Nucleotide & ribonucleic acid metabolism of corn seedlings

Abstract

The consideration of nucleotides and ribonucleic acid (RNA)2 in metabolism has become increasingly imiiportant in cellular biology during the past few years.

Acid-Soluble Nucleotides of Pinto Bean Leaves at Different Stages of Development

“…In Experiment 1, carried May, the harvests were made after 8, 14, and 21 days. In Experiment 3, which was performed in January, harvests of young, fully expanded, and senescent leaves were made after 11, 18, and 32 days, while in Experiment 3a the harvest of emergent leaves was made during April, 8 days after sowing.…”

“…It could be expected that these changes, occurring in different metabolic systems, would be reflected in the acid-soluble nucleotides of the leaf since these metabolites play a central role in the mediation and utilization of respiratory energy and in the synthesis of carbohydrates, lipids, proteins, and nucleic acids. Significant changes have been found in the nucleotide complement of developing seeds of wheat (19), pea (10), rice (23), and lettuce i (27), in germinating seeds of Phaseolus aureus (17), pea (11), and corn 1 (13,14,36) and in wheat embryos (21), wheat seedlings (8), and Vicia faba seedlings (1).…”

Nucleic Acid, Mitochondria, & Enzyme Changes in Cotyledons of Peanut Seeds during Germination

“…is accompl)niedl l a (lecrealse in the conitent of fat and ani inicrease ill cal-bolydrate ( 19 CHERRY-NUCLEIC ACID, -MITOCHONDRIA, & ENZY-ME CHANGES glucose-6-P dehydlrogenase (fig 7), the resting seed contained a fairly active isocitritase and the peak activity was reached earlier than with the respiratory activity of isolated mitochondria (fig 4). However, Beevers (3), and Marcus and Veslasco (18) Akazawa and Beevers (2) and Cherry and Hageman (6) showed that there is an increase in mitochondrial RNA in the castor bean endosperm and corn scutellum, respectively, during germination. This increase in RNA is not only a result of a larger mitochondlrial pelletbut is also dlue to an increase in RNA content.…”

Effects of X irradiation on corn seed

“…The entire extraction procedure was performed at 2 C. The combined supernatant solutions were made to volume and the soluble nucleotides were estimated by the difference in absorbancy at 260 and 290 my, using AMP as a standard. Experience from this laboratory indicates that data obtained from the above method closely compares to nucleotide measurement by ionexchange chromatography (2,3).…”

“…Experimentation has shown that essentially no DNA is present in these nuclei free homogenates; the method is quantitative for RNA (2,3). Aliquots of the cleared tissue homogenates were acidified with 1.2 M HClI4 to a final molarity of 0.2 The precipitates were sedimented by centrifuging and washed twice with 0.2 M HCl04.…”