Biosynthesis and Regulation of Herbivore-Induced Plant Volatile Emission

Abstract

Volatile phytochemicals function as air-borne communication signals between plants and insects. Plants emit a bouquet of volatile organic compounds not only from flowers and fruits but also from vegetative tissues. Herbivore-induced plant volatiles (HIPVs) are released de novo in response to tissue damage by insects. They act as an indirect defense by attracting natural enemies of the herbivore, which sense them as sources of food and/or reproduction. Additionally, HIPVs can inhibit pathogen growth and mediate inter- and intra–plant communication. HIPV emission varies with ontogeny, type of herbivore as well as environmental conditions. Plant hormones, particularly jasmonates, salicylic acid and ethylene, are implicated to play pivotal roles in the regulation of HIPV emission. Crosstalk among phytohormone signaling pathways enables fine-tuning of plant responses. This review presents biosynthesis of HIPVs and regulation by phytohormones.