Gene

Cell biology

Ecology

Biology

Abiotic component

Signal transduction

Biochemistry

Botany

Trichome

Plant tolerance to herbivory

Plant defense against herbivory

Plant hormone

Herbivore

Salicylic acid

Jasmonic acid

International Journal of Molecular Sciences

Plants have various self-defense mechanisms against biotic attacks, involving both physical and chemical barriers. Physical barriers include spines, trichomes, and cuticle layers, whereas chemical barriers include secondary metabolites (SMs) and volatile organic compounds (VOCs). Complex interactions between plants and herbivores occur. Plant responses to insect herbivory begin with the perception of physical stimuli, chemical compounds (orally secreted by insects and herbivore-induced VOCs) during feeding. Plant cell membranes then generate ion fluxes that create differences in plasma membrane potential (Vm), which provokes the initiation of signal transduction, the activation of various hormones (e.g., jasmonic acid, salicylic acid, and ethylene), and the release of VOCs and SMs. This review of recent studies of plant-herbivore-infection interactions focuses on early and late plant responses, including physical barriers, signal transduction, SM production as well as epigenetic regulation, and phytohormone responses.

Plant Responses to Herbivory, Wounding, and Infection