluation
    WANG Qiang
    2018, 17(05): 975-976.  DOI: 10.1016/S2095-3119(18)61960-4
    Abstract ( )   PDF in ScienceDirect  
    Cereal, oil and fruit are the foundation of human survival which attracted much attention by their quality characteristics and products.  Currently, there are about 410 000 wheat resources (Drikvand et al. 2013), 215 000 rice resources (Kaur et al. 2014), 35 000 peanut resources (Wang et al. 2014), and 7 000 apple resources (Nie et al. 2013).  The processing characteristics of different agricultural product raw materials are different.  And for a long time, lots of research are focusing on the development of processing technology.  The background and basis of different agricultural product raw materials, especially for the processing characteristics, is still unclear while the relationship between raw materials and products is just beginning.  According to the research, American peanut has been divided into four types while Virginia suitable for salt-baked, Runner suitable for butter, Spanish suitable for confectionery and Valencia suitable for roasting (Wang et al. 2017).  However, the lacking of process quality evaluation model, method and standard is still the bottleneck restricting the healthy development of agricultural product processing industry.  This special focus provides the most methods and updated knowledge of processing characteristics and quality evaluation.
    In the aspect of characteristic detection, Nagamoto et al. (2018) developed a microplate assay method for determining the contents of triacylglycerols (TAGs), phosphatidylcholines (PCs), and free fatty acids (FFAs) in the rice bran of one grain using enzymatic reactions.  This novel method could be used for screening oil-rich rice lines in the future rice processing.  And for the relationship between raw material characteristics and product quality, Cho et al. (2018) identified how the different levels of nitrogen application affected the variances of gluten properties and end-use qualities and the differences of variances among Korean wheat cultivars.  The Korean wheat cultivars showed a high proportion of (α+β)-gliadin increase for bread, a high proportion of γ-gliadin decrease for noodles and a high proportion of ω-gliadin decreased for cookies.  And Yan et al. (2018) also tested ten indices from 106 apple cultivars and finally found malic acid (Mal), total organic acids (ToA), and acidity value (AcV) of apple were normally distributed, titratable acid (TiA) was close to normally distributed, whereas pH value had a skewed distribution.  Using the fitted normal distribution curves, the grading standards of Mal, TiA, ToA, and AcV were established.  This study provides a scientific basis for evaluating apple flavor and selecting apple cultivars. 
    Actually, the finally purpose for the processing characteristics and quality evaluation is to find the special varieties for processing which could enhance the quality and value of products.  And Wang et al. (2018) could give a good example.  They clarified the relationship between peanut quality and storage stability of peanut butter.  It concluded that oleic acid and linoleic acid values of the peanut materials have greater impact on the storage stability of peanut butter while two peanuts varieties as HOP and Open 17-15 had the longest shelf life for butter. 
    I genuinely believe that the readers of the Journal of  Integrative Agriculture will be interested in these articles and inspired with the findings of the papers for developing future research on the given topics.  I want to express my deep appreciation to all authors for their high-quality contributions and efforts to this special focus.
    Rapid semi-quantification of triacylglycerols, phosphatidylcholines, and free fatty acids in the rice bran of one grain
    Junko Nagamoto, Ai Sawazaki, Motonori Miyago, Bungo Shirouchi, Mitsukazu Sakata, TONG Li-tao, Toshihiro Kumamaru, Masao Sato
    2018, 17(05): 977-981.  DOI: 10.1016/S2095-3119(17)61849-5
    Abstract ( )   PDF in ScienceDirect  
    We developed a microplate assay method for determining the contents of triacylglycerols (TAGs), phosphatidylcholines (PCs), and free fatty acids (FFAs) in the rice bran of one grain using enzymatic reactions.  In this method, enzymes from commercially available kits were used.  Optimum reaction conditions were established.  It was found that Nonidet P-40 was the optimal among the three surfactants used (Triton X-100, Tween 40, and Nonidet P-40) when lipid was dissolved in a reaction solution.  Using this method, it was possible to quantify TAGs, PCs, and FFAs in concentration ranges of 7–150, 5–70, and 8–200 mg L–1, respectively.  Furthermore, when the TAG contents in the rice bran were measured, the values closely corresponded to those obtained by extracting from large amounts of rice bran.  However, sufficient data on the PC and FFA contents in rice bran are not available for valid comparisons.  Although this method can accurately quantify the TAG contents in the rice bran of one grain, the accuracy of the PC and FFA contents has not been verified.  Hence, future study is necessary.  
    Influence of different nitrogen application on flour properties, gluten properties by HPLC and end-use quality of Korean wheat
    Seong-Woo Cho, Chon-Sik Kang, Taek-Gyu Kang, Kwang-Min Cho, Chul Soo Park
    2018, 17(05): 982-993.  DOI: 10.1016/S2095-3119(18)61920-3
    Abstract ( )   PDF in ScienceDirect  
    This study was performed to identify how the different levels of nitrogen application affected the variances of gluten properties and end-use qualities and the differences of variances among Korean wheat cultivars.  Protein and dry gluten content, SDS sedimentation volume and water absorption of Mixolab increased as nitrogen application increased.  This ratio of the increase was higher in Korean wheat cultivars for bread than in Korean wheat cultivars for noodles and cookies.  The proportion of (α+β)-gliadin measured by reversed-phase high-performance liquid chromatography (RP-HPLC) increased, but the proportion of ω- and γ-gliadin decreased as the protein content increased.  The Korean wheat cultivars for bread showed a high proportion of (α+β)-gliadin increase, the Korean cultivars for noodles had a high proportion of γ-gliadin decrease and the Korean wheat cultivars for cookies had a high proportion of ω-gliadin decrease.  However, there was no variation of the component in the proportion of glutenin component measured by RP-HPLC, even though the protein content was increased, but all of the protein fractions measured by size exclusion (SE)-HPLC were increased.  The soluble monomeric protein showed a high proportion of Korean wheat cultivars for bread by the increase of protein content.  Bread loaf volume increased by the increase of protein content but there were no variances in the ratio of increase among Korean wheat cultivars.  The cookie diameter decreased with the increase of protein content, and this ratio of decrease was the highest in Korean wheat cultivars for cookies.  The hardness of cooked noodles also increased by the increase of protein content but there were no variations in springiness and cohesiveness.  The decrease proportion of ω-gliadin affected the increase of bread loaf volume, the hardness of cooked noodles, and the decrease of cookie diameter.
