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 ...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.展开更多
Dear Editor, Root hairs create an enormous surface area to aid plants in nutrient and water acquisition, anchorage in the soil, and microbe interactions. Root hairs develop in two stages, including initiation and tip ...Dear Editor, Root hairs create an enormous surface area to aid plants in nutrient and water acquisition, anchorage in the soil, and microbe interactions. Root hairs develop in two stages, including initiation and tip growth. Initiation occurs when a portion of genetically determined epidermal cells develop wall loosening and form a disc-shaped area of cell swelling.展开更多
文摘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.
基金This work was supported by the National Key Research and Development Program of China （2016YFD0300102-3） and National Natural Science Foundation of China grants 31270297, 31470356 （to L,-G.L.） and a grant from the National Science Foundation IOS1339239 （to S.L.）.
文摘Dear Editor, Root hairs create an enormous surface area to aid plants in nutrient and water acquisition, anchorage in the soil, and microbe interactions. Root hairs develop in two stages, including initiation and tip growth. Initiation occurs when a portion of genetically determined epidermal cells develop wall loosening and form a disc-shaped area of cell swelling.
