Abstract:

WRKY is a superfamily of transcription factors in high plant. It involves in plant stress responses of biotic and abiotic and is key regulatory component of plant responses to microbial infection. Arabidopsis thaliana WRKY28 transcription factor contain one WRKYGQK domain and one Cys2His2 zinc-finger motifs, which is classified as a group IId WRKY protein. To elucidate the role of the WRKY28 proteins in the regulation of A. thaliana defense responses of pathogen, we generated transgenic A. thaliana that express their cDNAs under the control of CaMV35S promoter plant and antisense suppression of WRKY28 plant. After inoculation with Alternaria brassicicola, we found that the antisense suppression of WRKY28 plants was substantially more susceptible to necrotrophic fungal pathogens A. brassicicola than wild-type plants, on the contrast, transgenic overexpression of WRKY28 plants enhanced resistance to A. brassicicola. Thus, pathogen-induced WRKY28 transcription factor plays a positive role in plants defense responses to A. brassicicola.

Key words: Arabidopsis thaliana, WRKY transcription factor, Alternaria brassicicola

摘要：

WRKY是植物特有的一类转录因子,是一个超级大家族,与植物多种逆境胁迫应答密切相关,在植物防御病原菌的侵染中发挥十分重要的作用。拟南芥转录因子WRKY28属于WRKY家族的成员,包括一个WRKYGQK核心序列和一个Cys2His2锌指型结构。为了鉴定拟南芥WRKY28的功能,构建了反义抑制表达株系和转基因过表达株系并进行抗病性鉴定。研究表明,反义抑制表达株系降低了对腐生型真菌甘蓝链格孢菌(Alternaria brassicicola)的抗性,而转基因过表达株系提高了对甘蓝链格孢菌的抗性。由此可见,转录因子WRKY28参与了拟南芥对甘蓝链格孢菌的免疫应答,是其抗病反应中的一个正调控因子。

关键词: 拟南芥;WRKY转录因子;甘蓝链格孢菌