Auxin is unique among plant hormones in that its function requires polarized transport across plant cells.A chemiosmotic model was proposed to explain how polar auxin transport is derived by the H^(+)gradient across t...Auxin is unique among plant hormones in that its function requires polarized transport across plant cells.A chemiosmotic model was proposed to explain how polar auxin transport is derived by the H^(+)gradient across the plasma membrane(PM)established by PM H^(+)-adenosine triphosphatases(ATPases).However,a classical genetic approach by mutations in PM H^(+)-ATPase members did not result in the ablation of polar auxin distribution,possibly due to functional redundancy in this gene family.To confirm the crucial role of PM H^(+)-ATPases in the polar auxin transport model,we employed a chemical genetic approach.Through a chemical screen,we identified protonstatin-1(PS-1),a selective small-molecule inhibitor of PM H^(+)-ATPase activity that inhibits auxin transport.Assays with transgenic plants and yeast strains showed that the activity of PM H^(+)-ATPases affects auxin uptake as well as acropetal and basipetal polar auxin transport.We propose that PS-1 can be used as a tool to interrogate the function of PM H^(+)-ATPases.Our results support the chemiosmotic model in which PM H^(+)-ATPase itself plays a fundamental role in polar auxin transport.展开更多
基金supported by the National Key Research and Development Program of China (2017YFA0505200 to X.L.)the National Natural Science Foundation of China (21625201, 219611 42010, 91853202 to X.L.+1 种基金32070301, 31872659 to Y.Y.)the Beijing Outstanding Young Scientist Program (BJJWZYJH01201910001001 to X.L.)
文摘Auxin is unique among plant hormones in that its function requires polarized transport across plant cells.A chemiosmotic model was proposed to explain how polar auxin transport is derived by the H^(+)gradient across the plasma membrane(PM)established by PM H^(+)-adenosine triphosphatases(ATPases).However,a classical genetic approach by mutations in PM H^(+)-ATPase members did not result in the ablation of polar auxin distribution,possibly due to functional redundancy in this gene family.To confirm the crucial role of PM H^(+)-ATPases in the polar auxin transport model,we employed a chemical genetic approach.Through a chemical screen,we identified protonstatin-1(PS-1),a selective small-molecule inhibitor of PM H^(+)-ATPase activity that inhibits auxin transport.Assays with transgenic plants and yeast strains showed that the activity of PM H^(+)-ATPases affects auxin uptake as well as acropetal and basipetal polar auxin transport.We propose that PS-1 can be used as a tool to interrogate the function of PM H^(+)-ATPases.Our results support the chemiosmotic model in which PM H^(+)-ATPase itself plays a fundamental role in polar auxin transport.
