title: Identification of a Stelar-Localized Transport Protein That Facilitates Root-to-Shoot Transfer of Chloride in Arabidopsis.
abstract: Under saline conditions, higher plants restrict the accumulation of chloride ions (Cl(-)) in the shoot by regulating their transfer from the root symplast into the xylem-associated apoplast. To identify molecular mechanisms underpinning this phenomenon, we undertook a transcriptional screen of salt stressed Arabidopsis (Arabidopsis thaliana) roots. Microarrays, quantitative RT-PCR, and promoter-GUS fusions identified a candidate gene involved in Cl(-) xylem loading from the Nitrate transporter 1/Peptide Transporter family (NPF2.4). This gene was highly expressed in the root stele compared to the cortex, and its expression decreased after exposure to NaCl or abscisic acid. NPF2.4 fused to fluorescent proteins, expressed either transiently or stably, was targeted to the plasma membrane. Electrophysiological analysis of NPF2.4 in Xenopus laevis oocytes suggested that NPF2.4 catalyzed passive Cl(-) efflux out of cells and was much less permeable to NO3(-). Shoot Cl(-) accumulation was decreased following NPF2.4 artificial microRNA knockdown, whereas it was increased by overexpression of NPF2.4. Taken together, these results suggest that NPF2.4 is involved in long-distance transport of Cl(-) in plants, playing a role in the loading and the regulation of Cl(-) loading into the xylem of Arabidopsis roots during salinity stress.
authors.affiliation: Australian Centre for Plant Functional Genomics (B.L., J.Q., U.B., M.H., A.E., D.J., M.T., S.J.R.), School of Agriculture, Food, and Wine (B.L., C.B., J.Q., U.B., M.H., A.E., G.M.M., D.J., S.W.H., M.T., M.G., S.J.R.), and ARC Centre of Excellence in Plant Energy Biology (C.B., J.Q., S.W.H., M.G.), University of Adelaide, SA 5064, Australia;Centre for Desert Agriculture, King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia (B.L., M.T.);School of BioSciences, University of Melbourne, Parkville, Vic 3010, Australia (A.A.T.J.); and Centre for Genomics and Systems Biology, New York University, New York 10003 (K.D.B.).
authors.forename: Bo
authors.initials: B
authors.lastname: Li
authors.affiliation: Australian Centre for Plant Functional Genomics (B.L., J.Q., U.B., M.H., A.E., D.J., M.T., S.J.R.), School of Agriculture, Food, and Wine (B.L., C.B., J.Q., U.B., M.H., A.E., G.M.M., D.J., S.W.H., M.T., M.G., S.J.R.), and ARC Centre of Excellence in Plant Energy Biology (C.B., J.Q., S.W.H., M.G.), University of Adelaide, SA 5064, Australia;Centre for Desert Agriculture, King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia (B.L., M.T.);School of BioSciences, University of Melbourne, Parkville, Vic 3010, Australia (A.A.T.J.); and Centre for Genomics and Systems Biology, New York University, New York 10003 (K.D.B.).
authors.forename: Caitlin
authors.identifier: http://orcid.org/0000-0001-8549-2873
authors.initials: C
authors.lastname: Byrt
authors.affiliation: Australian Centre for Plant Functional Genomics (B.L., J.Q., U.B., M.H., A.E., D.J., M.T., S.J.R.), School of Agriculture, Food, and Wine (B.L., C.B., J.Q., U.B., M.H., A.E., G.M.M., D.J., S.W.H., M.T., M.G., S.J.R.), and ARC Centre of Excellence in Plant Energy Biology (C.B., J.Q., S.W.H., M.G.), University of Adelaide, SA 5064, Australia;Centre for Desert Agriculture, King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia (B.L., M.T.);School of BioSciences, University of Melbourne, Parkville, Vic 3010, Australia (A.A.T.J.); and Centre for Genomics and Systems Biology, New York University, New York 10003 (K.D.B.).
authors.forename: Jiaen
authors.identifier: http://orcid.org/0000-0001-9220-4219
authors.initials: J
authors.lastname: Qiu
authors.affiliation: Australian Centre for Plant Functional Genomics (B.L., J.Q., U.B., M.H., A.E., D.J., M.T., S.J.R.), School of Agriculture, Food, and Wine (B.L., C.B., J.Q., U.B., M.H., A.E., G.M.M., D.J., S.W.H., M.T., M.G., S.J.R.), and ARC Centre of Excellence in Plant Energy Biology (C.B., J.Q., S.W.H., M.G.), University of Adelaide, SA 5064, Australia;Centre for Desert Agriculture, King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia (B.L., M.T.);School of BioSciences, University of Melbourne, Parkville, Vic 3010, Australia (A.A.T.J.); and Centre for Genomics and Systems Biology, New York University, New York 10003 (K.D.B.).
