Abstract：The AP2/ERF family is widely involved in processes such as plant growth and development, hormonal response, and can affect changes in fruit texture. In order to investigate the expression pattern and function of AP2/ERF family member ABR1 (abscisic acid repressor 1) in the ripening process of jujube (Ziziphus jujuba) fruit, this study used 'Laoqiu zao' (Ziziphus jujuba cv. 'Laoqiu zao') as the material, ZjABR1 gene (LOC107409847) was cloned and its bioinformatics, subcellular localization, and expression were analyzed. An overexpression vector was constructed for transient transformation. Yeast one hybrid experiment was performed. The study found that the CDS region of the ZjABR1 gene was 1 344 bp, encoded 447 amino acids, and contained an AP2 binding domain. The subcellular localization analysis revealed that the ZjABR1 protein was presented in nucleus. RT-qPCR analysis revealed that ZjABR1 was highly expressed in the jujube fruit fully ripe stage. Transient overexpression of ZjABR1 gene enhanced polygalacturonase (PG) activity and the expression level of ZjPG. Yeast one hybrid demonstrated that ZjABR1 could directly bind to the ZjPG promoter. This study provided a basis for research on the molecular mechanisms of jujube fruit ripening.
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