Expression and functional validation of heat-labile enterotoxin B (LTB) and cholera toxin B (CTB) subunits in transgenic rice (Oryza sativa).

We expressed the heat-labile enterotoxin B (LTB) subunit from enterotoxigenic Escherichia coli and the cholera toxin B (CTB) subunit from Vibrio cholerae under the control of the rice (Oryza sativa) globulin (Glb) promoter. Binding of recombinant LTB and CTB proteins was confirmed based on GM1-ganglioside binding enzyme-linked immunosorbent assays (GM1-ELISA). Real-time PCR of three generations (T3, T4, and T5) in homozygous lines (LCI-11) showed single copies of LTB, CTB, bar and Tnos.