Elucidating the symbiotic signaling pathway in legumes

豆科植物贡献了人类蛋白质摄入量的三分之一，这一事实与它们通过与固氮细菌的共生关系获取大气氮的非凡能力直接相关。生物固氮也使豆科植物成为自然和农业系统的关键组成部分，因为它们将重要的氮返回到环境中。该项目将扩展现有的关于豆类及其共生细菌如何建立这种独特伙伴关系的知识，特别是通过将传统的遗传方法与研究人员为蛋白质生物化学和细胞生物学开发的专门工具相结合。这些研究的结果将增加对共生发展的关键阶段的理解，即豆科植物从土壤环境中选择有效共生细菌的时期。特别是，拟议的研究将确定新的基因和蛋白质的基础上的共生固氮。共生固氮的知识与农业系统有很大的相关性，因为美国农业高度依赖于输入氮，对于非豆科植物来说，这涉及到化石燃料的消耗，以驱动大气氮（N2）转化为肥料氮。豆科植物利用通过光合作用获得的太阳能直接产生氮肥，这一事实使它们成为具有成本效益、碳中和和可持续农业系统的关键组成部分。加深对共生发展的理解将增强我们建设性地操纵这一重要生物过程的能力。这项工作预计将产生更广泛的影响，包括培养研究生，学生将通过韩国农村振兴厅参与与大韩民国科学家的积极国际合作。

Legumes contribute 1/3 of humankind's protein intake, a fact that is directly related to their unusual capacity to access atmospheric nitrogen through symbiosis with nitrogen-fixing bacteria. Biological nitrogen fixation also makes legumes key components of both natural and agricultural systems because they return vital nitrogen to the environment. This project will extend existing knowledge of how legumes and their symbiotic bacteria establish this unique partnership, in particular by bridging traditional genetic methodologies with specialized tools that the investigators have developed for protein biochemistry and cell biology. The outcome of these studies will be increased understanding of a critical phase in symbiotic development, namely the period during which legumes select efficient symbiotic bacteria from the soil environment. In particular, the proposed research will identify new genes and proteins that underlie symbiotic nitrogen fixation. Knowledge of symbiotic nitrogen fixation has great relevance to agricultural systems, because US agricultural is highly dependent on input nitrogen, which for non-legumes involves consumption of fossil fuels to drive conversion at atmospheric nitrogen (N2) to fertilizer nitrogen. The fact that legumes produce fertilizer nitrogen directly, using solar energy obtained through photosynthesis, makes them key components of cost-effective, carbon-neutral, sustainable agricultural systems. Increased understanding of symbiotic development will enhance our ability to constructively manipulate this vital biological process. The anticipated broader impacts of this work include training of graduate students, and students will participate in an active international collaboration with scientists in the Republic of Korea through the Korean Rural Development Administration.