Chapter 23 - Salicylic Acid–Mediated Defense Mechanisms to Abiotic Stress Tolerance

Abstract

In the current era due to climate change plants are facing multitudinous environmental challenges from seeding to maturity stages. Salicylic acid (SA) is a phenolic compound involved in the regulation of growth and development of plants, and their responses to abiotic stress factors. SA is linked with regulation of dynamic physiological responses such as photosynthesis, nitrogen, and proline metabolism; introduction of cell reinforcement protection framework (antioxidant defense system); and plant–water associations under stress environments, and hence delivers operative defense in plants contrary to stress. SA has been known to improve tolerance to major abiotic stresses such as salinity, drought, osmotic, metal, heat and chilling, and radiation stress. Modern molecular research has illustrated that SA is a key regulator in controlling numerous physiognomies in plants at the gene level. SA was recounted to stimulate number of genes accountable for encoding chaperone, heat shock proteins (HSPs), antioxidants, and secondary metabolites sinapyl alcohol dehydrogenase (SAD), cinnamyl alcohol dehydrogenase (CAD), and cytochrome P450. Furthermore, SA contribution in mitogen activated protein kinase (MAPK) modulation has also been researched. Nonetheless, the transcriptional reprogramming that takes place through defense action counter to abiotic strain was reported to be controlled by SA, where the transcription factors of diverse arrays of defensive genes can be meticulous in a spatiotemporal manner via SA mediated mechanisms. In previous study, interaction of phytohormone such as abscisic acid, jasmonic acid, ethylene, and SA have been researched in signaling pathways involved in different plant defense mechanisms. This chapter summarizes the potential and prospective role of the SA in defense mechanisms for the improvement of plant resistance against abiotic stresses.