title: Sensitive and specific detection of phaseolotoxigenic and nontoxigenic strains of Pseudomonas syringae pv. phaseolicola by TaqMan real-time PCR using site-specific recombinase gene sequences.
abstract: Pseudomonas syringae pv. phaseolicola, the causative agent of halo blight, is the most important bacterial pathogen of bean. Both nontoxigenic (Tox(-)) and toxigenic (Tox+) strains of this pathogen cause halo blight in beans. However, nontoxigenic strains cannot be detected by currently available molecular and serological tools. In this study, a TaqMan probe and primer set were designed based on the phage integrase family site-specific recombinase of P. s. pv. phaseolicola 1448A because it is known that most site-specific recombinases are structurally and functionally diverse. The specificity of the probe and primers was evaluated using purified DNA from 29 isolates of 3 different pathovars of P. syringae. The probe and primer set were able to detect Tox(-) and Tox+ isolates of P. s. pv. Phaseolicola, but no other phytopathogenic bacteria. The assay was also able to detect at least 5 genome equivalents of cloned amplified target DNA, using purified DNA, or 7 colony forming unit (CFU) per reaction when using calibrated cell suspensions. Thus, the TaqMan real-time PCR-based method can be used for the rapid detection of both types of P. s. pv. Phaseolicola, and will potentially simplify and facilitate the diagnosis and monitoring of this pathogen, and guide plant disease management.
authors.affiliation: National Academy of Agricultural Science, Rural Development Administration, 441-707 Suwon, Republic of Korea.
authors.forename: Min Seok
authors.initials: MS
authors.lastname: Cho
authors.forename: Yong Ho
authors.initials: YH
authors.lastname: Jeon
authors.forename: Man Jung
authors.initials: MJ
authors.lastname: Kang
authors.forename: Hong Il
authors.initials: HI
authors.lastname: Ahn
authors.forename: Hyung-Jin
authors.initials: HJ
authors.lastname: Baek
authors.forename: Young Wang
authors.initials: YW
authors.lastname: Na
authors.forename: Yu Mi
authors.initials: YM
authors.lastname: Choi
authors.forename: Tae San
authors.initials: TS
authors.lastname: Kim
authors.forename: Dong Suk
authors.initials: DS
authors.lastname: Park
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics*; D007887:Fabaceae / Q000382:microbiology*; D009952:Ornithine / Q000031:analogs & derivatives / Q000235:genetics / Q000378:metabolism; D010935:Plant Diseases / Q000382:microbiology; D016133:Polymerase Chain Reaction / Q000379:methods*; D044224:Pseudomonas syringae / Q000201:enzymology / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D045522:Recombinases / Q000235:genetics* / Q000378:metabolism; D012680:Sensitivity and Specificity; D019914:Taq Polymerase / Q000737:chemistry
chemical_list: D001426:Bacterial Proteins; D017931:DNA Primers; D045522:Recombinases; C021234:phaseolotoxin; D009952:Ornithine; D019914:Taq Polymerase