Abstract:GluTR encoded by HEMA1 is the key enzyme in regulating chlorophyll biosynthesis. In this study, the encoding gene was cloned from apple leaves by RACE technology and designated as MdHEMA1. Bioinformatics analysis revealed that MdHEMA1 locates on chromosome 8 of apple genome, with a CDS length of 1638 bp and encodes 545 amino acid residues. The calculated molecular mass is 59279.4 Da with an isoelectric point of 8.45. Sequence analysis showed that MdHEMA1 protein contains 3 conserved domains. MdHEMA1 possesses the closest phylogenetic relationship with PbHEMA1 from Pyrus×bretschneideri. qRT-PCR results revealed that MdHEMA1 exhibited a highexpression level in photosynthetic tissues compared with that in other tissues. Besides, the expression level of MdHEMA1 varied in leaves and fruits at different developmental stages, which was positively correlated with the level of chlorophyll accumulation. The gene expression could also be induced by drought stress. Promoter analysis revealed that MdHEMA1 promoter possessed multiple putative cis-acting elements involved in abiotic stress.