• Korean Journal of Breeding Science
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• v.49 no.3
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• pp.180-189
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• 2017

Genetically modified (GM) crops have been developed worldwide through the recombinant DNA technology and commercialized by global agricultural companies. Until now, GM crops have not been cultivated commercially in Korea. Commercialization of GM crops requires a compulsory assessment of environmental risk associated with the release of GM crops. This study was conducted to evaluate the frequency of pollen mediated gene flow from Bt transgenic rice (Agb0101) to japonica non-GM rice (Nakdongbyeo), indica non-GM rice (IR36), and weedy rice (R55). A total of 729,917, 596,318 and 230,635 seeds were collected from Nakdongbyeo, IR36, and R55, respectively, which were planted around Agb0101. Selection of the hybrids was determined by repeated spraying of herbicide and Cry1Ac1 immunostrip assay. Finally, the hybrids were confirmed by PCR analysis using specific primer. The hybrids were found in all non-GM rice and out-crossing ranged from 0.0005% at IR36 to 0.0027% at Nakdongbyeo. All of hybrids were located within 1.2 m distance from the Agb0101 rice plot. The meteorological elements including rainfall and temperature during rice flowering time were found to be important factors to determine rice out-crossing rate. Consideration should be taken for many factors like the meteorological elements of field and physiological condition of crop to set up the safety management guideline to prevention of GM crops gene flow.

• Korean Journal of Medicinal Crop Science
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• v.15 no.4
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• pp.285-290
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• 2007

This study was conducted to introduce phosphinothricin acetyl transferase (PAT) gene, resistant to basta which was non-selective herbicide, into balloon flower (Platycodon grandiflorum A. De. candolle). Seeds were germinated on MS medium, and 10-day-old immature cotyledon explants and 30-day-old leaf explants were cocultured with Agrobacterium tumefaciens strain MP 90 (pBinSyn) on 1/10 MS medium for 48 hours in the dark at $25^{\circ}C$. The cultures were transferred for selection of kanamycin-resistant shoots to the MS medium supplemented with 0.2 $mg/{\ell}$ NAA, 1.0 $mg/{\ell}$ BA, 3% sucrose, 100 $mg/{\ell}$ kanamycin, 500 $mg/{\ell}$ carbenicillin. Shoots were obtained from 10-day-old immature cotyledon explants after 4 weeks of culture. The shoots were subcultured twice every 4 weeks on the same medium for growth of transgenic shoots. Successful transformation was confirmed by histochemical GUS assay, PCR analysis, RT-PCR analysis, 10 $mg/{\ell}$ phosphinothricin treatment and 0.3% basta spray. The basta-resistant transgenic plants flowered normally.

• Korean Journal of Environmental Agriculture
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• v.32 no.2
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• pp.148-154
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• 2013

BACKGROUND: Genetically modified(GM) trigonal cactus(Hylocereus trigonus Saff.) contained a coat protein gene of cactus virus X (CVX), which conferred resistance to the virus, phosphinothricin acetyltransferase (bar) gene, which conferred herbicide resistance, and a cauliflower mosaic virus 35S promoter (CaMV 35S). This study was conducted to evaluate the possible impact of GM trigonal cactus cultivation on the soil microbial community. METHODS AND RESULTS: Microorganisms were isolated from the rhizosphere of GM and non-GM trigonal cactus cultivation soils. The total numbers of bacteria, and actinomycete in the rhizosphere soils cultivated GM and non-GM trigonal cactus were similar to each other, and there was no significant difference. Dominant bacterial phyla in the rhizosphere soils cultivated with GM and non-GM trigonal cactus were Proteobacteria, Uncultured archaeon, and Uncultured bacterium. The denaturing gradient gel electrophoresis (DGGE) profiles show a similar patterns, significant difference was not observed in each other. DNA was isolated from soil cultivated GM and non-GM trigonal cactus, we analyzed the persistence of the inserted gene by PCR. Amplification of the inserted genes was not observed in the soil DNA, which was collected after harvest. CONCLUSION(S): This result suggests that the GM trigonal cactus cultivation does not change significantly the microbial community.

