Abstract
BACKGROUND: WD40 proteins represent a major conserved eukaryotic family, participating broadly in regulating diverse biological processes and secondary metabolite biosynthesis, including anthocyanin production. While peanut (Arachis hypogaea) ranks among the world’s most significant oilseed crops, the AhWD40 family remains uncharacterized, with unknown regulatory roles in anthocyanin accumulation. RESULTS: Our genome-wide analysis identified 367 AhWD40 members. Bioinformatics characterization revealed both conserved features and subgroup-specific attributes among family members. Evolutionary analysis further indicated segmental duplications as principal drivers of AhWD40 family expansion. Ka/Ks calculations demonstrated dominant purifying selection during AhWD40 evolution. Notably, six members exhibit high sequence similarity to Arabidopsis TRANSPARENT TESTA GLABRA1 (TTG1). Transcriptomic and qRT-PCR analyses established strong correlations between AhWD40-170 and AhWD40-171 expression and anthocyanin accumulation. Transient overexpression of either gene in apple skin significantly enhanced anthocyanin biosynthesis. CONCLUSION: This study provides a comprehensive understanding of the structure, classification, evolution, and anthocyanin accumulation of WD40 genes in peanut. These findings establish a functional framework for AhWD40s in anthocyanin regulation and propose novel genetic targets for enhancing plant anthocyanin production. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12870-025-07618-z.