生防解淀粉芽孢杆菌CC09菌株环脂肽合成酶基因的转录调控机理研究

项目名称： 生防解淀粉芽孢杆菌CC09菌株环脂肽合成酶基因的转录调控机理研究

项目编号： No.31272081

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 农业科学

项目作者： 刘常宏

作者单位： 南京大学

项目金额： 78万元

中文摘要： 环脂肽(CLPs)是生防芽孢杆菌通过非核糖体肽合成酶催化合成的次生代谢物质，在防治植物病害过程中发挥着关键作用。虽然CLPs合成酶的生化性质和操纵子结构已比较清楚，但其转录调控机制至今尚未充分阐明。本项目以生防内生解淀粉芽孢杆菌CC09菌株为出发菌株，利用RNA聚合酶突变技术，制备一系列对CLPs(Iturin A和Surfactin)合成具有促进(正突变)和抑制(负突变)作用的突变菌株；以上述野生型和突变型菌株为材料，采用RNA聚合酶的体内和体外转录研究技术，研究CLPs合成酶基因的转录特性；通过芯片分析以及二维电泳等手段，分析不同生长阶段各菌株之间的转录组学和蛋白质组学差异，了解CLPs合成酶基因转录过程中存在的调控因子及其相互作用，揭示尚未知晓的解淀粉芽孢杆菌非核糖体合成CLPs的转录调控机制，并为研究其他微生物非核糖体合成抗生素的转录调控机理提供新思路和新方法。

中文关键词： 贝莱斯芽孢杆菌；环脂肽；转录调控；非核糖体肽合成酶；RNA聚合酶突变

英文摘要： Cyclic lipopeptides (CLPs) that are synthesized by nonribosomal synthetic pathway are a group of the important secondary metabolites, which play a key role in control of plant diseases. Although the biochemical and operon properties of CLPs synthetases are known relatively well, the transcriptional regulation mechanism of the synthetase genes is not understood yet. At the present project, a biocontrol endophytic strain of Bacillus amyloliquefaciens CC09 that was isolated from Cinnamomum camphora is used as a start strain to prepare a seris of RNA polynerase mutated mutants, which show both increase and decrease of CLPs (iturin A and surfactin) production by using the RNA polymerizing (RNAP) mutation technique. The wild type and the mutant strains are used as materials to study the transcriptional properties of CLPs synthetase encoding genes by in vitro and in vivo transcriptional detection methods. Meanwhile, DNA chips and 2-D electrophoresis techniques are used to analyze the transcriptomics and proteomics spectra of these test strains at different growth phases. All the regulators invoving CLPs synthetase transcription and their interation will be studied.The unknown transcriptional regulation mechanisms of CLPs in B. amyloliquefaciens CC09 will be disclosed by comparing all the data between wild strain and it

英文关键词： Bacillus velezensis；cyclic lipopeptides；transcriptional regulation；nonribosomal lipopeptide synthetases；RNA polymerase mutation