The GLABROUS1 enhancer-binding protein (GeBP) gene family encodes typical transcription factors containing an atypical leucine zipper motif, and plays a critical role in regulating plant growth and development, as well as multiple abiotic stresses response, but little is known about the role of GeBP transcription factors in apple. In this study, seven GeBP family members were identified in apple by genome-wide analysis, expression response analysis showed that MdGeBPs had different tissue expression patterns and were responsive to a variety of hormonal and abiotic stresses. Subsequently, MdGeBP3 was cloned and transgenic Arabidopsis and apple callus were obtained for further functional characterization. MdGeBP3 protein was localized in the nucleus, and overexpression of MdGeBP3 was more sensitive to cytokinins and less sensitive to ABA. In addition, ectopic expression of MdGeBP3 in Arabidopsis resulted in reduced drought tolerance, promoted adventitious root development and delayed flowering. Overall, these results suggest that MdGeBP3 may play an important role in regulating apple growth and development, as well as abiotic stress responses.

GLABROUS1 enhancer-binding protein (GeBP)基因家族编码含有非典型亮氨酸拉链基序的典型转录因子，在调控植物生长发育以及多种非生物胁迫响应中起着关键作用，但对其作用知之甚少苹果中的GeBP转录因子。本研究通过全基因组分析在苹果中鉴定出7 个GeBP家族成员，表达响应分析表明MdGeBPs具有不同的组织表达模式，对多种激素和非生物胁迫均有响应。随后，MdGeBP3被克隆和转基因拟南芥获得苹果愈伤组织用于进一步的功能表征。MdGeBP3蛋白定位于细胞核，过表达MdGeBP3对细胞分裂素更敏感，对ABA不太敏感。此外，MdGeBP3在拟南芥中的异位表达导致耐旱性降低，促进不定根发育和延迟开花。总体而言，这些结果表明MdGeBP3可能在调节苹果生长发育以及非生物胁迫反应中发挥重要作用。