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 CPAI gene family using the potato DM v6.1 genome and analyzed genomic and amino acid sequence features. Results demonstrated that eight CPAI 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 StCPAI genes in potato development.