    Evaluation indices of sour flavor for apple fruit and grading standards
    YAN Zhen, ZHENG Li-jing, NIE Ji-yun, LI Zhi-xia, CHENG Yang
    2018, 17(05): 994-1002.  DOI: 10.1016/S2095-3119(17)61795-7
    Abstract ( )   PDF in ScienceDirect  
    In order to establish grading standards of evaluation indices for sour flavor of apples, 10 indices of samples from 106 apple cultivars were tested, including: malic acid (Mal), oxalic acid (Oxa), citric acid (Cit), lactic acid (Lac), succinic acid (Suc), fumaric acid (Fum), total organic acids (ToA, the sum of the six organic acids tested), titratable acid (TiA), acidity value (AcV), and pH value.  For most of the cultivars studied (85.8%), the order of the organic acid contents in apples was Mal>Oxa>Cit>Lac>Suc>Fum.  Mal was the dominant organic acid, on average, accounting for 94.5% of ToA.  Among the 10 indices, the dispersion of pH value was the smallest with a coefficient of variation of only 8.2%, while the coefficients of variation of the other nine indices were larger, ranging between 31 and 66%.  There were significant linear relationships between Mal and two indices (ToA and AcV) as well as between ToA and AcV.  There were significant logarithmic relationships between pH value and four indices: Mal, TiA, ToA, and AcV.  All the equations had very high fitting accuracy and can be used to accurately predict related indices.  According to this study, Mal, ToA, and AcV of apple were normally distributed, TiA was close to normally distributed, whereas pH value had a skewed distribution.  Using the fitted normal distribution curves, the grading standards of Mal, TiA, ToA, and AcV were established.  The grading node values of pH value were obtained using the logarithmic relationship between pH value and Mal.  The grading standards of these five indices can be used to evaluate the sour flavor of apple.  This study provides a scientific basis for evaluating apple flavor and selecting apple cultivars.
    Relationship of chemical properties of different peanut varieties to peanut butter storage stability
    GONG A-na, SHI Ai-min, LIU Hong-zhi, YU Hong-wei, LIU Li, LIN Wei-jing, WANG Qiang
    2018, 17(05): 1003-1010.  DOI: 10.1016/S2095-3119(18)61919-7
    Abstract ( )   PDF in ScienceDirect  
    This study examined the effect of peanut quality on the storage stability of peanut butter.  The quality of 17 varieties of peanuts was analyzed, and each was used to prepare peanut butter.  For different storage temperatures and durations, stability of the peanut butter was measured according to three indicators: peroxide value, acid value, and centrifugal rate.  The correlation between peanut components and peanut butter storage stability was also investigated.  The results indicated significant differences in fatty acid composition between different varieties of peanut.  Peanut butter prepared with high oleic peanuts (Kainong 17-15) had a significantly longer shelf life than that of other varieties.  The significant correlation between the stability of peanut butter and peanut quality suggests that oleic acid and linoleic acid were the main influencing factors on stability.  This study finds that the high oleic peanuts (HOP) is the most suitable variety for making peanut butter, which can allow farmers and processors to choose the specific variety for better product and shelf life. 
    Special Focus: Insect heat shock proteins and their underlying functions
    Editorial- Insect heat shock proteins and their underlying functions
    DU Yu-zhou
    2018, 17(05): 1011-1011.  DOI: 10.1016/S2095-3119(18)61951-3
    Abstract ( )   PDF in ScienceDirect  
    Considering huge number of insect species in the world, studies of heat shock proteins on insects are still very limited.  Special focus of “Insect heat shock proteins and their underlying functions“ provides a comprehensive knowledge for the given topics, which focuses on the heat shock proteins from four insect species: i) Five heat shock proteins (HSPs) from Cotesia chilonis were identified, and their expressional patterns under different temperatures were examined; ii) two novel HSP70s of Frankliniella occidentalis possessed different family characteristics; iii) less reported T-complex polypeptide 1 (TCP-1) from Chilo suppressalis HSP60 family showed different functions; iv) HSP18.3 of Tribolium castaneum played important roles in stress resistance, development and reproduction.   
    The first article regarding five HSPs of C. chilonis from Pan et al. (2018) described the cDNA sequences and genomic DNAs of Cchsp40, Cchsp60, Cchsp70, Cchsc70 and Cchsp90, and their expression levels under low or high temperatures.  The second article about the two HSP70s of F. occidentalis from Qin et al. (2018) examined the full length cDNAs of Fohsc704 and Fohsc705, as well as their positions and size of the introns.  The results also demonstrated that these two HSP70s played important roles in the thermotolerance of F. occidentalis.  The third paper of Yu et al. (2018) detailed the characterization of the Tcp-1 from C. suppressalis.  Genomic analyses indicated that there were no introns in the Tcp-1 gene, but the expression levels of Tcp-1 weren’t induced by temperature stresses.  Finally, Xiong et al. (2018) described the transcriptome profiles of RNA interference (RNAi)-treated larvae (ds-Tchsp18.3) and control larvae of T. castaneum.  The results showed that the knockdown of Tchsp18.3 gene expression affected various stress responses, innate immunity and the antioxidant activity process. 
    I genuinely hope that the readers of the Journal of Integrative Agriculture will be interested in these topics, and these papers could provide useful information for their research.  I appreciate all authors give their high-quality contributions and efforts to this special focus.
