外膜型β-1,6-葡聚糖酶在捕食性粘细菌识别真菌中的作用机制

粘细菌作为一种自然环境中广泛存在的微生物类群，与微生物共进化过程中形成了其独特的捕食功能。粘细菌对植物病原真菌的捕食具有广谱性，且其捕食作用在植物真菌病害防控中发挥着关键作用。课题组前期在开展捕食性粘细菌与植物病原真菌互作关系研究中，发现粘细菌利用一种全新的TonB外膜型β-1,6-葡聚糖酶Oar实现对真菌的识别和捕食。然而，粘细菌如何利用该外膜蛋白识别真菌从而实现群体捕食的作用机制尚不清楚。本项目以稻瘟病菌为模式菌，拟从三个方面研究粘细菌利用外膜蛋白Oar识别真菌的作用机制：（1）外膜蛋白Oar在稻瘟病菌中的识别位点的鉴定及其互作关系研究；（2）粘细菌与真菌互作过程中Oar表达的调控机制；（3）粘细菌利用Oar识别真菌后粘细菌菌群的响应机制。本项目通过揭示粘细菌识别稻瘟病菌的作用机制，为理解捕食性细菌与真菌互作提供新的视角，同时也为植物真菌病害控制提供机制明确的菌种资源和抗性基因资源。

Myxobacteria are ubiquitous Gram-negative soil bacteria with the capacity to prey on fungi during the co-evolution with microbes. Myxobacteria exhibit predatory broad-spectrum toward plant pathogenic fungi, which play key role in the biocontrol of plant fungal diseases. In our previous study, a novel outer membrane β-1,6-glucanase was deployed in the perception and predation of fungi by myxobacteria, which is important for the interaction of bacteria and fungi. However, the mechanisms of the outer membrane Oar in the perception of fungi by myxobacteria are unclear. In this study, the mechanisms involved in the myxobacterial perception toward model fungus Magnaporthe oryzae are investigated: (1) Identification of the recognition site in M. oryzae and its interaction with Oar; (2) Expression regulation of the outer membrane protein Oar during myxobacteria-fungus interaction; (3) Group response of myxobacteria towards fungus that recognized by Oar. According to the study of the molecular mechanism involved in the perception of M. oryzae by myxobacteria, our research will provide new implications for understanding the molecular ecological basis of bacteria-fungi interaction. Otherwise, the antifungal strain and genes will find potential applications in the biocontrol of plant fungal disease with clear mechanism.