• Journal of the Korean Society of Tobacco Science
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• v.13 no.2
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• pp.52-58
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• 1991

Interspecific cross between Nicotiana trigonophylla and N. tabacum cv. BY4 is highly sterile because of abnormal ovule and embryo development. In vitro culture of excised N. trigonophylla ovules after polination by N. tabacum allows significant numbers of hybrid embryos to develop into mature plants. Total yield of seedlings and number of normal seedlings were produced following in vitro culture of individual fertilized ovules of N. trigonophylla X N. tabacum at four days post-pollination on B5 medium containing 6% sucrose. Hybrids were uniform in morphology and peroxidase isozyme composition and the majority were cytologically stable: flower characteristics were generally intermediate between those of the parents. All hybrids evaluated were self-sterile.

• Journal of the Korean Society of Tobacco Science
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• v.15 no.2
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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.

• Journal of the Korean Society of Tobacco Science
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• v.17 no.2
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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.

• Journal of Plant Biology
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• v.18 no.4
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• pp.150-154
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• 1975

Four kinds of Nicotiana species and five varieties belonging to N. tabacum were used as materials for electrophoretic analysis of the tetrazolium oxidase isozyme to examine the taxonomic affinity among them based on the biochemical property. All the five verieties of N. tabacum showed same isozyme bands despite the fact that these varieties had notably varied characteristics including morphological traits. The band patterns were more or less different among the four species. Although N. rustica and N. tabacum were of the same genome group of AABB, their isozyme bands showed considerable difference. N. sylvestris, genome A donor of Nicotiana species, was found to be markedly different from N. tatacum in band pattern, including the absence of system 2 in N. sylvestris.

• Proceedings of the Korean Society of Crop Science Conference
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• 1988.02a
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• pp.94-95
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• 1988

• BMB Reports
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• v.40 no.1
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• pp.107-112
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• 2007

To study the functioning of HSP70 in Escherichia coli, we selected NtHSP70-2 (AY372070) from among three genomic clones isolated in Nicotiana tabacum. Recombinant NtHSP70-2, containing a hexahistidine tag at the amino-terminus, was constructed, expressed in E. coli, and purified by $Ni^{2+}$ affinity chromatography and Q Sepharose Fast Flow anion exchange chromatography. The expressed fusion protein, $H_6NtHSP70$-2 (hexahistidine-tagged Nicotiana tabacum heat shock protein 70-2), maintained the stability of E. coli proteins up to 90$^{\circ}C$. Measuring the light scattering of luciferase (luc) revealed that NtHSP70-2 prevents the aggregation of luc without ATP during high-temperature stress. In a functional bioassay (1 h at 50$^{\circ}C$) for recombinant $H_6NtHSP70$-2, E. coli cells overexpressing $H_6NtHSP70$-2 survived about seven times longer than those lacking $H_6NtHSP70$-2. After 2 h at 50$^{\circ}C$, only the E. coli overexpressing $H_6NtHSP70$-2 survived under such conditions. Our NtHSP70-2 bioassays, as well as in vitro studies, strongly suggest that HSP70 confers thermo-tolerance to E. coli.

• KSBB Journal
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• v.6 no.3
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• pp.289-297
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• 1991

The insecticidal protein gene in the pKL-20-1 clone derived from Bacillus thuringiensis serovar. kurstaki plasmid was subcloned in the plant shuttle vector, pGA643. The 7.3 kb fragment was cloned in the BglII and Hpal sites of pGA643 vector and expressed in E. coli S17-1, which produced insecticidal proteins killing Bombyx mori larvae. The clone was named pHL-20. The protoplast formation, calli induction and plantlet regeneration of Nicotiana tabacum was carried out. A tremendous number of mesophyll protoplasts of N. tabacum were formed, up to 7$\times$105 protoplast per ml, for 20 hours in darkness in the enzyme solution of 0.5% cellulase and 0.1% macerosin, pH 5.8. The viabilities of the protoplasts were maintained above 80% for 6 days in the media containing 2mg/1 of NAA and 1mg/1 of kinetin. Calli were induced from the protoplasts and leaves of the N. tabacum on MS medium containing 0.5mg/1 BAP. Under the culture conditions the protoplasts underwent repeated cell division into calli. Plantlets were regenerated from callus cultures derived from protoplast and leaves. Shoots were induced in a medium containing 1mg/1 of BAP.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.5
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• pp.649-654
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• 1995

This study was conducted to investigate the utility and agronomic characteristics and use of cytoplasmic. male-sterile (CMS) haploid plants derived from interspecific cross between (male-sterile NC82$\times$burley21) F$_1$ plant (Nicotiana tabacum L.) and Nicotiana africana. Abundant seeds of high germinability were obtained when Nicotiana tabacum (cytoplasmic male-sterile F$_1$ plants) is pollinated by Nicotiana africana. Most of seedlings died at the cotyledonary stage. The remaining seedlings are viable F$_1$ hybrids or maternal haploids that can be easily distinguished. Number of interspecific Fl hybrids and matermal haploids per capsule obtained from the interspecific cross between cytoplasmic male-sterile tobacco F$_1$ plants and N.africana yielded 2.2 and 0.5 plants, respectively. Out of 149 CMS haploid plants obtained from interspecific cross, 102 plants showed green type while the others were yellow type for leaf and stem. This results agreed with the genetic ratios expected among haploid plants from the F$_1$ hybrids heterozygous for two recessive genes of yellow color of burley tobacco plant. Out of 83 CMS haploid plants inoculated with TMV, 48 plants showed resistant, while the others was susceptible. It agreed with the expected genetic ratios for a single dominant gene of TMV resistance. CMS haploid plant will be useful as a source material for breeding of CMS doubled haploid lines

• Journal of the Korean Society of Tobacco Science
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• v.1 no.1
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• pp.46-50
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• 1979

Four cytoplasmic male-sterile lines of burley tobacco (Nicotiana tabacum L. ) and their male- fertile counterparts were evaluated for their characteristics in replicated field trials. Cytoplasmic male -sterile lines were comparable to the male- fertile varieties for agronomic and chemical traits and these suggest that the cytoplasmic male - sterility can be used in the production of hybrid seed without loss of vigour or undesirable changes On other characteristics.

• Journal of Plant Biology
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• v.30 no.1
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• pp.69-77
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• 1987

From the single cell cultures of haploid tobacco (Nicotiana tabacum L. cv. NC 2326) glyphosate-resistant plants were regenerated. After treated with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and then inoculated onto the LS medium supplemented with 1 mM glyphosate, the single cells survived formed colonies and calluses in 65 and 95 days after culture, respectively, and then whole plants were regenerated in 0.1 mM glyphosate-containing medium from the selected calluses. There was no difference in fresh weight and shikimate content between the selected and normal haploid calluses. When sprayed with 0.1 mM glyphosate, the shikimate contents in the regenerated and normal plants were 0.659 and 20.816 mol/g fr. wt., while that in other normal plants which were not sprayed was 0.921. In addition, the calluses induced from the regenerated plants grew without showing any retardation when treated with glyphosate. These results indicate that the secelcted calluses and regenerated plants are resistant to glyphosate.