• Applied Biological Chemistry
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• v.38 no.3
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• pp.224-231
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• 1995

To increase the expression of a foreign protein in transgenic plant, the benefits of 5'-untranslated leader sequences of tobacco mosaic virus (TMV) RNA or soybean glycinin gene, Gy2, fused to a protein coding sequence were exploited. pGA643-derived plasmid contains 355 promoter of cauliflower mosaic virus, protein coding sequence of maize 10 kDa zein (10kZ) and Gy2 terminator. The leader from Gy2 or TMV RNA was inserted between the promoter and the coding sequence in each construct. The recombinant DNAs were introduced into tobacco plants by Agrobacterium mediated leaf disc transformation method. Although the transgene without the leader had more transcripts than the others, mRNAs containing the leader were translated more efficiently. It might be due to difference in the length of 5'-untranslated sequence and context surrounding the AUG codon, but could be sequence specific rather. These results suggest that the leader sequences of Gy2 and TMV play important roles as an enhancer in translational control of foreign gene in transgenic tobacco plant.

• The Plant Pathology Journal
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• v.20 no.3
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• pp.206-211
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• 2004

Transgenic Nicotiana benthamiana plants harboring coat protein (CP) gene of Zucchini green mottle mosaic virus (ZGMMV) were generated for virus-resistant screening and complementation analysis of related viruses for environmental safety assessment (SA) of living modified organism (LMO) purposes. Transformation of leaf disc of N.benthamiana was performed by using Agrobacterium-mediated method and the pZGC-PPGA748 containing the ZGMMV CP and NPTII genes. Two kinds of transgenic homozygous groups, virus-resistant and virus-susceptible N.benthamiana lines, were obtained by screening of challenging homologous virus for Tl generations. These two pathologically different lines can be useful for host-virus interactions and LMO environmental SA.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.54 no.4
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• pp.422-426
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• 2009

Sweetpotato is one of the important starch crops, current more considered as an industrial crop rather than food because it has higher starch content (over 80% of biomass), it is used for bio resources for industrial area. In this study, we generated S598A (a mutant gene of oat phytochrome A) sweetpotato plant using Agrobacterium-transformation method. Morphological characteristics of S598A plant were compared with the wild type sweetpotato, S598A had darker green leaves, increased chlorophyll content higher than to two-fold, delayed leaf senescence, shorter plant height (60% shorter than that of the wild type), more number of leaves and petioles about 1.8-fold, shorter petiole length (30% shorter), 1.2-fold more branches and 1.6-fold thicker stem diameters. From this study, S598A plants with such phenotypic characteristics might be able to use the solar energy efficiently, to have increased tolerance to biotic and abiotic stresses and finally to increase productivity (not only starch yield but also root biomass yield). S598A sweetpotato lines are under field trials.

• Journal of Microbiology and Biotechnology
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• v.12 no.3
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• pp.522-525
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• 2002

A very rapid and efficient separation technique for cellular rhizobial cyclosophoraoses was developed based on fractional precipitation and partition chromatography. Cyclosophoraoses are known to function in the osmotic regulation and root nodule formation of legumes during the nitrogen fixation process. Cyclosophoraoses are produced as unbranched cyclic (1longrightarrow12)-${\beta}$-D-glucans in Agrobacterium or Rhizobium species. Recent research has shown that cyclosophoraoses can form inclusion complexation with various unstable or insoluble guest chemicals, thereby implying great potential for industrial application. Typical separation of pure cellular cyclosophoraoses has been so far carried out by several time-consuming steps, including size exclusion, anion exchange, and desalting liquid chromatographies, with a relatively poor recovery. However, the proposed method demonstrated that the successive application of fractional ethanol precipitation and one step of silica gel-based flash column chromatography was enough to simultaneously purify neutral or anionic forms of cyclosophoraoses. This novel technique is very rapid and provides a high recovery.

• Journal of Microbiology and Biotechnology
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• v.24 no.10
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• pp.1421-1426
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• 2014

Although a large number of AroA enzymes (EPSPS: 5-enopyruvylshikimate-3-phosphate synthase) have been identified, cloned, and tested for glyphosate resistance, only two AroA variants, derived from Agrobacterium tumefaciens strain CP4 and Zea mays, have been utilized to produce the commercial glyphosate-resistant crops. Here, we have used a PCR-based twostep DNA synthesis method to synthesize an aroA gene ($aroA_{A.\;metalliredigens}$) from Alkaliphilus metalliredigens, encoding a new EPSPS. Furthermore, transgenic Arabidopsis with the new $aroA_{A.\;metalliredigens}$ gene was obtained to confirm the potential of the novel aroA gene in developing glyphosate-resistant crops.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.5
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• pp.434-439
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• 2004

Medicago truncatula is a model plant for molecular genetic studies of legumes and plant-microbe interactions. To accelerate finding of genes that play roles in the early stages of nodulation and stress responses, a trans-genic plant was developed that contains a promoter­reporter fusion. The promoter of rip], a Rhizobium-induced peroxidase gene, was fused to the coding region of $\beta-glucuronidase (GUS)$ gene and inserted into a modified plant transformation vector, pSLJ525YN, in which the bar gene was preserved from the original plasmid but the neomycin phosphotransferase gene was replaced by a polylinker. Transformation of M. truncatula was carried out by vacuum infiltration of young seedlings with Agrobacterium. Despite low survival rates of infiltrated seedlings, three independent transformants were obtained from repeated experiments. Southern blot analyses revealed that 7 of 8 transgenic plants of the T 1 generation contained the bar gene whereas 6 $T_1$ plants contained the GUS gene. These results indicate that vacuum infiltration is an effective method for transformation of M. truncatula. The progeny seeds of the transgenic plants will be useful for mutagenesis and identification of genes that are placed upstream and may influence the expression of rip] in cellular signaling processes including nodulation.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2005.11a
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• pp.88-94
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• 2005