    Genes encoding heat shock proteins in the endoparasitoid wasp, Cotesia chilonis, and their expression in response to temperatures
    PAN Dan-dan, CAO Shuang-shuang, LU Ming-xing, HANG San-bao, DU Yu-zhou
    2018, 17(05): 1012-1022.  DOI: 10.1016/S2095-3119(17)61737-4
    Abstract ( )   PDF in ScienceDirect  
    Five genes encoding heat shock proteins (HSPs), Cchsp40, Cchsp60, Cchsp70, Cchsc70 and Cchsp90, were cloned and sequenced from Cotesia chilonis using RT-PCR and RACE.  The cDNA sequences of Cchsp40, Cchsp60, Cchsp70, Cchsc70 and Cchsp90 were 1 265, 2 551, 2 094, 2 297 and 2 635 bp in length, respectively, with a molecular weight (MW) of 39.1, 60.6, 71.45, 70.19 and 82.92 kDa, respectively.  The predicted amino acid sequences of these proteins showed high similarities with published HSPs of other insects in Hymenoptera.  Analysis of genomic DNAs indicated that Cchsp40, Cchsp60, Cchsp70, Cchsc70 and Cchsp90 lacked introns, but Cchsc70 contained an intron.  The results also suggested that CcHSP40 in C. chilonis was the Type II HSP40, CcHSP60 was a member of the mitochondrial HSP60 family, and CcHSP90 was a part of cytoplasmic HSP90A family.  Expression patterns varied in the five Cchsps in response to temperature.  Expression of Cchsp40 and Cchsp60 was induced significantly by cold but not heat stress.  Cchsp70 and Cchsc70 showed similar response to the thermal stress and could be induced by both cold and heat, but their expression levels were consistently lower than that of Cchsp40 and Cchsp60Cchsp90 could be induced by heat stress and mild cold, but not cold stress.  In addition, the results demonstrated Cchsc70 might be constitutive and inducible protein that was expressed during normal cell functioning and also up-regulated in response to stressful stimuli while Cchsp70 was solely inducible protein induced by temperature changes.  Overall, results generated from this study could significantly advance the understanding of Cchsps in response to temperature and provide important biological information for C. chilonis insects that reared under different temperatures.  
    Characterization of two novel heat shock protein 70s and their transcriptional expression patterns in response to thermal stress in adult of Frankliniella occidentalis (Thysanoptera: Thripidae)
    QIN Jing, GAO Peng, ZHANG Xiao-xiang, LU Ming-xing, DU Yu-zhou
    2018, 17(05): 1023-1031.  DOI: 10.1016/S2095-3119(17)61725-
    Abstract ( )   PDF in ScienceDirect  

    Heat shock protein 70 (HSP70) is one of the most important members in the heat shock protein family, and plays important roles in the thermotolerance of insect.  To explore the molecular mechanism of thermotolerance of Frankliniella occidentalis adults, the difference in the expression of HSP70s in F. occidentalis male or female adults under the thermal stress was studied under the laboratory conditions.  Two full length cDNAs of HSP70s gene (Fohsc704 and Fohsc705) were cloned from F. occidentalis by using RT-PCR and RACE.  The genomic sequence was demonstrated by genomic validation, and the position and size of the intron were analyzed by sequence analysis of cDNA.  Real-time PCR was used to analyze the HSP70 expression patterns.  The cDNA of Fohsc704 and Fohsc705 possessed 2 073 and 1 476 bp which encoded 690 and 491 amino acids (aa) with a calculated molecular weight of 75 and 54 kDa, respectively.  Four introns in Fohsc704 and six introns in Fohsc705 protein were found.  However, the HSP70 protein sequences in our study were ended with EKKN and GIFL, which were different from the reported FoHSP70s.  Various expression patterns of Fohsc704 and Fohsc705 were found in both genders of F. occidentalis under thermal stress.  The expression of Fohsc704 and Fohsc705 reached to the highest level at –12 and –8°C in male adults, respectively, and Fohsc705 expressed the highest level at 33°C in female adults.  In conclusion, HSP70s of F. occidentalis in our study are novel heat shock proteins.  There were difference in expression patterns of the two hsc70s in genders of F. occidentalis, and the two HSP70s play important roles in the thermotolerance of F. occidentalis.  
    Characterization of T-complex polypeptide 1 (TCP-1) from the Chilo suppressalis HSP60 family and its expression in response to temperature stress
    YU Tong-ying, LU Ming-xing, CUI Ya-dong
    2018, 17(05): 1032-1039.  DOI: 10.1016/S2095-3119(17)61775-1
    Abstract ( )   PDF in ScienceDirect  
    Many proteins require assistance from molecular chaperones at various stages to attain correctly folded states and functional conformations during protein synthesis.  In this study, the gene encoding T-complex polypeptide 1 (TCP-1), which belongs to the heat shock protein 60 (HSP60) family, was isolated and characterized from the rice stem borer, Chilo suppressalis, by RACE and qPCR, respectively.  The full-length cDNA of Tcp-1 was 2 144 bp and encoded a 1 635-bp ORF; the deduced translational product contained 545 amino acids with 5´- and 3´-UTRs and an isoelectric point of 5.29.  Cluster analysis confirmed that the deduced amino acid sequence shared high identity (60–99%) with TCP-1 from other insects.  To investigate Tcp-1 expression in response to abiotic stress, qPCR was used to analyze expression levels of Tcp-1 mRNA in C. suppressalis larvae exposed to temperatures ranging from –11 to 43°C.  With respect to heat shock, Tcp-1 expression was higher than the control after a 2-h exposure to 30 and 36°C and declined at 39 and 43°C.  Difference in Tcp-1 expression was observed at temperatures ranging from –11 to 27°C.  qPCR analyses revealed that Tcp-1 expression was the highest in hindgut tissue as compared to heads, epidermis, fat body, foregut, midgut, and malpighian tubules.  Our results indicated that Tcp-1 expression was differentially expressed in C. suppressalis tissues, and was impacted by temperature stress.
