Identification of wheat AP2 gene family, Cloning of TaAP2-34, and patterns analysis by Overexpression in Arabidopsis

Background As a subfamily of the AP2/ERF gene family, the AP2 family is mainly involved in responses to abiotic stresses and the regulation of growth and development in various plant organs. Exploring the characteristics of wheat AP2 genes and understanding their expression patterns under diverse stress conditions is of great significance. In this study, we focused on TaAP2-34 , a member of the AP2 family that exhibits significant differential responses to stress, and performed its cloning and functional verification. We further clarified its expression patterns under low-temperature and drought stresses, aiming to provide a theoretical basis and experimental support for elucidating the stress-resistant regulatory mechanisms of the wheat AP2 gene family, mining key stress-resistant gene resources, and promoting molecular breeding for stress resistance in wheat. Results In this study, we found that most wheat AP2 proteins were weakly acidic and hydrophilic. Their corresponding genes were distributed on 21 chromosomes. Subcellular localization analysis revealed that they were mainly located in the plasma membrane and cytoplasm, with a few in the nucleus. The AP2 protein domains and core motifs of wheat were orderly, stable and highly conserved.One AP2 gene ( TaAP2-34 ) that was differentially expressed under various stresses in the transcriptome database was verified by quantitative real-time PCR (qRT-PCR). Under drought stress, the expression level of TaAP2-34 in wheat leaves first increased and then decreased with prolonged drought time, reaching the highest value at 6h. The expression level of TaAP2-34 in tiller nodes also showed a trend of first increasing and then decreasing with drought time, peaking at 12h. Under low-temperature stress, the expression levels of TaAP2-34 in both wheat leaves and tiller nodes increased with decreasing temperature and reached the maximum at -25 ℃. TaAP2-34 transgenic Arabidopsis thaliana exhibited significantly lower reactive oxygen species (ROS) and malondialdehyde (MDA) contents, but higher superoxide dismutase (SOD) and peroxidase (POD) activities, than WT plants. Conclusion The wheat AP2 gene family responds to various abiotic stresses. TaAP2-34 plays an important role in drought and low-temperature stresses, providing a theoretical basis for molecular breeding of stress resistance in wheat.