• Journal of Plant Biotechnology
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• v.2 no.1
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• pp.25-28
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• 2000

The anthocyanin gene encoding flavonoid 3',5'-hydroxylase(F3,5H) was normally expressed in Nicotiana tobacco (Xanthi) plants cocultivated with Agrobacterium tumefaciens LBA4404 carrying egg plant flavonoid 3',5'-hydroxylase cDNA. Northern blot analysis showed the normal expression of F3', 5'H gene from transgenic plants. Here we found the phenotypic differences between transgenic plants and wild-type plants. The petal shape of transgenic plants showed more round shape and around petal tube area was compared to that of wild-type tobacco plants. And the petal color of transgenic plants was much lighter than that of wild-type tobacco plants.

• Journal of the Korean Society of Tobacco Science
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• v.23 no.2
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• pp.115-122
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• 2001

The effect of mineral oil treatment in Burley 21 tobacco field on the control of potato virus Y(PVY-VN) mostly transmitted by green peach apid(Myzus persicae Sulzer) in nature was studied and the virus infection in some plants including potato, pepper, bramble, radish, etc near the tobacco fields as a virus infection source was tested by capillary tube precipitatioin test with PVY-antibody and bioassay in Xanthi-nc tobacco. The main source of PVY-VN infection in tobacco field in korea was potato(ca. 40% of test plants infected). Pepper and bramble were also infected by PVY-VN. The control level of PVY-VN infection by treatment of 0.75% liquid mineral oil with 3 % nonionic emulsifier to the plants was 84.8 % in case of the artificial transfection with a infected apterous aphid in laboratory. However, the reduction of PVY-VN disease severity in tobacco fields treated with mineral oil at late June was only 35.5%. These results suggest that mineral oil treatment is not so effective for the protection of aphid-born virus(PVY - VN) infection in tobacco fields.

• Molecules and Cells
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• v.19 no.3
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• pp.418-427
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• 2005

When inoculated into sensitive tobacco Xanthi-nn plants, the crucifer and garlic-infecting Tobacco mosaic virus (TMV-Cg) induces local necrotic lesions that resemble those seen in the hypersensitive response (HR) of resistant tobacco plants. However, unlike these, tobacco Xanthi-nn plants do not become resistant to infection and the virus spreads systemically causing a severe disease characterized by necrotic lesions throughout the plant. To identify the viral protein that elicits this necrotic response, we used a set of hybrid viruses constructed by combination of TMV-Cg and the tobacco mosaic virus strain U1 (TMV-U1). In this study we present evidence that the coat protein of TMV-Cg (CPCg) is the elicitor of the necrotic response in tobacco Xanthi-nn plants. Local and systemic necrotic lesions induced by TMV-Cg and by the hybrid U1-CPCg -that carries CPCg in a TMV-U1 context- are characterized by cell death and by the presence of autoflorescent phenolic compounds and $H_2O_2$, just like the HR lesions. In addition, defense-related genes and detoxifying genes are induced in tobacco Xanthi-nn plants after TMV-Cg and U1-CPCg inoculation. We postulate that in our system, CPCg is recognized by sensitive tobacco plants that mount an incomplete defense response. We call this an HR-like since it is not enough to induce plant resistance.

• Korean Journal of Plant Tissue Culture
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• v.28 no.1
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• pp.41-45
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• 2001

Transgenic tobacco plants were produced by the transformation of ginseng CAB gene using Agrobacterium tumefaciens LBA4404. The presence of CAB gene in the second generation of transgenic tobacco plant was confirmed by genomic PCR. The photosynthetic ability of transgenic plants was higher than normal tobacco plants and the maximum photosynthetic point of transgenic and normal tobacco plants was 500 $\mu$mol m$^{-2}$ s$^{-1}$ . The photosynthesis of C7, C11, 1, C14 cell lines was higher than normal plants at all the light intensities investigated. The photosynthesis of C2, C11, C14 cell lines in 90% dark condition was higher than normal plants. The chlorophyll contents of transgenic tobacco plants were almost same as normal plants. The % of dry weight, nicotine content, total sugar and nitrogen contents of harvested transgenic tobacco plant leaves were almost same as normal plants.

• Journal of the Korean Society of Tobacco Science
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• v.19 no.2
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• pp.77-82
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• 1997

In order to investigate biochemical activities of harvested tobacco leaves, photosynthetic rate, soluble protein contents, and peroxidale activities were analysed during different maturing period. Physiological activities of harvested leaves during maturing period were higher in topped than those of non-topped plants. Chlorophyll content and photosynthetic rate in both topped and non-topped plants decreased at 4 days and 3 days before harvest, respectively. The chloroplast numbers in topped and non-topped plants decreased at 3 days and 5 days before harvest, respectively. Changes of soluble protein and total RNA contents showed similar patterns during maturing period. Soluble protein contents were slightly decreased from 5 days before harvest in topped plants, but decreased drastically from 3 days before harvest in non-topped plants. Not much changes were found in total RNA contents in topped plants until 2 days before harvest, and it was largely decreased after 5 days before harvest in non-topped plants. The peroxidase activities drastically decreased in topped plants and increased in non-topped plants after 3 days before harvest during maturing period. The largest change of biochemical activities in tobacco leaves during maturing periods were observed at 3 days before harvest.