• Korean Journal of Microbiology
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• v.33 no.1
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• pp.1-6
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• 1997

5-Enolpyruvylshikimate 3-phosphate(EPSP) synthase is the sixth enzyme of the shikimate pathway that synthesizes aromatic amino acids. The enzyme is a primary target for the glyphos'lte which is a broad-spectrum and environmetally safe herbicide. As a first step toward development of glyphpsate-resistant EPSP synthase, the EPSP synthase gene(aroA) was amplified by polymerase chain reaction and cluned into pET-25b vector. In this construct. designated pET-aro, the aroA gene is expressed under control of strong T7 promoter. and the EPSP synthase is produced as a fusion protein with pelB leader at N-terminus and HSV-tag and His-tag at C-terminus. When the pET-aro clone was induced to produce the enzyme, it was found that the EPSP synthase was successfully exported to peri plasmic space. The periplasmic transport was greatly dependent on the induction temperatures. Among the induction temperatures examined($25^{\circ}C$, $30^{\circ}C$, $34^{\circ}C$ and $37^{\circ}C$). induction at $34^{\circ}C$ gave rise to maximal periplasmic transport. The recomhinant EPSP synthase could have been purified hy $Ni^{2+}$ -affinity chromatography using the His-tag. and detected hy anti-HSV -tag antibody. The recombinant EPSP synthase also hound to phosphocellulose resin and was eluted hy shikimate 3-phosphate and phosphoenolpyruvate. as expected. The recombinant EPSP synthase purified from phosphocellulose resin showed typical EPSP synthase activity.

• Journal of Applied Biological Chemistry
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• v.54 no.1
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• pp.26-32
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• 2011

To improve genetic transformation of Brassica napus winter cultivar 'Youngsan', factors influencing shoot regeneration and transformation from cotyledonary petioles were investigated. Shoot induction was enhanced in the combination of 0.5 mg/L NAA and 2~4 mg/L kinetin. Silver nitrate was essential for successful shoot regeneration, ranging from 5 to 9 mg/L. The addition of $GA_3$ promoted plant regeneration. Among the tested Agrobacterium strains, co-cultivation times, and antibiotic selection regimes, choice of appropriate Agrobacterium strain was the most critical factor for efficient transformation of B. napus cv. 'Youngsan'. The EHA105 succinamopine strain was the most efficient and the maximum transformation efficiency was 26.8%. Transgenic shoots were selected on 10 mg/L phosphinothricin (PPT) containing media. The transgenic plants expressing bar and gus genes were resistant for commercial herbicide "Basta" and stained with X-Gluc. Southern blot hybridization indicated that the presence of one to three gus gene copies per genome and inheritance of the gus gene into the $T_1$ generation.

• 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.

• Horticultural Science & Technology
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• v.29 no.3
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• pp.247-254
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• 2011

The agronomic characteristics, nutritional contents, and insect response of the potato clones transformed with a glufosinate ammonium resistance gene were evaluated. Among the 4 transgenic potato clones, the Bar 3 clone was selected as a promising one for commercialization. The Bar 3 clone showed similar tuber yield capacity but higher herbicide resistance as compared with the non-transgenic potato cv. Dejima. The herbicide resistance of the Bar 3 clone was more than 5 times higher when tested with the herbicide concentration recommended by the producer. The major agronomic characteristics of the Bar 3 clone were not different from those of the non-transgenic Dejima. The annual variation in yields and agronomic characteristics showed similar tendency for 2 years from the third to fourth generation after transformation. The tubers of the Bar 3 clone also showed low occurrence in common scab and physiological disorders such as cracking and secondary growth. But the reasons for such results are yet to be studied. Also, it was considered that the Bar 3 clone have a potential of reducing not only common scab occurrence but also soil erosion during potato cultivation in field. The nutritional contents (mineral compound, vitamin C and amino acid) and response to Spodoptera exigua of the transgenic potato clones were not significantly different.