    Transcriptome analysis of hsp18.3 functions and regulatory systems using RNA-sequencing in the red flour beetle, Tribolium castaneum
    XIONG Wen-feng, XIE Jia, WEI Lu-ting, ZHANG Si-si, SONG Xiao-wen, GAO Shan-shan, LI Bin
    2018, 17(05): 1040-1056.  DOI: 10.1016/S2095-3119(17)61886-0
    Abstract ( )   PDF (1946KB) ( )  
    The red flour beetle, Tribolium castaneum, is a major agriculture pest of stored grain, cereal products and peanuts for human consumption.  It is reported that heat shock protein 18.3 of T. castaneum (Tchsp18.3) plays a significant role in stress resistance, development and reproduction.  However, the regulatory systems of Tchsp18.3 remain unknown.  Therefore, we compared the global transcriptome profiles of RNA interference (RNAi)-treated larvae (ds-Tchsp18.3) and control larvae of T. castaneum using RNA sequencing.  Overall, we obtained 14 154 435 sequence reads aligned with 13 299 genes.  Additionally, 569 differentially expressed genes (DEGs) were identified from the ds-Tchsp18.3 and control groups, of which 246 DEGs were annotated in the 47 Gene Ontology (GO) functional groups and 282 DEGs were assigned to 147 Kyoto Encyclopedia of Genes and Genomes (KEGG) biological signaling pathways.  The DEGs encoding viperin, dorsal, Hdd11, PGRP2, defensin1 and defensin2 were simultaneously related to immunity and stress responses, which suggests that cross-talk might exist between the immunity and stress responses of T. castaneum.  The knockdown of Tchsp18.3gene expression suppressed the antioxidant activity process, which most likely modulated the effects of Tchsp18.3 on development and reproduction.  Furthermore, the DEGs, including Blimp-1, Gld, Drm, Kinesin-14, Pthr2, Delta(11)-like and EGF-like domain protein 2, were also associated with the development and reproduction of ds-Tchsp18.3 insects.  Additionally, knockdown of Tchsp18.3 amplified the serine protease (SP) signaling pathway to further regulate stress responses and innate immunity as well as development and reproduction of the red flour beetles.  These results provide valuable insight into the molecular regulatory mechanism of Tchsp18.3 involved in insect physiology and further facilitate the research of suitable and sustainable management for pest control.
    Crop Science
    Phenotypic analysis of a dwarf and deformed flower3 (ddf3) mutant in rice (Oryza sativa L.) and characterization of candidate genes
    WANG Yu-peng, TANG shuang-qin, WU Zhi-feng, SHI Qing-hua, WU Zi-ming
    2018, 17(05): 1057-1065.  DOI: 10.1016/S2095-3119(17)61770-2
    Abstract ( )   PDF in ScienceDirect  
    Dwarf mutants are the crucial resources for molecular biology research and rice breeding.  Here, a rice mutant, dwarf and deformed flower3 (ddf3), was identified in tissue culture of Oryza sativa cv. Dongjin.  Compared with wild type, the ddf3mutant exhibited severe dwarfism, a greater number of tillers and significantly decreased fertility.  In addition, leaf length, panicle length, and grain length, were significantly shorter.  All internodes of ddf3were shorter than those of wild type, and histological analysis revealed that internode cell elongation was significantly inhibited in ddf3.  In the ddf3mutant, pollen activity was significantly decreased, and the development of most stigmas was abnormal.  Genetic analysis indicated that the ddf3mutant phenotypes are controlled by a single or tightly linked nuclear genes.  Using an F2 mapping population generated from a cross between ddf3and Yangdao 6 (9311), the DDF3 gene was mapped to a 45.21-kb region between insertion-deletion (InDel) markers M15 and M16 on the long arm of chromosome 7.  Sequencing revealed a 13.98-kb-deletion in this region in the ddf3 mutant genome that resulted in the complete or partial deletion of ZF (DHHC type zinc finger protein), EP (expressed protein), and FH2 (actin-binding FH2 domain-containing protein) genes.  Quantitative RT-PCR analyses revealed that in wild type, the transcript levels of FH2 were almost the same in all organs, while ZF was mainly expressed in the panicle, and no expression of EP was detected in any organ.  Based on these results, ZF and FH2 could be potential DDF3 candidate genes involved in the regulation of rice morphology and flower organ development.  Our work has laid the foundation for future functional analysis of these candidate genes and has provided a profitable gene resource for rice breeding for increased fertility in the future. 
    Effect of high-molecular-weight glutenin subunit deletion on soft wheat quality properties and sugar-snap cookie quality estimated through near-isogenic lines
    ZHANG Xiao, ZHANG Bo-qiao, WU Hong-ya, LU Cheng-bin, Lü Guo-feng, LIU Da-tong, LI Man,
    2018, 17(05): 1066-1073.  DOI: 10.1016/S2095-3119(17)61729-5
    Abstract ( )   PDF in ScienceDirect  
    High-molecular-weight glutenin subunits (HMW-GSs) play a critical role in determining the viscoelastic properties of wheat dough.  The HMW-GSs are encoded by Glu-A1, Glu-B1, and Glu-D1 loci on the long arms of chromosomes 1A, 1B, and 1D, respectively.  In the present study, four near-isogenic lines with different HMW-GS deletions and compositions at the Glu-A1 and Glu-D1 loci in Yangmai 18 background were used for quality analysis.  Deletion in Glu-D1 showed much weaker gluten quality and dough strength than null Glu-A1 genotype and wild genotype (WT), based on the measurements of sodium dodecyl sulfate (SDS)-sedimentation, lactic acid solvent retention capacity (SRC), gluten index, development time, stability time, and alveograph P and L values.  The deletion of Glu-D1 did not significantly affect grain hardness, grain protein content, water SRC, sodium carbonate SRC, and sucrose SRC.  Double null genotype in Glu-A1 and Glu-D1 and single null genotype in Glu-D1 showed significantly higher cookie diameter, crispness, and lower cookie height compared with single null genotype in Glu-A1 and WT.  These indicate that the null Glu-D1 genotype is useful for improvement of biscuit quality, and use of this germplasm would be a viable strategy to develop new wheat varieties for biscuit processing.
