Regional variations in the population structure of Pseudomonas syringae pathovar phaseolicola from Spain are revealed by typing with PmeI pulsed-field gel electrophoresis, plasmid profiling and virulence gene complement.
One hundred and twenty pathogenic isolates of Pseudomonas syringae pv. phaseolicola recovered in Spain were subjected to biochemical and genomic typing, and investigated for virulence gene complement. Fifty-six were recovered from common beans (Phaseolus vulgaris) of the type Granja Asturiana, grown in a northern Spanish region (Asturias), and 64 from other common beans cultured in the neighbouring region of Castilla y León. Typing by PmeI digestion followed by pulsed-field gel electrophoresis revealed 27 profiles, with only three being common to both regions. Relationships between profiles distributed the isolates into two clusters: A (subdivided into subclusters A1 and A2) and B. Cluster A included all isolates from Granja Asturiana and about a quarter of the isolates from Castilla y León. Isolates from cluster A were negative for mannitol utilization and hybridized to probes for the argK-tox region responsible for phaseolotoxin production. Isolates that grouped in cluster B, which were only found in Castilla y León, were able to utilize mannitol but did not hybridize to probes for the argK-tox region. Separation of the isolates into three genomic groups, subsequently termed PphA1, PphA2 and PphB, was also supported by effector gene complement and location. In PphB, all effector genes tested (hopX1, hopF1, avrB2 and avrD1) mapped on chromosomal fragments, but faint hybridization of avrB2 with plasmids of about 40 kb was also observed. In PphA hopX1 mapped on the chromosome; in PphA1 avrB2 and avrD1 were carried on virulence plasmids (most of approx. 125 kb) and hopF1 was not detected, while in PphA2 the three genes were located on plasmids (approx. 75-160 kb). These results can be used as a framework to investigate the basis of regional variation in population structure, and for further epidemiological surveillance of P. syringae pv. phaseolicola.
San José
Mateo
M
Departamento de Biología Funcional (área de Microbiología) and Instituto Universitario de Biotecnología de Asturias (IUBA), Universidad de Oviedo, 33006 Oviedo, Spain.
Rodicio
M Rosario
MR
Departamento de Biología Funcional (área de Microbiología) and Instituto Universitario de Biotecnología de Asturias (IUBA), Universidad de Oviedo, 33006 Oviedo, Spain.
Argudín
M Ángeles
MÁ
Departamento de Biología Funcional (área de Microbiología) and Instituto Universitario de Biotecnología de Asturias (IUBA), Universidad de Oviedo, 33006 Oviedo, Spain.
Mendoza
M Carmen
MC
Departamento de Biología Funcional (área de Microbiología) and Instituto Universitario de Biotecnología de Asturias (IUBA), Universidad de Oviedo, 33006 Oviedo, Spain.
González
Ana J
AJ
Servicio Regional de Investigación y Desarrollo Agroalimentario (SERIDA), Principado de Asturias, 33300 Villaviciosa, Spain.
D016521:Electrophoresis, Gel, Pulsed-Field / Q000379:methods*; D005798:Genes, Bacterial; D009952:Ornithine / Q000031:analogs & derivatives / Q000235:genetics; D027805:Phaseolus / Q000382:microbiology*; D010957:Plasmids / Q000032:analysis*; D044224:Pseudomonas syringae / Q000145:classification / Q000235:genetics* / Q000472:pathogenicity*; D013030:Spain; D037521:Virulence Factors / Q000235:genetics*
D037521:Virulence Factors; C021234:phaseolotoxin; D009952:Ornithine