VIEW ARTICLE

Characterization of the Cytoplasmic Ribosomes and Ribosomal RNA from Mycelium of Various Species of Phytophthora. J. V. Leary, Assistant Professor, Department of Plant Pathology, University of California, Riverside 92502; J. R. Roheim(2) and G. A. Zentmyer(3). (2)(3)Graduate Student, and Chairman, respectively, Department of Plant Pathology, University of California, Riverside 92502, (2)Present address: Department of Plant Pathology, University of Nebraska, Lincoln. Phytopathology 63:1148-1151. Accepted for publication 22 March 1973. DOI: 10.1094/Phyto-63-1148.

Ribosomes from the vegetative mycelium of several species of Phytophthora were characterized by sucrose density-gradient centrifugation. The monosomes had a Svedberg sedimentation coefficient (S-value) of approximately 80, with the large and small subunits being 60S and 40S, respectively. The ribosomal RNA, isolated in the total cellular RNA, sedimented to a position in the gradient corresponding to RNA’s of known 28S and 18S values. These data indicate that the ribosomes of Phytophthora spp. are typical of eukaryotes and that the susceptibility of these species to certain antibacterial antibiotics is not due to prokaryotic 70S ribosomes.