How does a plant pathogen hijack its host's secretory pathway?

植物病原体如何劫持宿主的分泌途径？

• 批准号: 2110940
• 金额: --
• 依托单位: University of Leeds
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2018
• 资助国家: 英国
• 起止时间: 2018 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2110940
• 关键词: How; does; plant; pathogen; hijack

Background. Plant-parasitic nematodes are important agricultural pests that have complex interactions with their host. The most damaging species secrete effector proteins into their host roots to induce and maintain unique structures, termed feeding-sites. A striking feature of the affected root cells is proliferated cytoplasm enriched in organelles, formed at the expense of the central vacuole. Our core hypothesis is that nematodes can use effectors to re-programme membrane trafficking of plant cells to achieve this fundamental remodelling whilst also exploiting the secretory pathway to exert effector function.Objectives.1. Characterise the early changes to secretory pathway organelles that occur in plant parasitic nematode feeding sites.2. Investigate the role of nematode effectors in influencing secretion, ER retention and vacuolar transport.3. Elucidate the pathways by which nematode effectors introduced into the host cytoplasm are delivered to the apoplast.Novelty. The mechanism driving the cytological changes that occur in nematode feeding sites, and the specific effectors involved, are currently unknown. The work will also provide new insights into protein trafficking pathways in plants. Timeliness. The project is facilitated by tools recently developed by the Denecke Group, such as the full portfolio of vacuolar and endosomal markers and secretory cargo protoplast assays.Experimental Approach. Double-fluorescent reporter lines of Arabidopsis with different secretory pathway organelles marked will be infected with nematodes. Confocal microscopy will be used to examine subcellular changes taking place during the early stages of feeding site formation. A range of nematode effectors will be expressed in secretory cargo protoplast assays to identify those that influence vacuolar and/or ER function. Yeast-2-hybrid analysis will identify plant interacting partners for effectors of interest - confirmed by coimmunoprecipitation. Protoplast secretion assays using native and mutant effectors will define the export pathway of nematode effectors that function in the apoplast despite being delivered into the cytoplasm.The project is built on the hypothesis that plant parasitic nematodes can re-programme embrane trafficking of host plant cells so that the normal route to maintain the central vacuole is eliminated to enable expansion of the plasma membrane and the ribosome rich cytosol. The student will test this hypothesis and establish if the secreted protein effectors produced by the nematode are responsible for the fundamental reprogramming of the plant secretory pathway. By dissecting the mechanisms involved in this parasitic interaction, the project will shed new light on a key aspect of plant cell biology.

背景。植物寄生线虫是重要的农业害虫，与寄主有复杂的相互作用。最具破坏性的物种分泌效应蛋白到它们的宿主根部，以诱导和维持独特的结构，称为取食部位。受影响的根细胞的一个显著特征是细胞器丰富的细胞质增生，以牺牲中央液泡为代价形成。我们的核心假设是，线虫可以利用效应物重新编程植物细胞的膜运输，以实现这种基本的重塑，同时也利用分泌途径发挥效应功能。描述植物寄生线虫取食部位分泌途径细胞器的早期变化。研究线虫效应物在影响分泌、内质网滞留和液泡运输中的作用。阐明引入宿主细胞质的线虫效应物传递到胞外体的途径。驱动线虫取食部位细胞学变化的机制，以及所涉及的具体效应物，目前尚不清楚。这项工作还将为植物蛋白质运输途径提供新的见解。及时性。该项目由Denecke集团最近开发的工具促进，如液泡和内体标记和分泌货物原生质体测定的完整组合。实验方法。标记不同分泌途径细胞器的拟南芥双荧光报告系会被线虫感染。共聚焦显微镜将用于检查在进食部位形成的早期阶段发生的亚细胞变化。一系列线虫效应物将在分泌货物原生质体检测中表达，以确定那些影响液泡和/或内质网功能的效应物。酵母-2杂交分析将确定感兴趣效应物的植物相互作用伙伴-通过共免疫沉淀确认。原生质体分泌分析使用原生和突变效应物将定义线虫效应物的输出途径，这些效应物在外质体中起作用，尽管被输送到细胞质中。该项目建立在假设植物寄生线虫可以重新编程寄主植物细胞的膜运输，从而消除维持中央液泡的正常途径，从而使质膜和富含核糖体的细胞质扩张。学生将测试这一假设，并确定线虫产生的分泌蛋白效应器是否负责植物分泌途径的基本重编程。通过剖析这种寄生相互作用的机制，该项目将揭示植物细胞生物学的一个关键方面。