Study of the roles and dynamics of plant processing bodies during bacterial infection

植物加工体在细菌感染过程中的作用和动态研究

• 批准号: 457286425
• 负责人: Dr. Manuel Gonzalez Fuente
• 金额: --
• 依托单位: Lehrstuhl für Pflanzliche Zellbiologie
• 依托单位国家: 德国
• 项目类别: WBP Position
• 财政年份: 2021
• 资助国家: 德国
• 起止时间: 2020-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/457286425?language=en
• 关键词: Study; roles; dynamics; plant; processing

Understanding the molecular dialogue between plants and pathogens is vital for developing effective and sustainable control strategies against the plant diseases that currently threaten food security worldwide. To protect themselves from these pathogens, plant immunity is efficiently regulated at the transcriptional and post-transcriptional level. The compartmentalization of mRNA into translationally repressed aggregates called processing bodies (PBs) is a key post-transcriptional regulatory process involved in development and stress responses. Preliminary results from the host team have shown that the bacterial plant pathogen Pseudomonas syringae (Pst) induces the formation of PB upon infection in an effector-dependent manner and that PB-defective Arabidopsis plants are more tolerant to Pst. This suggests that PBs are negative regulators of plant immunity that can be targeted by the bacterial effectors. The proposed project aims precisely at studying the role of PBs as post-transcriptional regulators of plant immunity and the ability of Pst effectors to modulate them. For this, a combination of genetic, biochemical, proteomic and cell biology approaches will be conducted to address: 1) the dynamics and roles of PBs, 2) the effector-mediated modulation of PB formation and 3) the interplay between PBs and autophagy, all in the context of a compatible plant-bacterium interaction. The proposed project is structured in three work packages corresponding to the three beforementioned objectives. In the first part, the dynamics, involvement in immunity and composition of the assembled PBs upon infection will be studied. The dynamics of PB formation will be determined by confocal microscopy; the involvement in immunity, by the characterization of defence responses and transcriptomic features of a PB-defective Arabidopsis mutant; and the protein and RNA composition of purified PBs, by mass spectrometry and RNA sequencing respectively. In the second part of the project, Pst effectors will be screened for their ability to singly modulate PB formation, co-localize with PB markers and physically interact with PB components. The mechanisms behind this modulation will be further studied in the case of HopM1, the first identified effector able to associate with PBs and modulate their assembly. In the third part of the project, the interplay between PB formation and autophagy will be explored based on the preliminary result that PBs interact and co-localize with the selective autophagy receptor NBR1. For this, different combination of transgenic plants expressing PB markers and NBR1 and the respective mutants will be generated and characterized to determine genetically the contribution of each process to each other. Altogether, the propose project constitutes an innovative and well-rounded strategy to characterize for the first time the role of PBs in a compatible plant-pathogen interaction and identify the potential interplay between PBs and autophagy.

了解植物和病原体之间的分子对话对于制定针对目前威胁全球粮食安全的植物病害的有效和可持续的控制策略至关重要。为了保护自己免受这些病原体的侵害，植物免疫在转录和转录后水平上得到有效调节。 mRNA 划分为被称为加工体 (PB) 的翻译抑制聚集体，是参与发育和应激反应的关键转录后调节过程。宿主团队的初步结果表明，细菌性植物病原体丁香假单胞菌（Pst）在感染后以效应子依赖性方式诱导PB的形成，并且PB缺陷的拟南芥植物对Pst具有更强的耐受性。这表明 PB 是植物免疫的负调节剂，可以成为细菌效应子的目标。该项目旨在研究 PB 作为植物免疫转录后调节剂的作用以及 Pst 效应子调节它们的能力。为此，将结合遗传、生化、蛋白质组学和细胞生物学方法来解决：1）PB的动力学和作用，2）效应介导的PB形成调节和3）PB和自噬之间的相互作用，所有这些都在兼容的植物-细菌相互作用的背景下进行。拟议项目分为三个工作包，分别对应上述三个目标。第一部分将研究感染后组装的 PB 的动态、免疫参与和组成。 PB 形成的动态将通过共聚焦显微镜确定；通过表征 PB 缺陷拟南芥突变体的防御反应和转录组特征来参与免疫；分别通过质谱和 RNA 测序分析纯化 PB 的蛋白质和 RNA 组成。在该项目的第二部分中，将筛选 Pst 效应器单独调节 PB 形成、与 PB 标记共定位以及与 PB 成分物理相互作用的能力。这种调节背后的机制将在 HopM1 的情况下得到进一步研究，HopM1 是第一个被识别的能够与 PB 结合并调节其组装的效应器。在该项目的第三部分中，基于PB与选择性自噬受体NBR1相互作用和共定位的初步结果，将探讨PB形成与自噬之间的相互作用。为此，将生成表达 PB 标记和 NBR1 的转基因植物以及相应突变体的不同组合，并对其进行表征，以确定每个过程彼此之间的遗传贡献。总而言之，该项目构成了一项创新且全面的策略，首次描述了 PB 在相容的植物-病原体相互作用中的作用，并确定了 PB 与自噬之间的潜在相互作用。