组蛋白去甲基化酶 BcJar1调控植物灰霉病菌发育及致病机理研究

Plant gray mold, caused by Botrytis cinerea, seriously threatens the sustainable development of vegetable, fruit, wine and other industries and annually results in enormous economic losses. The evolutionarily conserved histone H3K4 demethylase, JARID1B/Jar1, is an important epigenetic modification enzyme that activates the expression of phenotype-related genes by regulating H3K4 methylation level in cells to better adjust itself to the growth and development or to adaptation of the changing environment. JARID1B is highly expressed in many human malignant tumor cells and is a potential drug target for treatment. However, at present, the function of B. cinerea BcJar1 and its molecular mechanism of regulating the pathogen development and pathogenicity remain to be a mystery. Our findings demonstrate that BcJar1 is involved in regulation of the pathogen growth, stress adaptation and pathogenicity. Here, employing the plant gray mold pathogen B. cinerea as a model necrotrophic plant fungal pathogen, we propose to systematically investigate the roles of BcJar1 in B. cinerea development, stress adaptation and pathogenicity. By using multiple state-of-the-art techniques such as gene knockout, methylation detection at different sites of H3K4, immunofluorescence confocal microscopy, transcriptome and proteomic data analysis, etc., we aim to: 1) clarify biological functions of BcJar1; 2) elucidate mechanisms by which BcJar1 regulates the development, stress adaptation and host infections of the pathogen; 3) provide new insights into our understanding of molecular mechanisms of B. cinerea pathogenesis, the development of new strategy for controlling plant fungal diseases and a new avenue for powerful fungicide development. The featured research thoughts and contents in this proposal are highly innovative.

植物灰霉病严重威胁果蔬、葡萄酒等产业的可持续发展，给人类造成巨大的经济损失。组蛋白H3K4去甲基化酶JARID1B/Jar1是一种重要的表观遗传修饰酶，生物体通过调控细胞H3K4甲基化水平激活/抑制相关基因表达，以更好地调整自身生长发育或适应环境变化。JARID1B是人类恶性肿瘤潜在的药物靶标。灰霉菌BcJar1的功能及其调控病原发育和致病机制仍是个迷。项目组研究发现BcJar1参与灰霉菌生长发育，胁迫适应和致病过程。我们拟通过基因敲除、H3K4不同位点甲基化水平检测、免疫荧光共聚焦显微分析、转录组和蛋白组分析等综合技术，研究植物灰霉菌BcJar1的功能及其调控病原发育、胁迫适应和致病的机理；阐明BcJar1调控灰霉菌附着胞/侵染垫形成及致病过程的分子机理，揭示病原真菌致病的内在本质，为制定植物真菌病害防控提供全新的思路和为研制新型杀菌剂提供理论依据和潜在作用靶标。项目特色鲜明，创新性强。

由灰葡萄孢或灰霉菌侵染引起的植物灰霉病是一种世界性的真菌病害。灰霉菌可侵染1,000多种植物，严重严重威胁果蔬、葡萄酒等产业的可持续发展，给人类造成巨大的经济损失。组蛋白H3K4去甲基化酶JARID1B/Jar1是一种重要的表观遗传修饰酶，生物体通过调控细胞H3K4甲基化水平激活/抑制相关基因表达，以更好地调整自身生长发育或适应环境变化。JARID1B是人类恶性肿瘤潜在的药物靶标。我们对灰霉菌BcJar1的功能及其调控病原发育和致病机制知之甚少。项目组通过基因敲除、H3K4不同位点甲基化水平检测、免疫荧光共聚焦显微分析、转录/蛋白组分析等综合技术展开相关研究。研究发现：BcJar1在营养生长和致病发育过程中分别调节H3K4me3 以及H3K4me2 和H3K4me3 甲基化水平。缺失BcJAR1损害灰霉菌产孢、附着胞(AP)形成和胁迫适应；使基因缺失突变体ΔBcjar1侵染垫(IC)形成和致病力丧失，但却促进菌核产生。BcJar1通过控制活性氧(ROS)的产生和核心隔膜蛋白及毒力决定因子Sep4的正确组装以启动感染结构(IFS)形成和寄主侵入。外源cAMP部分恢复突变体AP但不恢复IC形成能力。基因/蛋白互作研究发现BcJar1协调ROS产生、应激反应、碳水化合物跨膜转运、次级代谢产物等致病相关基因的全局表达，这可能是灰霉菌致病相关发育、寄主侵入和致病/毒力所必需的。项目还系统研究并阐明了受BcJar1调控的灰霉病菌Bchbf1、Bccgf1和Bcccyp2等基因的功能及调控病原致病机理。总之，项目系统地阐明了BcJar1的功能、调控全局基因表达及病原致病机制，为Jar1/KDM5介导的H3K4去甲基化在调节真菌发育和发病机制方面提供了新的见解，为制定植物真菌病害防控提供全新的思路和为研制新型杀菌剂提供理论依据和潜在作用靶标。因此，项目实施具有重要的科学和实践意义。