MLO Signaling in Polarized Plasma Membrane Domains

人类利用植物的力量，通过授粉的直接产物种子来提供大部分热量。植物扎根于地方，因此不断受到自然界生物和非生物压力源的攻击，同时也努力生长和繁殖。随着世界人口在不断变化的气候中持续增长，确保粮食安全的能力依赖于更好地了解植物细胞如何对来自其环境的信号做出适当反应。该项目使用授粉和尖端生长细胞作为模型系统，解剖植物细胞如何感知来自其他细胞的信号，并扩展它们的反应，以促进有益的相互作用和阻止有害的相互作用。如果全球气候变化以目前的速度持续下去，这项研究有可能通过引导新的方法来增强植物与生物在极端环境中有益的相互作用，从而影响社会。除了通过本科生、研究生和博士后的直接参与来培养下一代科学家之外，该项目还将通过在市中心社区中心的暑期教育推广和指导计划，加强高中阶段少数族裔的STEM参与和教育。受体样激酶（RLKs）在感知和反应入侵生物分泌的外部信号或细胞壁干扰中起关键作用。FERONIA （FER）和相关的RLKs被认为是细胞外扰动的传感器，触发信号转导级联，导致与入侵细胞的通信。在授粉过程中，FER信号传导的一个结果是信号介导MLO蛋白NORTIA转运到雌性配子体协同细胞的极化膜结构域。ferr介导的MLO蛋白运输到离散的极性膜结构域可能作为一种机制来提高细胞外反应的体积。然而，关于MLO蛋白在植物其他部位作为FER信号放大器的程度，目前还缺乏知识。本项目的总体目标是了解RLK信号与MLO在极化膜域的积累和功能之间的联系。核心假设是，MLO将FER信号放大到细胞外空间是RLK调节植物与生物在极化膜域的相互作用和极化细胞扩增的共同机制，并调节细胞对外部信号的反应。总体目标将通过三个具体目标来实现：1)测试FER/MLO信号模块在植物-生物相互作用和尖端生长细胞中的保护作用；2)确定极化膜域中FER和MLO活性的交集；3)鉴定参与极化膜结构域MLO功能的新蛋白。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Humans have harnessed the power of plants to provide the bulk of their calories through seeds which are a direct product of pollination. Plants are rooted in place and are therefore continually assaulted by both biotic and abiotic stressors in nature while also striving to grow and reproduce. As the world population continues to grow in a changing climate, the ability to ensure food security relies on a better understanding of how plant cells make the appropriate response to signals from their environment. This project uses pollination and tip-growing cells as model systems for dissecting how plant cells perceive signals from other cells and scale their responses to promote beneficial interactions and discourage harmful interactions. This research has the potential to impact society by leading to new approaches for enhancing beneficial plant-biotic interactions in the extreme environments that plants will face if global climate change continues at its current pace. In addition to training the next generation of scientists through direct participation of undergraduates, graduate students, and a postdoc, this project will also enhance STEM participation and education of underrepresented minorities at the high school level through a summer educational outreach and mentoring program at an inner city community center.Receptor-like kinases (RLKs) play key roles in perceiving and reacting to external signals secreted from an invading organism or cell wall perturbations that result from attempted invasions. FERONIA (FER) and related RLKs have been proposed to be sensors of extracellular perturbations that trigger a signal transduction cascade that results in communication with the invading cell. In pollination, one outcome of FER signaling is the signal-mediated trafficking of the MLO protein NORTIA to a polarized membrane domain in the synergid cells of the female gametophyte. FER-mediated trafficking of MLO proteins to discrete polar membrane domains may act as a mechanism to turn up the volume on the extracellular response. However, knowledge is lacking on the extent to which MLO proteins act as amplifiers of FER signaling in other parts of the plant. The overall objective of this project is to understand the link between RLK signaling and MLO accumulation and function at polarized membrane domains. The central hypothesis is that MLO amplification of FER signals to the extracellular space is a common mechanism in RLK regulation of both plant-biotic interactions at polarized membrane domains and polarized cell expansion and acts to modulate the cellular response to external signals. The overall objective will be met through three specific aims: 1) testing conservation of the FER/MLO signaling module in plant-biotic interactions and tip-growing cells; 2) determining the intersection of FER and MLO activities in polarized membrane domains; and 3) identifying new proteins involved in MLO function in polarized membrane domains.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.