Identification and characterization of inward K(+) -channels in plasma membranes ofArabidopsis root cortex cells

Patch clamping whole-cell recording techniques were applied to study the inward K(+) -channels inArabidopsis 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 highly selective for K(+) ions over Na(+) ions. The channel activity was significantly inhibited by the external TEA(+) or Ba(2+). The changes in cytoplasmic Ca(2+) concentrations did not affect the whole-cell inward K(+) -currents. The possible association between the channel selectivity to K(+) and Na(+) ions and plant salt-tolerance was also discussed.