    Meta-analysis of soybean amino acid QTLs and candidate gene mining
    GONG Qian-chun, YU Hong-xiao, MAO Xin-rui, QI Hui-dong, SHI Yan, XIANG Wei, CHEN Qing-shan,
    2018, 17(05): 1074-1084.  DOI: 10.1016/S2095-3119(17)61783-0
    Abstract ( )   PDF in ScienceDirect  
    The composition and quantity of amino acids influence the protein content and nutritional value of soybeans and also have an important impact upon soybean quality.  After integrating and proofreading 140 original QTLs associated with amino acid contentfrom soybase (http://www.soybase.org/), 138 QTLs were further analyzed to determine high-confidence QTL regions.  Meta-analysis was first carried out using the BioMercator ver. 2.1 software, yielding 33 consensus QTLs.  The consensus QTL confidence intervals (CIs) ranged from 0.07 to 19.85 Mb.  Next, the overview method was used to optimize the CIs, and 57 “real” QTLs were mapped.  Candidate genes in the consensus QTL regions were obtained from Phytozome and were annotated using the Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), Swissprot, and gene annotation databases.  Finally, 16 unpublished candidate genes controlling the content of five types of amino acids were identified with Blast.  These results laid the foundation for fine mapping of soybean amino acid-related QTLs and marker-assisted selection.
    Nectar secretion of RN-type cytoplasmic male sterility three lines in soybean [Glycine max (L.) Merr.]
    ZHANG Jing-yong, SUN Huan, ZHAO Li-mei, ZHANG Chun-bao, YAN Hao, PENG Bao, LI Wen-bin
    2018, 17(05): 1085-1092.  DOI: 10.1016/S2095-3119(18)61910-0
    Abstract ( )   PDF in ScienceDirect  
    Significant progress has been achieved in the use of heterosis in soybean and several soybean hybrids have been released in China. However, broad use of hybrid soybean seed is limited due to low seed setting of female parents.  Breeding cytoplasmic male sterile (CMS) lines with high out-crossing rate is necessary to solve the problem.  The objective of this study was to determine the relationship between out-crossing rate of CMS lines and their nectar secretion.  The daily nectar secretion rhythm, meteorological effect on nectar secretion, and differences in nectar secretion among genotypes and years were investigated in 27 soybean CMS lines (A-lines) with their maintainers (B-lines) and restorers (R-lines).  The correlation between out-crossing rate of CMS lines and nectar production was also evaluated.  Nectar secretion had diurnal variation.  Secretion initiated at about 06:00 for most materials and reached a peak at 07:00–08:30 after flower opened, then the nectar secretion decreased gradually.  A sub-peak appeared at about 13:00, while the nectar could not be detected at 17:00.  Nectar secretion was greatly influenced by the weather conditions.  The amount of nectar secretion increased gradually over time during periods of high temperature and no rainfall for several days.  Rainy weather and low temperatures inhibited nectar secretion.  There were obvious variations of nectar amount among different genotypes tested.  Significant nectar variation within a genotype among years was also observed, and the highest nectar secretion was 3-fold higher than the lowest.  The amount of nectar secretion from R-lines was significantly higher than that of A- and B-lines.  There was no significant difference in nectar secretion between A- and B-lines.  A- and B-lines with higher out-crossing rates secreted more nectar.  The amount of nectar secretion of A- and B-lines were significantly positively correlated with the out-crossing rate of A-lines.
    Shoot and root traits in drought tolerant maize (Zea mays L.) hybrids
    ZHAO Jin, XUE Qing-wu, Kirk E Jessup, HOU Xiao-bo, HAO Bao-zhen, Thomas H Marek, XU Wen-wei,Steven R Evett, Susan A O’Shaughnessy, David K Brauer
    2018, 17(05): 1093-1105.  DOI: 10.1016/S2095-3119(17)61869-0
    Abstract ( )   PDF in ScienceDirect  
    This study aimed to investigate the differences in shoot and root traits, and water use and water use efficiency (WUE) in drought tolerant (DT) maize (Zea mays L.) hybrids under full and deficit irrigated conditions.  A two-year greenhouse study was conducted with four hybrids (one conventional hybrid, 33D53AM, two commercial DT hybrids, P1151AM, N75H, and an experimental hybrid, ExpHB) grown under two water regimes (I100 and I50, referring to 100 and 50% of evapotranspiration requirements).  Under water stress, the hybids P1151AM, N75, and ExpHB showed more drought tolerance and had either greater shoot dry weight or less dry weight reduction than the conventional hybrid (33D53AM).  However, these three hybrids responded to water stress using different mechanisms.  Compared with the conventional hybrid, the two commercial DT hybrids (P1151AM and N75H) had a smaller leaf area, shoot dry weight, and root system per plant.  As a result, these hybrids used less water but had a higher WUE compared with the conventional hybrid.  In contrast, the experimental hybrid (ExpHB) produced more shoot biomass by silking stage at both irrigation levels than all other hybrids, but it had relatively lower WUE.  The hybrids demonstrated different drought response mechanisms that may require different irrigation management strategies.  More investigation and validation are needed under field conditions and in different soil types.  
    Effects of planting dates and shading on carbohydrate content, yield, and fiber quality in cotton with respect to fruiting positions
    ZHAO Wen-qing, WU You, Zahoor Rizwan, WANG You-hua, MA Yi-na, CHEN Bing-lin, MENG Ya-li, ZHOU Zhi-guo
    2018, 17(05): 1106-1119.  DOI: 10.1016/S2095-3119(17)61797-0
    Abstract ( )   PDF in ScienceDirect  
    Two cotton (Gossypium hirsutum L.) cultivars, Kemian 1 (cool temperature-tolerant) and Sumian 15 (cool temperature-sensitive) were used to study the effects of cool temperature on carbohydrates, yield, and fiber quality in cotton bolls located at different fruiting positions (FP).  Cool temperatures were created using late planting and low light.  The experiment was conducted in 2010 and 2011 using two planting dates (OPD, the optimized planting date, 25 April; LPD, the late planting date, 10 June) and two shading levels of crop relative light rate (CRLR, 100 and 60%).  Compared with fruiting position 1 (FP1), cotton yield and yield components (fiber quality, leaf sucrose and starch content, and fiber cellulose) were all decreased on FP3 under all treatments.  Compared with OPD-CRLR 100%, other treatments (OPD-CRLR 60%, LPD-CRLR 100%, and LPD-CRLR 60%) had significantly decreased lint yield at both FPs of both cultivars, but especially at FP3 and in Sumian 15; this decrease was mainly caused by a large decline in boll number.  All fiber quality indices decreased under late planting and shading except fiber length at FP1 with OPD-CRLR 60%, and a greater reduction was observed at FP3 and in Sumian 15.  Sucrose content of the subtending leaf and fiber increased under LPD compared to OPD, whereas it decreased under CRLR 60% compared to CRLR 100%, which led to decreased fiber cellulose content.  Therefore, shading primarily decreased the “source” sucrose content in the subtending leaf whereas late planting diminished translocation of sucrose towards cotton fiber.  Notably, as planting date was delayed and light was decreased, more carbohydrates were distributed to leaf and bolls at FP1 than those at FP3, resulting in higher yield and better fiber quality at FP1, and a higher proportion of bolls and carbohydrates allocated at FP3 of Kemian 1 compared to that of Sumian 15.  In conclusion, cotton yield and fiber quality were reduced less at FP1 compared to those at FP3 under low temperature and low light conditions.  Thus, reduced cotton yield and fiber quality loss can be minimized by selecting low temperature tolerant cultivars under both low temperature and light conditions.
