谷子WRKY转录因子对白发病菌胁迫的响应

WRKY Transcription Factor Response to Downy Mildew in Foxtail Millet

谷子白发病是谷子生产上的重要病害,可严重影响谷子的产量和品质。WRKY转录因子广泛参与植物的抗病,生长发育等多种生理过程。为了探究谷子WRKY转录因子对白发病菌胁迫的响应,进而发掘谷子特有的抗病基因并为以后的抗病研究提供参考,本研究以感病品种‘晋谷21’为试材,基于前期对转录组测序的基础上,筛选出8个与谷子白发病相关的WRKY转录因子基因,然后通过生物信息学技术,对这8个WRKY转录因子基因特征,基因序列及所在染色体位置,基因组结构模式启动子序列元件,与白发病菌相关的调控元件以及表达模式等进行了分析。研究发现,8个WRKY转录因子基因中5个基因分布在5号染色体上,在受白发病菌胁迫后其表达水平存在显著差异。启动子顺式元件分析的组成和分布也存在较大差异,8个基因的蛋白大小是202~440个氨基酸,系统进化树分析表明,基因Seita.8G123100,Seita.5G261700的亲缘关系较近,并且受侵染后的表达水平均高于正常水平。发现8个基因中5个基因在受到病原菌侵染时其表达水平高于其正常状态下的基因表达水平,可以作为谷子抗病的重要候选基因。本研究结果为后续筛选谷子抗病基因及谷子抗病机制的研究奠定了一定的理论基础。

The incidence of downy mildew is an important disease in the production of millet, which can seriously affect the yield and quality of millet. WRKY transcription factors are widely involved in various physiological processes such as plant stress resistance, growth and development. In order to explore the response of millet WRKY transcription factor to Sclerospora graminicola(Sacc.) Schroeter, the unique resistance genes of millet are explored and provide reference for future disease resistance research. In this study, the susceptible variety ’Jingu21’ was used as a test material and based on the previous sequencing of the transcriptome, 8 WRKY transcription factor genes related to the pathogenesis of Sclerospora graminicola(Sacc.) Schroeter were screened, and then these 8 WRKY were obtained through bioinformatics technology. Transcription factor gene characteristics, gene sequence and location of the chromosome, genomic structural model promoter sequence elements, regulatory elements related to white pathogens and expression patterns were analyzed. The study found that five of the four WRKY transcription factor genes are distributed on chromosome 5, and their expression levels are significantly different after stress from white-borne bacteria, and the composition and distribution of their promoter cis-elements are also quite different.The protein size of 8 genes is 202~440 amino acids. The phylogenetic tree analysis shows that the genetic relationship between Seita.8 G123100 and Seita.5 G261700 is relatively close, and the expression level after infection is higher than normal. It was found that 5 of the 8 genes were higher in expression level than those in their normal state when infected by pathogens, and could be used as an important candidate gene for millet disease resistance.The results of this study laid a theoretical foundation for the subsequent screening of the resistance genes of millet and the mechanism of resistance to millet.