Molecular Analyses of Plant Root-Microbe Interaction

植物根部-微生物相互作用的分子分析

• 批准号: RGPIN-2014-04582
• 负责人: Prithiviraj, Balakrishnan
• 金额: $ 1.89万
• 依托单位: Dalhousie University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2014
• 资助国家: 加拿大
• 起止时间: 2014-01-01 至 2015-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=566611
• 关键词: Molecular; Analyses; Plant; Root; Microbe

Plant roots offer mechanical support and absorb water and nutrients from the soil; however, roots also help plants interact with the soil environment. Plants’ survival and productivity largely depends on the ability of the root system to sense and respond to biotic and abiotic factors in the soil. One group of organisms that interact with plant root in the rhizosphere (the soil zone extending to a few millimeters immediately surrounding the root) is bacteria, a group consisting of both pathogenic and beneficial forms. Bacteria in the rhizosphere influence physiology of the plant roots and overall health of the plant. Thus, there is potential to improve plant health and productivity by selectively increasing the population of beneficial bacteria and reducing pathogens in the rhizosphere. To achieve this objective a clear understanding of the bacterial and plant factors that mediates root-bacteria interaction is critical. My research focuses on understanding plant factors that mediate root-microbe interaction. One of the questions we are asking is: are there plant genes that allow selective colonization of roots by beneficial bacteria? To this end we are using the plant model 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 pattern; 1. mutants that support growth of the pathogen Pst DC3000 and reduced colonization of the beneficial bacteria P. putida, 2. mutants that promote colonization by P. putida and reduced the growth of Pst DC3000. In silico analysis and supporting preliminary results suggest that the proteins encoded by these genes interact with a number of other Arabidopsis proteins that ultimately cause the differential root-colonization phenotype. The proposed research program will use the Arabidopsis mutant identified in the previous Discovery project to develop a systems biology approach to understand the molecular basis of root-microbe interaction. The objective of this research program are 1) to study the proteome of the mutants that are altered in root-colonization phenotype 2) to characterize the spatiotemporal expression of genes that affect root-microbe interaction identified in the previous project when exposed to pathogenic and the beneficial bacteria 3) to study plant protein-protein interaction in root-microbe interaction 4)to study the difference in the whole metabolome of the mutant plants in response to inoculation with the Pst DC3000 and P. putida and to compare with that of the wild type plant 5) integrating the transcriptomic, proteomic and metabolomics data to better understand the physiological networks that mediate plant root-microbe interaction. This proposed research program will add considerable new knowledge to the current understanding of rhizosphere plant-microbe interactions. The results of the genetic basis of root-microbe interaction will unravel molecular networks that promote plants’ interaction with beneficial bacteria while diminishing its association with pathogens. The genes identified in this research program will aid in the development of ‘designer’ crop varieties that have the enhanced ability to recruit beneficial microbes on to the root and rhizosphere . Development of such crop varieties will significantly reduce the use of agricultural inputs like fertilizer, pesticides and water ultimately promoting sustainable agriculture.

植物根系提供机械支撑，从土壤中吸收水分和养分；然而，根也帮助植物与土壤环境相互作用。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响应能力。在根际（根周围延伸到几毫米的土壤区域）中与植物根系相互作用的一类生物是细菌，这一类生物既有致病形式，也有有益形式。根际细菌影响植物根系的生理机能和植物的整体健康。因此，通过选择性地增加有益细菌的数量和减少根际的病原体，有可能改善植物的健康和生产力。为了实现这一目标，清楚地了解介导根-细菌相互作用的细菌和植物因素是至关重要的。我的研究重点是了解介导根与微生物相互作用的植物因子。我们要问的一个问题是：是否有植物基因允许有益细菌选择性地在根部定植？为此，我们采用拟南芥植物模型和番茄假单胞菌DC3000 [Pst DC3000]（病原体）和恶臭假单胞菌（有益）。在先前发现基金的支持下，我们已经确定了拟南芥单基因突变体，它们表现出两种截然不同的定植模式；1. 支持病原菌Pst DC3000生长并减少有益细菌恶臭杆菌定植的突变体，2。促进恶臭杆菌定植并降低Pst DC3000生长的突变体。计算机分析和支持的初步结果表明，这些基因编码的蛋白质与许多其他拟南芥蛋白相互作用，最终导致差异的根定植表型。拟议的研究计划将使用先前发现项目中鉴定的拟南芥突变体来开发系统生物学方法，以了解根与微生物相互作用的分子基础。本研究项目的目的是：1)研究根定殖表型改变突变体的蛋白质组学；2)表征先前项目中发现的影响根-微生物相互作用的基因在暴露于致病菌和有益菌时的时空表达；3)研究根-微生物相互作用中植物蛋白-蛋白相互作用；4)研究接种Pst后突变体植物全代谢组学的差异整合转录组学、蛋白质组学和代谢组学数据，以更好地了解介导植物根-微生物相互作用的生理网络。这一研究计划将为目前对根际植物-微生物相互作用的理解增加相当多的新知识。根与微生物相互作用的遗传基础的结果将揭示促进植物与有益细菌相互作用的分子网络，同时减少其与病原体的联系。在这个研究项目中发现的基因将有助于开发“设计”作物品种，这些品种具有增强的能力，可以将有益微生物招募到根和根际。开发这类作物品种将显著减少化肥、农药和水等农业投入物的使用，最终促进可持续农业。