    Fiber damage of machine-harvested cotton before ginning and after lint cleaning
    TIAN Jing-shan, ZHANG Xu-yi, ZHANG Wang-feng, LI Jian-feng, YANG Yan-long, DONG Heng-yi, JIU Xing-li, YU Yong-chuan, ZHAO Zhan, XU Shou-zhen, ZUO Wen-qing
    2018, 17(05): 1120-1127.  DOI: 10.1016/S2095-3119(17)61730-1
    Abstract ( )   PDF in ScienceDirect  
    Machine harvesting increases the foreign matter content of seed cotton.  Excessive cleaning causes fiber damage and economic loss.  Most trading companies in the Xinjiang Uygur Autonomous Region, China have indicated reluctance to use machine-harvested cotton.  The first objective was to determine how the fiber quality was affected by the ginning and lint cleaning and how the fiber damage during levels of lint cleaning changed. The second objective was to determine the optimum number of lint cleaners for machine-harvested cotton based on fiber damage.  Cotton samples were collected from 13 fields and processed in seven ginneries between 2013 and 2015.  The results indicated that ginning and lint cleaning didn’t have significant effect on fiber strength and significantly affected both fiber length and short fiber index.  Fiber length was reduced by more than 1.00 mm from six of 13 fields after lint cleaning, then the damage rate on short fiber index from 11 of 13 fields was more than 20%.  The third lint cleaning caused great fiber damage, reducing fiber length by 0.35 mm and increasing short fiber index by 0.65%.  So, the lint should be cleaned by one lint cleaner in the Xinjiang, however, the stage of lint cleaning was sometimes omitted when the foreign matter content of lint was little.
    Horticulture
    Heterologous expression of Lolium perenne antifreeze protein confers chilling tolerance in tomato
    Srinivasan Balamurugan, Jayan Susan Ann, Inchakalody P Varghese, Shanmugaraj Bala Murugan, Mani Chandra Harish, Sarma Rajeev Kumar, Ramalingam Sathishkumar
    2018, 17(05): 1128-1136.  DOI: 10.1016/S2095-3119(17)61735-0
    Abstract ( )   PDF in ScienceDirect  
    Antifreeze proteins (AFP) are produced by certain plants, animals, fungi and bacteria that enable them to survive upon extremely low temperature.  Perennial rye grass, Lolium perenne, was reported to possess AFP which protects them from cold environments.  In the present investigation, we isolated AFP gene from L. perenne and expressed it in tomato plants to elucidate its role upon chilling stress.  The T1 transgenic tomato lines were selected and subjected to molecular, biochemical and physiological analyses.  Stable integration and transcription of LpAFP in transgenic tomato plants was confirmed by Southern blot hybridization and RT-PCR, respectively.  Physiological analyses under chilling conditions showed that the chilling stress induced physiological damage in wild type (WT) plants, while the transgenic plants remained healthy.  Total sugar content increased gradually in both WT and transgenic plants throughout the chilling treatment.  Interestingly, transgenic plants exhibited remarkable alterations in terms of relative water content (RWC) and electrolyte leakage index (ELI) than those of WT.  RWC increased significantly by 3-fold and the electrolyte leakage was reduced by 2.6-fold in transgenic plants comparing with WT.  Overall, this report proved that LpAFP gene confers chilling tolerance in transgenic tomato plants and it could be a potential candidate to extrapolate the chilling tolerance on other chilling-sensitive food crops.
    The effect of ozone and drought on the photosynthetic performance of canola
    Bheki G Maliba, Prabhu M Inbaraj, Jacques M Berner
    2018, 17(05): 1137-1144.  DOI: 10.1016/S2095-3119(17)61834-3
    Abstract ( )   PDF in ScienceDirect  
    Canola plants were fumigated in open-top chambers with ozone (O3) (120 ppb) under well-watered (WW) and water-stressed (WS) conditions for 4 weeks.  Non-fumigated plants were also studied to facilitate comparison between treatments for the same week and over time.  Therefore, the treatments were: WW, WW-O3, WS and WS-O3.  The fast  chlorophyll a fluorescence transients OJIP for the four treatments emitted upon illumination of dark-adapted leaves were measured after week 1, 2, 3, 4 and analysed by the JIP-test to evaluate the resulting changes in photosynthetic performance.  Ozone fumigation led to a decline of total performance index (PItotal) in well-watered plants.  The effect of O3was minor under drought conditions, as revealed by a decrease of PItotal by 3%.  The PItotal decreased as the treatment was prolonged, due to leaf ageing for all cases and the decline was more pronounced under WW-O3.  Taking the average of all weeks, WW had the highest PItotal and the lowest WW-O3(decrease by 27%), while in WS and WS-O3, it was lower than WW (14 and 17%, respectively).  We found that the absorption (ABS)/reaction centre (RC) increases, while the maximum quantum yield of primary photochemistry (φPo) undergoes slight changes, and trapping (TR0)/RC closely followed the increase in ABS/RC.  This indicates that O3 and drought caused an increase in the functional antenna size.  The maximum quantum yield of primary photochemistry showed slight differences for all treatments and over time, suggesting that this parameter is less sensitive to drought and O3 stress.  Therefore, the more sensitive components of the photosynthetic electron transport chain appeared to be the probability that an electron from the intersystem electron carriers is transferred to reduce end electron acceptors at the PSI acceptor side (δRo) and the RC density on a chlorophyll basis (RC/ABS).   
