• Journal of Environmental Impact Assessment
• /
• v.22 no.2
• /
• pp.125-134
• /
• 2013

Plant virus coat (CP) gene-mediated protection is one of the best known approaches to protect against virus resistant transgenic plants. Transgenic N. benthamiana plants containing the CP gene of Zucchini green mottle mosaic virus (ZGMMV) were used for the environmental risk assessment of the living modified (LM) plants with plant virus resistance. The most optimal co-infection method of both ZGMMV and CMV (Cucumber mosaic virus) on Non-LM and CP-expressing LM tobacco plants was established and co-infection of CMV and ZGMMV was confirmed by polymerase chain reaction (PCR). To address the effects of LM tobacco plants on the mutation of the virus, in-vitro transcripts of CP and Replicase (Rep) derived from CMV and/or ZGMMV were inoculated onto Non-LM or LM tobacco plants. Mutation frequency of CP and Rep from CMV and ZGMMV was examined through six serial passages in Non-LM and LM tobacco plants. Little actual frequency of mutation was estimated, probably due to the limited number of transgenic plants tested in this study. However, it does not suggest environmental safety of these CP-mediated LM plants. Further study at a larger scale is needed to evaluate the environmental risk associated with the CP-expressing LM plants.

• Journal of Plant Biotechnology
• /
• v.31 no.2
• /
• pp.175-178
• /
• 2004

Transgenic tobacco (Nicotiana tabacum L. cv Bright Yellow-2) cell lines expressing a human histone H1.5 (referred to as hH1.5), which suppress collagen-induced rheumatoid arthritis, were developed under the oxidative stress-inducible peroxidase (SWPA2) promoter. Tobacco BY-2 cells were transformed by Agrobacterium-mediated method. The kanamycin-resistant calli were selected on the modified MS medium containing 150mg/L kanamycin and 300mg/L claforan. Transgenic cell lines were confirmed by PCR and northern blot analysis. Recombinant hH1.5 (rhH1.5) protein (42 kDa) was also detected by Western blot analysis, showing a different molecular weight of human hH1.5 (32 kDa). These results suggested that a hH1.5 gene was properly introduced in tobacco cultured cells under the control of SWPA2 promoter. The further characterization of rhH1.5 protein remains to be studied.

• Journal of Life Science
• /
• v.14 no.4
• /
• pp.657-663
• /
• 2004

Tobacco transformants harboring cinnamic acid 4-hydroxylase gene (C4H) fused with susquiterpene cyclase promoter was developed in order to regulate biosynthesis of phenolic compounds by the expression of the introduced gene. Twenty transformants for each specific promoter were used to analyze the incorporation of the chimeric genes by PCR and Southern blot analysis. PCR products of NPTII(neomycin phosphotransferase) gene (553bp) were detected in the transgenic tobacco plants. The incorporation of the chimeric gene was confirmed in the Southern blot analysis. C4H activity in the transgenic plants was elevated by UV-irradiation and its level was higher compared to that of control plants.

• Journal of Bio-Environment Control
• /
• v.11 no.3
• /
• pp.139-143
• /
• 2002

Cotton Glutathione S-Transferase (GST: EC 2.5.1.18) was cloned and overexpressed in tobacco (Nicotiana tabacum) plants. Northern blot analysis confirmed the successful transformation of cotton gst gene in tobacco plant. Type I and Type ll transcript patterns were identified in transgenic tobacco plants and only Type I transcripts were discussed in this paper, The activity of GST in the type II transgenic plants was about 1.5-fold higher than those of the wild type and non-expresser by using 1-chloro-2,4-dinitrobenzene (CDNB) and reduced glutathione as the substrate. The expression of cotton GST in tobacco plants proved that Gh-5 could be translated into functional protein. Type II transgenic plants produced functional GST in the cells. The effects of cotton GST in the seedlings was evaluated by growing the control and transgenic seedlings at $15^{\circ}C$ in the growth chamber in the light. Overexpressors were grown well compared to the control plants (non-expressors). lo test far tolerance to salinity, seeds of Gh-5 overexpressors and the wild type Xanthi seedlings were grown at 0, 50, 100, 150, and 200 mM NaCl solution. Gh-5 transgenic seedlings showed higher growth rate over control seedlings on 50 and 100 mM NaCl solution. There was no difference in growth rate at 150 and 200mM NaCl concentration.

