To the core of the cell wall integrity pathways in land plants

陆地植物细胞壁完整性途径的核心

• 批准号: 451735121
• 负责人: Privatdozent Dr. Aurélien Boisson-Dernier, Ph.D.
• 金额: --
• 依托单位: Institut Sophia Agrobiotech - INRAE PACA
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2020
• 资助国家: 德国
• 起止时间: 2019-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/451735121?language=en
• 关键词: core; cell; wall; integrity; pathways

In plants, cell growth is a complex process that requires the turgor-derived stretching of the pre-existing cell wall to be compensated by the secretion of new cell wall material. Higher plants have developed cell wall integrity mechanisms that monitor and coordinate the performance of their extracellular cell wall with their intracellular activities to avoid growth accidents. These mechanisms are orchestrated by a complex and robust interplay between the transmembrane malectin-like receptors (MLRs), their secreted peptide ligands of the Rapid Alkalinisation Factor (RALF) family and downstream effectors such as the receptor-like cytoplasmic kinase MARIS (MRI) of the PTI1-like family. In the flowering plant model Arabidopsis thaliana, the MLRs AtFERONIA (AtFER) and its closest homologues AtANXUR1/2 (AtANX1/2) function upstream of AtMRI to govern the cell wall integrity pathways of the tip-growing root hairs and pollen tubes, respectively. However, these pathways remain particularly hard to decipher due to complex, sometimes partial, functional redundancy between the multigene family members of regulators.Recently, we demonstrated that cell wall integrity of the tip-growing rhizoids in the early diverging land plant Marchantia polymorpha, also required the receptor-like kinases MpFER and MpMRI, both unique representatives of the MLR and PTI1-like families in Marchantia. Thus, a genetic program maintaining rhizoid cell wall integrity was established early during land plant evolution and then adopted by vascular plants for root hair growth control and much later by pollen tubes, the male gametophyte of flowering plants.Here, we propose to exploit the morphological and genetic simplicity of Marchantia and the conservation of the MLR/PTI1-like genetic pathway by using MpFER and MpMRI as anchor points for protein-protein interactions and genetic screens combined with Next Generation Sequencing strategies. These screens will provide us with new interactors and downstream components of the MLR/PTI1-like module that governs cell wall integrity mechanisms. Comparatively studying the roles of these new regulators (and their homologues) in both Marchantia and Arabidopsis in the context of tip-growth and other developmental/environmental responses will be fundamental for apprehending cell growth control in plants.

在植物中，细胞生长是一个复杂的过程，它需要先前存在的细胞壁的膨胀性拉伸来通过分泌新的细胞壁物质来补偿。高等植物已经发展出细胞壁完整性机制来监测和协调细胞外细胞壁和细胞内活动的表现，以避免生长事故。这些机制是由跨膜雄激素样受体（MLRs）、它们分泌的快速碱化因子（RALF）家族的肽配体和下游效应物（如pti1样家族的受体样细胞质激酶MARIS (MRI)）之间复杂而强大的相互作用所协调的。在开花植物模型拟南芥中，MLRs AtFERONIA （AtFER）及其最接近的同源基因AtANXUR1/2 （AtANX1/2）在AtMRI上游发挥作用，分别调控顶端生长的根毛和花花管的细胞壁完整性通路。然而，由于调节因子的多基因家族成员之间的复杂，有时是部分的功能冗余，这些途径仍然特别难以破译。最近，我们证明了早期分化的陆地植物多形地豆（Marchantia polymorpha）顶端生长的根状体细胞壁的完整性也需要受体样激酶MpFER和MpMRI，这两个受体样激酶都是地豆中MLR和pti1样家族的独特代表。因此，维持根状细胞壁完整性的遗传程序是在陆地植物进化早期建立的，然后被维管植物用于控制根毛生长，后来被花粉管（开花植物的雄配子体）所采用。在这里，我们建议利用Marchantia的形态和遗传简单性以及MLR/ pti1样遗传途径的保守性，通过MpFER和MpMRI作为蛋白质-蛋白质相互作用和遗传筛选结合下一代测序策略的锚点。这些筛选将为我们提供新的相互作用器和控制细胞壁完整性机制的MLR/ pti1样模块的下游组件。比较研究这些新的调控因子（及其同源物）在麻地兰和拟南芥中在尖端生长和其他发育/环境响应中的作用，将是理解植物细胞生长控制的基础。