Actin-depolymerizing factors 8 and 11 promote root hair elongation at high pH  

作　　者：Dong Qian Tian Li Chen Zheng Yue Niu Yingzhi Niu Chengying Li Muxuan Wang Yang Yang Lizhe An Yun Xiang 

机构地区：[1]Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations,School of Life Sciences,Lanzhou University,Lanzhou 730000,China [2]These authors contributed equally to this article

出　　处：《Plant Communications》2024年第3期232-247,共16页植物通讯（英文）

基　　金：supported by the National Natural Science Foundation of China (grants 31970195,31700161,32170331,32170330,and 6232300303);Hainan Yazhou Bay Seed Lab grant B23YQ1510,China Postdoctoral Science Foundation grant 2022M720058;the Fundamental Research Funds for the Central Universities grants lzujbky-2022-ey06,lzujbky-2023-I02 and lzuibky-2023-pd10.

摘　　要：A root hair is a polarly elongated single-celled structure that derives from a root epidermal cell and func-tions in uptake of water and nutrients from the surrounding environment.Previous reports have demon-strated that short periods of high pH inhibit root hair extension;but the effects of long-term high-pH treat-ment on root hair growth are still unclear.Here,we report that the duration of root hair elongation is signicantly prolonged with increasing external pH,which counteracts the effect of decreasing root hair elongation rate and ultimately produces longer root hairs,whereas loss of actin-depolymerizing factor 8 and 11(ADF8/11)function causes shortening of root hair length at high pH(pH 7.4).Accumulation of ADF8/11 at the tips of root hairs is inhibited by high pH,and increasing environmental pH affects the actinlament(F-actin)meshwork at the root hair tip.At high pH,the tip-focused F-actin meshwork is absent in root hairs of the adf8/11 mutant,actinlaments are disordered at the adf8/11 root hair tips,and actin turn-over is attenuated.Secretory and recycling vesicles do not aggregate in the apical region of adf8/11 root hairs at high pH.Together,our results suggest that,under long-term exposure to high extracellular pH,ADF8/11 may establish and maintain the tip-focused F-actin meshwork to regulate polar trafcking of secretory/recycling vesicles at the root hair tips,thereby promoting root hair elongation.

关 键 词：PH ADF ACTIN Rab GTPase VESICLE root hair 

分 类 号：Q94[生物学—植物学]