Two different domain architectures generate structural and functional diversity among genes in the Solanaceae family.

The gene family is one of the largest transcription factor families and has important roles in plant growth, development, and stress responses. However, genes in the Solanaceae family have not been extensively investigated. Here, we conducted genome-wide re-annotation in nine Solanaceae species and . We annotated 935 genes, including 107 (11%) that were newly identified. Structural analyses of genes in the Solanaceae family revealed that the bZIP domain displayed two types of architectures depending on the presence of an additional domain, suggesting that these architectures generate diversified structures and functions. Motif analyses indicated that the two types of genes had distinct sequences adjacent to the bZIP domain. Phylogenetic analyses suggested that the two types of genes distinctly evolved and ultimately adapted in different lineages. Transcriptome analyses in pepper () and tomato () revealed putative functional diversity between the two types of genes in response to various abiotic stresses. This study extensively updated gene family annotations and provided novel evolutionary and functional evidence for the role of genes in Solanaceae plants. Our findings provide evolutionary and functional characteristics of genes for a better understanding of their roles in Solanaceae plants.