Understanding plant root immunity against the global crop destroyer Macrophomina phaseolina using natural variation in Arabidopsis

利用拟南芥的自然变异了解植物根部对全球农作物破坏者Macrophhomina Phaseolina的免疫力

• 批准号: 2129302
• 负责人: Thomas Eulgem
• 金额: $ 39.78万
• 依托单位: University of California-Riverside
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-05-15 至 2025-04-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2129302&HistoricalAwards=false
• 关键词: Understanding; plant; root; immunity; against

Plant diseases caused by pathogenic microbes, such as fungi and bacteria, cause massive agricultural losses. Dubbed a “global destroyer of crops”, the soilborne fungal pathogen Macrophomina phaseolina infects the roots of more than 500 plant species including many economically significant crops. Global warming promotes the spread of M. phaseolina. Losses in US field crop production caused by this fungus are increasing due to restrictions on toxic fumigation methods. Thus, alternative, innovative methods to reduce damage caused by M. phaseolina are urgently needed. Plant defense processes against M. phaseolina are poorly understood and immunity in roots is an understudied area. Taking advantage of the model plant species Arabidopsis thaliana, which allows for rapid progress in experimental studies, the genetic basis of natural disease resistance in plant roots against M. phaseolina will be examined. This study is expected to identify genes and biological processes which mediate protection of plants against this detrimental fungus. Results from this study will accelerate the development of crop cultivars with enhanced disease resistance against M. phaseolina. Its ultimate goal is to reduce the negative impact of M. phaseolina on the U.S. economy. This study will be performed at UC Riverside, a Hispanic Serving Institution, and one of the most ethnically diverse research universities in the USA. The investigators are deeply committed to the scientific training of members of historically underrepresented minority groups.The diploid model plant Arabidopsis thaliana offers substantial advantages over crop systems to study the molecular genetic basis of host resistance against M. phaseolina. Arabidopsis is easily transformed, has genome-wide collections of mutants and transgenics, has a very short generation time, and large populations grow in minimal space. A particularly useful resource is a collection of 1000 natural A. thaliana accessions for which genome sequences have been determined. In this collection, a substantial degree of variation in M. phaseolina resistance is observed, allowing defense loci and biological processes contributing to root immunity against this detrimental pathogen to be uncovered. The central hypothesis of this project is: Natural variation in Arabidopsis thaliana will allow the discovery of fundamental mechanisms of root defenses against M. phaseolina. The specific aims being pursued are:(1) Use natural variation within A. thaliana to uncover defense mechanisms against M. phaseolina.(2) Study root cell type-specific immune responses against M. phaseolina.(3) Identify key loci mediating protection against M. phaseolina. By profiling transcriptional patterns associated with M. phaseolina resistance among A. thaliana accessions a description of transcriptionally-controlled regulatory, physiological, and biochemical processes involved in host immunity against M. phaseolina will be delivered. Using root cell type-specific fluorescent marker lines, information on how distinct root tissues operate to mediate protection against M. phaseolina will be provided. Reverse genetics and gene mapping will identify plant genes that contribute to immunity against M. phaseolina, which can be used to inform molecular genetic breeding approaches in crops.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

由真菌、细菌等病原微生物引起的植物病害造成了巨大的农业损失。被称为“全球农作物破坏者”的土传真菌病原菌菜豆巨藻侵染了500多种植物的根，其中包括许多重要的经济作物。全球变暖促进了菜豆根结线虫的传播。由于对有毒熏蒸方法的限制，这种真菌在美国大田作物生产中造成的损失正在增加。因此，迫切需要替代的、创新的方法来减少菜豆根结线虫造成的损害。植物对菜豆根结线虫的防御过程知之甚少，根中的免疫也是一个研究较少的领域。利用在实验研究中取得快速进展的模式植物拟南芥，将研究植物根系对菜豆根部自然病害抗性的遗传基础。这项研究有望确定介导植物免受这种有害真菌侵害的基因和生物过程。本研究结果将加速培育对菜豆根腐病抗性较强的作物品种。其最终目标是减少菜豆根结线虫对美国经济的负面影响。这项研究将在加州大学河滨分校进行，这是一家西班牙裔服务机构，也是美国种族最多元化的研究型大学之一。研究人员致力于对历史上代表性不足的少数群体成员进行科学培训。二倍体模式植物拟南芥在研究寄主对菜豆根结线虫抗性的分子遗传基础方面比作物系统具有显著的优势。拟南芥很容易转化，拥有全基因组范围的突变和转基因集合，世代时间非常短，大量种群在极小的空间中生长。一个特别有用的资源是1000个已确定其基因组序列的天然A.thaliana种质的集合。在这个收集中，观察到了菜豆根结线虫抗性的很大程度的变异，使得有助于对这种有害病原菌的根免疫的防御基因和生物过程被发现。该项目的中心假设是：拟南芥的自然变异将有助于发现根对菜豆根部防御的基本机制。其具体目标是：(1)利用拟南芥中的自然变异来揭示对菜豆根结线虫的防御机制；(2)研究根细胞类型对菜豆根结线虫的免疫应答；(3)确定介导对菜豆根结线虫的保护作用的关键基因。通过分析与菜豆根结线虫抗性相关的转录模式，将描述参与寄主对菜豆根结线虫免疫的转录调控、生理和生化过程。使用根细胞类型特定的荧光标记系，将提供关于不同的根组织如何运作以介导对菜豆根结线虫的保护的信息。反向遗传学和基因图谱将识别有助于对菜豆根结线虫免疫的植物基因，这可用于为作物的分子遗传育种方法提供信息。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。