• Journal of Plant Biotechnology
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• v.39 no.4
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• pp.295-299
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• 2012

We performed in vitro assay and field trials to assess levels of changes in intrinsic properties and resistance against soft rot of the potato cv. Dejima upon the introduction of a soybean calmodulin 4 gene (SCaM4). Field trials with four lines overexpressing SCaM4 gene were conducted over two seasons, and harvested tubers were evaluated in bioassay for resistance to Pectobacterium carotovorum ssp. carotovorum. The SCaM4 transgenic potato lines inoculated with $10^8$ CFU/ml of P. carotovorum ssp. carotovorum showed enhanced resistance compared to control. Among the SCaM4 transgenic lines, the transgenic line SCaM4-4 exhibited the highest tolerance to soft rot in vitro assays, so did in field trials. In the field trial, the soft rot resistance of SCaM4-4 line was more than 5 times higher compared to that of control cultivar, Dejima. The major agronomic characteristics of the SCaM4 transgenic lines were not different from those of the nontransgenic 'Dejima'. The result demonstrated that the transformation of a calmodulin 4 gene was a successful strategy in development of potato cultivar enhanced to soft rot.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.148.2-149
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• 2003

Cucumber fruit mottle mosaic tobamovirus (CFMMV) causes severe mosaic symptoms with yellow mottling on leaves and fruits, and occasionally severe wilting of cucumber plants. No genetic source of resistance against this virus has been identified. The genes coding for the coat protein or the putative 54-kDa replicase were cloned into binary vectors under control of the SVBV promoter. Agrobacterium-mediated transformation was peformed on cotyledon explants of a parthenocarpic cucumber cultivar with superior competence for transformation. R1 seedlings were evaluated for resistance to CFMMV infection by lack of symptom expression, back inoculation on an alternative host and ELISA. From a total of 14 replicase-containing R1 lines, 8 exhibited immunity, while only 3 resistant lines were found among a total of 9 CP-containing lines. Line 144 homozygous for the 54-kDa replicase was selected for further resistance analysis. Line 144 was immune to CFMMV infection by mechanical and graft inoculation, or by root infection following planting in CFMMV-contaminated soil. Additionally, line 144 showed delay of symptom appearance following infection by other cucurbit-infecting tobamoviruses. Infection of line 144 plants with various potyviruses and cucumber mosaic cucumovirus did not break the resistance to CFMMV. The mechanism of resistance of line 144 appears to be RNA-mediated, however the means is apparently different from the gene silencing phenomenon. Homozygote line 144 cucumber as rootstock demonstrated for the first time protection of a non-transformed scion from soil inoculation with a soil borne pathogen, CFMMV.

• Journal of Life Science
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• v.19 no.7
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• pp.839-844
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• 2009

This experiment was conducted to evaluate pollen viability of Nakdongbyeo, transgenic rice lines, an F$_1$ hybrid from a cross between Milyang weedy rice and ABC-promoter transgenic rice line containing basta-resistant (bar) gene and subsequent selfed progenies, F$_2$ and F$_3$. The reaction of pollen with 3-{4,5 dimethylthiazolyl-2}-2,5-diphenyl monotetrazolium bromide (MTT) as a staining chemical immediately after pollen shedding showed maximum pollen viability of 86% in Nakdongbeyo, 75% in ABC-promoter transgenic rice line, 62% in ubiquitin-promoter transgenic line, 68% in F$_1$, 79% in F$_2$ and 78% in F$_3$. Viability gradually declined during subsequent observations at 20-minute intervals. However, there was a drastic decline in pollen viability after 40 minutes of pollen shedding. The mean difference of pollen viability among rice lines and time was highly significant, indicating significantly different pollen viabilities at different time intervals. Maximum viability of 36.2% was observed in F$_3$ and minimum viability of 3.5% was found in F$_2$ at 90 min after pollen shedding. Results of this experiment on pollen viability and longevity elucidate potential risks of pollen-mediated flow of herbicide-resistant gene from transgenic rice lines and possible integration of it into the weedy rice population.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.58 no.2
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• pp.203-211
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• 2013

Selected 11 rice transgenic lines, through preliminary yield trials on 32 lines, were evaluated on important agronomic traits as well as grain quality by conducting replicated yield trials having three replication plots. Japonica recipients, Nipponbare, Nagdongbyeo, and Dongjinbyeo, were the recipients of 7 transformed genes, which were putatively related with high yield, abiotic stress tolerance, and disease resistance. To estimate the degrees of deviations from the wild types, 11 traits of transgenic lines, relating with grain quality were evaluated and subjected to multivariate analyses. Principal coordinate and clustering analyses did not support collection manners of transgenic lines in terms of the genes transformed as well as the genetic background. Meanwhile, some transgenic lines would be acceptable due to their over-all performances were similar to their wild types, it was hardly possible to declare any transgenic line, which adhered closely to the commercial profits of wild type. Thereby, with considerations on the demanding resources in establishing rice transgenic lines having market competitiveness, it was speculated that proper application of breeding strategies would be crucial factor for the efficiency of developing prospective rice transgenic lines.

