Plasmodesmata as regulators of the growth-defence trade-off

胞间连丝作为生长-防御权衡的调节者

基本信息

批准号：
BB/X007685/1
负责人：
Christine Faulkner
金额：
$ 70.07万
依托单位：
John Innes Centre
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2023
资助国家：
英国
起止时间：
2023 至无数据
项目状态：
未结题

来源：
https://gtr.ukri.org/projects?ref=BB%2FX007685%2F1
关键词：
Plasmodesmata regulators growth defence trade

项目摘要

Plant cells are connected to their neighbours for communication and resource exchange, with this interconnectivity enabling co-ordinated growth and responses across multicellular tissues and organs. Cell-to-cell connectivity is enabled by plasmodesmata, plasma membrane-lined 'tunnels' that connect neighbouring cells across the cell wall and establish both plasma membrane and cytoplasmic continuity between neighbouring cells. Plasmodesmata effectively act as 'sluice gates' to regulate the flux of soluble molecules, closing and opening in response to a range of stimuli. The plasma membrane that lines plasmodesmata is functionally distinct from the rest of the membrane, allowing discrete and independent functional control of their responses. Plasmodesmata respond to many stress signals by initiating a signalling cascade that results in their closure, and this was observed to be critical for optimal immune signalling when cells perceive microbe threats. In addition to contributing to immune responses, plasmodesmal closure induces cellular isolation that must limit the exchange of resources such as carbon, and signals relevant to other cellular processes. Indeed, plasmodesmata act as a key passage through which sugar is distributed through a plant, raising the possibility that plasmodesmal closure carries significant consequences for carbon allocation in a context in which sugars are required to maintain growth. We recently discovered that by contrast with mature leaves, young leaves do not close their plasmodesmata in response to microbe perception. This supports the hypothesis that young tissues prioritise growth over defence, keeping plasmodesmata open to maintain the flow of sugar from source tissues to sustain growth processes. This, and the observation that plasmodesmal responses are independently regulated, suggests plasmodesmata are a central component of the mechanism by which the trade-off between growth and defence is balanced.The proposal will test this model, determining whether plasmodesmal closure is differently regulated across a range of developmental stages, physiological states and stress contexts. We will exploit our knowledge that plasmodesmata regulate the amplitude and timing of immune responses, to profile how plasmodesmal manipulation perturbs the growth-defence trade-off in sink tissues.How plasmodesmata can differentially respond must depend on the machinery present to execute a response and therefore we will characterise the different protein composition of plasmodesmata in tissues that do and do not close their plasmodesmata. Further, as the structure of plasmodesmata has been shown to have some correlation with the sink or source status, we will profile plasmodesmal structure to identify what features define plasmodesmal responsiveness. Thus, we will define the mechanistic elements required for a plasmodesma to respond to stress. This proposal will detail how plasmodesmata regulate carbon allocation in an immune signalling context and how they function as a component of the signalling hub that controls the growth-defence trade-off. Beyond immune responses, regulation of carbon allocation is relevant to a range of physiological contexts and this proposal will therefore establish general understanding of how carbon resources are partitioned and consumed, finding application across plant growth, development and environmental responses.

植物细胞与邻居连接进行通信和资源交换，这种互连性使得在多细胞组织和器官之间的协调生长和反应。细胞对细胞连接性由质层膜，质膜衬里的“隧道”启用，这些隧道将相邻细胞连接在细胞壁上，并在相邻细胞之间建立质膜和细胞质连续性。疟原虫有效地充当“闸门”，以调节可溶性分子的通量，以响应一系列刺激而闭合和开口。质膜质膜在功能上与膜的其余部分不同，从而允许对其响应的离散和独立的功能控制。 plasmodesmata通过启动导致其闭合的信号传导级联反应，对许多应力信号做出反应，当细胞感知微生物威胁时，观察到这对于最佳免疫信号传导至关重要。除了有助于免疫反应外，浆膜闭合还会引起细胞分离，必须限制碳等资源的交换，以及与其他细胞过程相关的信号。实际上，疟原虫是通过植物分布糖的关键通过，从而提高了质体闭合在需要糖以维持生长的情况下对碳分配带来重大影响。我们最近发现，与成熟的叶子相比，幼叶不会因微生物感知而关闭其质量。这支持了以下假设：幼小的组织优先考虑生长而不是防御，从而保持质量肿瘤开放，以维持糖从源组织的流动以维持生长过程。这是对质体响应受到独立调节的观察，表明静脉模拟是该机制的核心组成部分，通过该机制，生长和防御之间的权衡是平衡的。该建议将测试该模型，确定质量性闭合是否在发育阶段，生理状态和压力状态和压力环境的范围内都不同地调节。 We will exploit our knowledge that plasmodesmata regulate the amplitude and timing of immune responses, to profile how plasmodesmal manipulation perturbs the growth-defence trade-off in sink tissues.How plasmodesmata can differentially respond must depend on the machinery present to execute a response and therefore we will characterise the different protein composition of plasmodesmata in tissues that do and do not close their plasmodesmata。此外，由于已证明质量化的结构与接收器或源状态有一定的相关性，因此我们将介绍质体结构，以确定哪些特征定义了质量响应性。因此，我们将定义质体响应压力所需的机械元素。该提案将详细说明质量量如何在免疫信号环境中调节碳分配，以及它们如何作为控制生长防御权衡的信号枢纽的组成部分。除了免疫反应之外，碳分配的调节还与一系列生理环境有关，因此该提案将确定对碳资源如何分配和消耗的一般理解，从而在植物生长，开发和环境反应中找到应用。