Pyrimidine metabolism in seeds and seedlings of jack pine (Pinus banksiana)

1975 ◽  
Vol 53 (7) ◽  
pp. 673-686 ◽  
Author(s):  
J. Pitel ◽  
D. J. Durzan
Keyword(s):  
Nucleic Acids ◽  
Dna Synthesis ◽  
Pinus Banksiana ◽  
Orotic Acid ◽  
De Novo ◽  
Jack Pine ◽  
Pyrimidine Metabolism ◽  
De Novo Synthesis ◽  
Pine Seedlings ◽  
Low Levels

Jack pine seedlings rapidly converted radioactive thymine-6-3H to dihydrothymine, β-ureidoisobutyric acid, and β-aminoisobutyric acid. Autoradiographs of hypocotyl cells showed radioactivity largely in the cytoplasm. A small percentage of radioactivity from thymine-2-14C was salvaged via uracil for the synthesis of RNA. DNA was not labelled significantly. The occurrence of a mechanism to utilize thymidine-methyl-3H for DNA synthesis was detected at low levels in germinating seedlings but was absent in seeds up to 16 h imbibition. Among pyrimidines tested thymidine was the most specific for the labelling of DNA and radioactivity was detected almost entirely over nuclei.The occurrence of an active pathway for the de novo synthesis of the pyrimidine portions of nucleic acids was demonstrated by the use of orotic acid-4-14C. Native DNA and all major types of RNA were labelled and radioactivity resided in pyrimidines. Synthesis of DNA involved the conversion of pyrimidine ribonucleotides to deoxyribonucleotides.

Apoptosis in megaloblastic anemia occurs during DNA synthesis by a p53-independent, nucleoside-reversible mechanism

Blood ◽  
2000 ◽  
Vol 96 (9) ◽  
pp. 3249-3255 ◽  
Author(s):  
Mark J. Koury ◽  
James O. Price ◽  
Geoffrey G. Hicks
Keyword(s):  
Dna Synthesis ◽  
De Novo ◽  
Megaloblastic Anemia ◽  
Experimental Studies ◽  
Hematopoietic Cells ◽  
S Phase ◽  
De Novo Synthesis ◽  
Complete Reversal ◽  
Phase Accumulation

Abstract Deficiency of folate or vitamin B12 (cobalamin) causes megaloblastic anemia, a disease characterized by pancytopenia due to the excessive apoptosis of hematopoietic progenitor cells. Clinical and experimental studies of megaloblastic anemia have demonstrated an impairment of DNA synthesis and repair in hematopoietic cells that is manifested by an increased percentage of cells in the DNA synthesis phase (S phase) of the cell cycle, compared with normal hematopoietic cells. Both folate and cobalamin are required for normal de novo synthesis of thymidylate and purines. However, previous studies of impaired DNA synthesis and repair in megaloblastic anemia have concerned mainly the decreased intracellular levels of thymidylate and its effects on nucleotide pools and misincorporation of uracil into DNA. An in vitro model of folate-deficient erythropoiesis was used to study the relationship between the S-phase accumulation and apoptosis in megaloblastic anemia. The results indicate that folate-deficient erythroblasts accumulate in and undergo apoptosis in the S phase when compared with control erythroblasts. Both the S-phase accumulation and the apoptosis were induced by folate deficiency in erythroblasts fromp53 null mice. The complete reversal of the S-phase accumulation and apoptosis in folate-deficient erythroblasts required the exogenous provision of specific purines or purine nucleosides as well as thymidine. These results indicate that decreased de novo synthesis of purines plays as important a role as decreased de novo synthesis of thymidylate in the pathogenesis of megaloblastic anemia.

