Comprehensive analysis of VOZ proteins in sweet potato and related species reveals their evolutionary dynamics and responses to abiotic stresses

VOZ (Vascular Plant One-Zinc Finger) transcription factors represent a plant-specific family of regulatory proteins that are pivotal in controlling plant growth, developmental processes, and adaptive responses to biotic and abiotic stresses. Although VOZ genes have been reported in multiple plant species, their genomic organization, evolutionary history, and functional dynamics in sweet potato remain largely unexplored. In this study, a comprehensive genome-wide investigation of VOZ family members was conducted across six Ipomoea species, namely I. aquatica (Iaq), I. cairica (Ica), I. nil (Inil), I. triloba (Itb), I. trifida (Itf), and Ipomoea batatas (Ib). In terms of their phylogenetic relationships, protein properties, gene architecture, conserved motifs, promoter cis -elements, chromosomal localization, and collinearity patterns, 14 VOZ genes were identified and systematically analyzed. The findings reveal a contraction in VOZ copy number, accompanied by structural and functional divergence during the evolutionary trajectory of these Ipomoea species. Furthermore, transcriptional profiling and protein-protein interaction network characterization in sweet potato indicate that VOZs from I. trifida (ItfVOZs) and I. batatas ( IbVOZs ) are implicated in developmental regulation, hormone-mediated signaling pathways, and stress adaptation. Collectively, this study provides a comprehensive genomic framework for the VOZ gene family across six Ipomoea species and provides a solid foundation for elucidating their functional roles in sweet potato.