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

• 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

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.

植物细胞与其邻居相连以进行通信和资源交换，这种互连性可以实现多细胞组织和器官的协调生长和反应。细胞间的连接是通过胞间连丝实现的，胞间连丝是质膜内衬的“隧道”，它跨细胞壁连接相邻的细胞，并在相邻细胞之间建立质膜和细胞质的连续性。胞连丝有效地充当“闸门”来调节可溶性分子的流量，响应一系列刺激而关闭和打开。胞间连丝的质膜在功能上与膜的其余部分不同，允许对其反应进行离散且独立的功能控制。胞间连丝通过启动导致其关闭的信号级联反应来响应许多应激信号，并且观察到当细胞感知微生物威胁时，这对于最佳免疫信号传导至关重要。除了促进免疫反应之外，胞间连丝闭合还会诱导细胞隔离，这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。事实上，胞间连丝是糖在植物中分布的关键通道，这增加了胞间连丝闭合在需要糖来维持生长的情况下对碳分配产生重大影响的可能性。我们最近发现，与成熟的叶子相比，幼小的叶子不会响应微生物的感知而关闭其胞间连丝。这支持了这样的假设：年轻组织优先考虑生长而不是防御，保持胞间连丝开放以维持糖从源组织的流动以维持生长过程。这一点，以及胞间连丝反应是独立调节的观察结果表明，胞间连丝是平衡生长和防御之间平衡的机制的核心组成部分。该提案将测试这个模型，确定胞间连丝闭合是否在不同的环境中受到不同的调节。一系列发育阶段、生理状态和压力环境。我们将利用胞间连丝调节免疫反应的幅度和时间的知识，来分析胞间连丝的操纵如何扰乱库组织中的生长-防御权衡。胞间连丝如何做出不同的反应必须取决于存在的执行反应的机制，因此我们将描述关闭和不关闭胞间连丝的组织中胞间连丝的不同蛋白质组成。此外，由于胞间连丝的结构已被证明与汇或源状态有一定的相关性，我们将分析胞间连丝结构，以确定哪些特征定义胞间连丝反应性。因此，我们将定义胞间连丝响应应激所需的机制要素。该提案将详细说明胞间连丝如何在免疫信号传导背景下调节碳分配，以及它们如何作为控制生长与防御权衡的信号中枢的组成部分发挥作用。除了免疫反应之外，碳分配的调节还与一系列生理环境相关，因此该提案将建立对碳资源如何分配和消耗的一般理解，并在植物生长、发育和环境反应中找到应用。

项目成果

On the pixel selection criterion for the calculation of the Pearson's correlation coefficient in fluorescence microscopy.

关于荧光显微镜中皮尔逊相关系数计算的像素选择标准。

• DOI: http://dx.10.1111/jmi.13273
• 发表时间: 2024
• 期刊: Journal of microscopy
• 影响因子: 2
• 作者: Lopez SG