pBI121/HB, which carried the synthetic 681-bp gene encoding the recombinant hepatitis B surface antigen of the adr serotype (HBsAg/adr). The HBsAg gene fragment containing CaMV35S promoter and nitric oxide synthetase (NOS) terminator was cut out from the plasmid pBI121/HB, cloned into pCAMBIA1301 after digestion with both Hind III and EcoR I endonucleases, and transformed into DH5α and screened for recombinant plasmid named pCAMBIA1301/HB.