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Title: Alterations in polyribosome and messenger ribonucleic acid metabolism and messenger ribonucleoprotein utilization in osmotically stressed plant seedlings

Abstract

Polyribosome aggregation state in growing tissues of barley and wheat leaf of stems of pea and squash was studied in relation to seedling growth and water status of the growing tissue in plants at various levels of osmotic stress. It was found to be highly correlated with water potential and osmotic potential of the growing tissue and with leaf of stem elongation rate. Stress rapidly reduced polyribosome content and water status in growing tissues of barley leaves; changes were slow and slight in the non-growing leaf blade. Membrane-bound and free polyribosomes were equally sensitive to stress-induced disaggregation. Incorporation of /sup 32/PO/sub 4//sup 3 -/ into ribosomal RNA was rapidly inhibited by stress, but stability of poly(A)/sup +/RNA relative to ribosomal RNA was similar in stressed and unstressed tissues, with a half-life of about 12 hours. Stress also caused progressive loss of poly(A)/sup +/RNA from these tissues. Quantitation of poly(A) and in vitro messenger template activity in polysome gradient fractions showed a shift of activity from the polysomal region to the region of 20-60 S in stressed plants. Messenger RNA in the 20-60 S region coded for the same peptides as mRNA found in the polysomal fraction. Nonpolysomal and polysome-derived messengermore » ribonucleoprotein complexes (mRNP) were isolated, and characteristic proteins were found associated with either fraction. Polysomal mRNP from stressed or unstressed plants were translated with similar efficiency in a wheat germ cell-free system. It was concluded that no translational inhibitory activity was associated with nonpolysomal mRNP from barley prepared as described.« less

Authors:
Publication Date:
Research Org.:
Arizona Univ., Tucson (USA)
OSTI Identifier:
6703620
Alternate Identifier(s):
OSTI ID: 6703620
Resource Type:
Thesis/Dissertation
Resource Relation:
Other Information: Thesis (Ph. D.)
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; BIOLOGICAL STRESS; BIOLOGICAL EFFECTS; NUCLEOPROTEINS; BIOCHEMISTRY; RNA; BARLEY; LEAVES; MESSENGER-RNA; OSMOSIS; PEAS; PHOSPHATES; PHOSPHORUS 32; PLANT GROWTH; PLANT STEMS; RIBOSOMAL RNA; RIBOSOMES; SEEDLINGS; VEGETABLES; WATER; WHEAT; BETA DECAY RADIOISOTOPES; BETA-MINUS DECAY RADIOISOTOPES; CELL CONSTITUENTS; CEREALS; CHEMISTRY; DAYS LIVING RADIOISOTOPES; DIFFUSION; FOOD; GRASS; GROWTH; HYDROGEN COMPOUNDS; ISOTOPES; LIGHT NUCLEI; NUCLEI; NUCLEIC ACIDS; ODD-ODD NUCLEI; ORGANIC COMPOUNDS; ORGANOIDS; OXYGEN COMPOUNDS; PHOSPHORUS COMPOUNDS; PHOSPHORUS ISOTOPES; PLANTS; PROTEINS; RADIOISOTOPES 550201* -- Biochemistry-- Tracer Techniques

