关键词: 山荆子, Nramp1, MbNramp1, 铁转运蛋白, 锰转运蛋白

Abstract: Degenerate primers corresponding to the conserved motifs of NRAMP1 in plants were used to amplify specific DNA fragments from Malus baccata（L.）Borkh. roots cDNA. Then the gene specific primers were designed based on the obtained specific DNA fragments，the 3′ end and 5′ end fragments were amplified by RACE. A 2 090 bp full length cDNA MbNramp1 containing a 1 656 bp ORF was obtained based on specific DNA fragments. MbNramp1 encodes a polypeptide of 551 amino acids with a predicted molecular mass of 59.7 kD and a membrane protein with more than 76% non-polar amino acids. All conserved features of NRAMP described previously were present in the predicted MbNRAMP1 sequence，such as putative N-linked glycosylation sites，10 transmembrane domains（TMS）and a consensus transporter motif（CTM）located between Ⅵ and Ⅶ TM. Expression of MbNramp1 was increased in roots under iron deficiency，and its mRNA accumulation patterns differed with the induction time.

Key words: Malus baccata（L.）Borkh., Nramp1, MbNramp1, iron transporter, manganese transporter