Identification, characterization, and expression analysis of PpCPK gene family in response to Alternaria-infected peach fruits collected from different geographical regions of China

•Alternaria is a deadly disease agent that causes significant damage to peach crops.•The CPK gene family plays a vital role in the biotic stress response of plants.•The expression pattern of PpCPK was analyzed using real-time quantitative PCR in Alternaria-infected peach fruits from different regions of China.•The results indicated a differential expression pattern of PpCPK genes in response to alternaria infection, suggesting their potential role in defense against biotic stress.