Testing the role of microbial distribution and functional traits in the ecology and evolution of symbiosis

所有大型宿主，包括海藻、植物和动物，都被微生物共生体定居，这些共生体共同构成了生物多样性的很大一部分。共生体有助于宿主的新陈代谢，抵御病原体，甚至改变宿主的生长发育方式。共生菌可以与宿主产生积极的、消极的或中性的相互作用，这些结果通常取决于环境背景。随着时间的推移和种群间的变化，可能会有许多共生体在特定宿主物种的健康和生物学中发挥关键作用。在这些旋转的共生体中，功能是通过功能冗余来维持的：许多微生物可以完成一个功能角色。我们知道，共生群落受到环境的影响，并会随着持续的环境变化而变化。但我们无法预测改变后的群落会是什么样子，也无法预测对宿主的后果。这项拟议的研究试图填补这一知识空白。为了解决这个突出的问题，我们需要更好地了解共生菌的分布，导致微生物与宿主联系的因素，共生关系随时间的稳定性，以及共生菌分布与功能之间的关系。我的团队将通过以下方式实现这些目标：1.绘制海藻共生体在不同环境中的分布及其功能图，以确定宿主的专一性。2.将海带培育成实验室研究共生的模式系统。我们将开发一个培养的微生物分离库，包括来自一般海洋环境的微生物和那些专门针对糖海带的微生物。我们将检验这一假设，即特定的共生体在宿主生物学中发挥更大的功能作用。该系统还能够测试由其他目标引起的关于功能和/或环境影响的假设。3.从种群和个体两个层面研究环境条件变化时共生体的稳定性及其功能。拟议的工作还将有助于培训来自不同背景的16名总部工作人员。这项拟议的工作有助于我们对微生物多样性和形成微生物群落的因素的了解。了解构成共生体群落的因素将使从人类健康到农业和水产养殖的各个领域都能够开发利用微生物群的力量的工具，此外还可以揭示我们生物圈这一大片区域的自然历史。

All large hosts, including seaweeds, plants, and animals are colonized by microbial symbionts, and these symbionts collectively make up a huge portion of biodiversity. Symbionts contribute to host metabolism, defend against pathogens, and even change the way hosts grow and develop. Symbionts can have positive, negative, or neutral interactions with the host, and these outcomes often depend on environmental context. There can be many symbionts that play critical roles in the health and biology of a given host species over time and across populations. Functions are maintained amidst this rotating cast of symbionts by functional redundancy: many microbes can fulfill a functional role. We know that symbiont communities are influenced by the environment and will change with ongoing environmental change. But we cannot predict what altered communities will look like, or the consequences to their hosts. The proposed research seeks to fill in this knowledge gap. In order to tackle this overarching question, we need a better understanding of symbiont distributions, the factors that cause microbes to associate with hosts, the stability of symbiotic relationships over time, and the relationship between symbiont distribution and function. My group will achieve these goals by: 1. Mapping the distribution of seaweed symbionts, and their functions, across environments to determine host specificity. 2. Develop sugar kelp into a model system for studying symbiosis in the lab. We will develop a library of cultured isolates of microbes, including microbes from general marine environments and those specific to sugar kelp. We will test the hypothesis that specific symbionts play larger functional roles in host biology. This system also enables testing hypotheses on function and/or environmental influence that arise from the other objectives. 3. We will investigate the stability of symbionts and their functions in the face of changing environmental conditions at both the population and individual level. The proposed work will also contribute to the training of 16 HQP from diverse backgrounds. The proposed work contributes to our knowledge of microbial diversity in general and the factors that shape microbial communities.  Understanding the factors that structure symbiont communities will enable fields ranging from human health, to agriculture and aquaculture to develop tools harnessing the power of the microbiome, and in addition to shedding light on the natural history of this vast part of our biosphere.