Molecular analysis of plant root-microbe interaction

目的植物根系提供机械支撑，吸收土壤中的水分和养分，但也有助于植物与土壤环境的相互作用。植物的生存和生产力在很大程度上取决于根系对土壤中生物和非生物因素的感知和反应能力。细菌是根际的生物因子之一，影响植物根系的生理，进而影响植物的整体健康。这就有可能通过选择性地增加有益细菌的数量，同时减少或减少那些在根际表现出致病活性的细菌，从而改善植物的健康和生产力。为了实现这一目标，对介导根-细菌相互作用的植物和细菌因子的清楚了解是至关重要的。我的研究重点是了解影响这种根-微生物相互作用的植物因素，并探索如何利用这些信息来提高农业生产力。我们正在问的问题之一是：是否有植物基因允许有益细菌选择性地在植物根上定居？为了解决这个问题，我们使用了模式植物拟南芥和细菌假单胞菌注射器PV番茄DC3000[PST DC3000](病原菌)和恶臭假单胞菌(有益)。在之前的发现基金的支持下，我们已经确定了拟南芥的单基因突变体，它们表现出两种截然不同的定殖模式：i)支持病原菌PST DC3000的生长和减少有益细菌恶臭疫霉的定殖的突变体，以及ii)促进恶臭疫霉定殖的与PST DC3000的生长减慢相关的突变体。拟议的研究计划将使用这些突变体来了解根-微生物相互作用的分子基础，重点是目标基因编码的蛋白质。本研究计划的目标是：*1.研究致病细菌和有益细菌存在时目标基因的时空表达*2.鉴定这些基因编码的蛋白质并鉴定相互作用的蛋白质。*本研究计划将增加有关根-微生物相互作用的遗传学基础的新知识。这项研究计划中确定的基因将有助于作物品种的开发，这些品种可以选择性地促进根际有益微生物的生长。这种作物品种的开发将减少化肥、杀虫剂和水等农业投入的使用，最终有助于可持续的农业实践。

Objective*******Plant roots offer mechanical support and absorb water and nutrients from soil; however, roots also help plants interact with the soil environment. The survival and productivity of plants depends largely on the ability of the root system to sense and respond to biotic and abiotic factors in the soil. Bacteria, one of the biotic factors in the rhizosphere influence the physiology of the plant root and subsequently the overall health of the plant. This opens the potential to improve plant health and productivity by selectively increasing the population of beneficial bacteria while reducing or minimizing those bacteria exhibiting pathogenic activity in the rhizosphere. To achieve this objective a clear understanding of the plant and bacterial factors that mediate root-bacteria interaction is essential. My research focuses on understanding the plant factors that influence this root-microbe interaction and exploring how this information can be used to improve agricultural productivity. One of the questions we are asking is: Are there plant genes that allow selective colonization of plant roots by beneficial bacteria? To address this question we are using the model plant Arabidospsis thaliana and bacteria Pseudomonas syringe pv tomato DC3000 [Pst DC3000] (pathogen) and Pseudomonas putida (beneficial). With the support from the previous Discovery Grant funding we have identified Arabidopsis single gene mutants that exhibited two contrasting colonization patterns: i) mutants that support growth of the pathogen Pst DC3000 and reduced colonization of the beneficial bacteria P. putida, and ii) mutants that promote colonization by P. putida linked to reduced growth of Pst DC3000. The proposed research program will use these mutants to understand the molecular basis of root-microbe interaction with emphasis on the proteins coded by the target genes. The objectives of this research program are:****1. To study the spatiotemporal expression of target genes in the presence of pathogenic and beneficial bacteria****2. To characterize the protein coded by these genes and to identify interacting proteins.****This proposed research program will add new knowledge on the genetic basis of root-microbe interactions. The genes identified in this research program will aid in the development of crop varieties that can selectively promote beneficial microbes in the rhizosphere. Development of such crop varieties will reduce the use of agricultural inputs like fertilizer, pesticides and water ultimately contributing to sustainable agricultural practices.***