EAPSI: Elucidating the Role of SYP132A during Arbuscular Mycorrhizal Symbiosis in Oryza Sativa

植物常常招募土壤微生物，以通过各种机制来提高养分的有效性和吸收。固氮共生和丛枝菌根共生是两个重要的例子。氮肥共生对大豆、菜豆、豌豆、花生、紫花苜蓿等能够形成共生关系的作物具有重要的生长效应，而AM共生对玉米和水稻等许多形成共生关系的作物也有同样的作用。尤其是水稻，接种菌根真菌可以显著增加水稻的产量，因为它能促进养分的吸收。这在世界上依赖这种特殊作物提供大部分卡路里的地区尤其重要。该奖项支持通过定义水稻SYP132A突变体的菌根表型来研究SYP132A基因在水稻中的作用。这项研究最终可能揭示水稻的一个基本过程(AM共生)，如果进行优化，该过程可能会极大地提高产量。这项研究将与上海植物生理生态研究所水稻AM共生专家王尔涛博士合作进行。植物固氮共生途径是由丛枝菌根共生途径进化而来的，其分子机制有许多共同之处。在氮肥共生过程中，蛋白质从植物到细菌的运输已被证明是必不可少的，但AM共生过程中的蛋白质运输很可能也是重要的。在这个拟议的项目中，我将研究合成素基因(SYP132a)在菌根共生中的作用。该基因在元胞杆菌的核因子共生中起作用，也就是说，它特异性地标记了胞内细菌周围的膜，以进行靶向的蛋白质输送。我将通过鉴定水稻T-DNA突变系的菌根表型来研究SYP132a的功能。我的假设是，这种蛋白质标志着植物细胞内将宿主与真菌分开的膜。本研究将为SYP132A的功能具有普遍性并跨越多种寄主和微生物提供证据。该NSF EAPSI奖支持一名美国研究生的研究，并与中国科技部合作提供资金。

Plants often recruit soil microbes in order to enhance nutrient availability and absorption by an assortment of mechanisms. Nitrogen-fixing (NF) symbiosis and arbuscular mycorrhizal (AM) symbiosis are two important examples. NF symbiosis has major growth effects on the crops that can form this relationship such as soybean, common bean, pea, peanuts, alfalfa, etc., while AM symbiosis can do the same for many crops that form this symbiosis such as maize and rice. Rice (Oryza sativa), specifically, can have a significant grain yield increase when inoculated with mycorrhizal fungi because of the enhanced nutrient uptake. This can be especially important in parts of the world that rely on this particular crop for the majority of its calories. This award supports research to investigate the role of the SYP132A gene in rice (Oryza sativa) by defining the mycorrhizal phenotype of rice SYP132A mutants.The research could ultimately shed light on a fundamental process in rice (AM symbiosis) that has the potential to greatly increase yield if optimized. The research will be conducted in collaboration with Dr. Ertao Wang, an expert in AM symbiosis in rice, at the Institute of Plant Physiology and Ecology in Shanghai, China. The nitrogen-fixing (NF) symbiotic pathway in plants evolved from the arbuscular mycorrhizal (AM) symbiotic pathway, and therefore the molecular mechanisms share many common elements. Protein trafficking from the plant to the bacteria during NF symbiosis has been shown to be indispensable, but protein trafficking during AM symbiosis is most likely important as well. For this proposed project, I will study the role of a syntaxin gene (SYP132A) in mycorrhizal symbiosis. This gene was previously identified to have a role in NF symbiosis in M. truncatula, namely, it specifically marks the membrane surrounding the intracellular bacteria for targeted protein delivery. I will investigate the function of SYP132A by characterizing the mycorrhizal phenotype of rice T-DNA mutant lines. My hypothesis is that this protein marks the membrane that separates host from the fungus within plant cells. This study will provide evidence that the function of SYP132A is universal and spans multiple host and microbial species. This NSF EAPSI award supports the research of a U.S. graduate student and is funded in collaboration with the Chinese Ministry of Science and Technology.