Membrane potentials of protoplasts isolated from Vigna mungo hypocotyl segments were measured using the fluorescent probe diS-C3-(5). The fluorescence intensity changed in response to the external K+ concentration. Membrane potential was estimated to be inside negative (-85±8 mV at 0.1 mM KCl) from the Nernst equation for K+. The membrane potential was not affected by DCCD (50 μM) or low temperature (5°C). Addition of 0.5 mM Ca2+ to the protoplast suspension markedly depolarized the membrane potential, and subsequent EDTA treatment repolarized it to the initial level. The Ca2+ effect on the membrane potential may be due to change in the permeability ratio of Cl- to K+.
|ジャーナル||Plant and Cell Physiology|
|出版ステータス||Published - 1987 7月|
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