Role of Jasmonates and Salicylates in Plant Allelopathy

Phytohormones reported to be the most important category of hormones playing key role in the plant growth and developmental processes. Most of these hormones are considered to be strongly communicative in nature. Among the diversified forms of phytohormones the jasmonates and salicylates have profound role in plant defense process. These phytohormones act as signaling molecules in secondary metabolite production for plant defense responses which is mainly due to their methylated products. These vital chemical messengers of the plant system cause wide range of morphological and physiological changes. The Biological encroachment has found its way into the flashes of Allelopathy, the mechanism that by its defensive nature influences the native plant species, by the continuous production of chemical exudates thereby hindering the growth of the plant. Allelopathy provides an insight for herbicide and weed control. The exogenous application of phytohormones can upraise allelopathic potential in plants. The plants acquire a wide radius of mechanisms to combat invasion of other plants which include physical, chemical barriers and defense responses that get started off upon exogenous application of communicating molecules, in which rhizosphere being the utmost sink for allelochemicals. This chapter describes the role of jasmonates and salicylates in plant allelopathy and different pathways of signal transduction involved.