野油菜黄单胞菌群体感应信号DSF生物合成途径和机理研究

项目名称： 野油菜黄单胞菌群体感应信号DSF生物合成途径和机理研究

项目编号： No.31471743

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 农业科学

项目作者： 何亚文

作者单位： 上海交通大学

项目金额： 85万元

中文摘要： 黄单胞菌是一类重要植物病原细菌，DSF是黄单胞菌产生和分泌的一类新型群体感应信号。DSF信号依赖的群体感应机制是调控黄单胞菌致病因子表达的重要方式，目前，DSF信号的生物合成途径和机理还不清楚。本项目以野油菜黄单胞菌为模式菌株，研究内容包括：（1）研究DSF生物合成所需的关键酶RpfF的生化功能、酶活性和结构，揭示RpfF合成DSF的催化机理；（2）通过比较基因组学和突变与功能分析等方法，揭示更多参与DSF生物合成的基因，建立DSF生物合成途径，进一步体外重建DSF生物合成途径；研究DSF生物合成的起始原料；（3）以DSF生物合成关键酶RpfF为药物设计靶标，建立高通量筛选平台，从化合物文库中筛选或通过计算机分子模拟设计DSF生物合成抑制剂，淬灭群体感应机制。本项目的目标是揭示DSF生物合成途径和机制，预期成果有助于阐明黄单胞菌致病机理，为进一步研发高效、特异的新一代绿色农药奠定基础。

中文关键词： 野油菜黄单胞菌；群体感应；DSF信号；生物合成途径；致病性

英文摘要： The genus Xanthomonas is one of the most important phytopathogens.Members of this genus have been shown to infect more than 400 plant species, including those agriculturally important crops, such as rice, cotton, soybean, etc. DSF (Diffusible signal factor)is a novel quorum sensing signal identified in Xanthomonas. DSF-dependent quorum sensing is one of the most importatn mechanism to control virulence in Xanthomonas. Over the last ten years, we have elucidated DSF's chemical structure, DSF signaling pathway and the autoinduction mechanism in DSF biosynthesis. In this proposal, we set out to investigate three important and interesting questions using the model bacterial strain Xanthomonas campestris pv. campestris, a causal agent of black rot in crucifers:(1)to characterize the enzymatic activity and catalytic mechanism of RpfF, which is essential for DSF biosynthesis;(2)to establish DSF biosynthetic pathway through comparative genomics and bioinformatic analysis, deletion analysis of all the putative genes involved in long-chain fatty acid biosynthesis;to reconstruct DSF biosynthetic reaction in vitro; (3)to establish highthroughput screening system based on RpfF's 3-D structure or the DSF-overproduction strain to find specific inhibitors for DSF biosynthesis. Unraveling how DSF is synthesized in Xanthomonas is essential to not only understand the pathogenesis of the phytopathogen, but also to facilitate the discovery of novel methods or biopesticides to effectively control Xanthomonas infection.

英文关键词： Xanthomonas campestris pv.campestris;Quorum sensing;DSF;Biosynthetic pathway;Virulence