基因组信息指导下烟草内生真菌1022LEF代谢产物多样性的挖掘及农用生物活性研究

植物内生真菌具有显著的次级代谢产物生产潜力，但编码合成这些代谢产物的基因簇在常规培养条件下较少表达。在青年基金资助下，申请人分离获得了一株烟草内生真菌Aspergillus tennesseensis 1022LEF，发现在烟碱胁迫下，其代谢产物谱发生了积极的响应，产生了新的聚酮类化合物。基于基因组生物信息学分析定位了23个I型PKS生物合成基因簇，大多数基因簇可生产的化合物处于未知状态，其具有很大的新颖化合物的生产潜力可供挖掘。本项目拟在前期工作的基础上，基于OSMAC策略下的培养调控，利用烟碱胁迫和小分子表观遗传修饰因子等激活沉默的代谢途径。同时，应用基因组挖掘技术下的转录调控和异源表达，深入发掘菌株代谢潜力，提高新颖化合物合成量或数量。最后，对获得的目标化合物，运用多种活性模型对其进行广泛的农业活性筛选评价和机理研究。本研究将为具有自主知识产权的农业生物药物创制开发提供化合物实体。

Plant endophytes possess significant secondary metabolites production potential; however, the synthetic gene clusters of these metabolites were rarely expressed under the conventional cultural conditions. During our ongoing investigations on the secondary metabolites from endophytic fungi, we isolated a fungal strain Aspergillus tennesseensis 1022LEF from Nicotiana tabacum L. Under the stress of nicotine, the secondary metabolites of this strain occurred positive responses, leading to the production of a series of new polyketids. Bioinformatics analysis of its genome revealed 23 PKS-I gene clusters, and most of them are silent. Therefore, based on previous studies, this project will focus on cultivation regulation using OSMAC strategy, especially nicotine and epigenetic modifiers, to optimize and design different cultural conditions to activate silent metabolic pathways. Moreover, the target gene clusters will be activated and regulated by transcriptional regulation and heterologous expression to obtain structurally novel metabolites. Finally, the agricultural activities including anti-phytopathogenic, insecticidal, and herbicidal activity will be evaluated. This study will offer novel lead compounds for the agricultural biological drug development with independent intellectual property rights.