authors.forename: Ute
authors.initials: U
authors.lastname: Baumann
authors.affiliation: Australian Centre for Plant Functional Genomics (B.L., J.Q., U.B., M.H., A.E., D.J., M.T., S.J.R.), School of Agriculture, Food, and Wine (B.L., C.B., J.Q., U.B., M.H., A.E., G.M.M., D.J., S.W.H., M.T., M.G., S.J.R.), and ARC Centre of Excellence in Plant Energy Biology (C.B., J.Q., S.W.H., M.G.), University of Adelaide, SA 5064, Australia;Centre for Desert Agriculture, King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia (B.L., M.T.);School of BioSciences, University of Melbourne, Parkville, Vic 3010, Australia (A.A.T.J.); and Centre for Genomics and Systems Biology, New York University, New York 10003 (K.D.B.).
authors.forename: Maria
authors.initials: M
authors.lastname: Hrmova
authors.affiliation: Australian Centre for Plant Functional Genomics (B.L., J.Q., U.B., M.H., A.E., D.J., M.T., S.J.R.), School of Agriculture, Food, and Wine (B.L., C.B., J.Q., U.B., M.H., A.E., G.M.M., D.J., S.W.H., M.T., M.G., S.J.R.), and ARC Centre of Excellence in Plant Energy Biology (C.B., J.Q., S.W.H., M.G.), University of Adelaide, SA 5064, Australia;Centre for Desert Agriculture, King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia (B.L., M.T.);School of BioSciences, University of Melbourne, Parkville, Vic 3010, Australia (A.A.T.J.); and Centre for Genomics and Systems Biology, New York University, New York 10003 (K.D.B.).
authors.forename: Aurelie
authors.initials: A
authors.lastname: Evrard
authors.affiliation: Australian Centre for Plant Functional Genomics (B.L., J.Q., U.B., M.H., A.E., D.J., M.T., S.J.R.), School of Agriculture, Food, and Wine (B.L., C.B., J.Q., U.B., M.H., A.E., G.M.M., D.J., S.W.H., M.T., M.G., S.J.R.), and ARC Centre of Excellence in Plant Energy Biology (C.B., J.Q., S.W.H., M.G.), University of Adelaide, SA 5064, Australia;Centre for Desert Agriculture, King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia (B.L., M.T.);School of BioSciences, University of Melbourne, Parkville, Vic 3010, Australia (A.A.T.J.); and Centre for Genomics and Systems Biology, New York University, New York 10003 (K.D.B.).
authors.forename: Alexander A T
authors.initials: AA
authors.lastname: Johnson
authors.affiliation: Australian Centre for Plant Functional Genomics (B.L., J.Q., U.B., M.H., A.E., D.J., M.T., S.J.R.), School of Agriculture, Food, and Wine (B.L., C.B., J.Q., U.B., M.H., A.E., G.M.M., D.J., S.W.H., M.T., M.G., S.J.R.), and ARC Centre of Excellence in Plant Energy Biology (C.B., J.Q., S.W.H., M.G.), University of Adelaide, SA 5064, Australia;Centre for Desert Agriculture, King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia (B.L., M.T.);School of BioSciences, University of Melbourne, Parkville, Vic 3010, Australia (A.A.T.J.); and Centre for Genomics and Systems Biology, New York University, New York 10003 (K.D.B.).
authors.forename: Kenneth D
authors.initials: KD
authors.lastname: Birnbaum
authors.affiliation: Australian Centre for Plant Functional Genomics (B.L., J.Q., U.B., M.H., A.E., D.J., M.T., S.J.R.), School of Agriculture, Food, and Wine (B.L., C.B., J.Q., U.B., M.H., A.E., G.M.M., D.J., S.W.H., M.T., M.G., S.J.R.), and ARC Centre of Excellence in Plant Energy Biology (C.B., J.Q., S.W.H., M.G.), University of Adelaide, SA 5064, Australia;Centre for Desert Agriculture, King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia (B.L., M.T.);School of BioSciences, University of Melbourne, Parkville, Vic 3010, Australia (A.A.T.J.); and Centre for Genomics and Systems Biology, New York University, New York 10003 (K.D.B.).
authors.forename: Gwenda M
authors.initials: GM
authors.lastname: Mayo
authors.affiliation: Australian Centre for Plant Functional Genomics (B.L., J.Q., U.B., M.H., A.E., D.J., M.T., S.J.R.), School of Agriculture, Food, and Wine (B.L., C.B., J.Q., U.B., M.H., A.E., G.M.M., D.J., S.W.H., M.T., M.G., S.J.R.), and ARC Centre of Excellence in Plant Energy Biology (C.B., J.Q., S.W.H., M.G.), University of Adelaide, SA 5064, Australia;Centre for Desert Agriculture, King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia (B.L., M.T.);School of BioSciences, University of Melbourne, Parkville, Vic 3010, Australia (A.A.T.J.); and Centre for Genomics and Systems Biology, New York University, New York 10003 (K.D.B.).
