Inward-rectifying K+ channels in guard cells provide a mechanism for low-affinity K+ uptake.

Inward-rectifying K+ channels in guard cells provide a mechanism for low-affinity K+ uptake.

The molecular mechanisms by which higher plant cells take up K+ across the plasma membrane (plasmalemma) remain unknown. Physiological transport studies in a large number of higher plant cell types, including guard cells, have suggested that at least two distinct types of K(+)-uptake mechanisms exist, permitting low-affinity and high-affinity K+ accumulation, respectively. Recent patch clamp st...

Inward-Rectifying K+ Channels in Root Hairs of Wheat (A Mechanism for Aluminum-Sensitive Low-Affinity K+ Uptake and Membrane Potential Control).

K+ is the most abundant cation in cells of higher plants, and it plays vital roles in plant growth and development. Extensive studies on the kinetics of K+ uptake in roots have shown that K+ uptake is mediated by at least two transport mechanisms, one with a high and one with a low affinity for K+. However, the precise molecular mechanisms of K+ uptake from soils into root epidermal cells remai...

Physiological Roles of Inward-Rectifying K+ Channels.

Hyposmotic challenge inhibits inward rectifying K+ channels in cerebral arterial smooth muscle cells.

This study sought to define whether inward rectifying K(+) (K(IR)) channels were modulated by vasoactive stimuli known to depolarize and constrict intact cerebral arteries. Using pressure myography and patch-clamp electrophysiology, initial experiments revealed a Ba(2+)-sensitive K(IR) current in cerebral arterial smooth muscle cells that was active over a physiological range of membrane potent...

Deltamethrin rescues run down of K+ outward rectifying channels in Vicia faba guard cells

The dominant outward rectifier K+ currents were examined in protoplasts from Vicia faba guard cells. In whole-cell patch-clamp recordings, we generally observed that the conductance of the K+ inward and the outward rectifier gradually decreases. As a consequence of this run down a new steady state was achieved which was 90 ± 5% lower than that obtained at the beginning of the recording. The run...