title: The use of subtractive hybridization to obtain a DNA probe specific for Pseudomonas solanacearum race 3.
abstract: Pseudomonas solanacearum, the causal agent of bacterial wilt, has been classified into three races based on host range and into five biovars based on physiological properties. Strains of race 3 belong exclusively to biovar 2 and primarily affect potatoes. Although this race is thought to have originated in the Andean highlands, it has unusual physiological properties that make it a potential threat to potatoes grown at the cooler latitudes worldwide. Consequently, there is need for a rapid and sensitive method for detection of race 3 strains. We have used subtractive hybridization to enrich for race 3-specific DNA sequences in total race 3 genomic DNA, and thereby obtained a 2 kb clone homologous to DNA from all 28 race 3 strains tested, but with only five of 90 non-race 3 strains. In addition, two larger regions of the genome, containing a minimum of 23 kb of DNA, are also specific for race 3. Deletion of this DNA did not affect virulence. This race 3-specific DNA is a potentially useful diagnostic tool for the detection of race 3 strains.
authors.affiliation: Department of Plant Pathology, University of Wisconsin-Madison 53706.
authors.forename: D
authors.initials: D
authors.lastname: Cook
authors.forename: L
authors.initials: L
authors.lastname: Sequeira
mesh_terms: D015139:Blotting, Southern; D015342:DNA Probes; D004269:DNA, Bacterial / Q000235:genetics; D005798:Genes, Bacterial; D007612:Kanamycin / Q000494:pharmacology; D009693:Nucleic Acid Hybridization; D010957:Plasmids; D011549:Pseudomonas / Q000235:genetics* / Q000472:pathogenicity; D015183:Restriction Mapping; D013045:Species Specificity; D014170:Transformation, Genetic; D014774:Virulence
chemical_list: D015342:DNA Probes; D004269:DNA, Bacterial; D007612:Kanamycin