• Applied Biological Chemistry
• /
• v.39 no.5
• /
• pp.355-360
• /
• 1996

In vitro-tested ribozyme against synthesized cucumber mosaic virus (CMV) RNA (Agric. Chem. & Biotech. 37:56-63(1994)) was expressed in tobacco plant to develop virus resistant plants. The ribozyme sequence was linked to cauliflower mosaic virus 35S promoter and nopaline synthase(nos) terminator and this chimeric 35S-ribozyme-nos gene was sequenced. The sequenced chimeric gene was transferred to Agrobacterium tumefaciens LBA4404 using tri-parental mating system. The E. coli HB101 containing chimeric gene was incubated with E. coli HB101(pRK2073) as a helper and Agrobacterium tumefaciens LBA4404. Then Agrobacterium cells containing the ribozyme construct was cocultivated with tobacco leaf pieces. Ten different plants were regenerated from kanamycin containing MS medium. The presence of the ribozyme construct in the transgenic tobacco plants was confirmed by polymerase chain reaction (PCR). Seven different transgenic plants in ten different kanamycin resistant plants showed the expected size (570 base pairs) of 35S-ribozyme-nos gene fragment. Total RNAs were isolated from four different transgenic plants and separated on a 1% agarose gel containing formamide. Northern hybridization with 35S-ribozyme-nos gene fragment as a probe indicated that ribozyme transcripts may be degraded tv nuclease. Therefore, nuclease-resistant ribozymes are needed for the development of virus-resistant transgenic plants using ribozymes.

• Research in Plant Disease
• /
• v.8 no.2
• /
• pp.78-83
• /
• 2002

Tobacco diseases have not been recorded until 1900s in Korea, where tobacco plants were introduced at early 1700s. Practical researches on the disease have been conducted since mid 1960s. Major ten tobacco diseases were mosaic caused by tobacco mosaic virus·potato virus Y·cucumber mosaic virus, bacterial wilt, hollow stalk, wild fire caused by angular leaf spot strain, black shank, brown spot, powdery mildew and fusarium wilt. But their annual occurrences were varied according to changes of tobacco varieties and their cultivating practices. As no useful chemicals, several biological tactics have been developed to control the viral or bacterial diseases that give significant economic damages on sustainable crop yield, but not practicable to field farming condition yet. Transgenic tobacco plants containing foreign disease resistant genes have been developed by current bio-technology, but not released to farmers yet. Though some disease-resistant tobacco varieties have been developed by the conventional breeding technology and currently used by farmers, their disease controlling efficacy have been diminished by occurrence of the new strain or race. Future research on tobacco diseases has been focused on technical development to produce high quality tobacco with less production cost, which leads Korean tobacco industry to keep its competence against foreign industry and decreasing overall market.

• Horticultural Science & Technology
• /
• v.31 no.6
• /
• pp.748-755
• /
• 2013

This study was conducted to find a salt tolerance gene in Brassica rapa. In order to meet this objective, we analyzed data from a KBGP-24K oligo chip [BrEMD (Brassica rapa EST and microarray database)] of the B. rapa ssp. pekinensis 'Chiifu' under salt stress (250 mM NaCl). From the B. rapa KBGP-24K microarray chip analysis, 202 salt-responsive unigenes were primarily selected under salt stress. Of these, a gene with unknown function but known full-length sequence was chosen to closely investigate the gene function. The selected gene was named BrSSR (B. rapa salt stress resistance). BrSSR contains a 285 bp open reading frame encoding a putative 94-amino acid protein, and a DUF581 domain. The pSL94 vector was designed to over-express BrSSR, and was used to transform tobacco plants for salt tolerance analysis. T1 transgenic tobacco plants that over-expressed BrSSR were selected by PCR and DNA blot analyses. Quantitative real-time RT PCR revealed that the expression of BrSSR in transgenic tobacco plants increased by approximately 3.8-fold. Similar results were obtained by RNA blot analysis. Phenotypic characteristics analysis showed that transgenic tobacco plants with over-expressed BrSSR were more salt-tolerant than the wild type control under 250 mM NaCl for 5 days. Based on these results, we hypothesized that the over-expression of BrSSR may be closely related to the enhancement of salt tolerance.

