Silicon-mediated alleviation of salinity stress in horticultural crops: mechanisms and applications

When salinity stress is raised to a level of concern for world food supply, mostly horticulture-based crops in arid and semi-arid zones are negatively affected in terms of plant yield, growth and quality. High salinity stress including ion poisoning, osmotic as well as oxidative stress intervene on the plant’s chief operations thus leading to constraints on plant and reduced yields. Unveiled also through this review is the mechanism by which silicon mitigates high levels of salinity; effects of which on various physiological and biochemical processes in the plants are highlighted. Salinity regulates nutrient provision via membrane ion balance and with creation of channels that it actively excludes the poisonous ions like Na+ and Cl− and at the same time includes Minerals like K+ and Ca2+. This one-way regulation is the way of maintaining the strict ionic balance and the normal functioning of the plant cells. For this review, research was conducted in several academic databases; PubMed, Scopus, ISI/Web of Science and Google Scholar. Besides that, silicon enhances the antioxidant defense through induction of enzymes such as SOD, CAT and POD thus resulting in minimal damage from the generated ROS under salt stress. At the molecular level silicon plays the role in genes regulation by which stress-related pathways in plants are to function and thus endows the plant with adaptative capacity. The future work will probably focus on enhancing the techniques on silicon basis in order to preserve the food respectively for handling the situation of the increasing salinity stress.