A DTX/MATE-Type Transporter Facilitates Abscisic Acid Efflux and Modulates ABA Sensitivity and Drought Tolerance in Arabidopsis

作     者：Haiwen Zhang Huifen Zhu Yajun Pan Yuexuan Yu Sheng Luan Legong Li 

作者机构：College of Life Sciences Capital Normal University Beijing 100048 China Department of Plant and Microbial Biology University of California Berkeley CA 94720 USA Institute of Plant Molecular Biology School of Life Sciences Nanjing University Nanjing 210093 China 

出 版 物：《Molecular Plant》 (分子植物（英文版）)

年 卷 期：2014年第7卷第10期

页      面：1522-1532页

核心收录：

学科分类：0710[理学-生物学] 07[理学] 09[农学] 071007[理学-遗传学] 0901[农学-作物学] 0902[农学-园艺学] 090102[农学-作物遗传育种] 

基　　金：supported by the National Program on Key Basic Research Projects to L.L the National Science Foundation of China to L.L from the National Science Foundation to S.L the China Postdoctoral Science Foundation Grant Project to H.Z 

主　　题：hormone biology molecular transport Arabidopsis. 

摘      要：Abscisic acid （ABA） regulates numerous physiological and developmental processes in plants. Recent studies identify intracellular ABA receptors, implicating the transport of ABA across cell membranes as crucial for ABA sensing and response. Here, we report that a DTX/Multidrug and Toxic Compound Extrusion （MATE） family member in Arabidopsis thaliana, AtDTX50, functions as an ABA efflux transporter. When expressed heterologously in both an Escherichia coli strain and Xenopus oocyte cells, AtDTX50 was found to facilitate ABA efflux. Furthermore, dtx50 mutant mesophyll cells preloaded with ABA released less ABA compared with the wild-type （WT）. The AtDTX50 gene was expressed mainly in the vascular tissues and guard ceils and its expression was strongly up-regulated by exogenous ABA. The AtDTX50：：GFP fusion protein was localized predominantly to the plasma membrane. The dtx50 mutant plants were observed to be more sensitive to ABA in growth inhibition. In addition, compared with the WT, dtx50 mutant plants were more tolerant to drought with lower stomatal conductance, consistent with its function as an ABA efflux carrier in guard cells.