title: Coordination of plasma membrane and vacuolar membrane ion channels during stomatal movement.
abstract: Transduction of extracellular signals in guard cells requires coupling of ion fluxes across the vacuolar and plasma membrane. Changes in cytoplasmic proton and Ca2+ concentrations are important messages during stomatal movement. Here we summarize the different biophysical properties of voltage- and ligand-dependent ion channels in both the vacuolar and plasma membranes of guard cells, focusing on how cytoplasmic Ca2+ and proton concentrations direct ion fluxes towards stomatal opening or closure. Particular attention is given to the patch clamp analysis of plasma membrane cation channels (GCKCin, GCKCout and Ca2+ channels), the anion channel (GCAC1) and the vacuolar SV-type channels. A working model is presented of how the ion channels of both membrane systems could communicate to synchronize potassium salt release during stomatal closure.
authors.affiliation: Institut für Biophysik, Universität Hannover, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Schulz-Lessdorf
authors.forename: P
authors.initials: P
authors.lastname: Dietrich
authors.forename: I
authors.initials: I
authors.lastname: Marten
authors.forename: G
authors.initials: G
authors.lastname: Lohse
authors.forename: H
authors.initials: H
authors.lastname: Busch
authors.forename: R
authors.initials: R
authors.lastname: Hedrich
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007425:Intracellular Membranes / Q000378:metabolism*; D007473:Ion Channels / Q000378:metabolism*; D008954:Models, Biological; D018408:Patch-Clamp Techniques; D010944:Plants / Q000378:metabolism*; D011188:Potassium / Q000378:metabolism; D015221:Potassium Channels / Q000378:metabolism; D015398:Signal Transduction; D014617:Vacuoles / Q000378:metabolism*
chemical_list: D007473:Ion Channels; D015221:Potassium Channels; D011188:Potassium; D002118:Calcium