Arabidopsis AIP1-1 regulates the organization of apical actin filaments by promoting their turnover in pollen tubes

作     者：Min Diao Xin Li Shanjin Huang Min Diao;Xin Li;Shanjin Huang

作者机构：Institute of BotanyChinese Academy of SciencesBeijing 100093China Center for Plant BiologySchool of Life SciencesTsinghua UniversityBeijing 100084China University of Chinese Academy of SciencesBeijing 100049China iHuman InstituteShanghai Tech UniversityShanghai 201210China 

出 版 物：《Science China(Life Sciences)》 (中国科学（生命科学英文版）)

年 卷 期：2020年第63卷第2期

页      面：239-250页

核心收录：

学科分类：09[农学] 0903[农学-农业资源与环境] 

基　　金：supported by a grant from the National Natural Science Foundation of China(31671390) funding from the Tsinghua-Peking Joint Center for Life Sciences 

主　　题：pollen tube apical actin structure actin dynamics actin turnover ADF AIP1 

摘      要：Apical actin filaments are highly dynamic structures that are crucial for rapid pollen tube growth, but the mechanisms regulating their dynamics and spatial organization remain incompletely understood. We here identify that AtAIP1-1 is important for regulating the turnover and organization of apical actin filaments in pollen tubes. AtAIP1-1 is distributed uniformly in the pollen tube and loss of function of AtAIP1-1 affects the organization of the actin cytoskeleton in the pollen tube. Specifically, actin filaments became disorganized within the apical region of aip1-1 pollen tubes. Consistent with the role of apical actin filaments in spatially restricting vesicles in pollen tubes, the apical region occupied by vesicles becomes enlarged in aip1-1 pollen tubes compared to WT. Using ADF1 as a representative actin-depolymerizing factor, we demonstrate that AtAIP1-1 enhances ADF1-mediated actin depolymerization and filament severing in vitro, although AtAIP1-1 alone does not have an obvious effect on actin assembly and disassembly. The dynamics of apical actin filaments are reduced in aip1-1 pollen tubes compared to WT. Our study suggests that AtAIP1-1 works together with ADF to act as a module in regulating the dynamics of apical actin filaments to facilitate the construction of the unique apical actin structure in the pollen tube.