软珊瑚共附生真菌抗植物病原菌肽类化合物的结构多样性挖掘及其初步作用机制

随着国家对粮食安全和环境生态的要求的不断提高，以及人们对高品质农产品的需求，迫切需要研发更加高效、低廉、低残留、环境友好的新型农用抗生素。肽类抗生素因活性显著、不易产生抗药性、作用机理独特而备受关注。珊瑚共附生微生物具备海洋微生物的特殊性和自身化学防御特性决定了其是新型农用抗生素的丰富来源。前期我们从南海软珊瑚共附生真菌中筛选到1株能显著抑制多种农业病原真菌的菌株，从中获得了结构多样的肽类化合物，进一步确证了环七肽类化合物在抗菌活性中发挥重要作用。本项目将以这株真菌为研究对象，通过改变发酵条件、添加生物前体和诱变等多种方式充分挖掘的代谢潜能，获取结构多样新颖的肽类化合物，开展农业致病菌抑制活性筛选和作用机理研究，希望从中发现活性强、作用广泛、机理明确、且有来源保障的农用抗生素先导化合物，为深入挖掘南海微生物资源和提升我国海洋微生物创新农用抗生素的研究水平和国际竞争力奠定基础。

With the continuous improvement of food security and environmental ecological requirements and the demand for high-quality agricultural products, it is particularly urgent to develop new highly efficient and low-toxic agricultural antibiotics. Due to its broad-spectrum and high antimicrobial activity, low drug resistance and unique mechanism, antimicrobial peptides has attracted more attentions. Marine microorgainism are considered as a promising source for the discovery of agro-antibiotic peptides. In our previous research, several fungus from soft coral-derived symbiotic and epiphyte microorganisms of the south China sea were discovered with their antifungal activities toward several pathogenic fungus. Several cyclodepsipeptide, isolated from one of these fungus, exhibited potent inhibition towards five plant pathogenic fungus. In this project, we will investigate the chemical components of selected fungal strains that could produce peptides and inhibite the growth of agricultural pathogenic fungi. Further studies, including comparison of microbial metabolites, will be done under different culture conditions and induced mutation, together with selecting aimed strains, fermentation studies, bioassay-guided fractionation, structural elucidation and evaluation for antifungal activities of pure peptides. In addition, it is also interesting to analyze the antifungal mechanism and the preliminary application study. Our research could provide the novel and abundant lead compounds with new mechanism for development of agro-antibiotic peptides, as well as to lay the foundation for more in-depth follow-up study.