Carbon Monoxide Based Ecological Interactions Between Legumes and Their Rhizobial Symbionts

基于一氧化碳的豆类及其根瘤菌共生体之间的生态相互作用

• 批准号: 0749665
• 负责人: Gary King
• 金额: $ 30.73万
• 依托单位: Louisiana State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-02-01 至 2009-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0749665&HistoricalAwards=false
• 关键词: Carbon; Monoxide; Based; Ecological; Interactions

Leguminous plants provide an important protein source for about one-third of the world's population. Nitrogen-fixing nodules on the roots of these plants produce relative large amounts of carbon monoxide (CO). Although CO plays important and well-known roles in the chemistry of the troposphere and in cellular biology, the roles of CO in ecological interactions between legumes and their microbial symbionts are poorly known. Preliminary results suggest that use of CO by many legume symbionts (including strains of agriculturally important nitrogen-fixing bacteria) may promote their survival and viability in soils. Symbiont survival and viability in turn can affect plant performance and ultimately impact the role of legumes in a variety of ecosystems. To test this concept, we will use pairs of legume symbionts. One strain in each pair will be manipulated genetically to eliminate the capacity for CO utilization. We will monitor relative and absolute survival of each member of these pairs singly and in mixed populations with and without added CO. We also propose that bacterial CO oxidation controls in part net CO emission by nodules and overall plant performance. We will test this notion using pairs of legumes inoculated with CO-oxidizing symbionts or mutants that do not oxidize CO. Finally, we will use cultivation methods and our recently developed molecular tools to determine relationships between the distribution of CO-oxidizing rhizobia in soil and root and nodule CO production. We will focus on bulk soil, the rhizosphere and the rhizoplane in greenhouse and field studies. In order to expand the impact of our work, we will incorporate appropriate aspects of our research into modules that will be used in science education programs at a K-8 school in South Bristol, Maine.

豆科植物为世界上约三分之一的人口提供了重要的蛋白质来源。 这些植物根部的固氮根瘤产生相对大量的一氧化碳（CO）。 虽然CO在对流层化学和细胞生物学中起着重要和众所周知的作用，但CO在豆科植物及其微生物共生体之间的生态相互作用中的作用却知之甚少。 初步结果表明，许多豆科植物共生体（包括农业上重要的固氮菌株）使用CO可能会促进它们在土壤中的生存和活力。 共生体的生存和活力反过来又会影响植物的性能，并最终影响豆类在各种生态系统中的作用。 为了验证这个概念，我们将使用成对的豆类共生体。 将对每对中的一个菌株进行遗传操作以消除CO利用能力。 我们将监测这些对单独和混合人口中的每个成员的相对和绝对生存，有和没有添加CO。我们还建议，细菌CO氧化控制部分净CO排放结核和整体植物性能。 我们将测试这一概念，使用对豆科植物接种CO氧化共生体或突变体，不氧化CO。最后，我们将使用栽培方法和我们最近开发的分子工具，以确定CO氧化根瘤菌在土壤中的分布和根和根瘤CO生产之间的关系。 我们将集中在散装土壤，根际和根面在温室和田间研究。 为了扩大我们的工作的影响，我们将把我们的研究的适当方面纳入模块，将在南布里斯托，缅因州的K-8学校的科学教育计划中使用。