ANION CONDUCTANCES IN INTACT GUARD-CELLS OF ARABIDOPSIS-THALIANA L. AND OTHER SPECIES

This note described the first recordings of slow anion currents in int act guard cells of Commelina communis and Arabidopsis thaliana, a spec ies of fundamental genetic interest. Experiments were conducted in the presence of potassium channels inhibitors, using the discontinuous si ngle electrode voltage-clamp (dSEVC) technique. Current recordings dis play slow activation upon membrane depolarization and slow deactivatio n during hyperpolarization. These currents were inhibited by NPPB, des cribed as a blocker of slow anion channels in Vicia faba guard cell pr otoplasts. Kinetic and pharmacological profiles of this current suppor t the hypothesis for an anion flux. These results show that A. thalian a anion currents can be easily studied in intact guard cells using the dSEVC technique.