Identification and Characterization of the StCPAI Gene Family in Potato

Carboxypeptidase A inhibitor (CPAI) is a globular polypeptide that specifically inhibits carboxypeptidase A activity in the insect gut, playing a vital role in plant defense against external stimuli. To date, this gene family has not been systematically characterized in potatoes. In this study, we identified the <i>CPAI</i> gene family using the potato DM v6.1 genome and analyzed genomic and amino acid sequence features. Results demonstrated that eight <i>CPAI</i> members in potatoes share high homology with orthologs in tomatoes, eggplants, and peppers. Their promoter regions contain predicted cis-acting elements associated with defense and stress responses. Additionally, qRT-PCR analysis revealed elevated expression of specific members in tubers and aerial tubers, with concurrent responses to auxin treatment. These findings provide a foundation for elucidating the roles of <i>StCPAI</i> genes in potato development.