title: A role for the AKT1 potassium channel in plant nutrition.
abstract: In plants, potassium serves an essential role as an osmoticum and charge carrier. Its uptake by roots occurs by poorly defined mechanisms. To determine the role of potassium channels in planta, we performed a reverse genetic screen and identified an Arabidopsis thaliana mutant in which the AKT1 channel gene was disrupted. Roots of this mutant lacked inward-rectifying potassium channels and displayed reduced potassium (rubidium-86) uptake. Compared with wild type, mutant plants grew poorly on media with a potassium concentration of 100 micromolar or less. These results and membrane potential measurements suggest that the AKT1 channel mediates potassium uptake from solutions that contain as little as 10 micromolar potassium.
authors.affiliation: Department of Horticulture and Program in Cellular and Molecular Biology, University of Wisconsin, Madison, WI 53706, USA.
authors.forename: R E
authors.initials: RE
authors.lastname: Hirsch
authors.forename: B D
authors.initials: BD
authors.lastname: Lewis
authors.forename: E P
authors.initials: EP
authors.lastname: Spalding
authors.forename: M R
authors.initials: MR
authors.lastname: Sussman
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins; D003470:Culture Media; D004269:DNA, Bacterial / Q000235:genetics; D017343:Genes, Plant; D008564:Membrane Potentials; D009154:Mutation; D018408:Patch-Clamp Techniques; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D018517:Plant Roots / Q000378:metabolism; D011188:Potassium / Q000378:metabolism*; D015221:Potassium Channels / Q000235:genetics / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D003470:Culture Media; D004269:DNA, Bacterial; D010940:Plant Proteins; D015221:Potassium Channels; C036483:T-DNA; C074500:AKT1 protein, Arabidopsis; D011188:Potassium