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Genetics

Restriction Enzyme Analysis of Plasmids from Syringomycin-Producing Strains of Pseudomonas syringae. Carlos F. Gonzalez, Department of Plant Pathology, University of Nebraska, Lincoln 68583, Present address of the senior author: Department of Microbiology, University of Michigan, Ann Arbor 48109; Anne K. Vidaver, Department of Plant Pathology, University of Nebraska, Lincoln 68583. Phytopathology 70:223-225. Accepted for publication 14 September 1979. Copyright 1980 The American Phytopathological Society. DOI: 10.1094/Phyto-70-223.

Plasmids of similar molecular mass were isolated from millet, almond, and apricot strains of Pseudomonas syringae. All three strains produced the phytotoxin syringomycin and contained a single plasmid with a mass of ~35 megadaltons. Restriction endonuclease digestion showed that each plasmid contained from four to thirteen fragments, depending on the plasmid and enzyme combination. Agarose gel analysis of EcoR1 digest showed that the three plasmids had one fragment (1.3 megadaltons) in common. The plasmids from the millet and almond strains also had 8.6- and 1.2-megadalton fragments in common, while the almond and apricot plasmids had a 1.7 megadalton fragment in common. Hind III digests showed that the plasmids of the millet and almond strains had a 2.1-megadalton fragment in common. Thus, the three plasmids showed different restriction endonuclease digest patterns.