Free Ribonucleic Acid Particles in Homogenates of Plant Tissue.

Abstract

High-weight free ribonucleic acids were found in homogenates of plant tissue from a number of different kinds of plants and were isolated by differential centrifugation followed by electrophoresis. The free nucleic acids are more mobile in electrophoresis than accompanying nucleoproteins and at least 4 types of free nucleic acids were detected. The free nucleic acids give typical nucleic acid absorption spectra, and on hydrolysis only the four bases adenine, guanine, cytosine, and uracil could be detected by paper chromatography. The free nucleic acids are unstable and care must be exercised in their isolation. Their concentration is usually inversely proportional to the age of the tissue, and mostly confined to the above ground portions of plants. If the epicotyl and axillary buds are removed from cucumber seedlings, relatively large amounts of free nucleic acids accumulate in the cotyledons; whereas only traces of free nucleic acids occur in cotyledons from intact plants.. It was concluded that free ribonucleic acid is a common constituent of young leaves, buds, and growing points of many kinds of plants. It is not known whether the free nucleic acid merely serves as a reserve or whether it has specific functions as well.