• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.6
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• pp.423-427
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• 2004

A simple purification procedure of bioactive human granulocyte macrophage colony stimulating factor (hGM-CSF) secreted in rice cell suspension culture has previously been described. In this study the protein was purified to apparent homogeneity with an overall yield of $80.1\%$ by ammonium sulfate precipitation and a single chromatographic step involving FPLCanion exchange chromatography. The purified hGM-CSF revealed at least five glycosylated forms ranging from $21.5{\~}29$ kDa, and its biological activity was independent of the glycosylation pattern. This is the first purification report of recombinant hGM-CSF to apparent homogeneity from rice cell suspension cultures.

• Applied Biological Chemistry
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• v.36 no.1
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• pp.1-6
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• 1993

Chitinase was induced in rice cell suspension culture with treatment of chitooligosaccharides mixture. Among eleven isozymes found in 10% polysacrylamide gel electropherogram, four isozymes were identified as induced enzymes. Acidic chitinase fraction separated in DEAE-cellulose column chromatography, includes three induced chitinase, while basic fraction contains only one induced isozyme. Treatment of chitooligosaccharides mixture enhanced the contents in both protein and chitinase activity in cell suspension culture media, but increase in chitinase activity was much higher than in protein.

• Journal of Plant Biology
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• v.36 no.3
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• pp.211-218
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• 1993

Plant regeneration was accomplished from protoplast culture of rice (Oryza sativa L. cv. Taebaeg). Embryogenic callus was induced from mature seed on MS medium containing 5 mM proline, 2.5 mg/L 2,4-D, 30 g/L sucrose in the dark at 28$^{\circ}C$ and used to establish embryogenic cell suspension culture. Suspension cells were subcultured every one week in N6 medium supplemented with 5 mM proline, 200 mg/L casein hydrolysate, 2.5 mg/L 2,4-D and amino acids of AA medium. Suspension cultures were composed of cells that were densely cytoplasmic, potentially embryogenic and were at least maintained for more than 6 months in liquid medium. Protoplasts were isolated from fast-growing suspension culture cells and cultured in a slightly modified KpR medium by mixed nurse culture. Isolated protoplasts began to divide within 5~7 days and thereafter, protoplast-derived calli were sequentially transferred to callus proliferating medium that soft agar MS medium contained 2 mg/L 2,4-D and produced distinct embryogenic cells. Microcolonies were then transferred to solid medium which consisted of MS medium containing 5 mg/L kinetin, 1 mg/L NAA, 1 mg/L ABA, 30 g/L sucrose and 10 g/L sorbitol under fluorescent light. Mulitple shoots of 4~5 per callus emerged and were transferred to hormone-free MS medium for root initiation. Thereafter, The plantlets were transferred to pots of soil to mature in the culture room.

• Journal of Life Science
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• v.17 no.2 s.82
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• pp.293-297
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• 2007

Green fluorescent protein (GFP) is an attractive reporter for bioprocess monitoring. A fluorescence-based method was developed to quantify GFP levels in transgenic plants and protein extracts. In this study, GFP was produced and secreted from suspension cells derived from transgenic rice. The RAmy3E promoter placed before the GFP gene controlled by sugars such as sucrose. The effects of sucrose concentration on the secretion of GFP and total protein into the medium were investigated in batch suspension culture. It was possible, therefore, to induce the expression of the GFP by removing sucrose from the cultured media or by allowing the rice suspension cells to deplete sucrose catabolically. The dry cell weight (7.06 g/L) and GFP level were detected as highest at 12%, 3% sucrose after 20 day culture, respectively. However secreted GFP fluorescence at the other sucrose concentrations (6%, 12%, 18% and 24%) were a little amount in media.

