• BMB Reports
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• 제34권5호
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• pp.472-477
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• 2001

Ornithine decarboxylase (ODC, EC 4.1.1.17) is the first and key enzyme in eukaryotic polyamine biosynthesis. The cDNA encoding ornithine decarboxylase from Nicotiana glutinosa was cloned ($GeBank^{TM}$ AF 323910) and expressed in E. coli. Site directed mutagenesis were performed on several highly conserved cysteine residues. Among the mutants, C115A showed significant changes in the kinetic properties. The $K_m$ value of the C115A mutant was $1790\;{\mu}M$, which was 3-fold higher than that of the wild-type ODC. There was a dramatic decrease in the $k_{cat}$, values of the C115A mutant, compared to that of the wild-type ODC, which had a $k_{cat}$ value of $77.75\;s^{-1}$. C115A caused a shift in the optimal pH from 8.0 to 8.4. Considering these results, we suggest that cys-115 is involved in the catalytic activity of N. glutinosa ODC.

• 한국연초학회지
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• 제17권2호
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• pp.109-113
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• 1995

Nicotiana repanda has resistance to many important tobacco diseases but no tobacco cultivars are currently available that carry risistance genes derived from this species. Numerous attempts to hybridize N, repanda with commercial tobacco cultivars have been largely unsuccessful because of cross incompatibility or the uncovering of lethal genes. In vitro pollination of placenta attached ovules was useful in by passing prezygotic barriers for interspecific hybrid combination between N.tabacum cv. NC82 and N. repanda. Six days after in vitro pollination of N. tabacum cv. NC82×N. repanda, enlarged ovules on plancenta were removed and transferred into ovule culture medium of kitsch and kitsch (1969). Within 15 days of ovule culture, germination occurred. Most of the hybrid seedlings obtained had poor root system and finally died, while few of them had good root system and grew well.

• 한국연초학회지
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• 제22권1호
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• pp.39-44
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• 2000

This study was carried out to obtain the basic information about the sucker producing characteristics of certain burley tobacco varieties(Nicotiana tabacum L. var. burley) at Suwon and Chonju Experiment Station, Korea Ginseng & Tobacco Research Institute in 1999. The number and weight of suckers for 12 varieties or breeding lines were investigated three times, 45 days after transplanting for ground sucker, 10 days after topping, and 10 days after maleic hydrazide(MH) applying for upstalk sucker. KB 103 and KB 9416-1 produced less ground suckers and upstalk suckers than other entries did. KB 9210-8 produced less ground suckers and (Male sterile TC 612 x KB 108)F$_1$ also produced less upstalk suckers than other entries did. There was no differences among entries in sucker production at 10 days after MH treatment. Between the weight of total sucker and days to flower revealed the negative correlation, but not significant. The low sucker producing entries described above could be used as a parental line in the breeding program for the low sucker producing variety.

• 한국연초학회지
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• 제15권2호
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• pp.123-129
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• 1993

Mesophyll protoplasts derived from young leaves of Nicotiana rustica and N. tabacum cv Burley 21 were fused with the aid of polyethylene glycol(PEG). Cytological examination of protoplasts after PEG treatment revealed 12.8 % heterokaryocytes. After 7 weeks culture, the hybrid calli showing greenish white with a compact appearance were selected in contrast to parental type calli tinged with white or green color. The somatic hybrid plants were verified by morphological, biochemical and cyclological analysis. A heterosis effect for plant vigor and height was observed but the shape of leaves and flower characteristics were intermediate between N. tabacum and N. rutstica. The isozyme banding patterns for peroxidase of somatic hybrid lines were compared with the parent species. A number of isozyme bands derived from both parental species were found in the hybrids. Somatic hybrid plants have been successfully backcrossed to the parental N. tabacum particularly with somatic hybrid plants as female parents. These hybrid plants yielded small seeds, only few which were germinable.

• 한국연초학회지
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• 제3권1호
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• pp.41-48
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• 1981

Dihaploid lines were derived from the anthers of the F, of single cross, "Va 115" x"SC 72" (Nicotiana tabacum L.). The path-analysis, correlation coefficient, and variation of characteristics among dihaploid families were evaluated. Dihaploid lines displayed much greater variation than their parents. The genetic correlation coefficient between yield and total alkaloids of dihaploids was significantly lower than that of conventional varieties and lines. In path-analysis which relates yield components to yield, number of leaves harvested and leaf width had a direct effect on yield. a direct effect on yield.

• 한국연초학회지
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• 제4권1호
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• pp.67-71
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• 1982

4, 8, 13-Duvatriene-1, 3-viols have been identified in the cuticular lipid of fresh Sohyang (aromatic cultivar) tobacco leaves. Their $\alpha, \beta$-isomers were directly separated by SE-54 glass capillary column and identified by mass spectrometry. Gas chromatographic analysis revealed that the duvatrienediols are major components in the culticular lipid of Nicotiana Tabacum.

• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2004년도 생명공학 실용화를 위한 비젼
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• pp.107-107
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• 2004

• Journal of Plant Biology
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• 제14권1호
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• pp.33-35
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• 1971

After topping, axillary buds of haploid plants derived from cultured anthers were treated with 0.4% aqueous solution of colchicine. Due to the high temperature and dry air at the time of treatment, most of the buds perished. A few months after the colchicine application, however, several shoots arose from the places where the dead buds were originally located. These shoots were mostly diploid. Induction of adventive shoots from the colchicine-treatedaxils was supposed to be rather effective method of obtaining diploid shoots from haploid plants. The diploid plants had larger floral organs than the haploid plants, and had good pollen fertility and seed setting. 24 bivalent chromosomes were observed at MI of the PMC's.

• 한국연초학회지
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• 제15권2호
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• pp.130-136
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• 1993

Protoplasts of palisade cells were aseptically isolated from leaves of Nicotiono apicona Merxm. by the one step enzymatic method. Efficiency of colony formation were depended on cell density and light condition during incubation, but an intensity of 47 ft-c during a period of 2 weeks after isolation of the protoplasts in the Nagata and Takebe's medium promoted the planting efficiency. Protoplast - derived calli of N. africana can be differentiated into shoot when cultured on Murashige and skoog's medium containing IAA(0.Smg/$\ell$) and zeatin(5.0mg/$\ell$).

• 한국작물학회:학술대회논문집
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• 한국작물학회 1988년도 춘계 학술대회지
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• pp.94-95
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• 1988