茶树WRKY转录因子基因CsWRKY57的克隆及表达分析

Cloning and Expression Analysis of WRKY Transcription Factor Gene CsWRKY57 in Tea Plant(Camellia sinensis)

WRKY转录因子是植物特有的一类转录因子,在植物生长发育及胁迫应答过程中均发挥重要的调控作用。为探究WRKY转录因子与茶树抗旱及耐盐性的关系,本研究基于茶树转录组数据库中的检索结果,以陕茶1号1年生茶树为试验材料,克隆获得了1个WRKY转录因子基因,命名为CsWRKY57。生物信息学分析表明,CsWRKY57基因cDNA全长为1 222 bp,编码303个氨基酸,预测分子量为33.5 kD,理论等电点为5.49;另外,蛋白比对分析显示,CsWRKY57包含1个典型的WRKY核心序列和1个C2H2型锌指结构,属于WRKYIIc家族。实时荧光定量PCR分析结果显示,CsWRKY57基因在高盐、干旱、ABA胁迫下均被诱导表达,且表现出先增加后降低的趋势,表明CsWRKY57基因参与了茶树体内干旱、高盐和ABA的调控途径。转录激活活性试验表明,CsWRKY57无转录激活活性,意味着CsWRKY57可能需要与其他元件结合才能启动基因的表达。

The WRKY is one of the characteristic transcription factors in plants,which play important roles in plant growth,development and stress regulation.In order to study the relationship between WRKY transcription factors and stress tolerance of tea plant(Camellia sinensis),a WRKY transcription factor was cloned from tea cultivar'Shanchayihao'and named CsWRKY57,based on the searching result of tea plant transcriptome database.Bioinformatics analysis showed that the full-length sequences of CsWRKY57was1222bp encoding303amino acids.The molecular weight of CsWRKY57was33.5kD and theoretical isoelectric point was5.49.The BLAST results showed that CsWRKY57contained one typical WRKY domain and one zinc finger motif(C2H2),suggesting that it was a member of the WRKYIIc family.In addition,quantitative real-time PCR(qRT-PCR)analysis showed that the expression of CsWRKY57was induced by salt,drought and ABA stresses,and showed a tendency to increase first and then decrease,which implies that CsWRKY57is involved in the process of tea plant responses to salt,drought and ABA.Furthermore,transcriptional activation activity assays indicated that CsWRKY57didn't have transcriptional activation activity,which means that CsWRKY57may be needed to combine with other elements to activate gene expression.