苦荞VQ基因家族的全基因组鉴定及其在叶斑病原与激素处理下的表达谱分析  

Genome-Wide Identification of VQ Gene Family in Fagopyrum tataricum and Its Expression Profiles in Response to Leaf Spot Pathogens

作　　者：郑逢盛 王海华[1,2] 邬清韬 申权 田建红 彭喜旭 唐新科[1,3] ZHENG FengSheng;WANG HaiHua;WU QingTao;SHEN Quan;TIAN JianHong;PENG XiXu;TANG XinKe(School of Life Science,Hunan University of Science and Technology,Xiangtan 411201,Hunan;Key Laboratory of Genetic Improvement and Multiple Utilization of Economic Crops in Hunan Province,Xiangtan 411201,Hunan;Key Laboratory of Ecological Remediation and Safe Utilization of Heavy Metal-polluted Soils,College of Hunan Province,Xiangtan 411201,Hunan)

机构地区：[1]湖南科技大学生命科学学院,湖南湘潭411201 [2]经济作物遗传改良与综合利用湖南省重点实验室,湖南湘潭411201 [3]重金属污染生态土壤修复与安全利用湖南省高校重点实验室,湖南湘潭411201

出　　处：《中国农业科学》2021年第19期4048-4060,共13页Scientia Agricultura Sinica

基　　金：国家重点研发计划(2017YFE0117600);湖南省教育厅重点科研项目(19A176)。

摘　　要：【目的】VQ基因家族在植物生长、发育以及对生物或非生物胁迫反应中发挥重要功能。在全基因组尺度上,全面鉴定苦荞(Fagopyrum tataricum L.Gaertn.)VQ(FtVQ)基因家族,分析其在苦荞叶斑病原——互格链格孢(Alternaria alternata)和黑孢霉(Nigrospora osmanthi)侵染和防御相关激素——水杨酸(SA)、茉莉酸(JA)、乙烯(ET)处理下的表达模式,为深入解析苦荞VQ基因家族在植物抗病防御中的功能及机理奠定基础,同时为优良基因资源发掘及抗病品种改良提供线索。【方法】基于VQ保守结构域的隐马尔可夫文件(PF05678),采用HMMER 3.0对苦荞平苦一号基因组数据库进行比对搜索,鉴定VQ基因;通过DNAMAN、MapInspect、MEGA、MEME、OrthoFinder、PLACE等生物信息学工具分析基因结构、染色体分布、启动子顺式元件、蛋白质理化性质、蛋白质保守基序、蛋白质亚细胞定位和蛋白质系统进化关系;采用实时荧光定量PCR(qPCR)方法分析苦荞叶VQ基因在病原侵染或激素处理下的表达模式。【结果】从苦荞基因组中鉴定获得28个VQ基因,大小为566—1454 bp,均无内含子,不均一地分布在8条染色体上。根据它们在染色体上的物理位置,命名为FtVQ1—FtVQ28。每一个FtVQ蛋白含有1个VQ基序——FxxxVQx(L/F/I/V/A/Y)TG(x代表任意氨基酸)。亚细胞定位预测表明,21个FtVQ蛋白定位在细胞核中,其余定位在叶绿体或细胞质中。根据蛋白质氨基酸序列与保守结构基序,FtVQ蛋白归类于5个亚家族,亚家族内基因结构和蛋白质基序相对保守。基因重复分析表明,苦荞基因组中有8对VQ旁系同源基因,均为大片段重复基因,提示大片段基因重复在FtVQ基因家族数量扩张中发挥主要作用;它们的非同义突变和同义突变的比值(Ka/Ks)均小于1,提示重复基因在进化中经历了纯化选择。启动子顺式元件预测表明,所有FtVQ基因启动子含有BIHD1OS、CGTCA、ERELEA4、W-box和类W-b【Objective】VQ gene family plays important roles in plant growth,development and responses to biotic or abiotic stress.The aim of this study is to comprehensively identify Fagopyrum tataricum L.Gaertn.VQ(FtVQ)gene family on genome-wide scale and analyze its expression profiles under challenge of leaf spot pathogens Alternaria.alternata and Nigrospora osmanthi,and treatment of defense-related hormones,such as salicylic acid(SA),jasmonic acid(JA)and ethylene(ET),thus providing a solid foundation not only for further elucidation possible roles of members of the VQ genes in defense response to leaf spot pathogens and underlying mechanisms in tartary buckwheat,but also for mining gene resources of breeding for crop disease resistance.【Method】Based on the Hidden Markov Model profile of the conserved VQ domain(PF05678),HMMER 3.0 software was used to identify FtVQ genes from F.tataricum cv.Pinku1 genome database.Bioinformatic tools such as DNAMAN,MapInspect,MEGA,MEME,OrthoFinder and PLACE were used to analyze gene structure,chromosomal location of genes,cis-elements of gene promoters,physicochemical properties of proteins,conserved motifs of proteins,subcellular localization of proteins,and phylogenetic relationships.Quantitative real-time PCR(qPCR)was employed to analyze the expression profiles of leaf FtVQ genes of tartary buckwheat plants under infection of the pathogens and treatment of the hormones.【Result】A total of 28 VQ genes were identified in the genomes of tartary buckwheat,with the gene size ranging from 566 to 1454 bp.The FtVQ genes contain no introns,and distribute unevenly on chromosomes 1-8.According to their physical locations on the chromosomes,the FtVQ genes were named from FtVQ1 to FtVQ28.Each of the FtVQ proteins has a highly conserved VQ motif FxxxVQx(L/F/I/V/A/Y)TG,where x represents any amino acid.Analysis of subcellular localization showed that 21 FtVQ proteins were predicted to the nucleus,and the others to the chloroplasts or cytoplasm.Based upon their amino acid sequence and presenc

关 键 词：苦荞 VQ基因家族 互格链格孢叶斑病 黑孢霉叶斑病 防御相关激素 

分 类 号：S435.17[农业科学—农业昆虫与害虫防治]