Maintenance of mesophyll potassium and regulation of plasma membrane H^+-ATPase are associated with physiological responses of tea plants to drought and subsequent rehydration  

作　　者：Xianchen Zhang Honghong Wu Linmu Chen Linlin Liu Xiaochun Wan 

机构地区：[1]State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University [2]Department of Botany and Plant Sciences, University of California

出　　处：《The Crop Journal》2018年第6期611-620,共10页作物学报（英文版）

基　　金：supported mainly by the Science Foundation for Anhui Province(KJ2017A126)to Xianchen Zhang; the Opening Fund of State Key Lab of Tea Plants Biology and Utilization at Anhui Agricultural University(SKLTOF20170112)to Honghong Wu;supported by the National Natural Science Foundation of China(11008389);the National Basic Research Program of China(11000206)to Xiaochun Wan

摘　　要：Drought stress is one of the main factors limiting yield in tea plants. The plant cell's ability to preserve K^+homeostasis is an important strategy for coping with drought stress. Plasma membrane H^+-ATPase in the mesophyll cell is important for maintaining membrane potential to regulate K^+transmembrane transport. However, no research to date has investigated the possible relationship between plasma membrane H^+-ATPase and mesophyll K^+retention in tea plants under drought and subsequent rehydration conditions. In our experiment, drought stress inhibited plasma membrane H^+-ATPase activities and induced net H^+influx, leading to membrane potential depolarization and inducing a massive K^+efflux in tea plant mesophyll cells. Subsequent rehydration increased plasma membrane H^+-ATPase activity and induced net H^+efflux, leading to membrane potential hyperpolarization and thus lowering K^+loss. A first downregulated and then upregulated plasma membrane H^+-ATPase protein expression level was also observed under drought and subsequent rehydration treatment, a finding in agreement with the change of measured plasma membrane H^+-ATPase activities. Taken together, our results suggest that maintenance of mesophyll K^+in tea plants under drought and rehydration is associated with regulation of plasma membrane H^+-ATPase activity.Drought stress is one of the main factors limiting yield in tea plants. The plant cell's ability to preserve K^+homeostasis is an important strategy for coping with drought stress. Plasma membrane H^+-ATPase in the mesophyll cell is important for maintaining membrane potential to regulate K^+transmembrane transport. However, no research to date has investigated the possible relationship between plasma membrane H^+-ATPase and mesophyll K^+retention in tea plants under drought and subsequent rehydration conditions. In our experiment, drought stress inhibited plasma membrane H^+-ATPase activities and induced net H^+influx, leading to membrane potential depolarization and inducing a massive K^+efflux in tea plant mesophyll cells. Subsequent rehydration increased plasma membrane H^+-ATPase activity and induced net H^+efflux, leading to membrane potential hyperpolarization and thus lowering K^+loss. A first downregulated and then upregulated plasma membrane H^+-ATPase protein expression level was also observed under drought and subsequent rehydration treatment, a finding in agreement with the change of measured plasma membrane H^+-ATPase activities. Taken together, our results suggest that maintenance of mesophyll K^+in tea plants under drought and rehydration is associated with regulation of plasma membrane H^+-ATPase activity.

关 键 词：DROUGHT stress H^+-ATPASE MEMBRANE potential POTASSIUM REHYDRATION 

分 类 号：S[农业科学]