authors.forename: Deepa
authors.initials: D
authors.lastname: Jha
authors.affiliation: Australian Centre for Plant Functional Genomics (B.L., J.Q., U.B., M.H., A.E., D.J., M.T., S.J.R.), School of Agriculture, Food, and Wine (B.L., C.B., J.Q., U.B., M.H., A.E., G.M.M., D.J., S.W.H., M.T., M.G., S.J.R.), and ARC Centre of Excellence in Plant Energy Biology (C.B., J.Q., S.W.H., M.G.), University of Adelaide, SA 5064, Australia;Centre for Desert Agriculture, King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia (B.L., M.T.);School of BioSciences, University of Melbourne, Parkville, Vic 3010, Australia (A.A.T.J.); and Centre for Genomics and Systems Biology, New York University, New York 10003 (K.D.B.).
authors.forename: Sam W
authors.identifier: http://orcid.org/0000-0003-3019-1891
authors.initials: SW
authors.lastname: Henderson
authors.affiliation: Australian Centre for Plant Functional Genomics (B.L., J.Q., U.B., M.H., A.E., D.J., M.T., S.J.R.), School of Agriculture, Food, and Wine (B.L., C.B., J.Q., U.B., M.H., A.E., G.M.M., D.J., S.W.H., M.T., M.G., S.J.R.), and ARC Centre of Excellence in Plant Energy Biology (C.B., J.Q., S.W.H., M.G.), University of Adelaide, SA 5064, Australia;Centre for Desert Agriculture, King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia (B.L., M.T.);School of BioSciences, University of Melbourne, Parkville, Vic 3010, Australia (A.A.T.J.); and Centre for Genomics and Systems Biology, New York University, New York 10003 (K.D.B.) mark.tester@kaust.edu.sa matthew.gilliham@adelaide.edu.au.
authors.forename: Mark
authors.identifier: http://orcid.org/0000-0002-5085-8801
authors.initials: M
authors.lastname: Tester
authors.affiliation: Australian Centre for Plant Functional Genomics (B.L., J.Q., U.B., M.H., A.E., D.J., M.T., S.J.R.), School of Agriculture, Food, and Wine (B.L., C.B., J.Q., U.B., M.H., A.E., G.M.M., D.J., S.W.H., M.T., M.G., S.J.R.), and ARC Centre of Excellence in Plant Energy Biology (C.B., J.Q., S.W.H., M.G.), University of Adelaide, SA 5064, Australia;Centre for Desert Agriculture, King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia (B.L., M.T.);School of BioSciences, University of Melbourne, Parkville, Vic 3010, Australia (A.A.T.J.); and Centre for Genomics and Systems Biology, New York University, New York 10003 (K.D.B.) mark.tester@kaust.edu.sa matthew.gilliham@adelaide.edu.au.
authors.forename: Mathew
authors.identifier: http://orcid.org/0000-0003-0666-3078
authors.initials: M
authors.lastname: Gilliham
authors.affiliation: Australian Centre for Plant Functional Genomics (B.L., J.Q., U.B., M.H., A.E., D.J., M.T., S.J.R.), School of Agriculture, Food, and Wine (B.L., C.B., J.Q., U.B., M.H., A.E., G.M.M., D.J., S.W.H., M.T., M.G., S.J.R.), and ARC Centre of Excellence in Plant Energy Biology (C.B., J.Q., S.W.H., M.G.), University of Adelaide, SA 5064, Australia;Centre for Desert Agriculture, King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia (B.L., M.T.);School of BioSciences, University of Melbourne, Parkville, Vic 3010, Australia (A.A.T.J.); and Centre for Genomics and Systems Biology, New York University, New York 10003 (K.D.B.).
authors.forename: Stuart J
authors.identifier: http://orcid.org/0000-0003-0411-9431
authors.initials: SJ
authors.lastname: Roy
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology; D000818:Animals; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001692:Biological Transport / Q000187:drug effects; D002462:Cell Membrane / Q000187:drug effects; D002712:Chlorides / Q000378:metabolism*; D019295:Computational Biology; D015536:Down-Regulation / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D055785:Gene Knockdown Techniques; D017343:Genes, Plant; D056726:Genetic Association Studies; D005966:Glucuronidase / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000378:metabolism; D009865:Oocytes / Q000187:drug effects / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism*; D018520:Plant Shoots / Q000187:drug effects / Q000378:metabolism*; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic / Q000235:genetics; D012965:Sodium Chloride / Q000494:pharmacology; D014982:Xenopus laevis; D052584:Xylem / Q000187:drug effects / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D002712:Chlorides; D026901:Membrane Transport Proteins; D012965:Sodium Chloride; D000040:Abscisic Acid; D005966:Glucuronidase