Resuscitation and assembly of the rhizosphere microbiome in response to plant stress

植物与一些土壤微生物密切相关，并在根表面附近与它们建立有益的关系。预计有益微生物可以支持植物适应环境中的压力，如干旱。然而，目前尚不清楚微生物是如何在胁迫下被招募到根系的，也不清楚不同土壤微生物群落中哪些成员在胁迫下反应最积极。这项研究将调查微生物如何对植物应激激素作出反应。了解胁迫下土壤微生物和植物之间的动态关系对于预测和潜在地管理在环境和土地利用变化下植物性能的预期变化非常重要。该项目将评估土壤微生物在暴露于植物激素时如何改变其生长和活动，量化胁迫下根系释放的分子如何变化，评估微生物对这些变化的反应，并确定土壤微生物群落成员如何在自然和受控环境中共同响应植物胁迫信号。这项工作对了解植物恢复力具有广泛意义，其预期结果对农业和土地管理、粮食和能源安全、可持续性和一般土壤健康具有国家利益。它还将通过在密歇根州立大学的科学节和其他公共校园活动中提供定量的科学劳动力培训和社区外展来造福社会。该研究的目的是了解暴露于植物激素信号胁迫下根际微生物组的组装和功能规则。对于植物来说，根系微生物群的招募和组装是通过土壤进行的，土壤为植物与微生物群的接触提供了物理、化学和生物环境。土壤蕴藏着丰富的微生物多样性，但土壤中高达80%的微生物处于休眠状态，具有不可接近的功能潜力。当植物受到压力时，它们会将代谢物释放到土壤中，这些代谢物可以作为微生物的信号。本研究旨在：1)揭示细菌在生长和复苏过程中对应激植物激素的反应；2)量化植物胁迫信号下微生物群落动态及其相互作用；3)鉴定在胁迫条件下复苏并聚集到根际的复杂土壤微生物群落成员。将采用多尺度方法，结合细菌对植物激素的体内定量反应，合成微生物组的构建和操作，以及土壤根际微生物组动态的原位实验。这项研究有望破译当植物受到压力时控制微生物组动态的规则。对植物、微生物和环境之间相互作用的基本理解将促进微生物组朝着预期功能的管理，并将支持实现可持续农业、粮食和能源安全的目标。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Plants associate closely with some soil microorganisms and engage with them in beneficial relationships near the root surface. It is expected that beneficial microbes can support plants to be resilient to stresses in the environment, such as drought. However, it is not well understood how microbes are recruited to the root during stress or which members of the diverse soil microbial community are most responsive during stress. This research will investigate how microorganisms respond to plant hormones that signal stress. Understanding the dynamic relationships between soil microbes and plants during stress is important for anticipating, and potentially managing, expected changes in plant performance given environmental and land-use changes. This project will assess how soil microorganisms alter their growth and activities when exposed to plant hormones, quantify how the molecules released from roots change during stress and assess the responses of microbes to those changes, and determine how members of soil microbial communities collectively respond to plant stress signals in natural and controlled environments. This work has broad significance for understanding plant resilience, with expected outcomes of national interest for agriculture and land management, food and energy security, sustainability, and general soil health. It will also benefit society by providing quantitative scientific workforce training and community outreach at Michigan State University's Science Festival and other public campus events. The objective of the research is to understand the rules of assembly and function of the rhizosphere microbiome given exposure to plant hormones that signal stress. For plants, root microbiome recruitment and assembly is facilitated through the soil, which provides the physical, chemical, and biological context for plant-microbiome engagement. Soil harbors a rich reservoir of microbial diversity, but up to 80% of microorganisms in soil are dormant and have inaccessible functional potential. When plants are stressed, they release metabolites into the soil that could serve as signals to microorganisms. This research aims to: 1) uncover bacterial responses in growth and resuscitation to stress phytohormones; 2) to quantify microbial community dynamics and interactions given plant stress signals; and 3) to identify members of complex soil microbial communities that resuscitate and assemble to the rhizosphere during stress. A multi-scale approach will be used that combines in vivo quantification of bacterial responses to phytohormones, synthetic microbiome construction and manipulation, and in situ experiments of rhizosphere microbiome dynamics in soil. This research is expected to decipher rules governing microbiome dynamics when plants are stressed. A foundational understanding of the interactions between plants, microorganisms and the environment will facilitate management of microbiomes towards desired functions, and will support goals towards sustainable agriculture and food and energy security.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.