The genetic and regulatory framework of cuticular wax formation: insights from model plants to cereal crops

Plant cuticular waxes form a critical hydrophobic barrier covering aerial organs, serving as the first line of defense against abiotic and biotic stresses and playing a vital role in reproductive development. However, regulatory networks that orchestrate cuticular wax deposition in response to environmental cues and developmental programs, particularly in cereal crops, remain elusive. This review integrates current knowledge by identifying genes implicated in wax formation in Arabidopsis and major graminaceous crops. We detail the molecular mechanisms of wax biosynthesis and export, and place a major focus on the intricate transcriptional regulatory modules that integrate signals from drought, salinity, and pathogens, as well as developmental signals critical for anther cuticle formation and male fertility. Conserved and species-specific adaptations in these networks are highlighted, emphasizing how natural variation in these pathways underpins adaptive traits. We also discuss evolutionary perspectives and critically identify key knowledge gaps, such as the unresolved trade-offs between abiotic and biotic stress resistance and the mechanistic basis of anther cuticle development under heat stress, providing insights into leveraging cuticular traits for climate-resilient crop design.