Genome‐Wide Identification of the MYB Gene Family and Discovery of Key Genes Regulating Rind Color in Watermelon

MYB transcription factors represent one of the largest transcription factor families in plants and play a critical role in regulating rind coloration. However, key MYB genes directly involved in rind color formation in watermelon have not yet been systematically identified or functionally characterized. In this study, a total of 115 MYB genes were systematically identified from the watermelon genome and classified into 25 distinct subclades based on phylogenetic analysis. Combined with bioinformatic characterization of conserved domains, motif composition, gene structure, and promoter cis‐elements, the molecular features of this gene family were comprehensively elucidated. Transcriptome analysis revealed significant differences in the expression levels of structural genes involved in chlorophyll biosynthesis during fruit development among watermelon accessions with different rind colors. WGCNA further identified key modules highly associated with rind color formation, from which two core candidate regulators, ClaMYB79 ( Cla97C08G155540.2 ) and ClaMYB71 ( Cla97C07G140720.1 ), were selected, and their regulatory networks were constructed. The reliability of the transcriptome results was further confirmed by qRT‐PCR validation. This research lays a solid foundation for future research to elucidate the molecular mechanisms by which MYB genes regulate rind color formation in watermelon.