Genome-Wide Identification and Expression Profiling of AP2/ERF Transcription Factor Genes in Prunus armeniaca L.

The APETALA2/Ethylene Responsive Factor (AP2/ERF transcription factor) family plays pivotal roles in plant growth, stress responses, and metabolic regulation. Here, we identified 118 AP2/ERF family members in the apricot (Prunus armeniaca L.) genome, which were classified into four major subfamilies (AP2, DREB, ERF, and RAV) and Soloists (few unclassified factors), through phylogenetic analysis. The ERF subfamily exhibited the largest expansion (55 members), driven predominantly by 10 tandem and 14 segmental duplication events. Gene structures and conserved motifs exhibited similar patterns within each subfamily. Chromosomal distribution was uneven, with chromosome 1 harboring the highest gene density. PaWRI1 was specifically expressed in apricot kernel and positively correlated with oil accumulation. A total of 47 lipid-related genes were predicted as potential targets of PaWRI1 through correlation analysis, which covers the entire three-stage process of plant oil synthesis. These results advance our understanding of how core AP2/ERF transcription factors modulate oil accumulation pathways in apricot, offering potential targets for metabolic engineering.