Plant tissue culture studies have been done for the preservation of medicinal plant resources and efficient production of pharmaceutically important secondary metabolites. Micropropagation methods for Cephaelis ipecacuanha have been established and these methods enabled much more efficient propagation of the plants than the conventional methods using seedling or layering. The C. ipecacuanha plants derived from tissue culture grew uniformly in the field and they showed higher alkaloid contents compared to the plants grown from seedlings. Hairy root cultures of C. ipecacuanha and Panax ginseng have been established by infection with Agrobacterium rhizogenes, and the production of important pharmaceuticals by these cultures have been successfully demonstrated. In the case of C. ipecacuanha, the highest alkaloid yields from the hairy roots cultured for 8 weeks were 2.75-fold cephaeline (5.5 mg) and one third emetine (0.7 mg) compared with those from the roots of one-year old plant propagated through shoot-tip culture and cultivated in a greenhouse (2.0 mg cephaeline and 2.0 mg emetine). In the case of P. ginseng, ginsenoside contents in the hairy roots optimally cultured for 4 weeks were much higher than those in the roots of 4-year old field-grown plant. Thus our medicinal plant tissue cultures demonstrate desirable properties. However, they are always exposed to danger of microbial contamination or unexpected trouble of culture facilities. Cryopreservation of plant tissue cultures is a reliable method for long-term preservation. Cryopreservation studies on these cultures are also presented.

• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.2
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• pp.154-159
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• 2006

Interleukin-18 (IL-18), otherwise known as interferon-gamma-inducing factor (IGIF), is one of several well characterized and important cytokines that contribute to host defenses. The complementary DNA (cDNA) of mature human interleukin-18 gene (hIL-18) was fused with the signal peptide of the rice amylase 1A gene (Ramy1A) and introduced into the plant expression vector under the control of a duplicated CaMV 35S promoter. The recombinant plasmid was transformed into tobacco (Nicotiana tabacum L. cv Havana) using the Agrobacterium-mediated transformation method. The integration of the hlL-18 gene into the genome of transgenic tobacco plants was confirmed by polymerase chain reaction (PCR) amplification and its expression was observed in the suspension cells that were derived from the transgenic plant callus by using Northern blot analysis. The hlL-18 protein was detected in the extracts of the transgenic callus and in the medium of the transgenic tobacco suspension culture by using immunoblot analysis. Based upon enzyme-linked immunosorbant assay (ELISA) results, the expression level of the hlL-18 protein approximated $166{\mu}g/L$ in the suspension culture medium. Bioassay results from the induction of $interferon-{\gamma}$ from a KG-1 cell line indicated that the hlL-18 secreted into the suspension culture medium was bioactive.

• Plant Biotechnology Reports
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• v.2 no.4
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• pp.227-231
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• 2008

D-class cyclins play important roles in controlling the cell cycle in development and in response to external signals by forming the regulatory subunit of cyclin-dependent kinase (CDK) complexes. To evaluate the effects of D-class cyclins in transgenic rice plants, Arabidopsis cyclin D2 gene (CycD2) was linked to the maize ubiquitin1 promoter (Ubi1) and introduced into rice by the Agrobacterium-mediated transformation method. Genomic deoxyribonucleic acid (DNA), ribonucleic acid (RNA), and Western blot hybridizations of the Ubi1:-CycD2 plants revealed copy number of transgene and its increased expression in leaf and callus cells at messenger RNA (mRNA) and/or protein levels. The H1 kinase assay using the immunoprecipitates of protein extracts from the Ubi1:CycD2 plants and nontransgenic controls demonstrated that the introduced Arabidopsis CycD2 forms a functional CycD2/CDK complex with an unidentified CDK of rice. Shoot and root growth was enhanced in the Ubi1:CycD2 seedlings compared with nontransgenic controls, together, suggesting that Arabidopsis cyclin D2 interacts with a rice cyclin-dependent kinase, consequently enhancing seedling growth.

• Journal of The Korean Society of Grassland and Forage Science
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• v.18 no.1
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• pp.69-76
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• 1998

This study was conducted to construct of the transgenic plants wliich are resistant to oxidative stresses including ozone with B. mpestris cytosolic glutathione reductase cDNA using the binary vector system of Agrobacterium tumefaciens. The 1.8kb B. campestris cytosolic GR cDNA was subcloned into the unique Sma I site of the plant transformation vector pBKSI- I, downstream of the constitutive CaMV 35s promoter and upstream of the nos termination sequence, in place of the uidA (GUS) reporter gene. The resulting plant transformation vector, pBKS-GRI, was introduced into A. tumefaciens LBA4404 by two cycles of tkeze-thaw method. The B. nqus cotyledonary petioles were transformed by the Agrubaferium harboring pBKS-GRI. Transformed shoots were induced and selected on regeneration medium supplemented with kanarnycin. The shoot formation was increased remarkably by addition of Ag$NO_3$, in MS media. The transgenic plants were analyzed for the presence of the B. campestris GR gene by Southern blot analysis and it was confirmed that a foregin gene was stably integrated into the genomes of B. nqus plants.