Citation Formats

Mason, H.S. Alterations in polyribosome and messenger ribonucleic acid metabolism and messenger ribonucleoprotein utilization in osmotically stressed plant seedlings. United States: N. p., 1986. Web.
Mason, H.S. Alterations in polyribosome and messenger ribonucleic acid metabolism and messenger ribonucleoprotein utilization in osmotically stressed plant seedlings. United States.
Mason, H.S. Wed . "Alterations in polyribosome and messenger ribonucleic acid metabolism and messenger ribonucleoprotein utilization in osmotically stressed plant seedlings". United States. doi:.
@article{osti_6703620,
title = {Alterations in polyribosome and messenger ribonucleic acid metabolism and messenger ribonucleoprotein utilization in osmotically stressed plant seedlings},
author = {Mason, H.S.},
abstractNote = {Polyribosome aggregation state in growing tissues of barley and wheat leaf of stems of pea and squash was studied in relation to seedling growth and water status of the growing tissue in plants at various levels of osmotic stress. It was found to be highly correlated with water potential and osmotic potential of the growing tissue and with leaf of stem elongation rate. Stress rapidly reduced polyribosome content and water status in growing tissues of barley leaves; changes were slow and slight in the non-growing leaf blade. Membrane-bound and free polyribosomes were equally sensitive to stress-induced disaggregation. Incorporation of /sup 32/PO/sub 4//sup 3 -/ into ribosomal RNA was rapidly inhibited by stress, but stability of poly(A)/sup +/RNA relative to ribosomal RNA was similar in stressed and unstressed tissues, with a half-life of about 12 hours. Stress also caused progressive loss of poly(A)/sup +/RNA from these tissues. Quantitation of poly(A) and in vitro messenger template activity in polysome gradient fractions showed a shift of activity from the polysomal region to the region of 20-60 S in stressed plants. Messenger RNA in the 20-60 S region coded for the same peptides as mRNA found in the polysomal fraction. Nonpolysomal and polysome-derived messenger ribonucleoprotein complexes (mRNP) were isolated, and characteristic proteins were found associated with either fraction. Polysomal mRNP from stressed or unstressed plants were translated with similar efficiency in a wheat germ cell-free system. It was concluded that no translational inhibitory activity was associated with nonpolysomal mRNP from barley prepared as described.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Wed Jan 01 00:00:00 EST 1986},
month = {Wed Jan 01 00:00:00 EST 1986}
}

