• Korean Journal of Plant Tissue Culture
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• v.28 no.4
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• pp.197-200
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• 2001

Agrobacterium tumefaciens MP90 harboring PAT (phosphinothricin acetyltransferase) and NPTII-GUS gene were used for the genetic transformation of lettuce (Lactuca Sativa L.). Shoot regeneration from cotyledon explants were obtained from the MS medium supplemented with 0.1 mg.L$^{-1}$ NAA, 1.0 mg.L$^{-1}$ 2ip, 50 mg.L$^{-1}$ kanamycin and 500 mg.L$^{-1}$ carbenicillin after cocultivation with A. tumefaciens for 2 days. Kanamycin resistance test of transgenic plants indicated that the NPTII gene was integrated into the lettuce genome and was stably expressed. PCR and northern blot analysis indicated that bialaphos resistance gene (PAT) was stably integrated into the lettuce genome. The transgenic plant sprayed with Basta (1500x) remained healthy with continuous growth, while the control group exhibited fatality.

• 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 Plant Biotechnology
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• v.50
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• pp.248-254
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• 2023

This study was conducted to establish an efficient plant regeneration system in 'Dayu', a Korean variety of Perilla frutescens developed for seed oil production, in conjunction with the previously studied variety 'Namcheon'. The healthiest callus was formed on the hypocotyl explants cultured on a medium containing 0.1 mg/L NAA and 0.5 mg/L BA, outperforming the leaf and cotyledon samples. In both dark and long-day conditions, Dayu consistently exhibited significantly higher shoot regeneration rates compared with Namcheon. The highest shoot regeneration rates in Dayu were observed from the hypocotyl explants cultured on 0.1 mg/L NAA and 0.5 mg/L BA media, with shoot regeneration rates of 84.4% and 86.7% under dark and long-day conditions, respectively. Various combinations of plant growth regulators were tested to establish the optimal shoot regeneration conditions for Dayu hypocotyl explants. The results demonstrated that the highest shoot regeneration rate (90%) was achieved when 0.5 mg/L of BA was added to the medium without NAA. Among the regenerated shoots, 70.5% were normal plants, while 19.3% were abnormal. The addition of NAA or an increase in its concentration led to a higher occurrence of abnormal plants. After the regenerated shoots were transferred to 1/2 MS medium, roots were observed within 10-15 days. By day 30, they had developed into complete plants. The results obtained from the regeneration experiments with the perilla variety Dayu can valuably inform molecular breeding reliant on transformation techniques such as genome-editing and genetic modification technology.

• Journal of Ginseng Research
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• v.37 no.3
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• pp.332-340
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• 2013

In this study, gamma rays were used to irradiate embryogenic calli induced from cotyledon explants of Panax ginseng Meyer. After the embryogenic calli were irradiated, they were transferred to adventitious roots using an induction medium; next, mutated adventitious root (MAR) lines with a high frequency of adventitious root formations were selected. Two MAR lines (MAR 5-2 and MAR 5-9) from the calli treated with 50 Gy of gamma rays were cultured on an $NH_4NO_3$-free Murashige and Skoog medium with indole-3-butyric acid 3 mg/L. The expression of genes related to ginsenoside biosynthesis was analyzed using reverse transcription polymerase chain reaction with RNA prepared from native ginseng (NG), non-irradiated adventitious root (NAR) and 2 MAR lines. The expression of the squalene epoxidase and dammarenediol synthase genes was increased in the MAR 5-2 line, whereas the phytosterol synthase was increased in the MAR 5-9 line. The content and pattern of major ginsenosides (Rb1, Rb2, Rc, Rd, Re, Rf, and Rg1) were analyzed in the NG, NAR, and 2 MAR lines (MAR 5-2 and MAR 5-9) using TLC and HPLC. In the TLC analysis, the ginsenoside patterns in the NG, NAR, and 2 MAR lines were similar; in contrast, the MAR 5-9 line showed strong bands of primary ginsenosides. In the HPLC analysis, compared with the NG, one new type of ginsenoside was observed in the NAR and 2 MAR lines, and another new type of ginsenoside was observed in the 2 MAR lines irradiated with gamma rays. The ginsenoside content of the MAR 5-9 line was significantly greater in comparison to the NG.

• Journal of Plant Biotechnology
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• v.41 no.3
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• pp.140-145
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• 2014

This study were carried out for selection of proper transformation variety and development of efficient regeneration and transformation methods. The number of shoot in commercial varieties of gourd plant were 0 ~ 7.3. and fusarium wilt resistant pure lines were 2.0 ~ 6.5 per dish containing on MS medium supplemented with 3 mg/L BA. The shoot regeneration frequency of fusarium wilt resistant pure lines were wide variation on the deviation. The expression of GFP was high 67% and 100% at the co-cultivation with Agrobacterium. The effective shoot regeneration plant hormone were combination BA and 2,4-D. The number and elongation condition of shoot was good after 4 weeks change with MS medium supplemented with 1 mg/L BA. Effective callus production plant hormone were combination of 3 mg/L BA and 0.1 mg/L 2.4-D.

• Journal of The Korean Society of Grassland and Forage Science
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• v.19 no.3
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• pp.273-280
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• 1999

Hypocotyl explants of Medicago saliva cv. Vernal were cultured on Murashige and Skoog (MS) medium supplemented with various combinations of growth regulators. After six weeks of culture, somatic embryos were formed from calli on MS medium containing $4mg/{\ell}$ 2,4-D and $0.1mg/{\ell}$ kinetin, or $4mg/{\ell}$ 2,4-D and $0.5mg/{\ell}$ kinetin. The mature somatic embryos were developed to plantlets when subcultured on MS basal medium. In order to obtain secondary somatic embryogenic calli, cotyledon of regenerated plantlets were cultured on a callus induction medium. Embryogenic calli were formed on MS medium containing $4mg/{\ell}$ 2,4-D alone. For induction and development of secondary somatic embryogenesis, the embryogenic calli were transferred to MS basal medium containing either 2,4-D or NAA. Multi-secondary somatic embryogenesis was the most effective on MS basal medium with $0.1mg/{\ell}$ 2,4-D. The rate of secondary somatic embryo formation of regenerated plants was 18 times higher than that of seed grown plants. The mature secondary somatic embryo were germinated into plantlets on MS basal medium after six weeks of culture.