DRM1/2、CMT3调节植物PTI信号通路的分子机制研究

Pathogen-associated molecular patterns (PAMPs) are recognized by host cell surface-localized pattern-recognition receptors (PRRs) to activate plant immunity. PAMP-triggered immunity (PTI) plays a vital role in the resistance of plants to numerous potential pathogens. Plant DRM1/2 and CMT3 methyltransferase are responsible for methylation at non-CG sites, which plays an important role in the regulation of functional gene. Our preliminary analysis indicates DRM1/2 and CMT3 involved in regulating early PTI signaling, drm1-2 drm2-2 cmt3-11（ddc）triple mutant showed reduced resistance to avirulent bacteria. In this program, we plan to detect the accumulation of small RNA, mRNA and DNA methylation level in water- or avirulent bacteria-treated wild type and ddc mutant; based on these data to identify the target sites of DRM1/2 and CMTs and to analyze the relationship between DNA methylation and small RNA in these sites. We will then investigate the methylation status of these sites and the expression patterns of the neighboring disease resistance related genes, some of which will be further tested for their function in PTI pathway. This project will firstly reveal the function of DNA methylation in regulating PTI pathway and provide great insights into the regulation mechanism of PTI pathway.

PAMPs 诱导的免疫反应（PTI）在植物抵御病原菌侵染过程中发挥重要作用，研究PTI信号通路的调节机制为有效提高植物抗病性提供理论依据。前期研究工作表明，催化DNA甲基化修饰的关键蛋白DRM1/2和CMT3调节植物PTI信号通路的早期防卫反应，drm1-2 drm2-2 cmt3-11（ddc）三突变体对非毒性细菌的抗性降低。本项目利用高通量测序检测非毒性细菌侵染条件下野生型和ddc突变体中small RNA、mRNA的积累水平及DNA甲基化程度；明确DRM1/2和CMT3调控的靶位点；研究small RNA在维持靶位点DNA甲基化中的作用；阐明靶位点DNA甲基化水平与邻近抗病相关基因表达的关系；验证部分候选基因的抗病功能。本课题首次揭示DNA甲基化调节植物PTI信号通路的作用机制，为深入理解植物PTI信号通路的调节机制提供重要依据。。