Brassinosteroids: Improving crop productivity and abiotic stress tolerance

Abstract

Brassinosteroids (BRs), a group of phyto-steroidal hormones, play crucial role in a wide spectrum of biochemical, physiological, growth, and developmental processes in plants. Recent molecular and physiological studies have further revealed the efficacy of BRs in improving the crop yield and productivity by controlling several genes regulated at cellular and sub-cellular levels. BRs also regulate several important agronomic traits like rhizogenesis, senescence, abscission, flower and fruit development, fruit ripening, flower sex expression, yield and quality of seed, grain, and fiber in horticultural and cash crops. These eco-friendly, nontoxic, and biosafe steroidal phytohormones when applied at specific dose at specific stage of development of specific crop enhanced quantity and quality of field-grown crops. Moreover, BRs also possess anti-ecdysteroidal, antiviral, and antifungal properties, and thus are considered as potential substitute to conventional pesticide, insecticide, and herbicide. Therefore, the present book chapter will update the knowledge of BRs in improving crop yield by ameliorating abiotic stresses such as salinity, drought, extreme temperatures, heavy metals, and pesticides. Besides, the current research has highlighted BRs-mediated cell elongation in vegetative organs as well as meristem homeostasis in plants. Various studies on BRs-related mutants indicated that steady BRs signaling is required for the optimal root growth, which further emphasized the indispensable roles of BRs in the regulation of the cell-cycle progression and differentiation in plants. Furthermore, the current chapter focuses on the exogenous application of effective doses of BRs to stress-affected plants as better and simple alternative approach for protecting plants from environmental stresses in comparison to the regular plant breeding practices.