title: Transformation of Pseudomonas syringae with nonconjugative R plasmids.
abstract: Transformation of Pseudomonas syringae strains with plasmid DNA occurs at a frequency of 1 x 10(-3) to 4 x 10(-9) per recipient cell, depending on the strain, plasmid, and conditions for transformation. R plasmids used successfully in transformation were pR0161 (26 x 10(6) molecular weight) and RSF1010 (5.5 x 10(6) molecular weight). Transformation involved growing the recipient cells to approximately 8 x 10(8) colony-forming units per millilitre in 50 mL of a nutrient broth. After washes with a 150 mM CaCl2 - 10% (v/v) glycerol mixture, cells were concentrated 20-fold and resuspended in this solution. The cells then were incubated with purified plasmid DNA for 1 h prior to heat pulse at 45 degrees C for 2 min. Transformants were selected by antibiotic resistance and plasmid presence was verified by agarose gel electrophoresis. With plasmid pCG131 (34 x 10(6) molecular weight; putatively associated with syringomycin production), transformation of syringomycin-negative P. syringae strains that contained no detectable plasmid or were cured of pCG131 was unsuccessful, whether the plasmid was used alone or in combination with either pR0161 or RSF1010.
mesh_terms: D000900:Anti-Bacterial Agents / Q000096:biosynthesis; D001426:Bacterial Proteins; D002122:Calcium Chloride / Q000494:pharmacology; D005990:Glycerol / Q000494:pharmacology; D007700:Kinetics; D011549:Pseudomonas / Q000235:genetics* / Q000378:metabolism; D011815:R Factors; D013696:Temperature; D014169:Transformation, Bacterial
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; C032677:syringomycin; D002122:Calcium Chloride; D005990:Glycerol