Orotic Acid, More Than Just an Intermediate of Pyrimidine de novo Synthesis

2015 ◽  
Vol 42 (5) ◽  
pp. 207-219 ◽  
Author(s):  
Monika Löffler ◽  
Elizabeth A. Carrey ◽  
Elke Zameitat
Keyword(s):  
Orotic Acid ◽  
De Novo ◽  
De Novo Synthesis

scholarly journals Height growth of black spruce and jack pine seedlings in flooded flats

1975 ◽  
Vol 51 (2) ◽  
pp. 53-54
Author(s):  
W. Stanek
Keyword(s):  
Nutrient Solution ◽  
Picea Mariana ◽  
Concentration Gradient ◽  
Pinus Banksiana ◽  
Black Spruce ◽  
Jack Pine ◽  
Height Growth ◽  
Distilled Water ◽  
Pine Seedlings ◽  
Water Height

Black spruce (Picea mariana [Mill.] B.S.P.) and jack pine (Pinus banksiana Lamb.) seedlings were grown in a green-house on peat-filled flats flooded with nutrient solution or distilled water. None was aerated. However, an O2 concentration gradient existed across the flats, 3.0 – 3.7 ppm along the edges, and 1.4 – 1.9 ppm in the centers. After 4½ months seedlings of both species grew taller with nutrient solution than with distilled water. In flats supplied with nutrient solution, seedlings of both species grew taller along the edges than in the centers, whereas in flats supplied with distilled water height differential did not develop. Jack pine grew taller than black spruce under similar conditions.

L'utilisation du compost de boues de stations d'épuration des eaux comme substrat de culture pour la production des plants forestiers en récipients

1993 ◽  
Vol 20 (3) ◽  
pp. 518-527
Author(s):  
Patrick Polan ◽  
Jean Gagnon ◽  
J. Peter Jones
Keyword(s):  
Pinus Banksiana ◽  
Wastewater Treatment Plants ◽  
Growth Parameters ◽  
Jack Pine ◽  
Peat Moss ◽  
Shoot Height ◽  
Containerized Seedlings ◽  
Pine Seedlings ◽  
Sludge Recycling ◽  
Collar Diameter

The Quebec government has established a program to treat industrial and domestic wastewaters. However, this program does make it necessary to dispose of large quantities of sludge. This sludge can be burned or landfilled but such solutions do not properly draw benefit from the sludge's potential as a fertilizer. There is a considerable interest in composting of the sludge. In this study, compost from the composting plant in Plattsburgh was mixed with the growing substrate normally used for the production of containerized jack pine (Pinus banksiana Lamb.) seedlings to determine if the compost could be used for the production in containers of forest seedlings. The growth of containerized seedlings produced with proportions by volume of 80% peat moss and 20% vermiculite was compared to the growth of seedlings when the peat moss (80%) was replaced by different proportions of compost (20, 40, 60, and 80%). After one growing season in tunnel, the best growth rates in terms of shoot height, root-collar diameter, and dry biomass were obtained with the control, followed in decreasing order by the treatments compost 20, 40, 60, and 80%. In this experiment, the use of compost from wastewater treatment plants reduced significantly the growth of jack pine and this can be explained mainly by the lack of nitrogen in the tissues of jack pine seedlings. However, the adjustment of nitrogen fertilization and conditions of cultivation by using compost may permit the production of containerized seedlings having the same dimensions as the controls. The seedling growth parameters when 20% compost was incorporated in the substrate were nearly the same as the control seedling. Key words: sludge, recycling, compost, substrate, container, forest seedlings, jack pine.

scholarly journals DNA synthesis primed by mononucleotides (de novo synthesis) catalyzed by HIV-1 reverse transcriptase: tRNALys,3 activation

FEBS Letters ◽  
1995 ◽  
Vol 373 (3) ◽  
pp. 255-258 ◽  
Author(s):  
Ol'ga D. Zakharova ◽  
Laura Tarrago-Litvak ◽  
Michel Fournier ◽  
Simon Litvak ◽  
Georgyi A. Nevinsky
Keyword(s):  
Reverse Transcriptase ◽  
Dna Synthesis ◽  
De Novo ◽  
De Novo Synthesis ◽  
Hiv 1

scholarly journals Short-term magnesium deficiency upregulates sphingomyelin synthase and p53 in cardiovascular tissues and cells: relevance to the de novo synthesis of ceramide

