Construction Of HBV S/HEV ORF2 Fusion Gene And Its Transformation Into Tomato

This research was to explore the feasibility of expressing HBV S/HEV ORF2 fusion gene in plants for the purpose of developing a new type of plant-derived hepatitis bivalent edible vaccine.Hepatitis B Virus S gene was connected to the 5' end of Hepatitis E Virus ORF2 partial sequence with the technique of recombinant PCR,a designed DNA sequence which encoded a polypeptide linker (Gly₄Ser)₂ was used to splice the two fragments. DNA sequencing results showed that the fusion gene(BE) was successfully constructed.The fusion gene(BE),approximatelyl300bp,was cloned to the plant binary expression vector pBin438.The recombinant plasmid pBin438BE under the control of DE35S promoter was constructed and transformed into Agrobactrium tumefaciens EHA105 via freeze-thaw method. Inoculated explants from cotyledons and hypocotyls were cultured successively on pre-culture medium co-cultivation medium selective medium and root-growth media 5 Km-resistant tomato plants were obtained .The regenerated plantlets were analyzed further by PCR and PCR-Southern blot.The results confirmed that the fusion gene had been integrated into tomato genome.