辣椒CaWRKY8基因克隆及胁迫下的表达分析

为了揭示辣椒WRKY基因功能,以辣椒PI201234为实验材料,克隆得到WRKY基因全长1 647bp的cDNA序列,命名为CaWRKY8。生物信息学分析表明,该基因含有一个1 647bp完整开放阅读框(ORF),编码548个氨基酸残基。氨基酸序列分析显示,CaWRKY8编码的蛋白含有2个WRKY结构域,属于Group I。氨基酸序列比对结果表明,CaWRKY8与辣椒WRKY25、马铃薯WRKY、番茄基因组中预测的WRKY26、烟草基因组中预测的WRKY33和猕猴桃WRKY的氨基酸序列之间均具有高度的保守性。实时荧光定量分析表明,CaWRKY8受盐、高温、干旱和辣椒疫霉菌诱导表达;其中CaWRKY8的表达量在盐和干旱处理下3h达到峰值,分别是对照的2.38倍和121.10倍,在高温和疫霉菌处理下12h达到峰值,分别是对照的6.12和6.81倍。以上研究结果表明,CaWRKY8基因在辣椒响应胁迫进程中发挥着重要作用。

Cloning and Expression Analysis of CaWRKY8 Gene in Pepper under Stress

In order to reveal the function of WRKY gene in pepper, we cloned the full length 1 647 bp cDNA of WRKY gene from pepper PI201234 and named as CaWRKY8. Bioinformatics analysis indicated that the gene contains a 1 647 bp complete open reading frame (ORF) box encoding 548 amino acid residues. Amino acid sequence analysis revealed that the CaWRKY8 encoded protein contains two WRKY domains belonging to Group I. The amino acid sequence alignment showed that there was a high degree of conservation between CaWRKY8 and the amino acid sequences of pepper WRKY25, potato WRKY, tomato predicted WRKY26, tobacco predicted WRKY33 and kiwi WRKY. Real time fluorescence quantitative analysis showed that CaWRKY8 was induced by salt, high temperature, drought and Phytophthora capsici, and CaWRKY8 peaked at 3 h under salt and drought treatments by 2.38 and 121.10 times of control, respectively. Under high temperature and P. capsici treatment, the peak reached at 12 h, which was 6.12 and 6.81 times of the control, respectively. The above results indicate that CaWRKY8 played an important role in the response of pepper to stress.