• Proceedings of the Korean Society of Plant Pathology Conference
• /
• 2003.10a
• /
• pp.75.2-75
• /
• 2003

To develop an effective protection strategy against tomato bushy stunt virus (TBSV), tobacco plants expressing single-chain Fv antibodies (scFv), were established. A previous had shown that the replication activity of viral replicase was inhibited by the selected scFvs. Moreover, no systemic symptom was found after virus inoculation on leaves of wt N. benthamiana infiltrated with an Agrobacterium suspension resulting i3l expression of the scFvs. However, control plants showed systemic symptoms. In this study the localization of the scFvs within two transgenic plant lines, (CP28H3, CP-P55) was demonstrated using immunogold labelling. The gold particles, indicating the presence of scFv, were mostly found In the cytoplasm of the plant cells including chloroplasts and in the cell walls. However, they were hardly found in the vacuole, nucleoplasm and intercellular spaces. Gold particles often accumulated in either the cytosol or chloroplasts showing a specific labeling, There was no difference in type of gold labeling between both transgenic lines. The localization of the scFv in the cytoplasm further conforms the inhibition of the RNA-dependent RNA polymerase (RdRp) by the selected scFv because it is known that the RdRp is localized to membraneous cytosolic structures.

• Korean Journal of Plant Tissue Culture
• /
• v.26 no.4
• /
• pp.265-269
• /
• 1999

Transgenic tobacco plants expressing either a sweet potato anionic peroxidase (POD) (swpal) or neutral POD (swpnl) were irradiated by gamma radiation, and the gamma radiation-induced biochemical changes in antioxidant enzymes and plant growth inhibition were investigated at 30 days after treatment. Gamma radiation significantly inhibited the growth of all plants regardless of transgenic or nontransformed plants, showing a dose-dependent inhibition. In high dosage of 50 and 70 Gy, plant heights were severely retarded and new leaves does not emerged. No significant changes in antioxidant enzymes such as POD, superoxide dismutase and catalase were observed in all plants regardless of irradiation dosages ranging from 10 to 50 Gy. These results suggest that sweet potato PODs may be not involved in the protection against the oxidative stress induced by gamma radiation.

• Korean Journal of Plant Tissue Culture
• /
• v.25 no.2
• /
• pp.89-93
• /
• 1998

Tomato phenylalanine ammonia-lyase 5 (tPAL5) was identified that alternate initiation sites were utilized differentially in response to environmental stimuli (Lee et al, 1992b). In this study, we tried to look into tissue -or cell- specific expression pattern of tPAL5 gene by fusing with ${\beta}-glucuronidase$ (GUS) gene in transgenic tobacco plants. In transgenic plants, root and stem extracts contained 8~12 fold higher levels of GUS activity than petiole or leaf tissue while the highest levels of induction was observed from leaf tissue by mechanical wounding (5~11 fold). In trans-sections of stems and petioles, GUS activity was restricted to phloem cells(outer region) of developing vascular bundle and mainly at apical tip region in the root tissues. The levels of GUS activity was drastically reduced (10~12 fold reduction) when the 5'-upstream region of tPAL5 gene (-1151bp from ATG codon) was deleted up to -665. The levels of GUS expression, however, raised up by 6~8 fold when deleted up to -455. Therefore, we conclude that there are positive cis-elements at the region -1151 to -1008 and at -455 to -195 while the negative cis-element is at -1008 to -455.