具有抑菌作用的挥发性物质（volatile organic compounds，VOCs）是枯草芽孢杆菌产生的一类重要活性物质，可有效防治作物产中和产后病害。前期研究发现枯草芽孢杆菌BAB-1产生的挥发性物质对番茄灰霉菌的生长抑制作用很强，并可显著防治番茄叶部和果实灰霉病的发生。为明确BAB-1菌株挥发性物质中抑菌活性成份及各成分在防病过程中的地位，本项目通过GC-MS方法在明确挥发性物质成份的基础上，采用活体和离体评价方法确定主要挥发性抑菌物质；通过KEGG通径分析明确其活性成份的合成途径，结合BAB-1菌株全基因组序列分析，明确主要活性成份合成相关基因（目的基因）；通过对目的基因进行定位突变与互补分析，结合抑菌测定和防病试验，最终确定影响BAB-1菌株挥发性抑菌活性物质产生和调控的相关基因，为进一步明确该菌株的防病机制奠定理论基础，为目标菌株的定向遗传改良提供科学依据。

Volatile organic compounds (VOCs) which showed antifungal activities are a class of antifungal substances produced by Bacillus subtilis, which played a significant role in control of plant diseases. Previous studies showed that the VOCs produced by B. subtilis BAB-1 exhibited strong antagonistic activity toward Botrytis cinerea and effective control of tomato gray mold. In order to clarify the major antifungal substances of VOCs and the role of various components in the disease prevention, the composition of VOCs will be identified by GC-MS. The antifungal activity and the control effect against the disease of synthetic organic volatile standard substances will be evaluated in vitro and in vivo. The biosynthetic pathway of active compounds will be cleared through KEGG pathway analysis, and the synthesis-related genes of active compounds will be selected combined with analysis of complete genome sequence of strain BAB-1. The related genes which affect the production and regulation of VOCs will be finally determined by gene in-frame deletion and complementation of target genes combing with the inhibitory activity and disease prevention. The results of the project will help to understand antifungal mechanism and enhance genetic modification of strain BAB-1.