Genome-wide Identification and Expression Analysis of the AP2/ERF Gene Family in Cucumis sativus L.

Purpose To identify the APETALA2/ethylene responsive factor (AP2/ERF) gene family in the genome-wide of cucumber, analyzing its gene structure, function and expression pattern, and providing reference for the role of this family gene in cucumber growth and development and resistance to stress.

Methods Using bioinformatics to identify the CsaAP2/ERF family, and analyze the physicochemical properties, structure and function, protein interactions, evolutionary relationships, and expression patterns of its members.

Results 148 AP2/ERF family members were identified in the cucumber genome. According to the homology, they were divided into five subfamilies: AP2, ERF, DREB, RAV, and Soloist. The gene structure of each subfamily member was similar to the conservative motif. CsaAP2-11 and CsaAP2-15, as the core proteins of the protein interaction network, interacted with multiple proteins. Collinearity analysis showed that CsaAP2/ERF had the most similar evolutionary relationship with the pumpkin homologous genes. Under stress (cold, heat, salt), the expression levels of genes such as CsaAP2-15, CsaAP2-18, CsaERF-31, CsaERF-54, CsaERF-64, CsaERF-65, CsaDERB-37, CsaDREB-38, and CsaDREB-45 had significantly changed.

Conclusion In this study, members of the AP2/ERF family in cucumber are systematically identified and characterized, and their expression patterns under various stresses are analyzed, which provide a theoretical basis for the biological function of this family gene and the cultivation of new stress resistant cucumber varieties.