The impact of diabetes and obesity on the severity and mortality of SARS-CoV-2 infection.

UNLABELLED: Auxin response factors (ARFs) are key transcription factors involved in auxin signaling and play important roles in plant growth and floral development. However, their evolutionary history and potential roles in sex-related floral development in spinach remain unclear. Here, we performed a comparative genomics analysis of ARF gene families across Chenopodium species and Beta vulgaris, together with Spinacia species, to investigate their evolutionary characteristics and potential functional divergence. A total of 269 non-redundant ARFs were identified across 20 genomes and classified into 12 phylogenetic subfamilies. Phylogenetic analysis revealed a conserved evolutionary framework with lineage-specific diversification. Motif, domain, and gene structure analyses indicated that structural variation among subfamilies, which was associated with differences in exon organization. Ka/Ks analysis suggested that ARF genes have mainly undergone purifying selection with variable evolutionary constraints among subfamilies. Cis-acting element analysis revealed abundant light-, stress-, and hormone-responsive elements in ARF promoters. Network analysis further indicated potential regulatory associations between a subset of SpARF proteins and floral development-related MADS-box genes. In spinach, ARF genes showed sex-biased expression patterns during floral development. Virus-induced gene silencing (VIGS) of six selected SpARF genes resulted in abnormal female flower development, suggesting their involvement in female flower development. Together, these results indicate that the spinach ARF gene family combines high conservation with structural and functional divergence. Our findings suggest that SpARF genes may play important roles in regulating female floral development, providing new insights into auxin-mediated regulatory networks in spinach and offering a foundation for future studies on floral development and breeding.

SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s11032-026-01706-0.