title: Isolation and Characterization of Plant-Pathogenic Streptomyces Species Associated with Common Scab-Infected Potato Tubers in Newfoundland.
abstract: Potato common scab (CS) is an economically important crop disease that is caused by several members of the genus Streptomyces. In this study, we characterized the plant-pathogenic Streptomyces spp. associated with CS-infected potato tubers harvested in Newfoundland, Canada. A total of 17 pathogenic Streptomyces isolates were recovered from potato scab lesions, of which eight were determined to be most similar to the known CS pathogen S. europaeiscabiei. All eight S. europaeiscabiei isolates were found to produce the thaxtomin A phytotoxin and to harbor the nec1 virulence gene, and most also carry the putative virulence gene tomA. The remaining isolates appear to be novel pathogenic species that do not produce thaxtomin A, and only two of these isolates were determined to harbor the nec1 or tomA genes. Of the non-thaxtomin-producing isolates, strain 11-1-2 was shown to exhibit a severe pathogenic phenotype against different plant hosts and to produce a novel, secreted phytotoxic substance. This is the first report documenting the plant-pathogenic Streptomyces spp. associated with CS disease in Newfoundland. Furthermore, our findings provide further evidence that phytotoxins other than thaxtomin A may also contribute to the development of CS by Streptomyces spp.
authors.affiliation: Department of Biology, Memorial University of Newfoundland, St. John's, NL, A1B 3X9, Canada.
authors.forename: Joanna K
authors.initials: JK
authors.lastname: Fyans
authors.affiliation: Department of Biology, Memorial University of Newfoundland, St. John's, NL, A1B 3X9, Canada.
authors.forename: Luke
authors.initials: L
authors.lastname: Bown
authors.affiliation: Department of Biology, Memorial University of Newfoundland, St. John's, NL, A1B 3X9, Canada.
authors.forename: Dawn R D
authors.initials: DR
authors.lastname: Bignell
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics; D001483:Base Sequence; D005838:Genotype; D007211:Indoles / Q000378:metabolism; D008969:Molecular Sequence Data; D009523:Newfoundland and Labrador; D010641:Phenotype; D010802:Phylogeny; D010879:Piperazines / Q000378:metabolism; D010935:Plant Diseases / Q000382:microbiology*; D018515:Plant Leaves / Q000382:microbiology; D035281:Plant Tubers / Q000382:microbiology; D012150:Polymorphism, Restriction Fragment Length; D017422:Sequence Analysis, DNA; D017384:Sequence Deletion; D011198:Solanum tuberosum / Q000382:microbiology*; D013302:Streptomyces / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity / Q000502:physiology; D014774:Virulence
chemical_list: D001426:Bacterial Proteins; D007211:Indoles; D010879:Piperazines; C406691:thaxtomine A