Synthetic elicitors-induced defense in crops against herbivory: A review

Synthetic elicitors are non-toxic chemicals and safe for the environment when applied to plants in a variety of ways. They have been shown to interact with defense mechanisms of plants and cause the production of a wide range of valuable secondary metabolites, both volatile and non-volatile. Plants primed with chemical elicitors are indirectly induced to increase their resistance to herbivore attacks in addition to imparting tolerance or resistance to nearby plants against biotic stresses. The market is stocked with jasmonic acid, salicylic acid, and their derivatives/analogues, which have been shown to either repel or attract herbivores. While phytotoxicity has only been documented in a small number of cases, a significant increase in yield has been reported in a wide range of crops. This review includes a detailed summary of various field and laboratory experiments elucidating the mechanism of action and efficacies of exogenous application and seed priming of synthetic phytohormones on plant growth, development, and yield of different crops.