    Variability in total antioxidant capacity, antioxidant leaf pigments and foliage yield of vegetable amaranth
    Umakanta Sarker, Md Tofazzal Islam, Md Golam Rabbani, Shinya Oba
    2018, 17(05): 1145-1153.  DOI: 10.1016/S2095-3119(17)61778-7
    Abstract ( )   PDF in ScienceDirect  
    Twenty vegetable amaranth genotypes were evaluated for total antioxidant capacity, antioxidant leaf pigments, vitamins, and selection of suitable genotypes for extraction of juice in a randomized complete block design (RCBD) with three replications.  Vegetable amaranth was rich in chlorophyll,  β-cyanins, β-xanthins, betalains, carotene, ascorbic acid and total antioxidant.  The genotypes VA14, VA16, VA18, VA15, and VA20 could be selected as amaranth vegtable varieties with high yields and abundance antioxidant leaf pigments and vitamins to produce juice.  The genotypes VA13 and VA19 had above-average foliage yield and high antioxidant profiles while the genotypes VA2, VA3, VA9, VA11, VA12, and VA17 had a high antioxidant profiles and below-average foliage yield.  These genotypes could be used as a donor parent for integration of potential high antioxidant profiles genes into other genotypes.  The correlation study revealed a strong positive association among all the antioxidant leaf pigments, total antioxidant capacity and foliage yield.  Selection based on total antioxidant capacity, antioxidant leaf pigments could economically viable to improve the yield potential of vegetable amaranth genotypes.  Total carotene and ascorbic acid exhibited insignificant genotypic correlation with all the traits except total antioxidant capacity.  This indicates that selection for antioxidant vitamins might be possible without compromising yield loss.
    Identification of miRNAs and target genes regulating catechin biosynthesis in tea (Camellia sinensis)
    SUN Ping, ZHANG Zhen-lu, ZHU Qiu-fang, ZHANG Guo-ying, XIANG Ping, LIN Yu-ling, LAI Zhongxiong, LIN Jin-ke
    2018, 17(05): 1154-1164.  DOI: 10.1016/S2095-3119(17)61654-X
    Abstract ( )   PDF in ScienceDirect  
    MicroRNAs (miRNAs) are endogenous non-protein-coding small RNAs that play crucial and versatile regulatory roles in plants.  Using a computational identification method, we identified 55 conserved miRNAs in tea (Camellia sinensis) by aligning miRNA sequences of different plant species with the transcriptome library of tea strain 1005.  We then used quantitative real-time PCR (qRT-PCR) to analyze the expression of 31 identified miRNAs in tea leaves of different ages, thereby verifying the existence of these miRNAs and confirming the reliability of the computational identification method.  We predicted which miRNAs were involved in catechin synthesis using psRNAtarget Software based on conserved miRNAs and catechin synthesis pathway-related genes.  Then, we used RNA ligase-mediated rapid amplification of cDNA ends (RLM-RACE) to obtain seven miRNAs cleaving eight catechin synthesis pathway-related genes including chalcone synthase (CHS), chalcone isomerase (CHI), dihydroflavonol 4-reductase (DFR), anthocyanidin reductase (ANR), leucoanthocyanidin reductase (LAR), and flavanone 3-hydroxylase (F3H).  An expression analysis of miRNAs and target genes revealed that miR529d and miR156g-3p were negatively correlated with their targets CHI and F3H, respectively.  The expression of other miRNAs was not significantly related to their target genes in the catechin synthesis pathway.  The RLM-RACE results suggest that catechin synthesis is regulated by miRNAs that can cleave genes involved in catechin synthesis. 
    Animal Science · Veterinary Medicine
    Effect of dietary supplementation with flavonoid from Scutellaria baicalensis Georgi on growth performance, meat quality and antioxidative ability of broilers
    LIAO Xiu-dong, WEN Qian, ZHANG Ling-yan, LU Lin, ZHANG Li-yang, LUO Xu-gang
    2018, 17(05): 1165-1170.  DOI: 10.1016/S2095-3119(17)61803-3
    Abstract ( )   PDF in ScienceDirect  
    An experiment was conducted to investigate the effect of dietary supplementation with flavonoid from Scutellaria baicalensis Georgi (SBGFN) as SBGFN-zinc (SBGFN-Zn) on growth performance, meat quality, immune responses and antioxidation of broilers.  A total of 450 one-d-old Arbor Acres male broilers were randomly allocated to 5 treatments with 6 replicates of 15 birds per replicate for each treatment in a completely randomized design.  Birds were fed a SBGFN-unsupplemented corn-soybean meal basal diet (control) or the basal diet supplemented with 60, 120, 180 or 240 mg SBGFN kg–1 from SBGFN-Zn for 42 d.  Dietary SBGFN supplementation affected (P<0.03) drip loss in thigh muscle, total superoxide dismutase (T-SOD) and glutathione peroxidase (GSH-Px) activity in liver of broilers at 42 d of age.  Chicks fed the diets supplemented with 120, 180 and 240 mg SBGFN kg–1 had lower (P<0.03) drip loss of thigh muscle than those fed the control diet.  Chicks fed the diet supplemented with 180 mg SBGFN kg–1 had higher (P<0.03) liver T-SOD and GSH-Px activity than those fed the diets supplemented with 0, 60 and 120 mg SBGFN kg–1.  The results from the present study indicate that dietary supplementation with 180 mg SBGFN kg–1 as SBGFN-Zn improved both meat quality and antioxidative ability of broilers.   
