Brassinosteroid Signaling in Adaptative Responses to Abiotic Stress

Abstract

Brassinosteroids (BRs), a class of steroid hormones, play a crucial role in plant growth and development. They control cell division and cell differentiation throughout the plant life cycle. The advancement in molecular tools and innovative approaches have enabled a deeper understanding of the BR signaling pathway. Much of the data on this pathway has been obtained from investigations on Arabidopsis thaliana. BR ligand binding to membrane steroid receptor BRASSINOSTEROID INSENSITIVE 1 (BRI1) involves the activation of a signal cascade in the cytoplasm, culminating in the transcription of BR-responsive genes. The versatile role of BR is evident from its interaction with other phytohormones like cytokinin, auxin, ethylene, jasmonic acid, gibberellin, abscisic acid, salicylic acid, and polyamines. This chapter presents major contributions to the development of BR signaling, homeostasis, and crosstalk with other phytohormones. Current understanding of BR signaling in fundamental physiological processes with an emphasis on signaling under abiotic stress, crosstalk with other phytohormones, and homeostasis are discussed in this chapter. Also, the development of predictive models that seek to modulate beneficial traits in plants exposed to abiotic stress with the aim of addressing challenges in agriculture is discussed.