模式识别受体在植物的天然免疫中发挥重要的作用。FLS2是目前研究较为清楚的模式识别受体，能够特异性的识别鞭毛蛋白N端高度保守的22个氨基酸（flg22），并引发胞吞和免疫反应。细胞骨架是在真核生物中普遍存在的网架结构，作为细胞质膜组织与动态的重要调节因子，在植物的免疫反应过程中发挥着重要的作用。然而，由于研究方法和手段的限制，细胞骨架是如何参与调控FLS2蛋白的胞吞缺乏深入研究，同时，细胞骨架在flg22诱导的植物免疫过程中发挥的作用也尚不清晰。因此，针对前人工作的不足，本项目将着重开展3方面的研究：（1）细胞骨架对FLS2在膜上分布和运动的调控作用；（2）细胞骨架对FLS2蛋白胞吞的影响；（3）细胞骨架在flg22诱导的植物免疫过程中的调控作用。本项目综合采用VA-TIRFM、SIM、FCS等新技术，在单分子水平上，探讨细胞骨架在FLS2蛋白运动、胞吞中的作用，旨在阐明细胞骨架在植物免疫信号传导中的调控机制，为深入了解植物响应生物胁迫的分子机制提供了重要理论依据。

Pattern-recognition receptors (PRR) play an important role in innate immunity. FLS2 is initially identified PRR in Arabidopsis and it can recognize flagellin via the direct binding of an immunogenic epitope defined by a conserved stretch of 22 amino acids, referred to as flg22, located closely to the N terminus of flagellin. Flg22 binding to FLS2 can lead to FLS2 endocytosis and trigger immune signaling. Cytoskeleton as a dynamically changing network structure in eukaryotic cells, is an important regulator of plasma membrane organization and dynamics having key roles in plant perception and resistance during the infection of pathogens. However, due to lacking of related methods, the regulatory mechanism of cytoskeleton on membrane protein FLS2 endocytosis and flg22-induced immunity in plant cells remains largely undefined. In consideration of the insufficiency of previous studies, this project focuses on three aspects of research. First, we will investigate the effects of cytoskeleton on FLS2 spatial distribution and movement in different scale. Then, we will detect the effects of cytoskeleton on FLS2 endocytosis. Finally, we will further explore the function of cytoskeleton in regulating flg22-induced immune. During the course of the investigation, some new methods and techniques including variable-angle total internal reflection fluorescence microscopy (VA-TIRFM), hessain-structured illumination microscopy (SIM) and fluorescence correlation spectroscopy (FCS) will be used to determine the roles of cytoskeleton in FLS2 the spatio-temporal dynamics and endocytosis at single-molecular level. The result will elucidate the regulatory mechanisms of cytoskeleton involved in plant immunity response, and provide new theoretical basis for improving the regulatory schemes of plant biological stress response.