Global diversity and ecosystem functions of plant-microbe symbioses

丛枝菌根(AM)是高等植物和真菌之间最广泛的共生现象，对陆地生态系统过程有重要影响，包括生物地球化学循环和植物群落的多样性和生产力。形成AM的真菌被认为是球菌门。然而，我们已经证明，形成独特的“细根内生菌”(FRE)AM形态模式的真菌实际上是毛霉门的成员，该门在7亿多年前从球菌门分化出来，之后植物才开始殖民土地。虽然我们知道FRE是全球分布的，并且可以在生态系统中大量存在，但我们对所涉及的真菌的多样性、生态学或生态系统功能几乎一无所知。然而，有证据表明，FRES和Glmer mycota与环境有不同的相互作用，可能在功能上是不同的。在本项目中，您将调查全球范围内FRE的多样性和组成，以及决定其丰度和分布的关键环境因素。为了了解FRES的生态功能，您将从环境元基因组中组装FRES的基因组。组装的基因组将用于研究与关键生物地球化学循环过程相关的特征的存在，以便建立FRE的生态意义。方法：对现有DNA数据库的初步分析将用于调查FRE和球孢子菌在不同生境中的多样性和分布，以及它们分布的生态驱动因素。在并行项目中使用的现有实地场地将用于更详细地分析FRE的分布，例如季节变化、植物种类偏好以及对土地使用和管理的反应。元基因组测序将用于重建FRE的基因组，以便能够分析FRE对土壤生物地球化学过程的潜在贡献。

Arbuscular mycorrhizas (AM) are the most widespread symbiosis between higher plants and fungi, and have major impacts on terrestrial ecosystem processes, including biogeochemical cycling and the diversity and productivity of plant communities. Fungi which form AM have been assumed to comprise the phylum Glomeromycota. However, we have shown that fungi which form the distinctive 'fine root endophyte' (FRE) AM morphotype are actually members of the phylum Mucoromycota, which diverged from the Glomeromycota over 700 million years ago, before the colonization of land by plants. Although we know that FRE are globally distributed, and can be abundant within ecosystems, we know almost nothing about the diversity, ecology or ecosystem function of the fungi involved. However, evidence suggests that FREs and Glomeromycota have different interactions with the environment and may be functionally distinct. In this project you will investigate the diversity and composition of FRE globally, and key environmental factors determining their abundance and distribution. In order to understand the ecological function of FREs, you will assemble genomes of FREs from environmental metagenomes. The assembled genomes will used to investigate the presence of traits associated with key biogeochemical cycling processes, so that the ecological significance of FRE can be established. Methodology: Initial analysis of existing DNA databases will be used to investigate diversity and distribution of FRE and Glomeromycota across habitats and the ecological drivers of their distribution. Existing field sites in use in parallel projects will be used for more detailed analysis of FRE distribution, such as seasonal variation, plant species preferences and responses to land use and management. Metagenome sequencing will be used to reconstruct genomes of FRE, to enable analysis of the potential contribution of FRE to soil biogeochemical processes.