Effect of X-Irradiation on Nucleic Acids in Zea mays: I. Nucleic Acid Distribution and Metabolism in the Subcellular Components of Corn Seedlings Grown from Normal and X-Irradiated Seeds

Journal Article · Thu Nov 01 04:00:00 EST 1962 · Radiation Research

DOI:https://doi.org/10.2307/3571221· OSTI ID:4776202

Cherry, Joe H.; Hageman, R. H.; Hanson, J. B.

X irradiation of dry Zea mays seeds decreased the content of microsomal RNA in the meristematic region of seed lings germinated from them. Meristematic cells from unirradiated seeds were characterized by a high level of microsomal RNA, whereas in maturing cells the majority of the RNA was associated with the mitochondria. Differential ultracentifugation and RNA analysis showed that exposure of seed to x rays apparently prevented the synthesis of new microsomes as ordinarily occurs with cell division but, not disrupt the metabolism of microsomes during expansion of cells in the root tip. This results in an increase in mitochondrial RNA. The RNA of the different sub, cellular fractions appear to have dissimilar nucleotide compositions. Microsomal RNA contains a higher amount of guanosine monophosphate (GMP) than the RNA of the other fractions, whereas the soluble RNA contains less GMP and more uridine monophosphate (UMP). X irradiation of dry Zea mays seeds enhanced the incorporation of precursors into the nucleic acitls of all subcellular components of growing roots. Results show that the nuclei incorporated More precursors in vivo than the other cellular components. Generally, there was a greater incorporation of precursors into the RNA of the heavy mitochondria than into the light mitochondrial or soluble RNA fractions. The least amount of incorporation was into microsomal RNA. The incorporation of P/sup 32/ into the RNA of the cytoplasmic components of intact roots was greater in the basal portion of the root (maturing cells) than in the meristematic zone. X irradiation inhibited the incorporation of amino acids into the protein of nuclei in vivo, but the incorporation was accelerated in vitro.

• Research Organization: Univ. of Illinois, Urbana
• Sponsoring Organization: USDOE
• NSA Number: NSA-17-001322
• OSTI ID: 4776202
• Journal Information: Radiation Research, Journal Name: Radiation Research Journal Issue: 5 Vol. 17; ISSN 0033-7587
• Publisher: Radiation Research Society
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ACIDS
AGE
AMINO ACIDS
BIOLOGY AND MEDICINE
CARBONATES
CENTRIFUGATION
CEREALS
DISTRIBUTION
LEACHING
MITOCHONDRIA
NUCLEIC ACIDS
ORE PROCESSING
PHOSPHATES
PHOSPHORUS 32
PLANT CELLS
PROTEINS
PROTOPLASM
QUANTITY RATIO
RADIATION EFFECTS
RIBONUCLEIC ACID
ROOTS
SEEDS
SEPARATION PROCESSES
SLURRIES
SOLUBILITY
TRACER TECHNIQUES
URANIUM ORES
X RADIATION
ZEA MAYS