Abstract:Primers were designed according to the published sequence of the apple genome and a Mdgal gene promoter of Malus× domestica Borkh ‘Gala’ were cloned. Online function prediction by PLACE and Plant CARE showed that Mdgal promoter contained a large number of phytohormone responsive elements, such as gibberellinresponsive elements (GAREmotif, Pbox), auxinresponsive element (TGAelement), MeJA responsive elements (CGTCAmotif, TGACGmotif) and some stress responsive elements. Meanwhile, to identify the upstream region of the Mdgal gene required for promoter activity, we constructed five Mdgal promoter deletion derivatives. Each deletion construct was analyzed by Agrobacteriummediated transient transformation in apple fruits and tobacco leaves. Then the transgenic apple and tobacco with GUS histochemical staining and quantitative detection of GUS enzyme activity were analyzed. The results indicated that all the five promoters had the promoter activity, and both activation and repression regulatory elements coexisted in the Mdgal promoter sequence. Positive regulatory elements may be located in a region from -1 206 to -754 bp and negative regulatory elements are present at position from -754 to -597 bp. Finally, hormone treatment assay suggested that the cisregulatory regions in the Mdgal promoter was responsive to different exogenous hormones in tobacco, and the highest level of GUS activity was observed in MeJA treatment. Taking together, our results demonstrate that Mdgal promoter with the basic structural characteristics of eukaryotes gene promoters has the up and downregulation function and hormonal treatment responsiveness, which might be involved in apple fruit development and ripening.