Explaining Variation in Legume-Rhizobium Mutualism

解释豆科植物-根瘤菌互惠关系的变异

• 批准号: 0416539
• 负责人: Robert Ford Denison
• 金额: $ 3.74万
• 依托单位: University of California-Davis
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-08-01 至 2005-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0416539&HistoricalAwards=false
• 关键词: Explaining; Variation; Legume; Rhizobium; Mutualism

Cooperation between species is important in many natural and agricultural ecosystems, from coral reefs to soybean plants that depend on bacteria (rhizobia) for nitrogen. Given the benefits of cooperation, why does itsometimes break down, as in the case of bleaching when corals expel symbiotic algae, or rhizobia that either parasitize their plant hosts or ignore them altogether? Previous NSF-funded research showed that plantsreduce resource supply to rhizobia that provide them with less nitrogen, so why are less-beneficial rhizobia still common in some soils? Maybe they escape host plant sanctions by hiding inside root nodules with morebeneficial rhizobia, or maybe they somehow manipulate their hosts into providing resources they haven't earned. Both hypotheses will be tested experimentally. Additional experiments will determine whether a documented reduction in oxygen supply to less-beneficial rhizobia is the primary way that plants reduce the reproduction and spread of these rhizobia, or whether other plant responses are also important. The earliest practical benefits of this work are likely to be agricultural, but understanding cooperation between species is also relevant to a wide variety of ecological problems, from the decline of coral reefs to the spread of invasive plants. The gained understanding in symbiosis applies to understanding human social systems. The studies will provide research opportunities for students at all levels.

物种之间的合作在许多自然和农业生态系统中都很重要，从珊瑚礁到依赖氮细菌（根瘤菌）的大豆植物。 鉴于合作的好处，为什么在珊瑚驱除共生藻类或根瘤菌的腐蚀植物宿主或完全忽略它们的根瘤菌时，为什么会崩溃？ 以前由NSF资助的研究表明，植物学对根瘤菌的资源供应为它们提供了较少的氮，那么为什么在某些土壤中仍然很少有弱的根瘤菌呢？ 也许他们是通过藏在根结节内的植物制裁，并以更多的呈根瘤菌的形式藏在根结节内，或者也许他们以某种方式操纵了他们的宿主，以提供尚未获得的资源。 这两个假设都将通过实验测试。 其他实验将确定对较不含氧的根瘤菌的氧气供应减少是植物减少这些根茎的繁殖和扩散的主要方式，或者其他植物反应也很重要。 这项工作的最早实际好处可能是农业，但是了解物种之间的合作也与各种生态问题有关，从珊瑚礁的衰落到入侵植物的传播。 在共生中获得的理解适用于理解人类的社会系统。 这些研究将为各级学生提供研究机会。