Silicon mediated abiotic stress tolerance in plants using physio-biochemical, omic approach and cross-talk with phytohormones

Silicon (Si) is the second most abundant element present on the lithosphere and a quasi-essential element for plants' cellular and developmental processes. Si is associated with augmented germination, growth, photosynthesis, gas exchange, photosystem efficiency, and yield attributes in unstressed and stressed plants. The exogenous application of Si facilitates morpho-physiological and biochemical traits. It triggers the content of compatible osmolyte and enzymatic and non-enzymatic antioxidants, which decreases reactive oxygen species like hydrogen peroxide and superoxide. Uptake and transport of Si in plants are discussed in this review. Furthermore, the potent roles of Si in plants are emphasized. The cross-talk of Si with phytohormones such as auxins, cytokinins, gibberellins, abscisic acid, brassinosteroids, salicylic acid, nitric oxide, jasmonic acid, and ethylene is also presented. Moreover, attempts have been made to cover the contribution of Si mediated enhancement in 'omics' (genomic, transcriptomic, proteomic, metabolomic, and ionomic) approach that is useful in diminishing stress. This review aims to provide Si integration with phytohormone and utilization of 'omic approaches' to understand the role of Si in plants. This review also underlines the need for future research to evaluate the role of Si during abiotic stress in plants and the identification of gaps in understanding this process as a whole at a broader level.