Regulation of plant defense against biotic stressors by brassinosteroids

Abstract Brassinosteroids (BRs) are steroidal phytohormones that play a multitasking role during the growth and development period as well as stress responses. Plant mutants in BR production or defective signaling result in various physiological as well as phenotypical abnormalities. Presently, various studies have highlighted stress tolerance induction by brassinosteroids in various plant species indicating BRs as a broad spectrum key regulator participating in various molecular processes. The present chapter highlights the studies on BRs regarding their potent role in inducing stress tolerance during viral, fungal, bacterial or nematode attacks in plants. BR's multifaceted role during stress and its potential cross-talk with other phytohormones in adapting and ameliorating the stress have been critically analyzed. The divergence in dosage of BR analogs and their mode of application for management of stress are also discussed which serves as a future area of interest in challenging agriculture, thereby highlighting relevant knowledge gaps.