SYRINGOMYCIN PRODUCTION AND HOLCUS SPOT DISEASE OF MAIZE - PLASMID-ASSOCIATED PROPERTIES IN PSEUDOMONAS-SYRINGAE

The majority of pathogenic strains of Pseudomonas syringae produce the phytotoxin syringomycin. After treatment of P. syringae with acridine organe, some surviving isolates were unable to produce the toxin or disease in maize plants. DNA analysis of strain HS191 revealed the presence of a single, 35-megadalton plasmid, designated pCG131; no detectable plasmid was seen in the cured derivative. Comparative studies with the parent and cured strains showed an association between the presence of the plasmid and the following properties: syringomycin production, resistance to bacteriocin PSC-1B, and resistance to phages Psp1 and Psy4A. © 1979 Springer-Verlag New York Inc.