水稻WRKY转录因子OsWRKY71的cDNA分离和表达分析

Isolation and expression analysis of Os WRKY71 transcription factor in rice

WRKY蛋白是植物中最大的转录因子家族之一,对植物的生长发育具有重要调控作用。利用SMART-RACE-PCR技术分离获得水稻WRKY转录因子基因(Os WRKY71)的全长c DNA序列,并进行了相关的生物信息学分析。分离到的水稻WRKY转录因子c DNA全长为1 245 bp(Gen Bank登录号KJ137000),开放阅读框1 047 bp,编码348个氨基酸,分子量为38.28 k Da,Os WRKY71具有WRKY转录因子家族典型的保守结构域,属于第Ⅱ组WRKY蛋白家族。系统进化分析表明,Os WRKY71氨基酸序列与禾本科作物小麦的亲缘关系最近,其中与小麦序列相似性为69%,和大麦的序列相似性为68%。荧光定量PCR检测表明,OsWRKY71在孕穗期剑叶中表达丰度最高,根中最低,具有表达的空间差异性。抗病品种‘IR28’在受到稻曲菌诱导的初期,Os WRKY71基因表达呈现先升高后下降趋势,易感品种‘甬优9号’在受到稻曲菌诱导后表达受到抑制。这些结果表明,Os WRKY71的表达对稻曲菌侵染有应答响应,很可能在水稻防御稻曲菌侵染的机制中发挥作用。

Proteins of WRKY family, one of the largest families of transcription factors, play an important role in regulation of plant growth and development. In this study ,The full length eDNA sequence of OsWRKY71 gene was cloned by SMART-RACE-PCR from rice （ Oryza sativa L. ） , which was named as OsWY71 （ GenBank Accession No. KJ137000）. The full length cDNA of OsWRKY71 is 1 245 bp,which includes 1 047 bp complete CDS and encodes 348 amino acid residues with a putative molecular mass of 38. 28 kDa. The bioinformatics characterization indicated that the protein encoded by OsWRKY71 gene has a typically conserved domain structure of WRKY family, and it shared 69% amino acid sequences similarity with WRKYs of wheat. It shared over 68% amino acid sequences similarity with WRKYs of barley. The results of quantitative real-time PCR（qRT-PCR） showed that the highest expression level appeared in flag leaf at heading stage. The lowest expression level appeared in root. The expression of Os- WRKYT1 was up-regulated at first and then down-regulated when the resistant line IR28 was inoculated with Ustilag# noidea viren, and expression was suppressed in the infectious line Yongyou 9. These results implied that OsWRKYT1 was a pathogen-responsive gene and might play an important role iu rice pathogen resistance.