    Identification of the strain-specifically truncated nonstructural protein 10 of porcine reproductive and respiratory syndrome virus in infected cells
    ZHANG Zhi-bang, XU Lei, WEN Xue-xia, DONG Jian-guo, ZHOU Lei, GE Xin-na, YANG Han-chun, GUO Xin
    2018, 17(05): 1171-1180.  DOI: 10.1016/S2095-3119(17)61896-3
    Abstract ( )   PDF (4491KB) ( )  
    The nonstructural protein 10 (nsp10) of porcine reproductive and respiratory syndrome virus (PRRSV) encodes for helicase which plays a vital role in viral replication.  In the present study, a truncated form of nsp10, termed nsp10a, was found in PRRSV-infected cells and the production of nsp10a was strain-specific.  Mass spectrometric analysis and deletion mutagenesis indicated that nsp10a may be short of about 70 amino acids in the N terminus of nsp10.  Further studies by rescuing recombinant viruses showed that the Glu-69 in nsp10 was the key amino acid for nsp10a production.  Finally, we demonstrated that nsp10a exerted little influence on the growth kinetics of PRRSV in vitro. 
    Agro-ecosystem & Environment
    A simulation of winter wheat crop responses to irrigation management using CERES-Wheat model in the North China Plain
    ZHOU Li-li, LIAO Shu-hua, WANG Zhi-min, WANG Pu, ZHANG Ying-hua, YAN Hai-jun, GAO Zhen, SHEN Si, LIANG Xiao-gui, WANG Jia-hui, ZHOU Shun-li
    2018, 17(05): 1181-1193.  DOI: 10.1016/S2095-3119(17)61818-5
    Abstract ( )   PDF (1260KB) ( )  
    To improve efficiency in the use of water resources in water-limited environments such as the North China Plain (NCP), where winter wheat is a major and groundwater-consuming crop, the application of water-saving irrigation strategies must be considered as a method for the sustainable development of water resources.  The initial objective of this study was to evaluate and validate the ability of the CERES-Wheat model simulation to predict the winter wheat grain yield, biomass yield and water use efficiency (WUE) responses to different irrigation management methods in the NCP.  The results from evaluation and validation analyses were compared to observed data from 8 field experiments, and the results indicated that the model can accurately predict these parameters.  The modified CERES-Wheat model was then used to simulate the development and growth of winter wheat under different irrigation treatments ranging from rainfed to four irrigation applications (full irrigation) using historical weather data from crop seasons over 33 years (1981–2014).  The data were classified into three types according to seasonal precipitation: <100 mm, 100–140 mm, and >140 mm.  Our results showed that the grain and biomass yield, harvest index (HI) and WUE responses to irrigation management were influenced by precipitation among years, whereby yield increased with higher precipitation.  Scenario simulation analysis also showed that two irrigation applications of 75 mm each at the jointing stage and anthesis stage (T3) resulted in the highest grain yield and WUE among the irrigation treatments.  Meanwhile, productivity in this treatment remained stable through different precipitation levels among years.  One irrigation at the jointing stage (T1) improved grain yield compared to the rainfed treatment and resulted in yield values near those of T3, especially when precipitation was higher.  These results indicate that T3 is the most suitable irrigation strategy under variable precipitation regimes for stable yield of winter wheat with maximum water savings in the NCP.  The application of one irrigation at the jointing stage may also serve as an alternative irrigation strategy for further reducing irrigation for sustainable water resources management in this area.
    Yield and water use responses of winter wheat to irrigation and nitrogen application in the North China Plain
    ZHANG Ming-ming, DONG Bao-di, QIAO Yun-zhou, SHI Chang-hai, YANG Hong, WANG Ya-kai, LIU Meng-yu
    2018, 17(05): 1194-1206.  DOI: 10.1016/S2095-3119(17)61883-5
    Abstract ( )   PDF in ScienceDirect  
    With increasing water shortage resources and extravagant nitrogen application, there is an urgent need to optimize irrigation regimes and nitrogen management for winter wheat (Triticum aestivum L.) in the North China Plain (NCP).  A 4-year field experiment was conducted to evaluate the effect of three irrigation levels (W1, irrigation once at jointing stage; W2, irrigation once at jointing and once at heading stage; W3, irrigation once at jointing, once at heading, and once at filling stage; 60 mm each irrigation) and four N fertilizer rates (N0, 0; N1, 100 kg N ha−1; N2, 200 kg N ha−1; N3, 300 kg N ha−1) on wheat yield, water use efficiency, fertilizer agronomic efficiency, and economic benefits.  The results showed that wheat yield under W2 condition was similar to that under W3, and greater than that under W1 at the same nitrogen level.  Yield with the N1 treatment was higher than that with the N0 treatment, but not significantly different from that obtained with the N2 and N3 treatments.  The W2N1 treatment resulted in the highest water use and fertilizer agronomic efficiencies.  Compared with local traditional practice (W3N3), the net income and output-input ratio of W2N1 were greater by 12.3 and 19.5%, respectively.  These findings suggest that two irrigation events of 60 mm each coupled with application of 100 kg N ha−1 is sufficient to provide a high wheat yield during drought growing seasons in the NCP. 
    Short Communication
    Detection and characterization of an isolate of Tomato mottle mosaic virus infecting tomato in China
    ZHAN Bin-hui, CAO Ning, WANG Kai-na, ZHOU Xue-ping
    2018, 17(05): 1207-1212.  DOI: 10.1016/S2095-3119(17)61895-1
    Abstract ( )   PDF in ScienceDirect  
    Tomato (Solanum lycopersicum) plants exhibiting severe leaf distortion, mottle and systemic crinkling symptoms were identified in Hainan province in China in 2016.  To survey and control the disease, it is necessary to identify and characterize the pathogen causing the disease.  Dot enzyme-linked immunosorbent assay showed that the crude saps of the infected tomato samples reacted positively with the monoclonal antibody against Tobacco mosaic virus which indicated that one or more tobamoviruses are likely associated with the disease.  RT-PCR and DNA sequence analysis results further elucidated that Tomato mottle mosaic virus (ToMMV) in Tobamovirus was the pathogen causing the mottle disease in tomato.  We amplified and sequenced the full-length sequence of the genome which showed the highest nucleotide identity with ToMMV YYMLJ and ToMMV TiLhaLJ isolates.  The putative virus isolate was named ToMMV Hainan.  Biological indexing studies showed that ToMMV Hainan can infect Nicotiana benthamiana, Capsicum annuum and Solanum lycopersicum showing serious symptoms.  This was the first identification and characterization of ToMMV infecting tomato in Hainan of China.