Effects of Abscisic Acid and Cytoplasmic pH on Potassium and Chloride Efflux in Arabidopsis thaliana Seedlings

概要

論文の詳細を見る
The effects of ABA, isobutyric acid (IBA) and nicotine on K^+ and Cl^- efflux were studied in Arabidopsis thaliana seedlings, and the role of pH_<cyt> and E_m in the regulation of the efflux of these ions was discussed. The data show that treatments with IBA and nicotine influenced in opposite directions the efflux of either K^+ or Cl^-: K^+ efflux was in-creased by nicotine and reduced in the presence of IBA, whereas Cl^- efflux was stimulated by IBA and decreased by nicotine treatment. Under all the conditions tested ABA induced cytoplasmic acidification and inhibition of K^+ and Cl^- net efflux. Experiments aimed to estimate the individual contribution of pH_<cyt> and E_m in modulating K^+ efflux indicated that, within the range of acidic pH_<cyt> values, a regulation of K^+ efflux was imposed by pH_<cyt> on the control exerted by E_m, the efflux being inhibited by lower pH_<cyt> values. Conversely, in the alkaline side of pH_<cyt> K^+ efflux seemed linked only to the E_m values. These results are consistent with the hypothesis that the decrease in K^+ efflux observed in non-stomatal tissues in the presence of ABA may be mediated by the cytoplasmic acidification induced by the hormone.
日本植物生理学会の論文