Harnessing molecular insights into plant biophysical traits: Prospects for priming defense against insect pests

Abstract

Among plant biotic stresses, insect pests are of major concern as they directly damage plant tissues and also act as vectors for plant pathogens. The co-evolution of crops and insect pests poses persistent challenges to agricultural productivity worldwide. Chemical insecticides have long served as the primary means of pest control. However, their indiscriminate use has resulted in increased production costs, environmental and ecosystem disruption, and increased risks to human health. These limitations underscore the need for sustainable, non-chemical pest management strategies that can effectively integrate and enhance existing Integrated Pest Management (IPM) programs. One of the most sustainable components of IPM is host plant resistance (HPR), in which plants employ antixenosis and antibiosis as defense strategies mediated through various biophysical, biochemical and behavioral responses. Cultivated genotypes and their wild relatives exhibit diverse resistance mechanisms against insect pests. Key biophysical traits contributing to resistance include leaf glossiness, trichome density, pod and leaf sheath pigmentation, plant vigor, pod wall thickness, cuticle thickness, lignification and other structural defenses. These biophysical traits are regulated by complex molecular and metabolic pathways that determine pest resistance. Understanding the genetic basis of these biophysical traits provides valuable opportunities for identifying and manipulating specific resistance-related genes. Deciphering the complex plant biophysical traits and their genetic basis of resistance, offers promising avenues for immune priming by developing improved crop varieties through new breeding techniques (NBTs). By integrating ecological, genetics and breeding perspectives, this review provides a coherent framework for harnessing plant biophysical traits through modern breeding and genome editing to achieve durable and sustainable insect resistance.