Plant-insect interaction in underutilized horticultural crops for sustainable production

Abstract

Plants and insects have been living together for more than 350 million years. In co-evolution, both have evolved strategies to avoid each other’s defense systems. This evolutionary arms race between plants and insects has resulted in the development of an elegant defense system in plants that can recognise the non-self-molecules or signals from damaged cells, much like animals. It activates the plant’s immune response against the herbivores. Differences in genotypes of plant characters may affect insect-plant herbivore interactions, and variations in genotype traits are responsible for modifying the bottom-up effects. Recent evidence shows that the simultaneous occurrence of abiotic and biotic stress can positively affect plant performance by reducing the susceptibility to biotic stress, a positive sign for pest management. Plant responses to these stresses are multifaceted and involve copious antibiosis, physiological, antixenotic, molecular, molecular and cellular adaptations. Plants with antibiosis characteristics such as flavonoids, phenols, tannins, alkaloids, etc., may cause reduced insect survival, prolonged development time, decreased size and reduced new generation fitness. Quality and quantity of constitutive secondary metabolites production is species as well as cultivar specific and can be expressed as the signature of a particular plant or species and leads to the phenomenon of host-plant resistance. Hence, such plant resistance mechanisms have been effectively and widely used for managing insect pests in fields of underutilized crops. Natural defences are mediated through plant characteristics that affect insect biology, such as mechanical protection on the surface of the plants (e.g., hairs, trichomes, thorns, spines and thicker leaves) that either kill or retard the development of the herbivores. These phenomena of host plant resistance to insects can be exploited for the development of resistance crop cultivars which readily produce the inducible response upon mild infestation and can perform as one of the integrated pest management for sustainable crop production.