Molecular analysis of transgenic canola plant containing chimeric B subunit of bacterial toxin STX2 and CTX from Escherichia coli and Vibrio cholerae

Diarrheal diseases have been considered as one of the most major world health problems in all age categories. Among all the pathogens caused to diarrhea, entrohemorrhagic Escherichia coli (EHEC) and Vibrio cholerae are the most important agents. E. coli O157:H7 as the most important serotype of EHEC bacteria caused diarrhea by producing STX2 toxin. In vibrio cholerae the cholera toxin (CTX) also is the main virulence factor that leads to diarrhea. Both of these toxins are belong to AB5 family and due to non-toxicity and natural immunogenic characteristic of B subunit, it could be introduced as an appropriate candidate for immunogenicity against these toxins. Plant seeds are an effective biological bioreactor for production of recombinant immunogenic antigens and also foreign proteins can be expressed in plants with the native structure. In this research, the production of recombinant protein composed of binding subunits of STX2 and cholera toxin was evaluated in canola seed as an oral vaccine candidate. The SC construct composed of (stx2B and ctxB) was subcloned to plant vector under the control of canola seed specific promoter (fae) and transformed to Agrobacterium tumefaciens. Then the recombinant vector was transformed to plant host via Agrobacterium mediated transformation. Transgenic plants was evaluated and the amount of chimeric protein expressed in transgenic canola seed was determined by semi quantitative ELISA and subsequently the amount of chimeric proteins was estimated 40 milligram per 1 gram seed. The results showed that the canola seed can efficiently produce recombinant protein.