ABSTRACT
Plants respond to insect herbivores with the production and emission of a complex blend of—tens up to a few hundred—volatile compounds, consisting of e.g., terpenoids, fatty acid-derived compounds, nitriles, isothiocyanates, and phenylpropanoids. The composition of this diverse herbivore-induced volatile blend is specific for the plant that emits the blend as well as the herbivore species that attacks it. Moreover, the blend’s composition is further modulated by the attack by a second herbivore, interactions with microorganisms, and interactions with pollinators. The volatiles that plants emit in response to herbivore attack can attract carnivorous enemies of the inducing herbivore, but may also influence interactions with other herbivores, as well as pollinators. To understand how plants respond to attack by a diverse set of species, we pay attention to underlying mechanisms in terms of gene expression, phytohormonal signaling, and biosynthetic pathways. Finally, we focus on advances in the chemical analysis of plant volatiles, statistical analysis and genetic analysis, and how these can contribute to the understanding of the chemical ecology of plant-arthropod interactions. Being an important element underlying the dynamics of ecological communities, understanding how herbivore-induced plant volatiles influence plant-mediated interactions between community members is of key importance for our understanding of the ecology of plant-arthropod interactions.
