For further investigation of its biological functions and molecular mechanism of chloroplast heme oxygenase HO1,the recombinant protein expression vector pET28a-AtHO1 was constructed and transformed into E.coli BL21 (DE3) to express the recombinant protein.AtHO1 fusion protein was highly expressed as a soluble protein of 28-36 ku.After purification with Ni-NTA affinity chromatography and desalting,the fusion protein was used as antigen to prepare polyclonal antiserum in New Zealand rabbits.Western blot analysis showed that the antiserum could recognize the recombinant protein 6×His-AtHO1 specifically and a band between 28 ku and 36 ku of Arabidopsis and rice total proteins,indicating that the antiserum could react to the Arabidopsis and rice native protein specifically.Therefore,the polyclonal antiserum obtained by immunizing rabbits with the purified fusion protein 6×His-AtHO1 can be used for functional analysis of HO1 in rice.