Cold transiently activates calcium-permeable channels in Arabidopsis mesophyll cells.
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.
Carpaneto
Armando
A
Department of Molecular Plant Physiology and Biophysics, Julius-von-Sachs Institute of Biosciences, Wurzburg University, 97082 Wurzburg, Germany.
Ivashikina
Natalya
N
Levchenko
Victor
V
Krol
Elzbieta
E
Jeworutzki
Elena
E
Zhu
Jian-Kang
JK
Hedrich
Rainer
R
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
D029681:Arabidopsis Proteins; D015220:Calcium Channels; D002118:Calcium