陆地棉WRKYⅠ亚家族成员的鉴定与表达分析

Identification and Expression Analysis of Members of WRKYⅠSubfamily in Upland Cotton

WRKY转录因子参与植物生长发育以及胁迫响应等生命活动的调控。尽管棉花GhWRKY的研究已有报道,但有关GhWRKYⅠ亚家族成员的功能还知之甚少。研究聚焦陆地棉(Gossypium hirsutum)GhWRKYⅠ亚家族成员的全基因组鉴定,以期筛选到参与棉花种子萌发调控的GhWRKY成员;基于陆地棉基因组数据库,应用组学工具对陆地棉GhWRKYⅠ亚家族成员进行鉴定,分析基因结构、蛋白保守基序、保守结构域和蛋白理化性质以及进化关系;基于转录组数据分析GhWRKYⅠ成员在不同组织和5种非生物胁迫下的表达谱;定量PCR(qPCR)检测候选GhWRKY在发育种子的表达特性。结果表明,从陆地棉基因组共鉴定到35个GhWRKYⅠ亚家族基因,不均匀分布于A和D亚基因组的19条染色体上;GhWRKYⅠ蛋白由331~769个氨基酸组成,均为亲水性蛋白并定位于细胞核;GhWRKYⅠ亚家族基因具有3~6个外显子和2~5个内含子。GhWRKY3、GhWRKY6、GhWRKY7、GhWRKY11、GhWRKY12和GhWRKY15未检测到5'-UTR,其余29个GhWRKYⅠ亚家族基因则含有5'-UTR和3'-UTR。仅发现GhWRKY11蛋白C端WRKY保守结构域WRKYGQK序列突变为WRNYGQK,GhWRKYⅠ亚家族成员存在着3种不同的进化方向。转录组数据分析表明,GhWRKYⅠ家族成员在不同组织以及应对不同非生物胁迫呈现差异化表达模式。qPCR分析揭示,GhWRKY24在棉籽萌发72 h内持续上调表达,预示着GhWRKY24可能参与调控棉籽萌发过程。

WRKY transcription factors are involved in regulating multiple life activities including plant growth and development as well as stress responses.Although study on GhWRKY in cotton has been investigated,the knowledge of function of GhWRKYⅠsubfamily members is little.In this study,the genome-wide identification of GhWRKYⅠsubfamily members in upland cotton(Gossypium hirsutum)was focused,aiming to screen GhWRKY members involved in regulating cotton seed germination.Based on the upland cotton genome database,the“omics”tools were employed to identify the members of GhWRKYⅠsubfamily and to analysis their gene structures,protein conserved motifs,conserved domains,protein physicochemical properties,and evolutionary relationship.Expression profiles of GhWRKYⅠmembers in different tissues and five types of abiotic stresses were analyzed based on the transcriptome data.The expression patterns of candidate GhWRKYs were detected in developing cotton seeds by quantitative RT-PCR(qPCR).The results showed that a total of 35 GhWRKYⅠsubfamily genes were identified in upland cotton genome,which were unevenly distributed on 19 chromosomes in the A and D subgenomes.GhWRKYⅠproteins consisted of 331 to 769 amino acids,all of which were hydrophilic proteins and localized in the nucleus.The GhWRKYⅠsubfamily genes had 3-6 exons and 2-5 introns.The 5'-UTR was not detected in genes of GhWRKY3,GhWRKY6,GhWRKY7,GhWRKY11,GhWRKY12,and GhWRKY15 whereas both 5'-UTR and 3'-UTR were detected in the remaining 29 GhWRKYⅠgenes.Additionally,it was only detected in the GhWRKY11 protein that the WRKYGQK sequence in the C-terminal WRKY conserved domain mutated into WRNYGQK.There were three different evolutionary directions for members of the GhWRKYⅠsubfamily.Transcriptome data analysis showed that members of the GhWRKYⅠfamily members had different expressions in various tissues and in response to different abiotic stresses.The qPCR analysis revealed that GhWRKY24 expression was continuously upregulated within 72 h of cotton seed germination,indicating that GhWRKY24 might be involved in the regulation of cotton seed germination process.