Agrobacterium rhizogenes lacZ-rolC gene expression in Escherichia coli: detection of the product in transgenic plants using RolC-specific antibodies.

The rolC sequence of the Agrobacterium rhizogenes Ri plasmid was fused in-frame to the 3' end of the lacZ gene in plasmid pEX3. The fusion protein RolC-beta-galactosidase was accumulated as insoluble inclusion bodies in Escherichia coli. Antibodies were raised in rabbits against the fusion protein. After affinity purification, RolC-specific antibodies were found to react with a 22-kDa polypeptide prepared from roots of transgenic tobacco plants possessing a rolC gene. The result of differential centrifugation suggested that RolC is present in the soluble fraction of transformed cells.