UKRI/BBSRC-NSF/BIO:Hidden costs of infection: mechanisms by which parasites disrupt host-microbe symbioses and alter development

UKRI/BBSRC-NSF/BIO：感染的隐性成本：寄生虫破坏宿主-微生物共生并改变发育的机制

• 批准号: 2322173
• 负责人: Corlett Wood
• 金额: $ 121.55万
• 依托单位: University of Pennsylvania
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-15 至 2026-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2322173&HistoricalAwards=false
• 关键词: UKRI; BBSRC; NSF; BIO; Hidden

Plants are colonized by thousands of microscopic organisms, from bacteria to tiny animals like nematode worms. These microorganisms affect each other’s interactions with their shared host plant. Some make it easier for other microorganism to infect the host, while others prevent other microorganisms from successfully infecting. This research will investigate whether these interactions between microorganisms on the same host plant are due to resource competition or driven by the host’s immune response. The researchers will test these questions in a plant that is closely related to alfalfa. Like alfalfa, this plant relies on symbiotic bacteria that live within cells in the root for nitrogen - an important nutrient and a main ingredient in fertilizers. While these symbiotic bacteria provide an essential nutrient to the plant, they also make their host more vulnerable to infection by parasitic nematode worms. While this research focuses on a single species of plant, nearly all crop plants rely on symbiotic microbes for nutrients, so understanding how beneficial microbes influence the disease risk of their host is agriculturally relevant and ecologically significant. The broader impacts of this project include providing interdisciplinary training for the next generation of leaders in plant science; engaging undergraduate and high-school students from under-represented backgrounds in hands-on research; and developing a board game based on microbial colonization of plant roots.Microorganisms that share the same host affect each other’s colonization success. Cross-talk between co-colonizing microorganisms often manifests as a priority effect, in which an early encounter with one microorganism impacts the host’s response to later colonizers. This research will test two competing hypotheses to explain pervasive priority effects in host-associated communities: a defense-centered model, in which the host’s defense response to one invader has off-target effects on infection by another organism, and a resource-centered model, in which co-colonizers compete for host resources. This project will test these hypotheses in the model legume Medicago truncatula by experimentally infecting plants with a parasitic nematode that disrupts the symbiosis with nitrogen-fixing bacteria. Nematodes inhibit rhizobia colonization, while the rhizobia increase susceptibility to nematodes. The proposed research has five objectives: (1) determine the spatio-temporal scale of priority effects between rhizobia and nematodes and develop new tools to manipulate them; interrogate the relative roles of (2) defense and (3) carbon allocation in generating priority effects between these two microorganisms; (4) identify genes and pathways that underlie these priority effects; (5) train the next generation of plant researcher in essential concepts ecological theory, cell and molecular biology. This award is funded as part of a cooperative program with the UKRI/BBSRC in the UK.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.

植物被成千上万的微生物所占据，从细菌到像蠕虫这样的微小动物。 这些微生物影响彼此与其共享的宿主植物的相互作用。有些使其他微生物更容易感染宿主，而另一些则阻止其他微生物成功感染。本研究将调查同一宿主植物上微生物之间的这些相互作用是由于资源竞争还是由宿主的免疫反应驱动。研究人员将在一种与苜蓿密切相关的植物中测试这些问题。像紫花苜蓿一样，这种植物依赖于共生细菌，这些细菌生活在根部细胞中，用于氮-一种重要的营养素和肥料的主要成分。虽然这些共生细菌为植物提供了必需的营养，但它们也使其宿主更容易受到寄生蠕虫感染。虽然这项研究的重点是单一物种的植物，但几乎所有的作物都依赖共生微生物获得营养，因此了解有益微生物如何影响宿主的疾病风险在农业上和生态上都具有重要意义。该项目的更广泛影响包括为植物科学的下一代领导者提供跨学科培训;让来自代表性不足背景的本科生和高中生参与实践研究;以及开发基于植物根部微生物定殖的棋盘游戏。共定殖微生物之间的串扰通常表现为优先效应，其中与一种微生物的早期遭遇会影响宿主对后来的定殖者的反应。本研究将测试两个相互竞争的假设，以解释普遍的优先级效应在主机相关的社区：一个防御为中心的模型，其中主机的防御反应一个入侵者有脱靶影响感染另一种生物体，和资源为中心的模型，其中共同殖民者竞争主机资源。本项目将在模式豆科植物蒺藜苜蓿中测试这些假设，方法是用一种破坏与固氮细菌共生的寄生线虫感染植物。线虫抑制根瘤菌定殖，而根瘤菌增加线虫的易感性。本研究的主要目的是：（1）确定根瘤菌和线虫优先效应的时空尺度并开发新的调控工具;（2）探讨防御和碳分配在产生优先效应中的相对作用;（4）确定优先效应的基因和途径;（5）培养下一代植物研究人员掌握生态学理论、细胞和分子生物学的基本概念。该奖项是与英国UKRI/BBSRC合作项目的一部分。该奖项反映了NSF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。