VIEW ARTICLE

Studies on the Nucleic Acids of Avirulent, Attenuated, and Virulent Isolates of Agrobacterium tumefaciens. P. O. Larsen, Former Graduate Research Assistant, Department of Plant Pathology, University of Arizona, now Assistant Professor, Department of Plant Pathology, The Ohio State University, Columbus 43210; Milton Zaitlin, Professor, Departments of Plant Pathology and Agricultural Biochemistry, University of Arizona, Tucson 85721. Phytopathology 61:337-338. DOI: 10.1094/Phyto-61-337.

Deoxyribonucleic acid preparations from virulent and attenuated strains of Agrobacterium tumefaciens were compared using buoyant density and melting point determinations. No significant differences were found using either method of comparison. Ribonucleic acid (RNA) from virulent and avirulent A. tumefaciens strains were compared by fractionation on sucrose gradients. Both RNA preparations exhibited similar absorbance profiles. The magnesium concentration of the extraction buffer was found to be critical for the isolation of undegraded ribosomal RNA. A buffer containing 0.02 m magnesium was suitable for the isolation of native 16 and 23s ribosomal RNA components.