Role of silicon in abiotic stress tolerance in wheat

The prevailing environmental conditions control the growth and development of plant in one way or the other throughout the world. Abiotic stresses, i.e., drought, heavy metals, salinity, heat and cold and other environmental extremes negatively influence survival of plants and reduce the productivity of crops. The world's most popular grain, wheat (Triticum aestivum L.), is highly susceptible to abiotic stress, which is the major reason for yield losses in the crop. Silicon (Si) is the second most abundant element and gaining popularity for its multilateral role in providing significant advantages for growth and yield of crop plants. It is a non-essential nutrient, but it has been shown to have beneficial effects on the growth and development of several plant species. Si substantially reduces the most abiotic stresses and it is non-polluting, non-detrimental and non-harmful to plants even when used in large quantities. Exogenous Si application prevents the detrimental effect of drought, heat and cold stress by increasing cuticle and epidermal layer thickening from silica deposited. Si creates an apoplastic barrier in the endodermis closer to the root apex to prevent the uptake and mobility of heavy metals. Under adverse conditions, Si increases nutrient uptake and restores wheat growth and production. The review clearly reveals the importance of Si nutrition in imparting abiotic stress tolerance and the need for its application in the wheat crop. Plant producers can benefit from Si fertilizers both economically and environmentally.