Chapter 9 - Brassinosteroids and cold stress tolerance in plants

Abstract

The climate change events have increased the vulnerability of plants to cold or low temperature stress, leading to reduced plant growth and productivity. Brassinosteroids (BRs) are steroid plant hormones and can enhance cold stress tolerance in plants. BRs are involved in a number of growth and developmental processes of plants including, germination, reproductive development, photosynthesis, hormonal regulation, and gene expression. BRs pretreatment prior to cold stress exposure helps in cold acclimation in plants through physiological and molecular alteration. Likewise, exogenous application to cold stressed plants protects the photosynthetic apparatus and regulates the hormone synthesis and redox homeostasis through inhibiting ROS production in intercellular organelles. Moreover, BR treatment upregulates the enzymatic and nonenzymatic antioxidant activities and triggers the cellular signaling pathways and enhances the expression of genes related to cold stress tolerance. This chapter highlights the role of BRs in the mediation of cold stress–induced damage on plant morphology, physiology, and biochemical traits. It further highlights the interaction of BR with reactive oxygen species (ROS) and the role of BRs in redox homeostasis. Moreover, the molecular basis of BR-induced cold stress tolerance has also been elucidated.