二穗短柄草WRKY基因家族成员的鉴定和分析

Genome-wide Identification and Analysis of WRKY Gene Family Members from Brachypodium distachyon

WRKY转录因子以基因家族形式存在,在植物生长、发育和逆境反应中起着重要作用。二穗短柄草是大麦、小麦和禾本科牧草的模式植物,为了给基因表达和功能鉴定奠定基础,本研究利用生物信息学方法鉴定和分析其WRKY转录因子。结果表明,二穗短柄草有76个WRKY基因,它们具有0～6个内含子,编码区全长396～2 847 bp,基因分布在5条染色体上;进化分析结果表明,二穗短柄草WRKY在系统发生树上聚为3组,分属于I、II和III类转录因子;核心序列除WRKYGQK外,还有WKKYGQK、WRKYGKK、WRKY-GEK、WRKYGQT和WKKYGPK等多种变异类型;锌指模体也存在多种变异,它们是C-X4-C-X21-H-X1-H、C-X3-C-X22-H-X1-H、C-X7-C-X28-H-X1-C、C-X7-C-X24-H-X1-C、C-X7-C-X26-H-X1-C、C-X6-C-X24-H-X1-C、C-X7-C-X33-H-X1-C、C-X6-C-X32-H-X1-C和C-X7-C-X32-H-X1-C。

WRKY transcription factors belong to a gene family,and play important roles in plant growth,development as well as stress responses.Brachypodium distachyonacts as a model plant for Hordeum vulgare,Triticum aestivum and Gramineae grasses.To provide a basis for gene expression and functional characterization of genes,bioinformatic techniques were performed to identify WRKY transcription factors.Results indicated that there were 76 WRKY genes in B.distachyon with 0～6 introns.The coding sequences were 396～2 847 bp in length,and the genes distributed in 5 different chromosomes.Phylogenetic analysis revealed that the WRKYs were clustered into 3 groups and they belonged to I,II and III transcription factors,respectively.Besides WRKYGQK,several core sequence variants as WKKYGQK,WRKYGKK,WRKYGEK,WRKYGQT and WKKYGPK were identified.Mutations in zinc finger motifs were also observed,the variants included C-X4-C-X21-H-X1-H,C-X3-C-X22-H-X1-H,C-X7-C-X28-H-X1-C,C-X7-C-X24-H-X1-C,C-X7-C-X26-H-X1-C,C-X6-C-X24-H-X1-C,C-X7-C-X33-H-X1-C,C-X6-C-X32-H-X1-C and C-X7-C-X32-H-X1-C.