Plant Defense Responses to Insect Herbivores Through Molecular Signaling, Secondary Metabolites, and Associated Epigenetic Regulation

• Published in: Plant-environment interactions (Hoboken, N.J. : 2018) Vol. 6; no. 1; pp. e70035 - n/a
• Main Authors: Mahanta, Deepak Kumar, Komal, J., Samal, Ipsita, Bhoi, Tanmaya Kumar, Kumar, P. V. Dinesh, Mohapatra, Swapnalisha, Athulya, R., Majhi, Prasanta Kumar, Mastinu, Andrea
• Format: Journal Article
• Language: English
• Published: United States John Wiley & Sons, Inc 01.02.2025; John Wiley and Sons Inc; Wiley
• Subjects: Barriers; Biosynthesis; Cell membranes; Chemical damage; Chemical stimuli; Defense mechanisms; epigenetic regulations; Epigenetics; Flowers & plants; herbivore attack; Herbivores; Herbivory; Insects; Ion flux; Jasmonic acid; Membrane potential; Metabolites; molecular signaling; Organic compounds; Plant hormones; plant–herbivore interaction; Review; Salicylic acid; Secondary metabolites; Secretions; Signal transduction; Spines; Trichomes; VOCs; Volatile organic compounds; epigenetic regulations; molecular signaling; secondary metabolites; plant–herbivore interaction; herbivore attack
• ISSN: 2575-6265; 2575-6265
• DOI: 10.1002/pei3.70035

ABSTRACTOver millions of years of interactions, plants have developed complex defense mechanisms to counteract diverse insect herbivory strategies. These defenses encompass morphological, biochemical, and molecular adaptations that mitigate the impacts of herbivore attacks. Physical barriers, such as spines, trichomes, and cuticle layers, deter herbivores, while biochemical defenses include the production of secondary metabolites and volatile organic compounds (VOCs). The initial step in the plant's defense involves sensing mechanical damage and chemical cues, including herbivore oral secretions and herbivore‐induced VOCs. This triggers changes in plasma membrane potential driven by ion fluxes across plant cell membranes, activating complex signal transduction pathways. Key hormonal mediators, such as jasmonic acid, salicylic acid, and ethylene, orchestrate downstream defense responses, including VOC release and secondary metabolites biosynthesis. This review provides a comprehensive analysis of plant responses to herbivory, emphasizing early and late defense mechanisms, encompassing physical barriers, signal transduction cascades, secondary metabolites synthesis, phytohormone signaling, and epigenetic regulation. Plants have developed sophisticated defensive mechanisms against insect feeding techniques over millions of years. These defenses include physical barriers like spines and chemical barriers like secondary metabolites and volatile organic compounds (VOCs). The initial response involves sensing physical and chemical stimuli, leading to hormonal activation and various defensive actions, as detailed in contemporary research on plant–herbivore interactions.