Signaling and Defence Mechanism of Jasmonic and Salicylic Acid Response in Pulse Crops: Role of WRKY Transcription Factors in Stress Response

Jasmonic Acid (JA), Salicylic Acid (SA) and its derivatives are important phytohormones that play fundamental roles in the plant defence mechanisms against various biotic and abiotic stresses. These hormones are essential in enabling plants to respond and adapt to challenging environmental conditions. They serve as key players in various plant signalling pathways and exhibit both antagonistic and synergistic effects on each other. JA primarily functions in defence against pathogenic organisms and herbivores, while SA plays a crucial role in combating biotrophic pathogens. Apart from biotic stresses, studies have shown that the application of JA and SA can enhance the resistance of pulses to abiotic stresses such as drought, temperature extremes, metal toxicity, and salt stress, which could be achieved through the regulation of specific gene expression. Under such conditions, the magnitude of JA and SA is regulated through a complex signalling system, which includes coordinated actions of transcriptional and post-transcriptional regulation of enzymes, as well as modification of key proteins by other molecules. The WRKY70 transcription factor (TF) plays a significant role in the post-transcriptional regulation and modulation of genes such as NPR1, VSP1 VSP2, PR2, and PR10, which are associated with stimulating the plant defence response in the pulse crops. The regulation of JA and SA signalling pathways in pulse crops under stress conditions is complex, requiring a deeper understanding of the underlying mechanisms. Therefore, developing well-organized strategies for the exogenous application of JA/SA and its derivatives in pulses becomes crucial in mitigating the impact of these stresses. This paper sheds light on the recent understanding on mechanism and application of JA/SA, which could help in improving the resilience and defence mechanisms of pulse crops, leading to better stress tolerance and overall crop productivity.