T. Vallaeys et al., THE CONSTRUCTION OF A NOPALINE-INDUCIBLE MARKER SYSTEM FOR RAPID DETECTION OF AGROBACTERIUM STRAINS, Biotechnology letters, 18(9), 1996, pp. 991-996
An inducible marker system suitable for Agrobacterium tumefaciens was
constructed to enable detection and enumeration of specific bacterial
cells introduced into soil. A BamHI cassette carrying the catechol 2,3
-dioxygenase (C230) gene, tdnC, fused to the nopaline-inducible Agroba
cterium promoter Pi 2[noc] was constructed. This cassette was introduc
ed into the broad host range vector pDSK5019 resulting in plasmid pTVN
C2. Inducible C230 activity was observed in an A. tumefaciens strain c
arrying the plasmid pTVNC2 when nopaline was present. Colonies of bact
eria tagged with the system could easily be identified by spraying aga
r plates containing nopaline with catechol, which is converted to the
bright yellow compound 2-hydroxymuconic semialdehyde. The inducible td
nC cassette has also been introduced into the BamHI site of the transp
oson Tn5 carried by the pSUP1011 suicide vector which can be used as a
delivery system for the stable introduction of the inducible marker i
nto the chromosome of target cells.