Genome-Wide Identification and Expression Profiling of the DOG1-like Genes in Radish (Raphanus sativus L.)

Seed dormancy is a vital adaptive mechanism regulated by the DELAY OF GERMINATION (DOG) gene family. Here, we present the first systematic genome-wide identification and expression profiling of the DOG gene family (RsDOGs) in radish (Raphanus sativus). Comprehensive analysis of physicochemical properties, chromosomal distribution, and phylogeny revealed strong evolutionary conservation alongside functional divergence. Notably, several RsDOG proteins harbor natural fusions of the DOG1 domain with a bZIP domain, suggesting potential transcription factor activity and novel regulatory functions. Promoter analysis identified abundant ABA-responsive and abiotic stress-responsive cis-acting elements. Quantitative real-time PCR (qRT-PCR) profiling across contrasting cultivars—dormant variety Rs275 and non-dormant variety Rs100—at 4 h and 28 h post-imbibition revealed distinct differential expression patterns. In particular, TRs0x5c022182.1 exhibited high expression levels in dormant seeds, suggesting its potential involvement in seed dormancy regulation in radish. This study provides key insights into the structural evolution and expression dynamics of RsDOG genes, laying a solid foundation for molecular breeding aimed at optimizing seed germination traits.