Mechanisms of potassium uptake and transport in higher plants

Potassium, the second most abundant mineral nutrient, is essential to plant growth. Over millions of years, plants have evolved a sophisticated network of potassium transport systems. These include Shaker-type and "two-pore" potassium channels; various types of potassium-permeable non-selective cation channels; and KUP/ HAKKT, HKT and KC/H+ transporters. This chapter gives an overview of these transport systems and discusses their regulation and hnctional expression in plant membranes under potassium deficiency conditions. Molecular and electrophysiological data are discussed in the context of physiology and agronomy of the regulation of potassium nutrition at the whole plant level grown under various soil types and environmental conditions. An overview of modem methods for studying the mechanisms of potassium transport in plants is also discussed.