Submitted to: Journal of Applied Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 13, 2000
Publication Date: N/A
Interpretive Summary: Methods were developed to identify bacterial plant pathogens that produce tabtoxin, a compound that causes yellowing of leaf tissue and has demonstrated herbicidal activity. The method utilizes a sequence of the genes necessary for the production of the toxin. Using the polymerase chain reaction (PCR), the sequence was shown to be amplified only by tabtoxin producing organisms, proving its specificity. The method will be useful in verifying the identity of plant diseases suspected of producing tabtoxin.
Technical Abstract: A protocol for the PCR-based detection of tabtoxin-producing strains of bacteria was developed. The protocol used a set of primers designed to amplify the tblA gene, a gene required for tabtoxin production. The PCR reaction produced a predicted 829 bp amplification product. The 829 bp amplification product was the only product formed and, with the exception of an E. coli strain harboring the tabtoxin production plasmid pRTBL823, it was only formed when cells from bacteria that produced tabtoxin were included in the assay mixture. Reactions with cells from spontaneous tabtoxin-deficient strains, i.e. those either derived from or believed to be derived from previous tabtoxin-producing strains, also failed to produce an amplification product. Thus, the PCR protocol using the primer pair for the amplification of the tblA gene is a rapid and specific method for the detection of tabtoxin-producing bacterial strains.