盾叶薯蓣WRKY转录因子的鉴定和生物信息学分析

Identification and bioinformatic analysis on rhizomes of Dioscorea zingiberensis WRKY transcription factor

目的鉴定盾叶薯蓣WRKY(DzWRKY)转录因子家族基因,分析DzWRKY蛋白的序列特征,检测DzWRKY在根和叶中的表达量。方法以拟南芥WRKY基因的c DNA为查询序列,应用BLASTn进行比对,应用生物信息学方法进行全长开放阅读框(ORF)预测和蛋白序列特征分析,根据转录组数据检测DzWRKY的表达量。结果共检测到27个具有全长ORF的DzWRKY家族基因,其中6个基因编码的蛋白具有2个WRKY结构域。DzWRKY蛋白均为亲水性蛋白,亚细胞预测为核蛋白,WRKY结构域序列保守程度高。进化分析均把27个DzWRKY蛋白和19个At WRKY蛋白分为3个大类群。27个DzWRKY在叶片中的表达量均比根茎低,高表达的DzWRKY基因主要集中在第I类和第IId亚类。盾叶薯蓣WRKY与已知功能的WRKY序列相似性较低。结论首次从盾叶薯蓣中鉴定出DzWRKY基因,为进一步阐明DzWRKY在盾叶薯蓣生长发育和药效成分代谢中的作用奠定基础。

Objective To identify WRKY genes from the rhizomes of Dioscorea zingiberensis and analyze the protein characteristics andexpression level of these genes. Methods The transcriptional EST database of the rhizomes of D.zingiberensis was used to search the analogs of AtWRKY genes by BLASTn, the full-length open reading frames （ORF） of DzWRKY and its protein characteristics were studied using bioinformatic method, and the expression levels of DzWRKY genes in rhizomes and leaves were detected from transcriptional data of the rhizomes of D. zingiberensis. Results Twenty-seven DzWRKY transcription factors family genes with full length ORF were isolated from the rhizomes of D. zingiberensis, and two WRKY domains were confirmed in six WRKY genes. All the DzWRKY proteins were predicted as hydrophilic proteins and nucleoproteins with highly conserved WRKY domains. The 27 DzWRKY and 19 AtWRKY proteins were divided into three groups by phylogenetic analysis. All DzWRKY genes showed higher expression level in the leaves compared to the rhizomes, and highly expressed genes were mainly in groups I and IId. DzWRKY proteins exhibited lower sequence identity. Conclusion The DzWRKY genes are successfully isolated for the first time, which would provide a reference for the study on the roles of WRKY in development and active components biosynthesis of the rhizomes ofD. zingiberensis.