土壤因子对芽孢杆菌抗菌物质合成及其基因表达的影响

项目名称： 土壤因子对芽孢杆菌抗菌物质合成及其基因表达的影响

项目编号： No.41471214

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 地质学

项目作者： 蔡燕飞

作者单位： 华南农业大学

项目金额： 90万元

中文摘要： 针对作物土传病害生物防治中田间效果不稳定等问题，本研究在已筛选生防芽孢杆菌(B1、B2等)的基础上，采用全基因组测序和定量PCR等方法分析各菌株的防病相关基因和基因簇，高效液相色谱-电喷雾-质谱(LC-ESI-MS)方法检测主要抗菌物质种类和浓度，核磁共振(NMR)方法鉴定未知抗菌物质的化学结构，以期明确各菌株的主要抗菌物质和抗菌相关基因。采用响应面设计，找出供试菌株的主要抗菌物质合成和基因表达的最佳培养条件。以香蕉枯萎病为试验材料，采用盆栽和田间试验，比较不同土壤因子(pH, 粘土矿物，团聚体等)和施用方法(有机肥配合、浸种和浇根等)处理下植株病情指数、土壤中抗菌物质浓度和基因表达量的动态变化规律，进一步确证能提高芽孢杆菌抗菌活性物质浓度及其功能基因表达量的主导土壤养分因子、环境因子及田间施用方法。研究将为深入理解芽孢杆菌生防分子机理和保障田间生防潜力高效稳定发挥提供理论依据。

中文关键词： 土壤微生物群落结构；土壤养分；土传病害；微生物基因组；微生物功能

英文摘要： Due to instability of biocontrol effect of microbial agents on crop soil-borne diseases, this study will use the screened Bacillus strains (B1, B2, et al) with efficient biocontrol effect to identify antibiotic gene and gene clusters by using whole genome sequencing and real-time quantitative PCR. Identification and quantification of antibiotic compounds will be determined by LC-ESI-MS, The structure of unknown antibiotic compounds will be identified by NMR. The best culture conditions of the strain for increasing gene expression and antibiotic production will be determined by using response surface method. The pot and field experiments of banana wilt will be used to get the dynamic variation rule of disease indexes of banana plant wilt, concentrations of antibiotic substances, and gene expression level under various soil factors (pH, clay mineral, aggregate), as well as application processes ,such as organic fertilization, seed soaking, soil watering and soil inoculation.In consequence, the main soil nutrients, environmental factors and inoculants application methods in the field that affect the synthesis of antibiotic substances and the expression of functional genes will be clarified. This study will elucidate modes of action of growth-promoting and antibiotic Bacillus strains, and provide theoretical foundation for stabilizing effects of potential biocontrol agents in the field.

英文关键词： soil microbial community;soil nutrient;soil-borne disease;microbial genome;microbial function