Polyamines Bound to tRNA and rRNA of Eukaryotic Plant Organisms

The occurrence of polyamines in different RNAs was investigated in view of the importance of these organic cations in RNA function. RNA was extracted at low ionic strength and separated on Sephadex columns. tRNA and rRNA of plants (Spinacia oleracea leaves, etiolated epicotyls of Pisum sativum, and Neurospora crassa mycelia) contain polyamines although in a different ratio than they are found in a complete cell. Contrary to spermine and putrescine, spermidine is always present. The binding of polyamines to tRNA and rRNA is discussed applying the Liquori model to the double stranded regions, where it was possible. Polyamines were also detected in 5S RNA.