CAREER: EVOLUTION OF HOST CONTROL OVER SYMBIOSIS, DYSBIOSIS IN ANTHROPOGENIC LANDSCAPES

职业：人类景观中宿主对共生、失调的控制的演变

• 批准号: 1150278
• 负责人: Joel Sachs
• 金额: $ 58.75万
• 依托单位: University of California-Riverside
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-02-01 至 2018-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1150278&HistoricalAwards=false
• 关键词: CAREER; EVOLUTION; HOST; CONTROL; OVER

Rhizobial bacteria are key symbionts that infect the roots of pea plants and their relatives (legumes) and fix nitrogen for their hosts in exchange for carbon. Yet global changes are now altering nutrient fluxes of carbon and nitrogen that are the currency of trade between rhizobia and their hosts. In some soils, nitrogen levels have increased more than 100-fold due to pollution from fossil fuel combustion. Evolutionary theory predicts degradation of host systems that control symbiosis in such extreme settings, potentially unleashing epidemics of exploitative symbionts. This project investigates the rapid evolution of legumes and their symbionts in response to nitrogen pollution. Genetic and phenotypic analyses will resolve differences among populations in California that vary in nitrogen pollution levels and will uncover the extent and molecular mechanisms of rhizobial exploitation. This project will enhance our understanding of rhizobial symbioses, which are critical to wild plants and provide an important service to the bio-economy via enhanced crop growth and biofuel production. This project will also (i) train middle-school students and directly involve them in gathering data, (ii) develop a college course focused on the scientific method and its application to social and policy-related decisions, and (iii) initiate a microbiology-research training program that targets undergraduate students from groups underrepresented in the sciences.

根瘤菌是感染豌豆植物及其近缘植物（豆科植物）根部的关键共生体，并为其宿主固定氮以换取碳。然而，全球变化正在改变碳和氮的营养通量，而碳和氮是根瘤菌与宿主之间的交易货币。在一些土壤中，由于化石燃料燃烧的污染，氮含量增加了100倍以上。进化理论预测，在这种极端环境下，控制共生的宿主系统会退化，可能会释放出剥削共生体的流行病。本项目研究豆科植物及其共生体对氮污染的快速进化反应。遗传和表型分析将解决加州不同氮污染水平的人群之间的差异，并将揭示根瘤菌利用的程度和分子机制。该项目将提高我们对根瘤菌共生的理解，这对野生植物至关重要，并通过提高作物生长和生物燃料生产为生物经济提供重要服务。该项目还将（i）培训中学生，并直接让他们参与收集数据，（ii）开发一门侧重于科学方法及其在社会和政策相关决策中的应用的大学课程，以及（iii）启动一项针对科学代表性不足的本科生的微生物学研究培训计划。