Cellular mechanisms of potassium transport in plants.

The physiological aspects of potassium transport systems in the plasma membrane are reviewed, re-examining fundamental problems in the field such as the distinctions between high- and low-affinity transport systems, the interactions between K(+) and other ions such as NH(4)(+) and Na(+), the regulation of cellular K(+ pools, the generation of electrical potentials and the problems involved in measurement of unidirectional K(-) fluxes are reviewed.