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Genetics

Purification and Characterization of Cryptic Plasmids pLS1 and pLS2 from Erwinia chrysanthemi. Robert B. Sparks, Jr., Department of Genetics, The Connecticut Agricultural Experiment Station, P.O. Box 1106, New Haven, CT 06504; George H. Lacy, Department of Plant Pathology and Botany, The Connecticut Agricultural Experiment Station, P.O. Box 1106, New Haven, CT 06504. Phytopathology 70:369-372. Accepted for publication 17 October 1979. Copyright 1980 The American Phytopathological Society. DOI: 10.1094/Phyto-70-369.

Two cryptic plasmids were purified from cell lysates of Erwinia chrysanthemi NCPPB-377, an organism isolated from maize (Zea mays L.) with bacterial stalk rot. Electron microscopy of purified, supercoiled plasmid DNA revealed a large (pLS1, 50.4 ± 1.9 megadaltons) and a small (pLS2, 4.8 ± 0.3 megadaltons) plasmid. These plasmids were separated by centrifugation on linear-log sucrose gradients. Plasmids pLS1 and pLS2 were characterized by restriction endonucleases EcoRI, PstI, SalI, HindIII, and HincII.