Abstract: A Full length cDNA of MxIrt1 gene from the iron-stressed root cDNA library of Malus xiaojinensis Chent et Jiang was cloned using the RACE method with primers designed based on the conserved domain sequences of plant IRT gene families. The recombinant prokaryotic expression vector pEIrt was constructed using vector pET30a. Restriction endonuclease analysis, PCR amplifying and sequencing confirmed that the construction was correct and had no base mutant. The prokaryotic expression analysis was carried out through transformation of E.coli (BL21). The SDS-PAGE electrophoresis analysis showed that the best expression was induced by 30℃ and 0.5 mmol·L^-1 IPTG, under which a 40 kD recombinant protein was produced. These results will provide a foundation for further purifying and identifying objective protein

Key words: Apple, Malus x iaojinensis, Fe²⁺-transporter, Gene cloning, Prokaryotic exp ression