MSB: Bacterial endosymbionts of arbuscular mycorrhizal fungi: ecology and evolution

本项目的目标是了解丛枝菌根真菌（球囊菌门）和细菌之间的相互作用，居住在他们的菌丝和孢子。 AM真菌和它们的内生细菌是三方共生体的组成部分，该共生体还包括大多数陆生植物，并且可能是地球上最常见的共生体之一。 AM真菌定殖于陆地植物的根部，并帮助植物吸收矿物质营养素以交换植物同化的碳。 对美国北大西洋海岸沙丘植被AM真菌的内生细菌进行了研究。S.被选为研究的焦点系统。 AM真菌谱系中的内细菌分布的调查，结合相互作用的合作伙伴的共生关系的重建，将能够推断的进化起源，年龄的协会，和共生关系的内细菌与他们的自由生活的亲戚。 重建内生细菌的种群结构将有助于阐明其繁殖和传播模式。 评估的影响，窝藏内生细菌对真菌和植物的健身将揭示是否内生细菌是寄生虫或共生的AM fungies.This研究将提高了解AM真菌的生物学和功能的丛枝菌根在陆地生态系统，包括农业生态系统。 它将提供一般的细菌与真菌的相互作用的见解，并扩大了内共生相互作用的建立和维持所涉及的进化过程的知识。 通过关注沿海沙丘中自然发生的AM真菌，该项目将有助于保护和恢复脆弱的沙丘栖息地。 一名研究生和几名本科生和高中生将在项目过程中接受培训。

The goal of this project is to understand the interaction between arbuscular mycorrhizal (AM) fungi (phylum Glomeromycota) and bacteria that reside in their hyphae and spores. AM fungi and their endobacteria are components of a tri-partite symbiotic association that also includes the majority of terrestrial plants, and may be one of the most common symbioses on the planet. AM fungi colonize roots of land plants and assist in the uptake of mineral nutrients to the plant in exchange for plant-assimilated carbon. Endobacteria of AM fungi associated with dune vegetation of the North Atlantic coast of the U. S. were selected as a focal system for the study. A survey of endobacteria distribution among AM fungal lineages combined with reconstruction of phylogenies of the interacting partners will enable inferences about the evolutionary origin, the age of the association, and the phylogentic relationships of endobacteria with their free-living relatives. A reconstruction of the population structure of endobacteria will clarify their reproductive and transmission mode. An assessment of the effects that harboring endobacteria has on the fungal and plant fitness will reveal whether endobacteria are parasites or mutualists of AM fungi.This study will enhance understanding of the biology of AM fungi and of the functioning of arbuscular mycorrhizae in terrestrial ecosystems, including agroecosystems. It will provide insights into the interactions of bacteria with fungi in general, and expand the knowledge of evolutionary processes involved in the establishment and maintenance of endosymbiotic interactions. By focusing on AM fungi that occur naturally in coastal dunes, this project will contribute to the efforts to conserve and restore the fragile dune habitat. A graduate student and several undergraduate and high school students will be trained in the course of the project.