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亲属（豆类）根的关键共生体，并为其宿主固定氮，以换取碳。然而，全球变化现在正在改变碳和氮的营养通量，这些碳和氮是根瘤菌及其宿主之间贸易的货币。在某些土壤中，由于化石燃料燃烧受到的污染，氮水平增加了100倍以上。进化论预测，在这种极端环境中控制共生的宿主系统的降解，可能会释放剥削共生体的流行病。该项目调查了豆类及其共生体的快速发展，以响应氮污染。遗传和表型分析将解决加利福尼亚州种群之间的差异，这些人口在氮污染水平上有所不同，并将发现根瘤菌剥削的程度和分子机制。该项目将增强我们对根茎共生的理解，这对野生植物至关重要，并通过增强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）开发了一项专注于科学方法的大学课程及其在与社会和政策相关的决策中的应用，（iii）启动微生物研究培训计划，目标是针对科学不足的群体的本科生的微生物研究培训计划。