title: SLAH1, a homologue of the slow type anion channel SLAC1, modulates shoot Cl- accumulation and salt tolerance in Arabidopsis thaliana.
abstract: Salinity tolerance is correlated with shoot chloride (Cl(-)) exclusion in multiple crops, but the molecular mechanisms of long-distance Cl(-) transport are poorly defined. Here, we characterize the in planta role of AtSLAH1 (a homologue of the slow type anion channel-associated 1 (SLAC1)). This protein, localized to the plasma membrane of root stelar cells, has its expression reduced by salt or ABA, which are key predictions for a protein involved with loading Cl(-) into the root xylem. Artificial microRNA knockdown mutants of AtSLAH1 had significantly reduced shoot Cl(-) accumulation when grown under low Cl(-), whereas shoot Cl(-) increased and the shoot nitrate/chloride ratio decreased following AtSLAH1 constitutive or stelar-specific overexpression when grown in high Cl(-) In both sets of overexpression lines a significant reduction in shoot biomass over the null segregants was observed under high Cl(-) supply, but not low Cl(-) supply. Further in planta data showed AtSLAH3 overexpression increased the shoot nitrate/chloride ratio, consistent with AtSLAH3 favouring nitrate transport. Heterologous expression of AtSLAH1 in Xenopus laevis oocytes led to no detectible transport, suggesting the need for post-translational modifications for AtSLAH1 to be active. Our in planta data are consistent with AtSLAH1 having a role in controlling root-to-shoot Cl(-) transport.
authors.affiliation: School of Agriculture, Food, and Wine, University of Adelaide, PMB1, Glen Osmond, SA 5064, Australia Australian Centre for Plant Functional Genomics, PMB1, Glen Osmond, SA 5064, Australia ARC Centre of Excellence in Plant Energy Biology, PMB1, Glen Osmond, SA 5064, Australia.
authors.forename: Jiaen
authors.identifier: 0000-0001-9220-4219
authors.initials: J
authors.lastname: Qiu
authors.affiliation: School of Agriculture, Food, and Wine, University of Adelaide, PMB1, Glen Osmond, SA 5064, Australia ARC Centre of Excellence in Plant Energy Biology, PMB1, Glen Osmond, SA 5064, Australia.
authors.forename: Sam W
authors.identifier: 0000-0003-3019-1891
authors.initials: SW
authors.lastname: Henderson
authors.affiliation: Centre for Desert Agriculture, King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia.
authors.forename: Mark
authors.identifier: 0000-0002-5085-8801
authors.initials: M
authors.lastname: Tester
authors.affiliation: School of Agriculture, Food, and Wine, University of Adelaide, PMB1, Glen Osmond, SA 5064, Australia Australian Centre for Plant Functional Genomics, PMB1, Glen Osmond, SA 5064, Australia.
authors.forename: Stuart J
authors.initials: SJ
authors.lastname: Roy
authors.affiliation: School of Agriculture, Food, and Wine, University of Adelaide, PMB1, Glen Osmond, SA 5064, Australia ARC Centre of Excellence in Plant Energy Biology, PMB1, Glen Osmond, SA 5064, Australia matthew.gilliham@adelaide.edu.au.
authors.forename: Mathew
authors.identifier: 0000-0003-0666-3078
authors.initials: M
authors.lastname: Gilliham
mesh_terms: D000040:Abscisic Acid / Q000502:physiology; D000818:Animals; D030801:Animals, Genetically Modified; D017360:Arabidopsis / Q000378:metabolism / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000502:physiology*; D002594:Cetylpyridinium / Q000378:metabolism*; D015536:Down-Regulation; D018506:Gene Expression Regulation, Plant / Q000502:physiology; D009865:Oocytes / Q000378:metabolism; D010937:Plant Growth Regulators / Q000502:physiology; D018520:Plant Shoots / Q000378:metabolism* / Q000502:physiology; D030821:Plants, Genetically Modified; D055049:Salt Tolerance / Q000502:physiology*; D014982:Xenopus laevis
chemical_list: D029681:Arabidopsis Proteins; D010937:Plant Growth Regulators; D000040:Abscisic Acid; D002594:Cetylpyridinium
keywords: ABA; Arabidopsis; AtSLAH1; AtSLAH3; Cl− xylem loading; chloride; long-distance transport; nutrition; salinity; slow-type anion channel-associated homologue 1; slow-type anion channel-associated homologue 3.