Chlorogenic acid-mediated chemical defence of plants against insect herbivores.

Chlorogenic acid is one of the most abundant beneficial polyphenols in plants and is well known as a nutritional antioxidant in plant-based foods. Apart from its dietary antioxidant activity, it has been proved to be an efficient defence molecule against a broad range of insect herbivores. In the last two decades, several reports have shown the effectiveness of chlorogenic acid in insect growth deterrence. The pathway for chlorogenic acid biosynthesis in plants was previously elucidated, and metabolic engineering of the principal pathway showed high chlorogenic acid production in tomato plants. Herbivore-mediated induction of chlorogenic acid biosynthesis was also demonstrated both at metabolite and transcript level, although herbivore-mediated molecular regulation of chlorogenic acid biosynthesis is not yet fully elucidated. In this communication, we present our views on the efficacy of chlorogenic acid as an anti-herbivore defence molecule in plants and also discuss its future outlook.