Electrophysiological characterization of the node in Chara corallina: functional differentiation for wounding response.
Electrical characteristics of the node were analyzed in comparison with those of the flank of the internodal cell in Chara corallina. The dependence of the membrane potential of the node on pH and K+ concentration was almost the same as that of the flank. In the flank, the increase in the Ca2+ concentration stopped the depolarization in the presence of 100 mM KCl. In the node, however, Ca2+ could not stop the depolarization induced by 100 mM KCl. It has been reported that the node has a function to tranduce the signal of osmotic shock into a transient depolarization. In combination with osmotic shock, 10 mM K+ could induce a long-lasting depolarization of the node. These electrical characteristics of the node were suggested to be responsible for the electrical response to wounding in Characeae.
Shimmen
Teruo
T
Department of Life Science, Graduate School of Life Science, University of Hyogo, Harima Science Park City, Hyogo, 678-1297 Japan.
D000873:Anthracenes / Q000494:pharmacology; D001696:Biomechanical Phenomena; D002118:Calcium / Q000378:metabolism; D002462:Cell Membrane / Q000187:drug effects / Q000502:physiology*; D044784:Chara / Q000166:cytology* / Q000187:drug effects / Q000502:physiology*; D004594:Electrophysiology; D005682:Gadolinium / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D007473:Ion Channels / Q000037:antagonists & inhibitors; D008564:Membrane Potentials / Q000502:physiology; D009543:Nifedipine / Q000494:pharmacology; D009579:Nitrobenzoates / Q000494:pharmacology; D009997:Osmotic Pressure; D010658:Phenylglyoxal / Q000494:pharmacology; D011188:Potassium / Q000378:metabolism; D011189:Potassium Chloride / Q000378:metabolism / Q000494:pharmacology
D000873:Anthracenes; D007473:Ion Channels; D009579:Nitrobenzoates; C058176:5-nitro-2-(3-phenylpropylamino)benzoic acid; D011189:Potassium Chloride; C010030:9-anthroic acid; D005682:Gadolinium; D009543:Nifedipine; D010658:Phenylglyoxal; C038958:gadolinium chloride; D011188:Potassium; D002118:Calcium