Venus Flytrap HKT1-Type Channel Provides for Prey Sodium Uptake into Carnivorous Plant Without Conflicting with Electrical Excitability

作     者：J. Bohm S. Scherzer S. Shabala E. Krol E. Neher T.D. Mueller R. Hedrich 

作者机构：Julius-yon-Sachs Institute Department for Molecular Plant Physiology and Biophysics University of Wurzburg Julius-von-Sachs Platz 2 97082 Wurzburg Germany School of Land and Food University of Tasmania Hobart TAS 7001 Australia Zoology Department College of Science King Saud University PO Box 2455 Riyadh 11451 Saudi Arabia Department for Membrane Biophysics Max Planck Institute for Biophysical Chemistry 37077 Goettingen Germany 

出 版 物：《Molecular Plant》 (分子植物（英文版）)

年 卷 期：2016年第9卷第3期

页      面：428-436页

核心收录：

学科分类：0831[工学-生物医学工程（可授工学、理学、医学学位）] 07[理学] 08[工学] 0713[理学-生态学] 

基　　金：supported by the European Research Council under the European Union’s Seventh Framework Program ERC Grant Agreement supported by the International Research Group Program Deanship of Scientific Research, King Saud University, Saudi Arabia (E.N.) by grants from the Australian Research Counci the Grain Research and Development Corporation (to S. Shabala.) 

主　　题：sodium channel HKT1 Dionaea muscipula action potential glands sodium uptake 

摘      要：The animal diet of the carnivorous Venus flytrap, Dionaea muscipula, contains a sodium load that enters the capture organ via an HKT1-type sodium channel, expressed in special epithelia cells on the inner trap lobe surface. DmHKT1 expression and sodium uptake activity is induced upon prey contact. Here, we analyzed the HKT1 properties required for prey sodium osmolyte management of carnivorous Dionaea. Analyses were based on homology modeling, generation of model-derived point mutants, and their functional testing in Xenopus oocytes. We showed that the wild-type HKT1 and its Na^＋- and K^＋-permeable mutants function as ion channels rather than K^＋ transporters driven by proton or sodium gradients. These structural and biophysical features of a high-capacity, Na^＋-selective ion channel enable Dionaea glands to manage prey-derived sodium loads without confounding the action potential-based information management of the flytrap.