title: [Transfer of plasmid RP4 into some phytopathogenic bacteria and its relation to their virulence].
abstract: Plasmid RP4 were transferred from Escherichia coli into Pseudomonas solanacerum, Xanthomonas campestris pv. oryzae, X. campestris pv. campestris, and X. campestris pv. citri at the frequencies of 1.8 X 10(-6), 2.8 X 10(-6), 1.4 X 10(-2) and 2.0 X 10(-3), respectively. The frequencies of transfer depended on bacterial species and conjugation conditions. Treatment of bromide at the concentration of 2 micrograms/ml and acridine orange at 100 micrograms/ml for 32 hrs the plasmid RP4 could be cured from the transconjugant of P. solanacerum at the frequencies of 75% and 95%, respectively. When transconjugant of P. solanacearum was inoculated into tomato plants, the decrease in virulence was observed, furthermore, no plasmids were detected both in the wild-type strain and the cured transconjugant. It thus appears that the virulence may not be related to plasmids.
mesh_terms: D004926:Escherichia coli / Q000235:genetics*; D010945:Plants, Edible / Q000382:microbiology; D010957:Plasmids; D011549:Pseudomonas / Q000235:genetics* / Q000472:pathogenicity; D014169:Transformation, Bacterial; D014774:Virulence; D014974:Xanthomonas / Q000235:genetics* / Q000472:pathogenicity