2010 ◽  
Vol 299 (6) ◽  
pp. H2046-H2055 ◽  
Author(s):  
Burton M. Altura ◽  
Nilank C. Shah ◽  
Zhiqiang Li ◽  
Xian-Cheng Jiang ◽  
Aimin Zhang ◽  
...  
Keyword(s):  
De Novo ◽  
Magnesium Deficiency ◽  
Smooth Muscles ◽  
Ceramide Synthase ◽  
De Novo Synthesis ◽  
Short Term ◽  
Sphingomyelin Synthase ◽  
Coa Transferase ◽  
Ceramide Synthesis ◽  
Low Levels

The present study tested the hypotheses that 1) short-term dietary deficiency of magnesium (21 days) in rats would result in the upregulation of sphingomyelin synthase (SMS) and p53 in cardiac and vascular (aortic) smooth muscles, 2) low levels of Mg2+added to drinking water would either prevent or greatly reduce the upregulation of both SMS and p53, 3) exposure of primary cultured vascular smooth muscle cells (VSMCs) to low extracellular Mg2+concentration ([Mg2]o) would lead to the de novo synthesis of ceramide, 4) inhibition of either SMS or p53 in primary culture VSMCs exposed to low [Mg2+]owould lead to reductions in the levels of de novo ceramide synthesis, and 5) inhibition of sphingomyelin palmitoyl-CoA transferase (SPT) or ceramide synthase (CS) in primary cultured VSMCs exposed to low [Mg2+]owould lead to a reduction in the levels of de novo ceramide synthesis. The data indicated that short-term magnesium deficiency (10% normal dietary intake) resulted in the upregulation of SMS and p53 in both ventricular and aortic smooth muscles; even very low levels of water-borne Mg2+(e.g., 15 mg·l−1·day−1) either prevented or ameliorated the upregulation in SMS and p53. Our experiments also showed that VSMCs exposed to low [Mg2+]oresulted in the de novo synthesis of ceramide; the lower the [Mg2+]o, the greater the synthesis of ceramide. In addition, the data indicated that inhibition of either SMS, p53, SPT, or CS in VSMCs exposed to low [Mg2+]oresulted in marked reductions in the de novo synthesis of ceramide.

Anthocyanins of jack pine (Pinus banksiana) seedlings

2002 ◽  
Vol 80 (7) ◽  
pp. 796-801 ◽  
Author(s):  
Constance Nozzolillo ◽  
Pierre Isabelle ◽  
Øyvind M Andersen ◽  
Mamdouh Abou-Zaid
Keyword(s):  
Pinus Banksiana ◽  
Forest Tree ◽  
Jack Pine ◽  
Prominent Feature ◽  
Anthocyanin Pigmentation ◽  
Entire Spectrum ◽  
Pine Seedlings ◽  
Similar Range ◽  
Anthocyanin Pigments ◽  
Freezing Temperatures

Purpling of the needles of jack pine seedlings in forest tree nurseries in the autumn is a result of the production of at least five anthocyanin pigments: cyanidin 3-O-glucoside (~80%), delphinidin 3-O-glucoside (~8%), peonidin 3-O-glucoside (~8%), petunidin 3-O-glucoside (~3%) and malvidin 3-O-glucoside (trace). The twigs subtending the needles also produce a similar range of pigments. The entire spectrum of pigments is produced from the time of the first exposure to freezing temperatures. Proanthocyanidins are a prominent feature of the needle phenolics and the question of their possible involvement in the purpling phenomenon following exposure to sub-zero temperatures is raised. The red colour of the hypocotyl of the newly germinated seedling is also a result of a similar mixture of pigments.Key words: Pinus banksiana, Pinaceae, jack pine seedlings, anthocyanin pigmentation, hypocotyl, proanthocyanidins.

scholarly journals Effects of Plant Growth Regulators on Sturdiness of Jack Pine Seedlings

