玉米WRKY基因功能分析

Functional analysis for maize WRKY gene

【目的】分析WRKY基因在玉米生长发育及逆境胁迫下的功能,为阐明WRKY家族基因在玉米生长和逆境响应机制中的功能和作用打下基础。【方法】利用生物信息学技术从玉米基因组中得到3个进化关系较近的WRKY基因,应用在线预测软件对3个基因的功能和结构进行分析,并运用荧光定量RT-PCR(qRT-PCR)分析3个基因在玉米不同组织及在高盐、低温和干旱胁迫下的表达模式。【结果】从玉米基因组中得到ZmWRKY22-like、ZmWRKY55-like和ZmWRKY74-like 3个玉米WRKY转录因子家族基因,预测表明3个蛋白均定位于细胞核。荧光定量PCR分析结果表明,3个基因在玉米的不同器官中均有表达,但具有组织表达特异性。高盐处理24 h,ZmWRKY55-like基因的表达量上升为对照的4.5倍;低温处理24 h,ZmWRKY74-like基因的表达量上升为对照的2.1倍。【结论】ZmWRKY22-like、ZmWRKY55-like和ZmWRKY74-like基因可能在玉米果实发育过程中起到一定作用,其中ZmWRKY55-like和ZmWRKY74-like基因可能分别参与植物对盐和低温胁迫的响应。

[Objective]The function of maize WRKY gene in growth and stress was studied, in order to lay a foundation for researching the function of WRKY family genes in the growth and response mechanisms of stress in maize. [Method]Three WRKY genes which showed a close evolutionships in maize genome were found by using bioinformatics technology. Meanwhile, the structure and function of those ZmWRKY genes were analyzed. In addition, the expression levels of ZmWRKY genes in different maize tissues and under high salt, low temperature and drought stress were analyzed by fluore-scence quantitative RT-PCR（qRT-PCR）. [Result]Three WRKY transcription factor genes（ZmWRKY22-like,ZmWRKY55-like and ZmWRKY74-like） in maize were identified. It was predicted that these three proteins were all localized in nucleus. Fluorescence quantitative PCR assay showed that ZmWRKY22-like,ZmWRKY55-like and ZmWRKY74-like expressed in all tested maize tissues and had differential expressions. The expression of ZmWRKY55-like was up-regulated about 4.5 times under high salinity treatment for 24 h and that of ZmWRKY74-like was up-regulated about 2.1 times under low temperature stress. [Conclusion]ZmWRKY22-like, ZmWRKY55-like and ZmWRKY74-like genes might play a role in maize fruit growth. ZmWRKY55-like and ZmWRKY74-like may be involved into plant response to salt and low temperature stress respectively.