• Journal of the Korean Society of Tobacco Science
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• v.7 no.1
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• pp.25-31
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• 1985

For shortening the tobacco breeding cycle, seedlings with 6, 8 and II leaves of 2 flue.cured tobacco varieties, day. neutral type and photoperiod-sensitive type, were grown in controlled-environment room (CER), programmed for temperature of $18^{\circ}C$ and 8.hour day period of 30 klux, for 20, 30 and 40 days. All of plants of day.neutral type variety treated in CER, regardless of seedling stage and duration, flowered earlier than the untreated plants. In the 6.leaf seedlings stage of photoperiod-sensitive type variety, plants treated for 20 and 30 days in CER did not accelerate the flowering. the tobacco plants, treated with low temperature for 20 days at 8.leaf seedling stage, flowered earlier in comparison with. the other treatment.

• Journal of the Korean Society of Tobacco Science
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• v.16 no.2
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• pp.113-121
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• 1994

The green peach aphid was relatively the majority(36.9-72.3% ) among all alate aphids collected from tobacco plants. Density of glatae was relatively lower on varieties Tl 1112 and Br 21 than on Va 115 or Y S A among seven varieties tested. However, no considerable difference was observed in general biology of nymphs produced by alatae on the tobacco varieties. About 55% of alate green peach aphid collected from tobacco fields produced progency, and over 80% of the nymphs became adults on cut tobacco leaves in petri dish. Adult longevity of both alate and apteral green peach aphid was shorter, and numbers of nymphs produced by both types were lower in summer than in autumn. Apterae produced more nymphs than alatae, but the longevity of apterae was shorter.

• Journal of the Korean Society of Tobacco Science
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• v.27 no.1 s.53
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• pp.11-18
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• 2005

The nicotine converter genotypes of burley tobacco (Nicotiana tabacum L.), which convert nicotine to nornicotine, contain a high amount of nornicotine that degrades tobacco quality and smoking taste. Elimination of nicotine converter plants before seed harvesting is required for breeding nicotine low-converter lines and for increasing their seed production. This study aims to develop a rapid and convenient method of identifying nicotine converter plants of burley breeding lines of KB9118(KB108) using thin-layer chromatography (TLC) and isatin coloration method. Out of 223 plants in 10 lines harvested at maturity in 2002, 102 plants ($45\%$) were identified as nicotine converters by TLC of tobacco leaves air-cured. For 16 lines selected as low-converters in 2002, 148 plants grown in the field in 2003 were tested by the isatin coloration method using two detached leaves at the flowering stage thoroughly sprayed with $1\%\;NaHCO_3$ solution and cured in conditioned chambers for the early identification of nicotine to nornicotine conversion. From these samples, 46 plants ($31\%$) in 4 lines were identified as nicotine converters, indicating that the ratio of converters significantly decreased by one time selection. Mean percent conversion of non-screened lines was $14\%$ higher than that of following generation. Therefore in the burley tobacco, a rapid and convenient means of identifying and removing nornicotine converter plants by the isatin coloration method during growth in the greenhouse or field were effective in reducing the converter plants in the following generation.

• Journal of the Korean Society of Tobacco Science
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• v.13 no.2
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• pp.42-47
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• 1991

Control effect of an avirulent bacterlocin-producing strain(ABPS) Y6l-1 of Pseudomonas solanacearum on bacterial wilt was 58.8 % when the bacterial suspension had poured onto the rhizosphere soil of tobacco cultivar NC82 on one day before transplanting to the field and of hilling time. Until eight weeks after inoculation, survival of the strain on rhizoplane and in stem of the plants inoculated was better than that of other four strains tested. It suggested that survival of the ABPS in and on the plants should be supported for the sufficient protection.

• The Plant Pathology Journal
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• v.20 no.4
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• pp.293-296
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• 2004

During the screening of antiviral substances having inhibitory effects on Tobacco mosaic virus (TMV) infection on tobacco plants, we found a bacterial isolate KTB3, and identified it as Acinetobacter sp. which strongly inhibited the infection of TMV When the culture filtrate from KTB3 was applied on the upper surface of the Xanthi-nc tobacco leaves at the same time, or 24 hours before TMV inoculation, almost complete inhibition was achieved. Likewise, 86% inhibition was achieved, when the culture filtrate was applied on the underside of the leaves. In field trials, transmission of TMV from diseased seedlings to healthy ones during transplanting work was reduced by 92%, when the culture filtrate was sprayed onto the tobacco seedlings, cv. NC82, 24 hours before transplanting. No toxic effect was observed on the tobacco plants. Antiviral substance from the culture filtrate was purified by ethanol precipitation, dialysis, DEAE-cellulose, and Sephadex G75 gel column chromatography. The partially purified active material which showed positive color reaction to sugar and protein inhibited TMV infection by 60% at 1 ${\mu}$g/ml.