1996 ◽  
Vol 14 (4) ◽  
pp. 228-230 ◽  
Author(s):  
Jeffrey P. Schnurr ◽  
Zong-Ming Cheng ◽  
Arthur A. Boe
Keyword(s):  
Plant Growth ◽  
Plant Height ◽  
Growth Regulators ◽  
Pinus Banksiana ◽  
Weight Ratio ◽  
Dry Weight ◽  
Jack Pine ◽  
Growth Characteristics ◽  
Pine Seedlings ◽  
Growth Modification

Abstract Seven growth regulators (ancymidol, 6-benzylaminopurine, ethephon, flurprimidol, mefluidide, paclobutrazol, and uniconizole) at various concentrations were studied for their effects on sturdiness of greenhouse grown seedlings of jack pine (Pinus banksiana Lamb.), measured by a single parameter, growth modification index. All growth regulators at certain concentrations were effective in reducing plant height but none increased stem caliper. Several growth regulators increased shoot-to-root dry weight ratio. Benzylaminopurine greatly modified growth characteristics and resulted in deformed seedlings. Uniconizole was most promising for producing sturdier seedlings of jack pine.

Effect of sodium fluoride treatments on the mitotic cycle of root-tip cells in jack pine seedlings

1989 ◽  
Vol 67 (5) ◽  
pp. 1606-1608 ◽  
Author(s):  
J. J. Zwiazek ◽  
Jennifer M. Shay
Keyword(s):  
Sodium Fluoride ◽  
Pinus Banksiana ◽  
Mitotic Cycle ◽  
Jack Pine ◽  
Root Tip ◽  
Pine Seedlings ◽  
Induced Changes ◽  
Tip Cells ◽  
Accumulation Method ◽  
Root Tip Cells

Fluoride-induced changes in the mitotic cycle were studied in root-tip cells of jack pine (Pinus banksiana Lamb.) seedlings using the metaphase accumulation method. Sodium fluoride treatments resulted in lengthening of the mitotic cycle. This was due to an increase in the duration of interphase. The duration of mitosis and individual mitotic phases was not affected by the treatments.

Contrasting modes of survival by jack and pitch pine at a common range limit

2002 ◽  
Vol 32 (9) ◽  
pp. 1662-1674 ◽  
Author(s):  
Michael S Greenwood ◽  
William H Livingston ◽  
Michael E Day ◽  
Shawn C Kenaley ◽  
Alan S White ◽  
...  
Keyword(s):  
Pinus Banksiana ◽  
Pollen Viability ◽  
Jack Pine ◽  
Range Limit ◽  
Acadia National Park ◽  
Pinus Rigida ◽  
Pine Seedlings ◽  
Pine Regeneration ◽  
Pitch Pine ◽  
Dry Conditions

Freezing tolerance, reproductive development, and seed germination of jack pine (Pinus banksiana Lamb.) and pitch pine (Pinus rigida Mill.) were compared in a small sympatric population in Acadia National Park in Maine, at the southern range limit of the former and the northern limit of the latter. Freezing tolerances of vegetative shoots and roots were similar for both species. Both species flower prolifically, and there was no evidence of differences in either pollen viability, cone survival, or proportion of viable seed (65–70% of the total). Regeneration success (established seedlings ranging from 1 to 13 years old) was similar overall for both species, but success by species varied greatly in some years. Jack pine regeneration was significantly associated with thinner soils, while pitch pine regeneration was associated with thicker soils in hollows. Jack pine seed germinated significantly faster than pitch pine seed, especially when day–night temperature was reduced. Pitch pine seedlings always exhibited a significantly higher shoot/root ratio than those of jack pine. The most northerly provenances of jack pine germinated significantly faster than those from the most southerly provenances. Jack pine also germinated at a significantly higher percentage than pitch pine in exposed granite sand. Thus relatively cool, dry conditions may favor establishment of jack pine seedlings, while pitch pine establishment may be favored in warmer, wetter conditions.

Sign in / Sign up

Export Citation Format

Share Document