Ameliorative Effects of Potassium on the Salinity Stress in Plants: A Review

Salt stress is one of the major abiotic stresses decreasing crop production, particularly in dry and semi–arid regions. Reclamation of salt–damaged soil is important as it is sweeping cultivable land day by day. Potassium is an essential element for plant development which is an extremely active ion in the soil system. Potassium is second to nitrogen in plant tissue levels ranging from 1 to 3% by weight. As a cation, potassium is highly mobile in plant and moderately mobile in the soil system. The essentiality of potassium is identified with its multiple roles in plants. Among these are the maintenance of cell turgor pressure and cell lengthening, osmoregulation, leaf and stomata movements, enzyme activation, phloem solute transport, cation/anion balancing, control of membrane polarization, cytoplasmic pH regulation, chloroplast structure and functioning, protein and starch synthesis, and energy preservation across membranes. As almost all of these processes are directly associated to plant adaptation to the in hospitable environment. It could be concluded that potassium uptake, transportation, and homeostasis play important role in conferring salt tolerance in plants.