COLLABORATIVE RESEARCH: DIMENSIONS: Secondary metabolites as drivers of fungal endophyte community diversity

植物产生多种化学物质，介导它们与其他植物、动物以及有益和致病微生物相互作用的方式。通常存在与植物相关的真菌，其可以刺激植物产生的化学物质的产生和/或改变由植物产生的化学物质，或者真菌可以自身产生化学物质。这些化学物质可以帮助确定植物对疾病和环境压力的抵抗力。许多关于植物如何促进有益真菌的细节，以及真菌如何相互作用以影响植物防御的细节尚不清楚。该项目的目标是使用咖啡植物，它们的亲戚以及与不同植物物种相关的真菌微生物组来更好地了解这些细节。 了解植物叶片内和叶片上有益真菌的相互作用将导致疾病管理的改进策略。该项目的广泛影响包括植物和微生物收集，以及植物和真菌基因组信息数据库，可作为天然产品发现以及农业疾病预防和管理的资源。此外，学生和博士后将接受该项目所涉及的各个学科的培训，并将在美国和哥斯达黎加的两个地点教授环境基因组学短期课程。该项目将研究叶片组织中的次级代谢产物如何定义真菌内生菌群落，以及代谢物定义的生态位和代谢途径的水平基因转移如何促进物种和基因组多样性。依赖于文化和文化独立的方法将被用来确定与野生热带茜草科物种，咖啡种植园管理策略，叶代谢产物的配置文件相关的叶面内生菌群落。叶片和内生菌竞争相互作用的代谢组学分析将确定内生菌群落中关键真菌的作用及其对植物防御化学的贡献。新的，基因组规模的比较分析将确定参与次级代谢产物的生产和降解的基因簇，这些基因簇在内生菌功能冗余和真菌生殖隔离的作用将被调查。

Plants produce a diversity of chemicals that mediate they way they interact with other plants, with animals, and with beneficial and pathogenic microogranisms. There are often fungi associated with plants that can stimulate the production of and/or modify chemicals produced by the plant, or the fungi may produce the chemicals themselves. These chemicals can help determine plant resistance to disease and environmental stress. Many of the details of how plants promote beneficial fungi, and how fungi interact with one another to affect plant defenses are not known. The goals of this project are to better understand these details using coffee plants, their relatives, and the fungal microbiomes associated with different plant species. Understanding the interactions of beneficial fungi in and on plant leaves will lead to improved strategies of disease management. Among the broader impacts of this project are botanical and microbial collections, and a database of plant and fungal genomic information that can serve as a resource for natural product discovery, and prevention and management of agricultural diseases. Additionally, students and postdocs will be trained in the various disciplines that are involved in this project, and an environmental genomics short course will be taught in two locations in the US and in Costa Rica.This project will examine how secondary metabolites in foliar tissues define and are shaped by fungal endophyte communities, and how metabolite-defined niches and horizontal gene transfer of metabolic pathways promote species and genome diversity. Culture-dependent and culture-independent methods will be used to identify foliar endophyte communities associated with wild tropical Rubiaceae species, coffee plantation management strategies, and leaf metabolite profiles. Metabolomic analyses of leaves and endophyte competitive interactions will identify the roles of key fungi in the endophyte community and their contribution to the plant defense chemistry. Novel, genome-scale comparative analyses will identify gene clusters involved in the production and degradation of secondary metabolites, and the roles of these gene clusters in endophyte functional redundancy and fungal reproductive isolation will be investigated.