• Journal of Plant Biotechnology
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• v.34 no.1
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• pp.31-36
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• 2007

Though higher plants car not metabolize D-amino acid, many prokaryotes and eukaryotes have the D-amino acid metabolism. Therefore, we transformed tobacco plants with D-amino acid oxidase (DAO), which can metabolize D-amino acid, and confirmed that transgenic tobacco plants might metabolize D-amino acid. Transgenic tobacco plants were survived a high concentration of D-serine, however non-transgenic plants were not grown on D-serine medium. From Southern and Northern blot analysis, transgenic tobacco plants selected on D-serine medium were confirmed by insert and expression of transgene. $T_{1}$ tobacco seeds derived $T_{0}$ tobacco plants selfing were grown on D-serine medium and showed normal phenotype compared to wild tobacco plants. Transgenic tobacco plants displayed the metabolic capability of D-serine. Therefore, we suggested that DAO is useful selectable marker gene for plant transformation.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.1
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• pp.53-57
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• 2011

The MuSI is known as a multiple stress resistant gene with several lines. A previous study using RT-PCR showed that the expression of MuSI gene in tobacco plant induced its tolerance to Cd stress. This study was conducted to examine the enhanced Cd tolerance of the MuSI transgenic tobacco plant through germination test and to understand the role of the involved antioxidant enzymes for the exhibited tolerance. Germination rate of MuSI transgenic tobacco was more than 10% higher than that of wild-type tobacco, and seedlings of MuSI transgenic tobacco grew up to 1.6 times larger and greener than seedlings of wild-type tobacco at 200 and 300 ${\mu}M$ Cd. From the third to the fifth day, CAT activities at 100 and 200 ${\mu}M$ Cd and APX activities at 100, 200 and 300 ${\mu}M$ Cd of MuSI transgenic tobacco were up to two times higher than those of wild-type tobacco. MuSI gene is shown to enhance the activities of antioxidant enzymes resulting in higher tolerance to oxidative stress compared with the control plant.

• Plant Biotechnology Reports
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• v.5 no.1
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• pp.61-69
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• 2011

The dehydration-responsive element binding proteins (DREB1)/C-repeat (CRT) binding factors (CBF) function as transcription factors and play an important role in agricultural biotechnology and molecular biology studies of drought and freezing stress tolerance. We generated transgenic Lolium perenne plants containing the PCR-cloned Arabidopsis DREB1A/CBF3 gene (AtDREB1A/CBF3) to study the function of this gene construct in drought and freezing tolerance in a species of turfgrass. Compared to the control, AtDREB1A/CBF3 transgenic L. perenne plants showed enhanced drought and freezing stress tolerance. The activities of the enzymes superoxide dismutase (SOD) and peroxidase (POD) were higher in transgenic plants than in the non-transgenic plant control. These results demonstrate that the expression of the AtDREB1A/CBF3 gene in transgenic L. perenne plants enhanced drought and freezing tolerance and that the increased stress tolerance was associated with the increased activities of antioxidant enzymes. These results are relevant to stress biology and biotechnology studies of turfgrass.

• Journal of Plant Biotechnology
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• v.6 no.3
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• pp.145-150
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• 2004

Cabbage plants were transformed with the potato proteinase inhibitor II (PINII) gene, bar gene, and hpt gene using Agrobacterium. The expression of the PINII gene was driven by its own promoter which was wound-inducible. Ten transgenic plants were obtained from medium containing hygromycin as a selection antibiotic. The integration and expression of PINII and bar genes were confirmed by Southern and Northern hybridization. Growth and development of diamondback moths (Plutella xylostella) and tobacco cutworm (Spodoptera litura) larvae were examined on $T_1$ plants. The weight of the larvae and pupae of these two insects grown on transgenic plants was not different compared to those grown on wild type plants. However, the pupation and emergence rate of diamondback moths and tobacco cutworms fed on some transgenic plants was lower than on wild type plants. These results suggest that the PINII transgene under the control of a wound-induced promoter may be used for control of insects in transgenic cabbage through reduction of insect progeny number.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.121.2-122
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• 2003

Since the demonstration that the transgenic plants expressing tobacco mosaic virus(TMV) coat protein(CP) gene showed resistance to TMV infection, there have been numerous attempts to produce virus-resistant plant by introducing of a part of or modified viral genome. This study was conducted to investigate the characterization and variability of disease outbreak of transgenic potato(T-potato) with the CP gene of potato leaf roll virus(PLRV) in an isolated field from 2000 to 2002. In the field inspection, incidence of PLRV on T-potato showed only 3.5％, while non-transgenic potato(N-potato) revealed 13.4％. Infection rate of PLRV was considerably low on T-potato with 4.2％ compared to 15.4％ of N-potato in ELISA tests. Those of potato virus M, potato virus Y and potato virus X on both potatoes were not statistically different. Infection of potato virus A was not observed on both potatoes. Incidence of potato late blight caused by Phytopkhora infestans on T-potato and N-potato did not differ each other with 52.7％, and 50.8％, respectively, Mating type of the causal fungus isolated from both potatoes was all Al types. Results indicates that the CP gene of PLRV affects specifically to the virus in the transgenic potato.

