Harnessing plant susceptibility genes into strategies for enhanced disease resistance

Abstract Plant disease resistance has traditionally been framed around immune recognition, yet successful infection often equally depends on host functions that pathogens exploit. These host factors, known as susceptibility ( S ) genes, support compatible interactions by facilitating pathogen entry, nutrient acquisition, immune suppression, or infection‐associated cellular reprogramming. Their genetic attenuation can convert pathogen‐exploited host processes into sources of recessive resistance, but the durability and agronomic value of such resistance depend on whether susceptibility‐promoting functions can be uncoupled from essential roles in growth, metabolism and stress adaptation. Here, we review the major functional classes of plant S genes, recent strategies for their discovery and emerging approaches for their deployment in disease‐resistance breeding. We discuss how transcriptomics, genetic mapping, effector‐guided screening and genome editing are reshaping S gene biology from a catalogue of individual examples into a framework for allele design. Furthermore, we highlight key translational challenges, including pleiotropy, genetic background effects, pathogen adaptation, transgene footprints and regulatory divergence, that must be addressed to harness S genes for durable and agronomically balanced crop resistance.