MSB: Conflicts among members of interacting symbioses: How do symbiotic fungi influence plant defense against leaf-cutting ants?

植物和昆虫寄生着种类繁多的有益真菌。以前的研究主要集中在特定宿主-共生体对之间的互惠互利，但很少研究更复杂或相互关联的共生体之间的相互作用。将研究属于两个独立共生体对的真菌之间的相互作用：i)切叶蚂蚁及其真菌花园，以及ii)热带植物和叶内生植物，叶内隐秘的真菌。前者涉及蚂蚁和它们作为粮食作物种植的真菌。后者是一个广泛存在但不太为人所知的关联。在某些情况下，叶面内生植物通过化学手段保护叶片免受食草动物侵袭，从而提供了好处。将通过实验室和田间实验来测试内生菌的存在是否会降低蚂蚁群体的收获效率和长期发展。这种成本的生态影响是巨大的，因为成熟的切叶蚂蚁会在森林、重新造林的地块和人类农业中造成严重的落叶。除了对植物群落的影响外，这个项目还将描述切叶蚂蚁如何管理广泛的微生物，这些微生物是它们真菌作物的潜在拮抗者，并将阐明随着时间的推移控制这种感染的成本。据估计，切叶蚂蚁每年给农业和农林业造成10亿美元的损失。了解蚁穴密度是如何受到自然限制的，可能会导致环境友好型的生物防治形式，并减少这些蚂蚁的经济影响。其他更广泛的影响将来自巴拿马的合作者和学生通过增加代表不足的群体的参与。该项目包括通过视频链接向巴拿马和美国的K-12学生提供双语教育推广计划。让来自不同国家的学生通过视频链接与研究人员和彼此互动，将同时架起学生之间的桥梁？对生物和文化多样性的欣赏。

Plants and insects host a wide diversity of beneficial fungi. Previous studies have focused on the reciprocal benefits within a particular host-symbiont pair, but have rarely investigated interactions among more complex or linked symbioses. Interactions will be investigated between fungi that are part of two separate symbiont pairs; i) leaf-cutting ants and their fungal gardens, and ii) tropical plants and foliar endophytes, cryptic fungi within leaves. The former involves ants and the fungus they cultivate as a food crop. The latter is a widespread but less well understood association. In some cases foliar endophytes provide benefits by chemically defending leaves against herbivores. Laboratory and field experiments will be used to test whether the presence of endophytes reduces the harvesting efficiency and long-term development of ant colonies. The ecological implications of such costs are significant because mature leaf-cutting ants cause severe defoliations in forests, in reforestation plots, and in human agriculture. In addition to the implications for plant communities, this project will describe how leaf-cutting ants manage a wide spectrum of microbes that are potential antagonists to their fungal crops, and will elucidate costs of controlling such infections through time. Leaf-cutter ants cause an estimated US$1 billion in damages per year to agriculture and agroforestry. Understanding how nest density is limited naturally could lead to environmentally-friendly forms of biological control and lessen the economic impact of these ants. Additional broader impacts will result from increasing participation of under-represented groups by involving collaborators and students from Panama. The project includes a bi-lingual educational outreach program to Panamanian and U.S. K-12 students via video link. Allowing students from different countries to interact with researchers and with each other via video-link will simultaneously bridge the students? appreciation for biological and cultural diversity.