Patch clamping whole-cell recording techniques were applied to study the inward K + -channels in ,Ara-bidopsis root cortex cells. The inward K+-channels in the plasma membranes of the root cortex cell protoplasts were activated by hyperpolarized membrane potentials. The channels were miglv selective tor K + ions over Na + ions. The channel activity was significantly inhibited by the external TEA+, or Ba2+ The changes in eytoplasmic Ca2+ concentrations did not affect the whole-cell inward K + -currents. The possible asoeiation between the ehannel selectivity to K+ and Na+ ions and plant salt-toleranee was also discussed.
