Enzyme-mediated adaptation of herbivorous insects to host phytochemicals

Abstract

The review comprehensively explores factors influencing enzyme activities in insects and their implications in defense against toxicants. It encompasses a diverse array of enzymes involved in metabolizing synthetic chemicals, emphasizing their dynamic regulation. Key factors affecting enzyme activities, such as external and internal influences, are discussed, shedding light on the intricate regulatory mechanisms. The inhibitory effects of various compounds on insect GST activity are thoroughly examined, providing insights into potential avenues for insect control. The implications of insect defenses against toxicants are elucidated, emphasizing the complexity of plant–insect interactions. The review delves into the evolutionary adaptations of insects to plant defense mechanisms, highlighting the role of enzymes like thioglucosidase and myrosinase in detoxifying glucosinolates. The co-evolutionary dynamics between insects and plants, particularly in the Brassicaceae family, are explored, underscoring the intricate biochemical strategies employed by both parties. Additionally, the review addresses the challenges associated with developing pest-resistant crop plants through traditional breeding or genetic engineering. It discusses the need for a nuanced approach, considering the adaptability of insects to various toxicants and the potential drawbacks of repeated exposures. The success of chemical plant defenses, particularly monoterpene synthesis in pine trees, is noted, along with the distinctive biodegradability of plant metabolites. The review provides a thorough examination of the mechanisms underlying insect responses to toxic plant metabolites, offering valuable insights into the dynamic interplay between insects and plants. It suggests potential targets for insect control programs and highlights the importance of understanding the co-evolutionary processes that shape these interactions.