Arabidopsis SYP121 acts as an ROP2 effector in the regulation of root hair tip growth  

作　　者：Xiankui Cui Shuwei Wang Yaohui Huang Xuening Ding Zirong Wang Lidan Zheng Yujing Bi Fanghui Ge Lei Zhu Ming Yuan Shaul Yalovsky Ying Fu 

机构地区：[1]State Key Laboratory of Plant Physiology and Biochemistry,College of Biological Sciences,China Agricultural University,Beijing 100193,China [2]Joint Laboratory for International Cooperation in Crop Molecular Breeding,Ministry of Education,China Agricultural University,Beijing 100193,China [3]Department of Plant Sciences,Tel Aviv University,Tel Aviv 69978,Israel

出　　处：《Molecular Plant》2022年第6期1008-1023,共16页分子植物（英文版）

基　　金：supported by the National Natural Science Foundation of China(grant no.32061143018 and 91854119 to Y.F.);a China Postdoctoral Science Foundationgrant(2016M591291 to S.W.).Noconflict of interest declared.

摘　　要：Tip growth is an extreme form of polarized cell expansion that occurs in all eukaryotic kingdoms to generate highly elongated tubular cells with specialized functions, including fungal hyphae, animal neurons, plant pollen tubes, and root hairs (RHs). RHs are tubular structures that protrude from the root epidermis to facilitate water and nutrient uptake, microbial interactions, and plant anchorage. RH tip growth requires polarized vesicle targeting and active exocytosis at apical growth sites. However, how apical exocytosis is spatially and temporally controlled during tip growth remains elusive. Here, we report that the Qa-Soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) SYP121 acts as an effector of Rho of Plants 2 (ROP2), mediating the regulation of RH tip growth. We show that active ROP2 promotes SYP121 targeting to the apical plasma membrane. Moreover, ROP2 directly interacts with SYP121 and promotes the interaction between SYP121 and the R-SNARE VAMP722 to form a SNARE complex, probably by facilitating the release of the Sec1/Munc18 protein SEC11, which suppresses the function of SYP121. Thus, the ROP2-SYP121 pathway facilitates exocytic trafficking during RH tip growth. Our study uncovers a direct link between an ROP GTPase and vesicular trafficking and a new mechanism for the control of apical exocytosis, whereby ROP GTPase signaling spatially regulates SNARE complex assembly and the polar distribution of a Q-SNARE.

关 键 词：ROP GTPase SYP121 SNARE protein EXOCYTOSIS root hair tip growth 

分 类 号：Q94[生物学—植物学]