Brassinosteroids: characterization and influence on plant growth and development

Abstract

Some plant hormones are widely known to act on metabolic pathways and are responsible for promoting or inhibiting plants growth and development. Brassinosteroids (BRs), recently categorized as plant hormones, are steroid substances that were initially identified in Brassica napus in the 1960s. Although BRs are produced in small quantities by plants, one of the main characteristics that facilitates the mode of action of these hormones is their ability to spread in cells. The easy mobility through the cell membranes generates a rapid response in the metabolism of plants, as well as in the production of proteins and enzymes. The studies on BRs are elucidating their different functions in plant metabolism, especially related to the promotion and biosynthesis of ethylene, growth and development of the root system and control of abiotic stresses, caused by reduced availability of water, salinity and temperature. Furthermore, BRs seems to be involved in control of insect attack and other biotic factors, synthesis of nucleic acids and proteins, regulation in germination, and interaction with other plant hormones. Thus, this review aims to report the mode of action of Brassinosteroids, the effects of their interactions with other hormones and recent findings of important contributions to plant development.