• Journal of Plant Biotechnology
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• v.34 no.4
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• pp.347-354
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• 2007

Commercialization of genetically modified (GM) plants will be required the assessment of risks associated with the release of GM plants that should include a detailed risk assessment of their impacts in human health and the environment. Prior to GM plant release, applicants should provide the information on GM crops for approval. We carried out this study to provide the molecular data for risk assessment of the GM Chinese cabbage plants with insect-resistance gene, modified CryIAc, which we obtained by Agrobacterium-transformation. From the molecular analysis with GM Chinese cabbage, we confirmed the transgene copy number and stability, the expression of the transgene, and integration region sequences between the transgene and the Chinese cabbage genome. Based on the unique integration DNA sequences, we designed specific primer set to detect GM Chinese cabbage and set up the GM cabbage detection method by qualitative PCR analysis. Qualitative analysis with GM Chinese cabbage progenies analysis was revealed the same as the result of herbicide treatment. Our results provided the molecular data for risk assessment analysis of GM Chinese cabbage and demonstrated that the primer set proposed could be useful to detect GM Chinese cabbage.

• Korean Journal of Weed Science
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• v.30 no.2
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• pp.122-134
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• 2010

We investigated the levels of resistance and accumulation of terapyrroles, reactive oxygen species, lipid peroxidation, and antioxidative enzymes for reasons of growth reduction in herbicide-transgenic rice overexpressing Myxococcus xanthus, Arabidopsis thaliana, and human protoporphyrinogen oxidase (Protox) genes. The transgenic rice overexpressing M. xanthus (MX, MX1, PX), A. thaliana (AP31, AP36, AP37), and human (H45, H48, H49) Protox genes showed 43~65, 41~72 and 17~70-fold more resistance to oxyfluorfen, respectively, than the wild type. Among transgenic rice lines overexpressing Protox genes, several lines showed normal growth compared with the wild type, but several lines showed in reduction of plant height and shoot fresh weight under different light conditions. However, reduction of plant height of AP37 was much higher than other lines for the experimental period. On the other hand, the reduction of plant height and shoot fresh weight in the transgenic rice was higher in high light condition than in low light condition. Enhanced levels of Proto IX were observed in transgenic lines AP31, AP37, and H48 at 7 days after seeding (DAS) and transgenic lines PX, AP37, and H48 at 14 DAS relative to wild type. There were no differences in Mg-Proto IX of transgenic lines except for H41 and H48 and Mg-Proto IX monomethyl ester of transgenic lines except for MX, MX1, and PX. Although accumulation of tetrapyrrole intermediates was observed in transgenic lines, their tetrapyrrole accumulation levels were not enough to inhibit growth of transgenic rice. There were no differences in reactive oxygen species, MDA, ALA synthesizing capacity, and chlorophyll between transgenic lines and wild type indicating that accumulated tetrapyrrole intermediate were apparently not high enough to inhibit growth of transgenic rice. Therefore, the growth reduction in certain transgenic lines may not be caused by a single factor such as Proto IX, but by interaction of many other factors.

• Journal of Plant Biotechnology
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• v.45 no.3
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• pp.171-182
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• 2018

Papaya (Carica papaya L.) is one of the crops widely planted in tropical and subtropical areas. The papaya fruit has low calories and are plentiful in vitamins A and C and in minerals. A major problem in papaya production is a plant disease caused by the papaya ringspot virus (PRSV). The first PRSV-resistant GM papaya expressing a PRSV coat protein gene was developed by USA scientists in 1992. The first commercial GM papaya cultivars derived from the event was approved by the US government in 1997. Development of transgenic papayas has been focused on vaccine production and limited agricultural traits, including insect and pathogen resistance, long shelf life, and aluminum and herbicide tolerance. Approximately 17 countries, including the USA and China, produced transgenic papayas and/or commercialized them, which provoked studies on biosafety assessment and development of GM-detection technologies. For the biosafety assessment of potential effects on human health, effects of long-term feeding to model animals have been studied in terms of toxicity and allergenicity. Studies on environmental safety assessment include influence on soil-microbial biodiversity and transfer to soil bacteria of GM selection markers. Many countries, such as Korea, the European Union, and Japan, that have strict regulations for GM crops have serious concerns about unintended introduction of GM cultivars and food commodities using unauthorized GM crops. Transgene- and/or GM event-specific molecular markers and technologies for genomics-based detection of unauthorized GM papaya have been developed and have resulted in the robust detection of GM papayas.