高粱茎点霉菌中防除红花酢浆草高活性物质的分离及机理研究

Herbicidal active phytotoxins from microbes with novel chemical structure and unique action site could be used as important sources for bioherbicide development and novel lead compound. Oxalis debilis is one kind of common malignant weed in sugarcane field and results in the serious reduction of sugarcane production. In our previous work, a highly pathogenic strain Phoma sorghina was isolated from infected Oxalis debilis and the diluents of its fermentation products exhibited strong herbicidal activity against Oxalis debilis. Based on the results, this project will do (i) systematical separation and purification of herbicidal active components by using activity tracking method, (ii) verification their biocontrol efficiency, (iii) identification of the monomer structure of active compound by high resolution mass spectrum and nuclear magnetic resonance, (iv) investigation of its herbicidal mechanism by physiologic, biochemical, and transcriptome sequencing methods. The research of this project will provide the theoretic basis for the development of new herbicide and the mining of new target. The expected results will promote the creating of new herbicide with independent intellectual property rights in China.

微生物产生的具有杀草活性的植物毒素，往往具有新颖的化学结构及独特的作用位点，是开发生物源除草剂及新颖先导化合物的重要来源。红花酢浆草是甘蔗田常见的恶性杂草之一，造成甘蔗严重减产。申请者前期从罹病的红花酢浆草上分离出高致病菌株高粱茎点霉菌，其发酵产物的稀释液对红花酢浆草具有很强的除草活性。本项目拟在前期工作的基础上，采用活性追踪、高分辨质谱和核磁共振、生理生化和转录组测序等方法和技术，分离纯化除草活性成分并验证其防除效果；鉴定高活性成分的单体结构；阐明高活性成分防除杂草的作用机理。预期本项目的研究结果将为新型除草剂的开发和新靶点的发现提供理论依据，促进我国具有自主知识产权新农药的创制。

红花酢浆草是甘蔗田一种恶性杂草，严重威胁到甘蔗的产量。微生物毒素经常具有新颖的化学结构及独特的作用位点，是开发生物源除草剂及新颖先导化合物的重要来源。本项目从红花酢浆草上分离出多生防真菌，采用柱层析法、制备液相等方法从高粱茎点酶发酵液中分离出多个化合物，经色谱、质谱、核磁等手段鉴定出8个化合物；采用顶空GC-MS的方法鉴定到7个挥发性化合物。对其中一些化合物进行了活性测试，结果表明2个具有较好的触杀活性，1个化合物具有抑制萌发的活性。通过生理生化分析推测部分化合物可能是破坏细胞膜抑制光合作用影响杂草生长。该项目发表论文4篇，申请专利5件，授权专利3件。