Synergistic Effects of Silicon and Potassium in Enhancing Plant Tolerance to Abiotic Stresses: A Comprehensive Review

Abstract

Alliance of Research and College Potential Hydro seeding Drought resistance is an important part of limiting crop production. Mineral nutrition is being more and more investigated in an integrated approach to stress management; silicon (Si) and potassium (K) are of particular interest because they provide complementary functions. Silicon is an advantageous element that, in the leaf and other external tissues of plants, strengthens tissues, influences water relations, and limits translocation of potentially toxic ions, whereas K is an essential macronutrient with critical roles in osmotic regulation by modifying tissue osmoregulation via control of stomatal function, enzyme activation, and maintenance of ionic balance through different cellular compartments. Recent factorial experiments show improved protection against selected stress systems with combined Si and K supply, and there is evidence that such treatment tends to provide greater protective effects than either treatment alone; however, the strength of this evidence differs according to stress systems. Herein, we summarize the most recent understanding of Si and K uptake and function together with their interaction via ion homeostasis, water relations, antioxidant regulation, and structural protection based on experiments reflecting salinity-, drought-, and metal-toxicity-induced responses. It also separates direct evidence of Si-K interaction from studies with potassium silicate, since the individual contributions of Si and K cannot be experimentally separated, and classifies priority conclusions by field validation and agronomic optimization.