Abstract: A plant expression carrier containing HBsAg (hepatitis B virus surface antigen) gene was constructed in a plasmid,the plasmid was mobilized into a rhizogenes Strain LBA 1314 by freeze-thaw method,the HBsAg gene was planted into tobacco by leaf disc via Agrobacterium tumefaciens LBA 4404 as a vehicle and the tobacco hairy roots were received.Histochemical staining of GUS activity was made in the transgenic tobacco hairy roots:The roots with HBsAg genes can be dyed into bule,while those without have no reflection of color.So the conclusion can acquire that the gene has its expression in the roots.

Key words: hepatitis B virus surface antigen gene, tobacco, hairy roots, transformation