Genome-Wide Identification and Expression Analysis of the AP2/ERF Transcription Factor Gene Family in Hybrid Tea Rose Under Drought Stress

Drought stress is an important factor that reduces plant biomass production and quality. The <i>APETALA2/ETHYLENE RESPONSE FACTOR</i> (<i>AP2/ERF</i>) gene family is widely involved in biological processes such as plant growth, development, and stress response. However, the characteristics of the <i>AP2/ERF</i> gene family in hybrid tea rose (<i>Rosa × hybrida</i>) and their potential functions in responding to drought stress are still unclear. In the current study, 127 <i>AP2/ERF</i> genes were identified in hybrid tea rose. Phylogenetic analysis showed that the corresponding 127 AP2/ERF transcription factors belonged to five subfamilies. There was a large number of <i>cis</i>-acting elements in the <i>AP2/ERF</i> gene promoters related to regulation of stress response, growth and development. By examining the RNA sequencing data in the PlantExp database, the <i>RhAP2</i>/<i>ERF</i> genes exhibiting tissue-specific and stress-responsive expression in rose were identified. Furthermore, three candidate <i>RhAP2/ERF</i> genes (<i>RhDREB36</i>, <i>RhERF59</i>, and <i>RhDREB44</i>) that might participate in drought response were determined via qRT-PCR analysis in rose cultivars under drought treatment. Subcellular localization analysis revealed that <i>RhDREB44</i> was located in the nucleus. These results provide a foundation for exploring the regulatory functions of <i>RhAP2/ERF</i> genes in the growth and development of roses, as well as for selecting key genes for future molecular breeding.