• Korean journal of applied entomology
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• v.54 no.1
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• pp.7-15
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• 2015

CpBV (Cotesia plutellae bracovirus) is a polydnavirus and encodes a cystatin (CpBV-CST1) gene. Its overexpression suppresses insect immunity and alters insect developmental processes. This study aimed to construct a genetically modified (GM) tobacco to further explore the physiological function of the viral cystatin and to apply to control insect pests. To this end, the transgenic tobacco lines were screened in expression of the target gene and assessed in insecticidal activity. A recombinant vector (pBI121-CST) was prepared and used to transform a bacterium, Agrobacterium tumefasciens. The transformed bacteria were used to generate transgenic tobacco lines, which were induced to grow callus and resulted in about 92% of shoot regeneration. The regenerated plants were screened by PCR analysis to confirm the insertion of the target gene in the plant genome. In addition, the expression of the target gene was assessed in the regenerated plants by quantitative real-time PCR (qRT-PCR). The qRT-PCR analysis showed that the transgenic line plant expressed the target gene about 17 times more than the control tobacco, indicating a stable insertion and expression of the target gene in the transgenic tobacco line. The insecticidal activity was then analyzed using the screened transgenic tobacco lines against the teneral 1st instar larvae of the oriental tobacco budworm, Helicoverpa assulta. Though there was a variation in the insecticidal efficacy among transgenic lines, T9 and T12 lines exhibited more than 95% mortality at 7 days after feeding treatment. These results suggest that CpBV-CST1 is a useful genetic resource to be used to generate GM crop against insect pests.

• Journal of Microbiology and Biotechnology
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• v.15 no.1
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• pp.91-98
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• 2005

The hyoscyamine 6${\beta}$-hydroxylase (h6h) gene was introduced into the genome of Scopolia parviflora through the Agrobacterium rhizogenes binary vector system. The enzyme was expressed ally and tissue specific selectively in roots, resulting in five transgenic hairy root lines. The presence of the h6h gene in kanamycin-resistant hairy roots and its overexpression were confirmed by polymerase chain reaction (PCR), Northern blotting, and Western blotting, respectively. In the transgenic hairy root lines which constitutively expressed the H6H enzyme, hyoscyamine and scopolamine accumulated in high concentration. Among the transgenic hairy root lines that expressed the H6H enzyme, only two were more productive. The levels of tropane alkaloids in transgenic hairy root varied greatly: The best transgenic line (#5) contained 8.12 mg of scopolamine per g dry weight, which produced the compound three times more than wild-type root. These results suggest a possibility of improving the yield of tropane alkaloids in hairy root lines by genetic and metabolic engineering.

• Horticultural Science & Technology
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• v.29 no.2
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• pp.123-129
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• 2011

To identify unintended vertical gene-transfer rates from the developed transgenic plants, rapid and unequivocal techniques are needed to identify event-specific markers based on flanking sequences around the transgene and to distinguish zygosity such as homo- and hetero-zygosity. To facilitate evaluation of zygosity, a polymerase chain reaction technique was used to analyze a transgenic pepper line B20 (homozygote), P915 wild type (null zygote), and their F1 hybrids, which were used as transgene contaminated plants. First, we sequenced the 3'-flanking region of the T-DNA (1,277 bp) in the transgenic pepper event B20. Based on sequence information for the 3'- and 5'-flanking region of T-DNA provided in a previous study, a primer pair was designed to amplify full length T-DNA in B20. We successfully amplified the full length T-DNA containing 986 bp from the flanking regions of B20. In addition, a 1,040 bp PCR product, which was where the T-DNA was inserted, was amplified from P915. Finally, both full length T-DNA and the 1,040 bp fragment were simultaneously amplified in the F1 hybrids; P915 ${\times}$ B20, Pungchon ${\times}$ B20, Gumtap ${\times}$ B20. In the present study, we were able to identify zygosity among homozygous transgenic event B20, its wild type P915, and hemizygous F1 hybrids. Therefore, this novel zygosity identification technique, which is based on PCR, can be effectively used to examine gene flow for transgenic pepper event B20.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 1997.12a
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• pp.103-103
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• 1997

• Proceedings of the PSK Conference
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• 2000.04a
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• pp.135.2-136
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• 2000

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2001.10b
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• pp.181-181
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• 2001