Deciphering the molecular basis of organ-specificity in plant-microbe interactions

破译植物-微生物相互作用中器官特异性的分子基础

• 批准号: RGPIN-2015-06057
• 负责人: Joly, David
• 金额: $ 2.04万
• 依托单位: Université de Moncton
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=708731
• 关键词: Deciphering; molecular; basis; organ; specificity

Coevolution between plants and pathogens has culminated in intricate patterns where pathogens can have a narrow or wide host range. This evolutionary paradigm of host specialization also holds true for organ-specific infection processes. However, it remains elusive why some pathogens prefer a given organ, whereas others are able to infect the entire plant. Studies have shown that distinct plant organs may utilize distinct defense mechanisms, but not much is known about pathogens' molecular determinants involved in organ-specificity. Because of its broad ability to colonize different host organs, the potato late blight pathogen Phytophthora infestans is a perfect model to tackle organ-specificity. Moreover, while late blight resistance breeding has often focused on foliage, tuber resistance is an equally important trait since tuber infection can result in severe yield reduction and promotes colonization by secondary soft-rotting bacteria. Some late blight resistance genes have been shown to be ineffective in tubers, which could be explained by the absence of expression of the corresponding avirulence genes in these tissues. This proposal aims at identifying whether distinct effector complements act in various plant organs, and to decipher their contribution in dictating organ-specificity. Candidate organ-specific virulence factors will be identified by transcriptome profiling of effector-encoding genes across various organs and validated using functional assays. Organ-specific effectors are expected to possess a significantly higher expression level in a given organ relative to other organs and their virulence function (e.g. ability to suppress defense responses) should act in an organ-specific manner. In parallel, known avirulence factors will also be tested for their ability to trigger defense responses in various organs from genetically-resistant potato cultivars. From a fundamental point of view, the elucidation of organ-specific constraints is a neglected component of plant-microbe interactions that is crucial to our understanding of both evolutionary and ecological aspects of such interactions. Besides, by implementing novel knowledge on organ-specific vs. whole plant virulence and resistance mechanisms, this research program will have practical implications for the development of novel strategies for disease control in agricultural crops. This would represent an unprecedented opportunity to translate fundamental research into a crop improvement strategy that would benefit the Canadian industry.

植物和病原体之间的协同进化达到了复杂的模式，病原体可能具有狭窄或较宽的宿主范围。宿主专业化的这种进化范式也适用于特定器官特定的感染过程。但是，仍然难以捉摸，为什么有些病原体更喜欢给定的器官，而另一些病原体能够感染整个植物。研究表明，不同的植物器官可以利用不同的防御机制，但对于病原体与器官特异性涉及的分子决定因素知之甚少。 由于它具有殖民不同寄主器官的广泛能力，所以 马铃薯晚疫病病原体植物疫霉是一个理想的模型 铲球特异性。此外，虽然晚枯萎病 繁殖通常集中在叶子上，块茎耐药性是一种同样的 重要特征，因为块茎感染会导致严重的产量 通过二次软旋转细菌还原并促进定植。 一些晚期抗抗抗性基因已显示出无效的 块茎，这可以通过缺乏表达来解释 这些组织中的相应气相基因。 该提案旨在确定是否在各种植物器官中作用着独特的效应子，并破译其在规定器官特异性方面的贡献。候选器官特异性的毒力因子将通过对各种器官的效应子编码基因的转录组分析来鉴定，并使用功能测定进行验证。预期器官特异性效应子在给定器官相对于其他器官及其毒力功能（例如抑制防御反应的能力）的表达水平应具有明显的表达水平。同时，还将测试已知的气相因子的能力，以触发来自遗传耐药品品种的各种器官的防御反应的能力。 从基本的角度来看，阐明器官特异性约束是植物 - 微生物相互作用的忽视组成部分，这对于我们对这种相互作用的进化和生态方面的理解至关重要。此外，通过实施有关器官特异性与整个植物毒力和耐药机制的新知识，该研究计划将对农作物中疾病控制的新型策略的发展具有实际意义。这将代表一个前所未有的机会，将基本研究转化为一项将使加拿大行业受益的作物改善策略。