Background: Auxin, a plant hormone, plays diverse roles in the modulation of plant growth and development. The transport and signal transduction of auxin are regulated by various factors involved in shaping plant morphology and responding to external environmental conditions. The auxin signal transduction is primarily governed by the following two gene families: the auxin response factor (ARF) and auxin/indole-3-acetic acid (AUX/IAA). However, a comprehensive genomic analysis involving the expression profiles, structures, and functional features of the ARF and AUX/IAA gene families in Vaccinium bracteatum has not been carried out to date. Results: Through the acquisition of genomic and expression data, coupled with an analysis using online tools, two gene family members were identified. This groundwork provides a distinguishing characterization of the chosen gene families in terms of expression, interaction, and response in the growth and development of plant fruits. In our genome-wide search of the VaARF and VaIAA genes in Vaccinium bracteatum, we identified 26 VaARF and 17 VaIAA genes. We analyzed the sequence and structural characteristics of these VaARF and VaIAA genes. We found that 26 VaARF and 17 VaIAA genes were divided into six subfamilies. Based on protein interaction predictions, VaIAA1 and VaIAA20 were designated core members of VaIAA gene families. Moreover, an analysis of expression patterns showed that 14 ARF genes and 12 IAA genes exhibited significantly varied expressions during fruit development. Conclusion: Two key genes, namely, VaIAA1 and VaIAA20, belonging to a gene family, play a potentially crucial role in fruit development through 26 VaARF-IAAs. This study provides a valuable reference for investigating the molecular mechanism of fruit development and lays the foundation for further research on Vaccinium bracteatum.

The WRKY gene family is a widely distributed and highly conserved transcription factor (TF) family in plants, with its members playing key roles in plant growth and development, stress response, and metabolism. Although WRKY TFs have been extensively studied in many plant species, research on the WRKY gene family in Vaccinium bracteatum Thunb. remains limited. Therefore, integrating molecular biology and bioinformatics approaches to further explore the WRKY gene family in V. bracteatum is of considerable scientific importance. In this study, we employed various online tools to obtain genomic and expression data, which were subsequently analyzed to determine the composition, evolutionary relationships, and functions of WRKY family genes in V. bracteatum. A total of 66 WRKY genes (VaWRKY) were identified, named based on homology alignment. Phylogenetic analysis classified the 66 VaWRKYs into three major clades and seven subclades. Sequence and structural analyses of VaWRKY genes provided insights into their evolutionary and functional characteristics. Expression profile analysis revealed significant differences in the expression of 12 VaWRKY genes at various stages of fruit development. Protein interaction analysis further indicated that VaWRKY genes are functionally diverse, playing important roles in stress response, seed germination regulation, and plant growth and development. In summary, we have a deeper understanding of VaWRKY genes, and systematic analysis of structure, evolutionary characteristics, and expression patterns plays an important role in analyzing its biological functions, molecular breeding, and enhancing economic value.