AMINO ACID CROSS RESISTANCE IN AGROBACTERIUM TUMEFACIENS

Abstract

Beardsley, Robert E. (Manhattan College, New York, N. Y.). Amino acid cross resistance in Agrobacterium tumefaciens . J. Bacteriol. 84: 1237–1240. 1962.—Resistant clones selected on medium supplemented with glycine were also resistant to d -methionine, d -valine, dl -norleucine, and dl -serine. Cross resistance was similarly exhibited by clones selected on d -methionine, d -valine, or dl -norleucine. Two types of resistant organisms were observed. One produced colonies containing normal rods on selection medium. The other produced translucent colonies containing L forms. Both grew as typical rods in unsupplemented medium. Some resistant clones did not produce a temperate phage carried by the parental strain, but these retained immunity to homologous phage. The toxicity of d -methionine and d -valine for nonresistant bacteria is not reversed by the l isomers. The lethal effects of toxic amino acids are additive.