Role of Jasmonates in Pathogenesis and Crosstalk of Jasmonates with Other Hormones

As plants lack the locomotory capabilities, they have to defend themselves from all the stresses standing at the same place. Therefore, plants have developed various defence mechanisms, and the phytohormones play a very significant role in developmental processes as well as the response of plants against the biotic and abiotic stresses. The plants induce localised and systemic responses to defend themselves against the fungi and other microbial pathogens. Phytohormones, mainly ABA, Jasmonic Acid, and Salicylic Acid, have been shown to play a crucial role in mediating or regulating stress responses in plants. A localised hypersensitive response is triggered when a pathogen interacts with the resistant host plant, and a complex molecular mechanism regulates the spread and the intensity of these responses. Plants are protected against a wide range of insect herbivores, which feed on plants like chewers, suckers, and cell content feeders by jasmonate response. Various experiments have been done to prove the role of Jasmonic acid in plant defence against pathogenesis especially against the necrotrophic fungal and bacterial pathogens, insects, nematodes, etc. During the defence response, there is a crosstalk between jasmonic acid pathways with other phytohormones. In this chapter, we will focus on the role of Jasmonate in plant defence against pathogens and the crosstalk of Jasmonate with other hormones.