• Korean Journal of Plant Tissue Culture
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• v.27 no.6
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• pp.441-445
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• 2000

In order to improve phosphate use efficiency of rice using phosphate transporter (PT), transgenic rice plants containing a tobacco PT gene were developed. Calli from Dongjinbyeo (Oryza sativa L.) were cocultured with A. tumefaciens LBA 4404 harboring PT gene. Multiplied calli were transferred to MS medium supplemented with 50 mg/L hygromycin, 500 mg/L carbenicillin, 2 mg/L kinetin, 0.1 mg/L NAA. After 2 weeks, hygromycin resistant shoots were obtained from the calli on the selection medium. The putative transgenic shoots were transferred to rooting MS medium supplemented with 250 mg/L cabenicillin. Plant regeneration rate from the calli was about 52%. Stable incorporation of the tobacco PT gene into rice genomic DNA was confirmed by PCR and Southern blot analysis.

• Korean Journal of Medicinal Crop Science
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• v.11 no.4
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• pp.289-297
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• 2003

Using Agrobacterium-me야ated transformation method the auxin-regulated cotton GST (Gh-5) constructs were used to transform Rehmannia glutinosa L. The PCR analysis was conducted to verify transgenicity. Based on the PCR analysis, there was verified that the 988 bp DNA band had showed in transgenic plant genomes in PCR anaJysis using Gh5-1 and Gh5-2 primers. The effects of cocultivation with Agrobacterium tumefaciens, regeneration and selection conditions on the transformation efficiency of Chinese foxglove (Rehmannia glutinosa L.) were investigated. Factors such as cocultivation period, use of acetosyringone, postcultivation in darkness, and different kanamycin concentrations for selection were assessed. In vitro regeneration, the number of leaves, shoot lengths and numbers on MS medium were superior to on B5 and WPM medium, and the shoot formation rate was highest level of 95% in cultured base part containing leaf stalk. Addition of acetosyringone at concentration of $200{\mu}M$ to cocultivation medium and 3-day of cocultivation improved transformation frequencies. Exposure of explants to darkness for 4 weeks on selection medium resulted in further increased the regeneration frequency of transgenic shoots. In PCR analysis, the amplified fragments of Gh5 gene were detected (988 bp), and GST-expressing transgenic R. glutinosa L. plants had approximately three-fold higher activity in leaf extracts compared with control plant.

• Journal of Embryo Transfer
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• v.30 no.3
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• pp.225-228
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• 2015

Understanding the behavior of transgenes introduced into oocyte or embryos is essential for evaluating the methodologies for transgenic animal production. To date, many studies have reported the production of transgenic pig embryos with, however, low efficiency in environment of blastocyst production. The aim of present study was to determine the expression and duration of transgene transferred by intracytoplasmic sperm injection-mediated gene transfer (ICSI-MGT). Embryos obtained from the ICSI-MGT procedure were analysed for the expression of GFP and then for the transmission of the transgene. Briefly, fresh spermatozoa were bound to exogenous DNA after treatment by Triton X-100 and Lipofectin. When ICSI-MGT was performed using sperm heads with tails removed, the yield of blastocyst (25.3%), treated with Lipofectin (18.8%) and Triton X-100 (19.2%) were observed. Treatments of Lipofectin or Triton X-100 did not further improve the rates of blastocysts. Moreover, the apoptosis rates of embryos were obtained from the control and LIpofectin groups (8.7%, 9.7%, respectively), but were significantly higher in the Triton X-100 group (13.0%). Our results demonstrated that ICSI-MGT caused minimal damage to oocytes that could develop to full term. Moreover, the embryos derived by ICSI-MGT have shown prolonged exogenous DNA expression during preimplantation stage in vivo. However, more efforts will be required to improve the procedures of both sperm treatments cause of high frequency of mosaicisms.

