通过比较微生物宏基因组与植物基因组解析根表面微生物群落的构建机制

揭示植物根表面微生物群落的构建机制是微生物生态学研究的一个核心目标。现有研究认为植物会从非根际土的微生物中筛选一部分作为其根表面微生物—为其提供互补功能，强调共生关系为构建机制。实际上，微生物与植物需要共同的营养等条件，它们之间也可能存在竞争关系，但是现有研究忽略了这种机制。我们提出可以利用植物基因组、非根际土和根表面土的微生物宏基因组建立一个功能生态位图，并提出了一个概念框架，用来解析植物微生物之间的共生竞争关系。我们申请该项目，从三个方面来解析机制，并验证和完善该框架：1）比较不同植物种的根表面微生物群落的构建机制的差别；2）检验构建机制在空间上的普适性；3）探索构建机制在氮沉降干扰下的稳定性。研究结果将会探究竞争的重要性，从而补充传统的共生假说；概念框架将会激发新的研究，例如鉴定各种微生物类群与各种作物的竞争共生关系，结果将有助于高效开发和利用微生物菌剂。

Revealing the assembly mechanisms of plant root surface microbial communities is a central aim in microbial community ecology. It is generally thought that plants select a subset of bulk soil microorganisms as their root surface microbiome to provide complementary functions, emphasizing the mutualistic relationship as the main mechanism. In fact, microorganisms and plants need the same growth conditions such as nutrients, and there may be competition between them, but this mechanism is often neglected. We propose that plant genomes, and bulk soil and root-surface microbial metagenomes can be combined into a functional niche map, and also propose a conceptual framework to infer plant-microbiome interactions. Here we apply this project, aiming to explore the assembly mechanisms under three scenarios, and to test and improve the conceptual framework. First, we will analyze the similarities and differences in the assembly mechanisms of different plant species. Second, we will test the spatial generality of the assembly mechanisms. Third, we will test the stability of the assembly mechanisms under nitrogen deposition disturbance. This study will explore the importance of competition, complementing the traditional mutualistic hypothesis. Our conceptual framework will stimulate new researches, such as identifying the mutualistic vs. competitive relationships between various microbial groups and each crop, and the results will be helpful to effectively exploit and utilize microbial agents.