茶树WRKY转录因子的鉴定与分析

Identification and Analysis of the WRKY Transcription Factor in Tea Plant

本研究以三个不同品种的茶树叶片转录组数据为材料,通过PAFM、SMART数据库对茶树WRKY转录因子进行严格搜索与鉴定,得到45个茶树WRKY转录因子,利用生物信息学的方法分析了茶树WRKY蛋白的一级结构性质、分类、系统发生学和保守结构域等特征。结果表明,茶树基因组至少存在45个以上的WRKY转录因子,氨基酸数在44~613之间,部分WRKY不稳定,约占11%;根据WRKY结构域的数量及锌指结构特征可将其分为GroupⅠ、GroupⅡ和GroupⅢ三大类,GroupⅡ可分成多个亚类,有部分成员的七肽保守域和锌指结构域发生了突变;三级结构显示,茶树WRKY蛋白保守结构域含5个β折叠。采用比较转录组学的方法研究了茶树WRKY转录因子的表达模式,结果表明,不同茶树品种间存在较多的差异WRKY基因,有的呈显著上调表达趋势,有的下调表达;该研究是茶树WRKY基因进化及功能研究的理论基础,对进一步揭示不同茶树品种间差异性状的形成机理和转录调控机制具有重要意义。

Transcriptional data of three diffierent varieties of tea leaves were used as materials, and 45 WRKY transcription factors were identified according to strict search and identification of PAFM and SMART online database in this study. We analyzed the primary structure, classification, phylogenetic relationship and conserved domain of WRKY protein using bioinformatics methods. The results showed that there were at least 45 WRKY transcription factors in tea plant genome, Cs WRKY proteins contained from 44~613 of amino acids; some proteins were unstable, which accounted for 11% of the Cs WRKY families. Cs WRKY could be classified into 3 groups according to the WRKY domain and zinc finger structure, Group Ⅱ could divided into several subfamilies, and the heptapeptide conserved domain and zinc finger domain of some members were mutated; The three-dimension structures showed the conserved domain of WRKY proteins contained 5 β-strands. The expression patterns of WRKY transcription factors in tea plant were studied by comparative transcriptome analysis. The results showed that there were many differences in WRKY gene among different tea varieties, many of them showed asignificantly up-regulated trend, others showed down-regulated. This study provides a foundation for function and evolution of WRKY genes in tea plant, and has a very significant meaning for step revealing transcriptional regulation mechanism of differential gene in different tea cultivars.