• Journal of Plant Biology
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• v.36 no.1
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• pp.19-27
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• 1993

Effects of polyamines on DNA synthesis were studied in synchronized culture of Nicotiana tabacum L. When DFMO and DFMA, inhibitors of ornithine decarboxylase and arginine decarboxylase, respectively were initially applied to the cells, the polyamine contents were rapidly dropped and [methyl-3H] thymidine incorporation into DNA was markedly reduced during the early stage of culture period. Inhibition of DNA synthesis, however, was partially reversed when these inhibitors were applied simultaneously with putrescine. In addition, exogenous administration of putrescine also increased the DNA synthesis during the all over the culture period. In vitro activity of DNA polymerase from Nicotiana tabacum L. was promoted by increasing concentrations of polyamines in the reaction mixture. Maximal activity was shown at 5 mM putrscine, 0.5 mM spermidine and spermine, respectively. Lack of Mg2+ ion in the reaction buffer resulted in an inhibition of the enzyme activity by about 30%. The inhibition could not be completely reversed by application of polyamines at optimal concentrations. These results suggest that polyamines promote the DNA synthesis in vivo and in vitro by stabilizing the DNA-helix upon binding to negatively charged groups on DNA or increasing the activity of DNA polymerase in Nicotiana tabacum L.

• Journal of Plant Biology
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• v.30 no.1
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• pp.1-9
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• 1987

Leaf mesophyll protoplasts of Nicotiana tabacum (nitrate reductase deficient mutant) were fused with cell suspension protoplasts of albino Petunia inflata in an electric field. Hybrid cell colonies were selected for nitrate reductase proficiency and chlorophyll synthesis. Five hybrid plant lines, regenerated from the selected calli lines, were analysed by electrophoresis, number of chromosomes and morphological characters. Somtic hybrid plants showed both parent patterns in the isozymesof isoleucine aminopeptidase and esterase. The hybrids had the expected chromosome number of 62 and exhibited an intermediate floral morphology when compared with the parents, but plant height and leaf arrangement were similar to N. tabacum.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.11
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• pp.11-80
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• 1972

• Journal of the Korean Society of Tobacco Science
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• v.16 no.2
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• pp.102-107
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• 1994

This study was conducted to transfer the potato virus Y-necrosis strain resistance from Nicotiana africana to Nicotiana tabacum (cv. NC82) N. africana was crossed with NC82, GErmination of the cotyledon stage, at which time most of the seedling died. However, surviving seedlings continued to grow normally. Chromosomes of the these interspecific self-sterile F1 hybrids were doubled by tissue culture. Amphidiploid of F1 hybrid was self-fertile. Starting with amphidipliod, a wystematic backcross (BC) program was set up with NC82 as recurrent parent. In the BC5C2 generation, the resistant plant was selected. This resistant line, KF8833-1, had 48 chromosome and secreting glandular trichomes. It flowered 2days later than NC82, and stalk height, leaves per plant, leaf length and leaf width were similar to those of NC82.

• Proceedings of the Korean Society of Crop Science Conference
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• 1990.10a
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• pp.42-43
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• 1990

• Natural Product Sciences
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• v.7 no.1
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• pp.17-20
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• 2001

The activity of the lipase and phospholipase extracted from the seed meal of Nicotiana tabacum L. was studied with the help of Spectrophotometer at different pH, Temperatures and Solvents. Both lipase and phospholipase shown optimum activity at pH 6 and $45^{\circ}C$. Their activities also maximize when n-heptane was used as solvent media.

• Natural Product Sciences
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• v.7 no.4
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• pp.110-113
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• 2001

The lipid classes constituents; hydrocarbons, wax esters, sterol esters, triacylglycerols, free fatty acids, 1,3-diacylglycerols, 1,2-diacylglycerols, free sterols, 2-monoacylglycerols, 1-monoacylglycerols, phosphatidylethanolamines, phosphatidylcholines, lysophosphatidylethanolamines and phosphatidylinositols of Nicotiana tabacum L. seeds oil were investigated by thin layer and gas chromatography. Palmitic, oleic and linoleic acids were the major components in all lipid classes studied.

• Journal of Plant Biology
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• v.30 no.4
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• pp.287-298
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• 1987

The regenerative capacities of protoplasts isolated from potato (Solamum tuberosum L.) tubers and tobacco (Nicotiana tabacum L.) mesophyll tissues were examined, and then their intergeneric protoplast fusion was carried out. The potato tuber-derived protoplasts proliferated into the calli some of which showed rudimentary shoot-like structures, which had not been attempted before from tubers, while the tobacco protoplasts were regenerated into the whole plants. Intergeneric protoplast fusion between potato and tobacco was carried out and the heteroplasmic fusion products were formed. The first cell division of some of them was observed after 5 days of culture.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.317-320
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• 2000

Effects of supplementing various 0.1-1.0%(w/v) surfactants and 0.1-1.0%(v/v) oxygen vectors on postthaw growth following cryopreservation of transgenic Nicotiana tabacum(GUS) in suspension culture were investigated. The postthaw cell growth was increased 20.68% and 23.66% compared to control when Pluronic F-68 and polyethylene glycol(PEG) were added in recovery medium respectively. Addition of n-hexadecane and FC-40 also enhanced the recovered growth by 14.89% and 20.68%. These results demonstrate that the marked Protection could be achieved by using surfactants and oxygen vectors for plant cells recovered from cryostorage.

• Journal of the Korean Society of Tobacco Science
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• v.1 no.1
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• pp.9-13
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• 1979

Dihaploid lines of tobacco (Nicotiana Tabacum L.) were developed from vitro anther culture of single cross F 1, "SC 72"X "Hicks". All genetic materials were evaluated for agronomic performance and chemical composition. Compared with midparent value, pollen derived dihaploid progenies showed reduced vigor in all measured features of plant growth, and increased total alkaloids as well as decreased reducing sugar content.