• Journal of Plant Biotechnology
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• v.47 no.3
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• pp.227-234
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• 2020

To produce the miraculin protein in suspension cultures, rice (Oryza sativa L.) was transformed with Agrobacterium tumefacience EHA105 containing the miraculin AB512278 gene. The cell suspension cultures were established using cell lines selected from transgenic rice callus. The integration of the miraculin gene into the rice chromosome was confirmed using genomic PCR analysis. In addition, RT-PCR analysis indicated that the miraculin gene is expressed in the selected suspension cell lines. Thus, the recombinant miraculin was expressed in the transgenic suspension cell line, HK-2. Therefore, we have successfully developed a HK-2 line that produces miraculin. These results demonstrate that transformed cell suspension cultures can be used to produce a taste-modifying protein such as miraculin.

• Journal of Plant Biology
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• v.34 no.1
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• pp.19-23
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• 1991

Culture of embryogenic callus and suspension were induced from rice seeds in MS2.5 medium. In hormone free N6 medium, whole plantlets were regenerated from embryogenic callus. We observed cell division and reformation of embryogenic callus on culture of protoplast isolated from embryogenic cell suspensions. In addition, we studied the influencing factors on viability of protoplast treated with electroporation. Viability was decreased according to the increase of voltage and capacitance during electroporation. An optimal level of viability was obtained after treatment with $200-300\;V/1180\;\mu\textrm{F}$ in HEM buffer at $4^{\circ}C$..

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.206-209
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• 2001

Recombinant human GM -CSF was expressed and secreted from transgenic rice cell suspension cultures in its biologically active form. This was accomplished by transforming rice callus tissues with an expression vector, pMYN44. containing the hGM -CSF cDNA. Regulated expression and secretion of hGM -CSF from this vector achieved using the promoter, signal peptide, and terminator from a rice alfa-amylase gene Amy3D. The Amy3D gene is expressed in response to sugar deprivation. The recombinant hGM -CSF was expressed from the transgenic rice cell culture on the sugar-free medium as a yield of about 110 mg/L in the culture filtrate, which was determined by ELISA. Biological activity of hGM-CSF was confirmed by measuring the proliferation of the hGM -CSF dependent TF -1 cells.(This work was supported by a grant from the NRL program of the Korean Ministry of Science and Technology. Shin, Y.- J.. Lee. J.-H and Kwon, T.-H. have been supported by BK21 program from the Korean Ministry of Education)

• 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.

• Journal of Plant Biology
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• v.31 no.1
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• pp.41-49
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• 1988

Several cultivars of rice were examined for induction of embryogenic callus on a medium containing MS salts, vitamins and 2, 4-D under darkness. Embryogenic callus was obtained from cultivar Cheonma with high ratio and embryo-like structures were formed from the callus on a medium with or without reduced 2, 4-D. Somatic embryoids with a plumule and radicle axis surrounded by a scutellum were observed. These embryoids germinated and produced plantlets in 30 days on the same medium. Protoplasts isolated from an embryogenic cell suspension culture derived from embryogenic callus were cultured either in liquid or in agar medium and protoplast derived cell colonies were obtained in 3-4 weeks.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.3
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• pp.306-316
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• 1997

Embryogenic calli were induced from mature seed scutella of anther culture-derived rice variety Zhonghua 8. Cell suspension cultures were initiated from friable embryogenic calli and utilized as source material for protoplast isolation. Generally, the older and finer cell suspensions gave higher protoplast yields than younger suspension cultures. Protoplasts exhibited sustained cell division and formed microcalli when cultured in KPR medium supplemented with 0.5 mg $l^{-1}$ 2,4-D, 1.0 mg $l^{-1}$ NAA and 0.5 mg $l^{-1}$ zeatin using the agarose embedding procedure without feeder cells. Protoplast plating efficiencies ranged from 0.20 to 0.54％. Microcalli were transferred to MS medium supplemented with 2.0 mg $l^{-1}$ kinetin and 0.5mg $l^{-1}$ NAA for plant regeneration. The regeneration frequencies were 2 to 12％, depending on the cell suspension lines of Zhonghua 8. The plants were transferred to the glasshouse and were fertile.