• Journal of Plant Biotechnology
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• v.7 no.4
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• pp.211-218
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• 2005

Genetic transformation was carried out by using biolistic gun method. The hypocotyl derived embryogenic calli (explants) of cotton (Gossypium hirsutum L.) cv. Cocker-312 were transformed with a recombinant pGreen II plasmid, in which both, bar (selection marker) and GUS (${\beta}$-glucuronidase) reporter genes were incorporated. Explants were arranged on osmoticum-containing medium (0.5M mannitol) 4 hours prior to and 16 hours after bombardment that was resulted into an increase about >80% for GUS stable expression. 3 days after bombardment, GUS assay was performed, which exhibited, $18.36{\pm}1.00$ calli showed blue spots. The transformed embryogenic calli were cultured on selection medium (@ 6 mg/L basta) for 3 months. The putative transgenic plants were developed via selective somatic embryogenesis (@1.50 mg/L basta); maximum $27.58{\pm}1.25$ somatic embryos were obtained while $17.47{\pm}1.00$ embryos developed into plantlets (@ 0.75mg/L basta). In five independent experiments, up to 7.24% transformation efficiency was recorded. The presence of the transgenes was analyzed by using PCR and southern hybridization analysis. The transgenic plants were developed with in 6-7 months, but mostly transformants were abnormal in morphology.

• Journal of Plant Biotechnology
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• v.6 no.2
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• pp.69-75
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• 2004

Optimal protocol for efficient genetic transformation has been defined to aid future strategies of genetic engineering in pigeon pea with agronomically important genes. Transgenic pigeonpea plants were successfully produced through Agrobacterium tumefaciens-mediated genetic transformation method using cotyledonary node explants by employing defined culture media. The explants were co-cultivated with A. tumefaciens strain C-58 harboring the binary plasmid, pCAMBIA-1301 [con-ferring $\beta$-glucuronidase(GUS) activity and resistance to hygromycin] and cultured on selection medium (regeneration medium supplemented with hygromycin) to select putatively transformed shoots. The shoots were then rooted on root induction medium and transferred to pots containing sand and soil mixture in the ratio of 1:1. About 22 putative TO transgenic plants have been produced. Stable expression and integration of the transgenes in the putative transgenics were confirmed by GUS assay, PCR and Southern blot hybridization with a transformation efficiency of over 45%. Stable integration and expression of the marker gene has been confirmed in the TO and T1 transgenics through PCR, and Southern hybridization.

• Bulletin of the Korean Chemical Society
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• v.29 no.5
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• pp.959-962
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• 2008

We have performed FlexX docking experiments to predict the best docking poses of 5-androst-16-en-3-ol or 5-androst-16-en-3-one to Boar salivary lipocalin (SAL). Since no steroids were found inside of the binding pocket of the X-ray structure of 1GM6, we tried to find docking structures after opening the pocket using the random tweak option implemented in SYBYL. This operation allowed the ligand to enter the pocket. The best poses generated from FlexX were different from the structures reported earlier, which calculated docking poses by manual docking followed by minimization. Analysis of docking poses allowed us to identify pharmacophores. From this information, virtual screening experiments using UNITY were performed. Among six candidates, 3-(3,7-dimethyloct-6-enylamino)propane-1,2-diol (Leadquest code name: 5755) was chosen for further development. Future work will involve synthesis of some derivatives of 5755 and biological experiments if any derivatives can control the biostimulation and improve reproductive efficiency in pigs.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.04a
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• pp.36-36
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• 2018

Soybean is the important crop in Asian countries as protein source, oil production and animal feed. Improving soybean using genetic transformation is the principal tool in nowadays. Developing herbicide resistant transgenic soybean plants through Agrobacterium-mediated transformation has been worked in many previous studied. However, the transformation efficiency is still low. Many attempts try to find the optimum media condition for plant regeneration after infection. After transformation, the plant regeneration is very important condition to promote growth of transgenic plant. In this study, we optimized a regeneration condition for two Korean soybean cultivar, Dawonkong and Pungsannamulkong using cotyledon, cotyledonary nodes and hypocotyl as explant. The results showed that shoot regeneration of cotyledonary nodes on B5 medium containing 2 mg/L 6-benzylaminopurine showed the highest percentage of regeneration in Dawonkong (75.8%) while Pungsannamulkong presented high number of shoots 2.12 shoots per explant. For transformation condition, co-cultivation in 7 days showed a high number of GUS positive expression. Most of explants can survived under media including 5 mg/L of glufocinate which refers phosphinotricin for 2-week selection. Washing with 400 mg/L of cefotaxime in several times and selection in plant regeneration media with 400 mg/L of cefotaxime can prevent bacteria growth, effectively.

