Expression Of The VP2 Gene Of Infectious Bursal Disease Virus In Transgenic Tobacco Plants

The expression of recombinant infectious bursal disease (IBDV) VP2 gene in transgenic tobacco was studied. It revealed that the VP2 produced in transgenic tobacco could react with serum specific for IBDV. These results were the basic of investigating the immunological function of foreign protein VP2 produced in transgenic plants and bolstered the concept of using transgenic plants for a novel, edible, safe vaccine production.The plant expression vector pBIN19-ROK219 was constructed, which contains cauliflower mosaic virus (CaMV) 35S promoter and noster. Introduction of IBDV VP2 gene under control of CaMV 35S promoter resulted in the construction of binary expression vector pBR-VP2. Then the VP2 gene was in the left and right border regions, which denote the limits of the DNA that is integrated into the plant genomic DNA via Agrobacterium fwme/ac/ms-mediated transformation. Plasmids pBR-VP2 were mobilized into Agrobacterium tumefaciens LBA4404 by the freeze-thaw method. The plasmids were used to transform tobacco by the leaf disc method using the Agrobacterium strains described above. Tobacco tissues were cultured and shoots were regenerated, transplanted to soil. The VP2 gene was expressed with the growth of transgenic cells into full-blown plants.It confirmed that IBDV VP2 gene was integrated into nuclear chromosomal DNA by PCR. PCR positve plants were double checked for incorporation of the recombinant gene by Southern blots. Northern blot analysis indicated that foreign IBDV VP2 gene was correctly transcripted into mRNA. The recombinant protein from tobacco leaves was detected by Dot-ELISA and Western blot using antisera specific for IBDV. The protein IBDV VP2 expressed in tobacco appeared with apparent molecular mass of 52KD. The results above clearly demonstrated that the recombinant IBDV VP2 produced in transgenic tobacco is immunogenic.