水稻基腐病菌Dickeya zeae中新型群体感应信号的结构与功能研究

Quorum sensing (QS) coordinates various bacterial pathogenicity. Previously, the AHL quorum sensing signals in Gram-negative bacteria were well studied. The Dickeya spp. is soft-rot Gram-negative bacteria that cause severe disease in a wide range of plant species. Recently study shows that Dickeya pathogenicity is clearly a multifactorial process, including a novel quorum sensing pathway that senses the bacterial metabolic status or environmental stresses. In this study, we aim to isolate and identify the quorum sensing signals vfm in Dickeya zeae EC1 stains. By the means of gene knock out, complementation and intermediates metabolite analysis, the vfm biosynthetic pathway will be elucidated. In addition, the functions of vfm in novel quorum sensing system and pathogenic processes will be studied in vivo and in vitro. The results will be helpful to discover novel quorum sensing system and utilize this system to control bacterial pathogenicity.

细菌的致病性与群体感应现象密切相关。过去对革兰氏阴性细菌群体感应系统的研究主要集中在高丝氨酸内酯类化合物（AHLs）介导的群体感应系统。Dickeya属细菌是一类革兰氏阴性致病菌，它能引起多种作物严重的病害，造成经济损失。本课题组最新研究发现，水稻基腐病菌Dickeya zeae EC1中存在一种新型的vfm群体感应系统。本项目拟在前期研究工作的基础上，运用化学方法对水稻基腐病细菌Dickeya zeae EC1中新型群体感应信号vfm进行分离和结构鉴定；用生物信息学和分子生物学的方法，鉴定vfm功能基因；通过基因敲除、功能互补、以及中间产物分离鉴定等技术，推导vfm信号的生物合成途径；结合活体和离体接种和分子生物学试验，揭示其在新型群体感应系统中的功能以及致病过程中的作用。研究结果将有助于阐明新的群体感应系统的功能，为防治细菌性植物病害提供方法和理论基础。

细菌的致病性与群体感应现象密切相关。过去对革兰氏阴性细菌群体感应系统的研究主要集中在高丝氨酸内酯类化合物（AHLs）介导的群体感应系统。Dickeya属细菌是一类革兰氏阴性致病菌，它能引起多种作物严重的病害，造成经济损失。本项目研究发现了水稻基腐病菌Dickeya zeae EC1中的一种新型的vfm群体感应系统，确定了vfm生物合成功能基因簇，同时推导了vfm信号的生物合成途径；通过基因敲除互补，蛋白互作等试验，构建了vfm新型群体感应系统的调控网络以及在水稻基腐病致病过程中的作用。本研究结果将有助于阐明新的群体感应系统的功能，为防治细菌性植物病害提供方法和理论基础。