ABSTRACT
Phytohormones are small chemical messengers and key players that regulate plant growth and development as well as responses to biotic and abiotic stress factors that maintain plant homeostasis and allow adaptation to environmental changes. Plants possess the ability to produce various compounds that activate the expression of stress-related genes encoding products to protect their cellular components from the adverse impact of abiotic stresses. Extensive studies are being conducted on both traditional (auxin, cytokinin, gibberellin, ethylene, abscisic acid) as well as non-traditional (salicylic acid, jasmonates, strigolactones) hormones to understand the molecular interaction, mechanisms and crosstalk. Exogenous applications of phytohormones to impart tolerance against stresses are also being experimented with. Recently, the role of miRNAs in some stresses has been identified by regulating various phytohormone signaling pathways and by targeting several transcription factors (TFs) and defense-related genes. Emerging research based on priming techniques can be used as a practical management tool in agriculture to overcome the adverse impact of abiotic stress, improving cellular homeostasis and the growth of plants. This chapter focuses on the recent studies conducted to understand the role of numerous phytohormones in alleviating plants' tolerance to stresses.
