Over millions of years, plants have evolved a sophisticated network of K+ transport systems. This Botanical Briefing provides an overview of K+ transporters in various leaf tissues (epidermis, mesophyll, guard cells and vascular system) at both the cellular and organelle levels. Despite the tremendous progress in our knowledge of genes encoding K+ transport systems in plants, understanding has not developed of coordinated functioning and operation of these genes or proteins in the context of whole plant physiology and plant-environment interaction. This Botanical Briefing is aimed at filling that gap by analysing electrophysiological and molecular evidence for mechanisms coordinating K+ transport between various leaf cells and tissues in changing environments.