Plant Pathology Department


Date of this Version



Published in Proceedings of the National Academy of Sciences USA Vol. 72, No. 3 (March 1975), pp. 849–853. Copyright © 1975 National Academy of Sciences USA. Used by permission.


Pseudomonas phaseolicola infected with bacteriophage φ6 synthesized all three viral double-stranded RNA segments, three single-stranded RNAs, and three replicative intermediate-like RNAs in the presence of rifampin. The single-stranded RNA intermediates sedimented and electrophoresed along with melted viral double-stranded RNA, annealed with melted viral double-stranded RNA, and were transient in nature. The relative amounts of the single-stranded RNA intermediates varied during the infection cycle and were altered in the presence of chloramphenicol. The replicative intermediate-like RNAs sedimented faster than double-stranded RNA, failed to enter 2.5% polyacrylamide gels, eluted with double-stranded RNA from a CF-11 cellulose column, were precipitated with single-stranded RNA in 2 M LiCl, and yielded three genomesize pieces of double-stranded RNA upon digestion with RNase. These results are consistent with the hypothesis that complementary strands of the φ6 double-stranded RNAs are synthesized asynchronously during the infection cycle.