title: Cold transiently activates calcium-permeable channels in Arabidopsis mesophyll cells.
abstract: Living organisms are capable of discriminating thermal stimuli from noxious cold to noxious heat. For more than 30 years, it has been known that plant cells respond to cold with a large and transient depolarization. Recently, using transgenic Arabidopsis (Arabidopsis thaliana) expressing the calcium-sensitive protein aequorin, an increase in cytosolic calcium following cold treatment was observed. Applying the patch-clamp technique to Arabidopsis mesophyll protoplasts, we could identify a transient plasma membrane conductance induced by rapid cooling. This cold-induced transient conductance was characterized as an outward rectifying 33 pS nonselective cation channel. The permeability ratio between calcium and cesium was 0.7, pointing to a permeation pore >3.34 A (ø of cesium). Our experiments thus provide direct evidence for the predicted but not yet measured cold-activated calcium-permeable channel in plants.
authors.affiliation: Department of Molecular Plant Physiology and Biophysics, Julius-von-Sachs Institute of Biosciences, Wurzburg University, 97082 Wurzburg, Germany.
authors.forename: Armando
authors.initials: A
authors.lastname: Carpaneto
authors.forename: Natalya
authors.initials: N
authors.lastname: Ivashikina
authors.forename: Victor
authors.initials: V
authors.lastname: Levchenko
authors.forename: Elzbieta
authors.initials: E
authors.lastname: Krol
authors.forename: Elena
authors.initials: E
authors.lastname: Jeworutzki
authors.forename: Jian-Kang
authors.initials: JK
authors.lastname: Zhu
authors.forename: Rainer
authors.initials: R
authors.lastname: Hedrich
mesh_terms: D017360:Arabidopsis / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000235:genetics / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D003080:Cold Temperature; D009154:Mutation; D018408:Patch-Clamp Techniques; D010539:Permeability; D018515:Plant Leaves / Q000166:cytology / Q000378:metabolism / Q000502:physiology; D011523:Protoplasts / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D015220:Calcium Channels; D002118:Calcium