Nucleic Acid Metabolism in Pisum sativum Alaska

Sunmmary. Phosfon-S, a substance which inhibits stem elongation, alters nucleic acid metaboli,sm in Pisutm sativum Alaska. Methylated albumin kieselguhr (MAK) columns were used to fractionate 32P-labeled nucleic acids. Phosfon-S treatment of the plants resulted in a decrease in soluble RNA and an increase in ribo,somal RNA. Specific activities of the various nucleic acid fractions were lower as a result of treatment. The nucleic acids from treated tissues were more resistant to RNase degradation, and endogenous RNase activity was lower in treated tissues. When RNase treated nucleic acids were fractionated on MAK columns, the DNA-RNA fractions from treated plants had a higher specific activity than that of the control, which was not true before nuclease treatment. Spectrophotometric examination of this fraction revealed a difference in absoription spectra, possibly indicating a Phosfon-S nucleic acid complex. It is suggested that these alterations in nucleic acid metabolism could in turn alter a wide variety of metabolic processes, resulting in retarded growth.