Expression of Heat-labile Enterotoxin of Escherichia coli in Biolistic Transformed Hairy Roots of Daucus carota L.

Expression and secretion of recombination proteins in transgenic hairy roots have opened door to simple, feasible and economic option compared to animal and bacterial systems. Here, we report a feasibility study for producing the nontoxic B subunit of Escherichia coli heatlabile enterotoxin (LTB) in Daucus carota L hairy root where transformation is achieved by biolistic gene gun method. Agrobacterium rhizogenes strain (R-1000) cells containing synthetic LTB gene in pMYO51T plant expression vector under the CaMV 35S promoter introduced to Daucus carota L roots by biolistic gene gun method. PCR amplification confirmed the integration of synthetic LTB gene in carrot hairy roots. Western blot analysis confirmed production of LTB pentamer in similar banding pattern to the native bacterial derived LTB. 0.50-0.70% of LTB protein estimated in carrot hairy roots. GM1-ganglioside assay indicated formation of biological active pentamers. LTB protein with biochemical properties identical to native LTB protein in the hairy roots of edible carrot roots opens the way for inexpensive, safe, and effective plant-based edible vaccines for humans and animals.