Genome-Wide Identification and Comprehensive Analysis of AP2/ERF Gene Family in Adiantum nelumboides Under Abiotic Stress

The <i>AP2/ERF</i> (APETALA2/ethylene-responsive element binding factor) family represents one of the largest transcription factor families in plants, playing pivotal roles in abiotic stress responses and hormone signaling pathways. Through genome-wide analysis, we identified 163 <i>AnAP2/ERF</i> genes in <i>Adiantum nelumboides</i>. Transcriptome data revealed that 12 <i>AnAP2/ERF</i> genes were significantly upregulated under either drought or flooding stress, with 8 genes responding to both conditions. qRT-PCR validation confirmed that all 12 selected <i>AnAP2/ERF</i> genes exhibited differential expression under both stress types. Notably, these genes also showed significant induction by abscisic acid (ABA), auxin (IAA), and gibberellin (GA), suggesting their potential involvement in stress responses through hormone crosstalk. This study establishes a foundation for investigating <i>AnAP2/ERF</i> gene functions and their molecular mechanisms in abiotic stress adaptation in <i>A. nelumboides</i>.