• Korean Journal of Agricultural Science
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• v.47 no.2
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• pp.305-313
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• 2020

Root hair development has the potential to increase crop yields and at the same time to decrease fertilizer use, which will be required in the next 30 years to meet the demand for crop-derived commodities in a world with decreasing available natural resources. Root hair defective six (RHD6) encoding a basic helix-loop-helix transcription factor, is associated with root hair differentiation, and its roles are root hair initiation and elongation. Grass plants, rice and Brachypodium have been used as model plants to study the gene function of the root hair defective six like (RSL) subfamily which is orthologous to AtRHD6. The RSL subfamily has an identical gene function with AtRHD6 which is involved with root hair differentiation as well. Plants with longer root hairs within a species should have an improved Pi uptake efficiency; therefore, we would expect that a plant with a high Pi uptake could contribute to increasing the plant yield. We achieved increased root hair length by manipulating the RSL subfamily genes. It is expected that in these transgenic plants, the long root hairs would be sufficient to improve the Pi uptake and hence improve biomass and yield component (tiller, spikelet number, and spikelet weight) of the plant. Here, we demonstrate that Brachypodium transgenic plants overexpressing the BdRSL subfamily genes have an improved biomass and grain yield. The result of this study could be applied to important crop plants like rice.

• Journal of Plant Biotechnology
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• v.48 no.2
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• pp.93-99
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• 2021

This study was conducted to develop an Agrobacterium-mediated genetic transformation protocol for the carnation cv. "Jinju" to counteract its ethylene sensitivity. The new protocol involves the use of an improved shoot regeneration medium, optimized minimal concentrations of the selective agent, a pre-culture period, and co-cultivation periods. Silver nanoparticles (NAg) added at a concentration of 2.0 μM to the Murashige and Skoog (MS) basal shoot regeneration medium supplemented with 0.1 mg/L indole-3-butyric-acid (IBA) and 0.2 mg/L thidiazuron (TDZ) improved the shoot regeneration efficiency, number of shoots per explant, and plant growth compared to the control without the addition of NAg. The phosphinothricin (PPT) concentration of 1.0 mg/L was determined to be the minimal and optimal concentration for the selection of putative transgenic plants. When the explants were infected with Agrobacterium cells harboring the acdS gene, the explants that were pre-cultured for three days induced more putative transgenic plants than those that were co-cultivated for four days. Therefore, we expect that the results of this study will benefit researchers who are developing genetic transformations of carnations.

• Plant Biotechnology Reports
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• v.5 no.3
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• pp.245-254
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• 2011

This study describes an efficient protocol for Agrobacterium tumefaciens-mediated transformation of two subgroups of genotype AAA bananas (Musa acuminata cv. Pei Chiao and Musa acuminata cv. Gros Michel). Instead of using suspension cells, cauliflower-like bud clumps, also known as multiple bud clumps (MBC), were induced from sucker buds on MS medium containing $N^6$-Benzylaminopurine (BA), Thidiazuron (TDZ), and Paclobutrazol (PP333). Bud slices were co-cultivated with A. tumefaciens C58C1 or EHA105 that carry a plasmid containing Arabidopsis root-type ferredoxin gene (Atfd3) and a plant ferredoxin-like protein (pflp) gene, respectively. These two strains showed differences in transformation efficiency. The EHA105 strain was more sensitive in Pei Chiao, 51.3% bud slices were pflp-transformed, and 12.6% slices were Atfd3-transformed. Gros Michel was susceptible to C58C1 and the transformation efficiency is 4.4% for pflp and 13.1% for Atfd3. Additionally, gene integration of the putative pflp was confirmed by Southern blot. Resulting from the pathogen inoculation assay, we found that the pflp transgenic banana exhibited resistance to Fusarium oxysporum f. sp. cubense tropical race 4. This protocol is highly advantageous to banana cultivars that have difficulties in setting up suspension cultures for the purpose of quality improvement through genetic transformation. In addition, this protocol would save at least 6 months in obtaining explants for transformation and reduce labor for weekly subculture in embryogenic cell suspension culture systems.