Plant HAK/KUP/KT family members function as plasma membrane(PM)H^(+)/K^(+)symporters and may modulate chemiosmotically-driven polar auxin transport(PAT).Here,we show that inactivation of OsHAK5,a rice K^(+)transporter...Plant HAK/KUP/KT family members function as plasma membrane(PM)H^(+)/K^(+)symporters and may modulate chemiosmotically-driven polar auxin transport(PAT).Here,we show that inactivation of OsHAK5,a rice K^(+)transporter gene,decreased rootward and shootward PAT,tiller number,and the length of both lateral roots and root hairs,while OsHAK5 overexpression increased PAT,tiller number,and root hair length,irrespective of the K^(+)supply.Inhibitors of ATP-binding-cassette type-B transporters,NPA and BUM,abolished the OsHAK5-overexpression effect on PAT.The mechanistic basis of these changes included the OsHAK5-mediated decrease of transmembrane potential(depolarization),increase of extracellular pH,and increase of PM-ATPase activity.These findings highlight the dual roles of OsHAK5 in altering cellular chemiosmotic gradients(generated continuously by PM H^(+)-ATPase)and regulating ATP-dependent auxin transport.Both functions may underlie the prominent effect of OsHAK5 on rice architecture,which may be exploited in the future to increase crop yield via genetic manipulations.展开更多
基金supported by the National Key Research and Development Program of China(grant no.2016YFD0100700)National Natural Science Foundation of China(grant nos.31361140357,31872166,31800584)+2 种基金the 111 Project(grant no.12009)Innovative Research Team Development Plan of the Ministry of Education of China.supported by the Israel Science Foundation–Natural Science Foundation of China Joint Research Program(grant no.1842/13).
文摘Plant HAK/KUP/KT family members function as plasma membrane(PM)H^(+)/K^(+)symporters and may modulate chemiosmotically-driven polar auxin transport(PAT).Here,we show that inactivation of OsHAK5,a rice K^(+)transporter gene,decreased rootward and shootward PAT,tiller number,and the length of both lateral roots and root hairs,while OsHAK5 overexpression increased PAT,tiller number,and root hair length,irrespective of the K^(+)supply.Inhibitors of ATP-binding-cassette type-B transporters,NPA and BUM,abolished the OsHAK5-overexpression effect on PAT.The mechanistic basis of these changes included the OsHAK5-mediated decrease of transmembrane potential(depolarization),increase of extracellular pH,and increase of PM-ATPase activity.These findings highlight the dual roles of OsHAK5 in altering cellular chemiosmotic gradients(generated continuously by PM H^(+)-ATPase)and regulating ATP-dependent auxin transport.Both functions may underlie the prominent effect of OsHAK5 on rice architecture,which may be exploited in the future to increase crop yield via genetic manipulations.
