Unraveling the Mechanisms of Plant Structural Defenses against Insect Pests

Abstract

Plants employ a variety of physical, chemical, and genetic strategies to defend against herbivore attacks. These biochemical defense mechanisms are complex and dynamic, encompassing both direct and indirect responses. Defense-related chemicals, whether constitutive or induced by herbivore damage, significantly influence herbivore feeding behavior, growth, and survival. Plant defense systems impact herbivore nutrition, development, and survival, highlighting the importance of chemical substances in reducing plant vulnerability to insects. Plants release volatile chemicals that attract herbivores and these defense strategies are effective alone or in combination. Enhancing our understanding of these defense systems could promote the use of induced resistance as a sustainable pest control strategy, reducing reliance on pesticides. Chemical compounds play a critical role in strengthening plant resistance and understanding the pathways of induced resistance allows for accurate predictions of herbivore responses. Application of induced response elicitors to crops boosts their natural defenses against herbivores. Genetic modification can further enhance plant defenses by promoting the synthesis of defensive chemicals. While this review covers the structural defenses of plants extensively, it lacks a thorough analysis of their ecological impacts beyond deterring insects. Additionally, it focuses more on the mechanisms of these defenses rather than their variations across different ecological contexts or plant species. There is significant potential to leverage plant defense mechanisms in crop protection to address health, environmental, and pesticide-related issues. Utilizing induced resistance, we can develop crop cultivars that naturally respond to minor infections, integrating these traits into sustainable pest management strategies to boost agricultural productivity.