Silicon nutrition for alleviation of abiotic stress in plants: A review

Abstract

Silicon (Si) earth is known to have numerous beneficial effects on plants in alleviating diverse forms of abiotic and biotic stress. Available Si in soils refers to the amount of Si that can be taken up by plants during the growing season and usually considered an index of Si-supplying capacity of soils. The silicic acid (H4SiO4) is the plant-available form of soil silicon which is present in the soil solution at concentrations normally ranging from 0.1 to 0.6 millimolar (mM). Some important factors influencing availability of Si to plants include parent material and type of soil, land use pattern, soil pH, soil texture and soil redox potential. All terrestrial plants contain some silicon (Si) in their tissues and the concentration of Si in shoots varies greatly among plant species. By application of silicon solution externally plants lodging can be reduced. Abiotic stresses like heat, cold, drought, salt stress and heavy metal toxicity in plants can be alleviated with the application of silicon solution. Accumulated silicon can provide rigidity and roughness to the plant cell walls. Silicon plays a significant role in maintenance of the integrity of cell membranes during stress condition such as chilling, freezing, heat, drought, pollution etc. and therefore Si-treated plants acquire tolerance to these stress conditions.