• Korean Journal of Plant Tissue Culture
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• v.24 no.4
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• pp.225-231
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• 1997

For genetic engineering to be commercially viable, an efficient transformation system is needed to produce transgenic plane from diverse genotypes ("generalized protocol"). Development of such a system requires optimization of a number of components such as gene transfer agent, plant tissues competent for both regeneration and transformation, and control of transgene expression. Although several novel gene transfer methods have been developed for plane, a majority of stably transformed plane express the introduced genes at low levels. Moreover, silencing of selectable marker genes shortly after their incorporation into plant chromosomes may result in low recovery of transgenic tissues from selection. Matrix attachment regions (MARs) are DNA sequences that bind to the cell's proteinaceous nuclear matrix to form DNA loop domains. MARs have been shown to increase transgene expression in tobacco cells, and reduce position in mature transgenic plants. Flanking an antibiotic resistance transgene with MARs should therefore lead to improved rates of transformation in a diversity of species, and may permit recalcitrant species and genotypes to be successfully transformed. Literature review and recent data from my laboratory suggest that MARs can serve as a transformation booster in recalcitrant plant species.

• Journal of Life Science
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• v.7 no.3
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• pp.176-179
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• 1997

Environmental risk evaluation of transgenic Brassica napus introduced with glufosinate$.$ammonium-tolerance gene was carried out in a field. It is revealed that there was no difference between transgenic and non-transgenic B. napus for characteristics of ecology and morphology. Transgenic plants did not fertilize to any related Brassica species.

• Journal of Plant Biotechnology
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• v.7 no.4
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• pp.233-240
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• 2005

Slices of embryonic axis of mature pea (Pisum sativum L. cv. Green Arrow) seeds were used as explant. Transformation of explants was done via Agrobacterium tumefaciens bearing vector pBI-P5CS construct. The best results for inoculation of explants were obtained when they were immersed for 90 s at a concentration of $6{\times}10^8$ cell $ml^(-1)$ of bacterial suspension. Transformed pea plants were selected on $50\;mg\;l^(-1)$ kanamycin and successful transformants were confirmed by PCR and blotting. Transgenic plants were further analyzed with RT-PCR to confirm the expression of P5CS. Transgenic plants and non-transgenic plants were treated with different concentrations of NaCl 0 (control), 100, 150 and 200 mM in culture medium. Measurement of proline content indicated that transgenic plants produced more amino acid proline in response to salt in comparison with non-transgenic plants. Photosynthetic efficiency in transgenic plants under salt-stress was more than that of non-transgenic plants.

• BMB Reports
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• v.29 no.4
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• pp.308-313
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• 1996

An 1.4 kb of the fad3 cDNA encoding microsomal linoleic acid desaturase catalyzing the conversion of linoleic acid (18:2, ${\omega}-6$) to linolenic acid (18:2, ${\omega}-3$) was introduced into tobacco plants by the Agrobacterium-mediated plant transformation, Among the transgenic tobacco plants conferring kanamycin resistance, five transformants showing increment in unsaturated fatty acid contents were selected and further analyzed for the transgenecity, In genomic Southern blot analyses, copy numbers of the integrated fad3 DNA in chromosomal DNA of the five transgenic tobacco plants were varied among the transgenic lines. By Northern blot analyses, the abundancy of the fad3 mRNA transcript directed by Cauliflower Mosaic Virus 35S promoter was consistent with the relative copy number of the fad3 DNA integrated in the chromosome of transgenic tobacco plants. When compared with the wild type, accumulation of linolenic acid in transgenic tobacco roots was elevated 3.7- to 4.7-fold showing a corresponding decrease in the linoleic acid contents; however, slight increments for linolenic acid were noticed in transgenic leaf tissues. These results indicated that the elevated level of fad3 expression is achieved in transgenic tobacco plants.

• Molecules and Cells
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• v.26 no.2
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• pp.131-139
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• 2008

Expression of the seven open reading frames (ORFs) of single-stranded DNA Curtoviruses such as Beet curly top virus (BCTV) and Beet severe curly top virus (BSCTV) is driven by a bi-directional promoter. To investigate this bidirectional promoter activity with respect to viral late gene expression, transgenic Arabidopsis plants expressing a GUS reporter gene under the control of either the BCTV or BSCTV bi-directional promoter were constructed. Transgenic plants harboring constructs showed higher expression levels when the promoter of the less virulent BCTV was used than when the promoter of the more virulent BSCTV was used. In transgenic seedlings, the reporter gene constructs were expressed primarily in actively dividing tissues such as root tips and apical meristems. As the transgenic plants matured, reporter gene expression diminished but viral infection of mature transgenic plants restored reporter gene expression, particularly in transgenic plants containing BCTV virion-sense gene promoter constructs. A 30 base pair conserved late element (CLE) motif was identified that was present three times in tandem in the BCTV promoter and once in that of BSCTV. Progressive deletion of these repeats from the BCTV promoter resulted in decreased reporter gene expression, but BSCTV promoters in which one or two extra copies of this motif were inserted did not exhibit increased late gene promoter activity. These results demonstrate that Curtovirus late gene expression by virion-sense promoters depends on the developmental stage of the host plant as well as on the number of CLE motifs present in the promoter.