Decoding plant resistance mechanism in pigeonpea (Cajanus cajan) against major insect pests: Decade of efforts and emerging directions

• Pigeonpea is an important legume for nutritional security in semi-arid regions of Asia and Africa, but its productivity is significantly threatened by insect pests throughout all stages of growth and post-maturity stage. • Host plant resistance (HPR) has emerged as a sustainable and eco-friendly strategy to manage insect pests by reducing the dependence on chemical pesticides and contributing to environmentally sound pest management. • Substantial progress has been made in identifying pest-resistant pigeonpea genotypes and elucidating the biochemical, morphological, and genetic traits that confer resistance, supported by advances in molecular breeding, genomics, and other omics approaches. • Emerging technologies such as multi-omics approaches, gene editing, and innovative breeding tools are expanding our understanding of host–insect interactions and accelerating the development of precision pest-resistant varieties, with global implications for food security and integrated pest management. Pigeonpea ( Cajanus cajan (L.) Millsp.) is an important food and nutritional security crop, widely cultivated in the semi-arid regions of Asia and Sub-Saharan Africa. However, its productivity is hindered by various abiotic and biotic stress factors, including numerous insect pests that infest and damage the crop at all stages of development, both in the field and during post-maturity stage/ storage conditions. Host plant resistance (HPR) has emerged as a critical tool in the sustainable management of insect pests in pigeonpea as a vital legume crop. This review synthesizes key breakthroughs in understanding and applying HPR. It focuses on decades of development and recent advances in identifying resistant/tolerant pigeonpea genotypes and the mechanisms underlying their plant defense for major insect pests. Moreover, emphasis is placed on biochemical, morphological, and genetic traits conferring resistance to significant pests of pigeonpea. In addition, innovations in molecular breeding, genomics, and phenotyping are accelerating the development of pest-resistant genotypes, offering alternatives to chemical control and enhancing crop resilience. In this review, we explored emerging research directions, including multi-omics approaches, gene-editing techniques, and novel breeding techniques, thereby expanding our understanding of host-insect interactions and facilitating precision breeding research. This comprehensive review and opinion underscore the potential of HPR in integrated pest management (IPM) for pigeonpea and highlight future pathways for improving insect pest resistance and ensuring food security in pigeonpea-producing regions across the globe .