Molecular Insights into Powdery Mildew Pathogenesis and Resistance in Cucurbitaceous Crops

Powdery mildew, predominantly caused by Podosphaera xanthii and Golovinomyces orontii, presents a major constraint to cucurbitaceous crop production worldwide. Despite intensive research, the complex interplay between pathogen virulence factors and host immune responses remains only partially understood. Recent advances in genomics, transcriptomics, and gene editing technologies have shed light on key molecular mechanisms underlying host susceptibility, quantitative resistance, and potential durable control strategies. In this review, we summarize the biology of powdery mildew fungi infecting cucurbits, the latest findings on pathogen effectors, plant defense signaling, and the genetic basis of resistance. We also discuss novel breeding and biotechnological approaches for durable powdery mildew resistance and outline future directions for integrative disease management strategies.