Thesis/Dissertation:
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  • One of the most sensitive cells to ozone (O/sub 3/) damage is the pulmonary endothelial cell which may mediate the response of the lung to injury by productions of the autacoid prostacyclin (PGl/sub 2/), a metabolite of arachidonic acid. Exposure of endothelial cell cultures to ozone produced a concentration dependent decreases in the synthesis of PGl/sub 2/. Release of /sup 3/H-arachidonic acid from endothelial cells was increased after two hours of 0.3 and 1.0 ppm O/sub 3/ exposure while incubation of cells with 20 ..mu..M and arachidonate (4 min) after exposure resulted in a decreased PGl/sub 2/ synthesis. Cells exposedmore » to 1.0 ppm O/sub 3/ did not have a decreased PGl/sub 2/ production when incubated with 5 ..mu..M PGH/sub 2/ immediately after exposure. These results are consistent with an O/sub 3/-induced inhibition of cyclooxygenase activity. O/sub 3/ exposure (1.0 ppm) produced a rapid decrease in endothelial PGl/sub 2/ synthesis. The data suggest that cyclooxygenase was not inactivated by increased autooxidation due to metabolism of increased free arachidonate. PGl/sub 2/ synthesis returned to control amounts within 12 hours after ozone exposure similar to the recovery time of irreversibly inhibited cyclooxygenase suggesting that recovery was due to de novo synthesis of enzyme. Lipid peroxides and/or hydrogen peroxide (H/sub 2/O/sub 2/) may have caused the inhibition of cyclooxygenase. Incubation of cells with catalase (5 U/ml) protected against the O/sub 3/-induced depression in PGl/sub 2/ synthesis. Exogenously added H/sub 2/O/sub 2/ (greater than or equal to 75 ..mu..M) caused a stimulation of basal PGl/sub 2/ production but depressed arachidonate-stimulated synthesis. O/sub 3/ exposure (2 hr, 1.0 ppm) produced altered metabolism of arachidonate in other important lung cell types, e.g., a decreased PGl/sub 2/ synthesis in smooth muscle cultures. Exposure of lung macrophages to O/sub 3/ caused an increase in almost all arachidonate metabolites produced.« less
  • Extracts of sporangiospores of Mucor racemosus contained RNA that readily hybridized with (/sup 3/H)polyuridylic acid. Prior to germination, this RNA was in a form sedimenting at <80S. Within 10 minutes after initiating germination, most of this RNA sedimented with polyribosomes and 80S monoribosomes. Particulate material from spore extracts bound to oligo(dT)-cellulose at high ionic strength and was assumed to contain messenger ribonucleoprotein particles (mRNP's). A portion of the mRNP's was released from the column by lowering the ionic strength. Other portions were eluted stepwise in buffer containing 50% and 90% formamide and in 0.1-N NaOH. Identical elution patterns were observedmore » whether monitoring incorporated /sup 31/P-orthophosphate or L-(/sup 32/S)methionine, absorbance at 280 nm, or hybridization of (/sup 3/H)polyuridylic acid. mRNP's from the first two fractions were analyzed. A bimodal population of particles was detected in sedimentation velocity and sedimentation equilibrium centrifugation. Particles eluted at low ionic strength demonstrated a sedimentation coefficient distribution of 20S-to-80S. Particles eluted in formamide demonstrated a sedimentation coefficient distribution of 20S-to-60S. Particles eluted at low ionic strength displayed two peaks in CsCl centrifugation, with buoyant densities of 1.37 gm/cc and 1.59 gm/cc. Particles eluted in formamide displayed a single peak with a buoyant density of 1.61 gm/cc. Particles eluted at low ionic strength and centrifuged in metrizamide solution formed two bands having buoyant densities of 1.15 gm/cc and 1.30 gm/cc; formamide-eluted particles banded only at the higher density. Mucor 40S ribosomal subunits banded at 1.56 gm/cc and 1.28 gm/cc in CsCl and metrizamide solution respectively.« less
  • Greenhouse-grown Hordeum vulgare with 80 to 90% expanded first leaves were fumigated (F) with 1.0 to 10.0 ppM sulfur dioxide (SO/sub 2/) for 0.25 to 4.00 h within a chamber. Non-fumigated (NF) seedlings (controls) were kept within a greenhouse. Leaves from both F and NF plants were harvested 0 to 168 h after fumigation. Visibly injured F leaves always contained more SP than did NF leaves. Proline within necrotic areas of F leaves was 15 to 30 times > that within NF leaves, while SP of non-necrotic areas of F leaves increased 1.5 to 18-fold above that in corresponding areasmore » of NF leaves. Accumulation of SP occurred prior to the appearance of injury in those plants grown under short daylength, 18 to 21/sup 0/C, high relative humidity (winter greenhouse). In contrast, seedlings raised under long day-length, 21 to 32/sup 0/C, low relative humidity (summer greenhouse) accumulated SP following fumigation only if SO/sub 2/-induced visible foliar injury. These results suggest that foliar, SP accumulation within SO/sub 2/-stressed plants does not result from either proteolysis or synthesis from glutamate.« less
  • Seedlings of pond (Pinus serotina (Michx.)), sand (P. clausa (Engelm.) Sarg.), and loblolly pines (P. taeda L., drought-hardy and wet site seed sources) were grown in a non-circulating, continuously-flowing solution culture under anaerobic or aerobic conditions to determine the effects of anaerobics on overall growth, root morphology and efficiencies of nutrient uptake and utilization. Although shoot growth of the 11-week old loblolly and pond pines was not affected by anaerobic treatment, it did significantly reduce root biomass. Sand pine suffered the largest biomass reduction. Flooding tolerance was positively correlated with specific morphological changes which enhanced root internal aeration. Oxygen transportmore » from shoot to the root in anaerobically-grown loblolly and pond pine seedlings was demonstrated via rhizosphere oxidation experiments. Tissue elemental analyses showed that anaerobic conditions interfered with nutrient absorption and utilization. Short-term /sup 32/p uptake experiments with intact seedlings indicated that net absorption decreased because of the reduction in root biomass, since H/sub 2/PO/sub 4//sup -/ influx in the anaerobically-grown seedlings was more than twice that of their aerobic counterparts. Sand pine possessed the physiological but not morphological capacity to increase P uptake under anaerobic growth conditions. Pond and wet-site loblolly pine seedlings maintained root growth, perhaps through enhanced internal root aeration - an advantage in field conditions where the phosphorus supply may be limited or highly localized.« less