Potassium transport systems at the plasma membrane of plant cells: Tools for improving potassium use efficiency of crops

Abstract

Potassium (K+) is an essential macronutrient for plants, and it is acquired through specialized transport systems in their cell membranes that allow K+ accumulation under variable external conditions. Several gene families encode K+-permeable transport systems that take part in different physiological processes. In this chapter, we describe the main gene families that take part in K+ acquisition from the soil and in its distribution throughout the plant, and the physiological roles that they fulfill. We describe the main regulatory mechanism (including transcriptional and posttranslational mechanisms) that they have and allow the adjustment of the K+ transport to the plant demands. We also describe the current knowledge on K+ nutrition concerning the goals of present and future agriculture which requires crops that use K+ more efficiently and are tolerant to environmental stresses (salinity, drought, etc.). Finally, we devote a final section to biotechnological approaches and emerging techniques that will assist crop breeding. This chapter offers state-of-the-art knowledge on K+ transport in plants and how it could be helpful to agriculture worldwide.