• Journal of Plant Biotechnology
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• v.4 no.3
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• pp.123-127
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• 2002

Herbicide tolerant rice (Oryza sativa L. cv. Ilpumbyeo) cell lines were selected from $\gamma$-ray-irradiated anther-derived cell cultures. The anther-derived cell clusters were small (300 to 400 ${\mu}{\textrm}{m}$ in diameter) and uniform ones that were screened by miracloth filtering. The cell suspensions were very efficient to plate one layer onto agar medium and to screen target cell lines. Herbicide tolerant cell lines were selected by 5 mg/L cyhalofop butyl (CHB) treatment by using the small cell suspensions on agar N6 medium containing 1 mg/L 2,4-D and 0.2 mg/L kinetin. Of the cell lines, one line (CHB-1) showed stable tolerance at 10 mg/L concentration after 6-month culture without herbicide suspension. Growth stability of CHB-1 was similar to that of control cell line on 10 mg/L CHB containing medium. In this experiment we established herbicide tolerant cell line selection system by using anther-derived uniform-cell suspensions with $\gamma$-ray-irradiation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.3
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• pp.430-435
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• 1997

Protopectinases are heterologous group of enzymes that degrades insoluble protopectin which consists of middle lamella between cells of plant tissues. Tissues of potato and carrot could be separated to single cells by addition of protopectinase isolated from Rhizopus sp. Color changes ofthe suspensions treated with protopectinase and mechanically macerated after 2 weeks at 4$^{\circ}C$, were investigated. Color change of the latter was very serious, however, that of the former was insignificant. Furthermore, after heat treatment at 121$^{\circ}C$ for 5min, the constituents of mechanically macerted carrot suspension were separated into two layers, but those of single celled carrot were not. Yields of carrot juices extracted from single celled suspensions and mechanical maceration were 93.6% and 56.0%, respectively. These results support that treatment of protopectinase can increase yield of juices extracted from plant, and manufacture high value-added products in food processing.

• Journal of Microbiology and Biotechnology
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• v.16 no.5
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• pp.673-677
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• 2006

A perfusion culture of transgenic Nicotiana tabacum cell suspensions, transformed to express recombinant glucuronidase (GUS), was successfully performed in a 5-1 stirred tank bioreactor. With 0.1 $day^{-1}$ of perfusion rate, the maximum dry cell weight (DCW) reached to 29.5 g/l in 16 days, which was 2.1-fold higher than the obtained in batch culture (14.3 g/l). In terms of the production of GUS, the volumetric activity could be increased up to 12.8 U/ml by using perfusion, compared with 4.9 U/ml in batch culture. The specific GUS activities in both perfusion and batch cultures were maintained at similar levels, 200-400 U/g DCW. Consequently, a perfusion culture could be a good strategy for the enhanced production of recombinant proteins in a plant cell culture system.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.5
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• pp.615-625
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• 1997

An efficient protocol for plant regeneration from protoplasts of the indica rice variety IR43 has been developed. The procedure involved plating of embryogenic suspension-derived protoplasts on the surface of a filter membrane overlaying agarose-embedded feeder cells. Lolium multiflorum cell suspensions were preferable to these of Oryza ridleyi as feeder cells and Lolium suspensions supported colony formation from up to 0.68％ of the protoplasts, depending on the age of cell suspensions. Plant regeneration frequency was significantly improved by using maltose alone or in a 1:1(w/w) combination with sucrose as carbohydrate source and a simple dehydration treatment using a high concentration of agarose in the regeneration medium. Medium containing maltose or maltose mixed with sucrose increased the plant regeneration frequency compared with medium containing sucrose alone. The plant regeneration frequency was increased to 30.7 to 70.7％ following dehydration treatment, while the non-treated controls showed a regeneration frequency of 3.1 to 30.6％. Protoplast-derived plants were transferred to the glasshouse, flowered with morphologically normal.

• Proceedings of the Ginseng society Conference
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• 1993.09a
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• pp.150-154
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• 1993

• Plant Biotechnology Reports
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• v.2 no.1
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• pp.33-39
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• 2008

In this paper, we would like to show unexpected morphogenic potential of cell suspensions derived from seedling explants of Gentiana kurroo (Royle). Suspension cultures were established with the use of embryogenic callus derived from seedling explants (root, hypocotyl and cotyledons). Proembryogenic mass proliferated in liquid MS medium supplemented with $0.5mg\;l^{-1}$ 2,4-D and $1.0mg\;l^{-1}$ Kin. The highest growth coefficient was achieved for root derived cell suspensions. The microscopic analysis showed differences in aggregate structure depending on their size. To assess the embryogenic capability of the particular culture, 100 mg of cell aggregates was implanted on MS agar medium supplemented with Kin ($0.0-2.0mg\;l^{-1}$), $GA_3$ ($0.0-2.0mg\;l^{-1}$) and AS ($80.0mg\;l^{-1}$). The highest number of somatic embryos was obtained for cotyledon-derived cell suspension on $GA_3$-free medium, but the best morphological quality of embryos was observed in the presence of $0.5-1.0mg\;l^{-1}$ Kin, $0.5mg\;l^{-1}$ $GA_3$ and $80.0mg\;l^{-1}$ AS. The morphogenic competence of cultures also depended on the size of the aggregate fraction and was lower when size of aggregates decreased. Flow cytometry analysis reveled luck of uniformity of regenerants derived from hypocotyl suspension and 100% of uniformity for cotyledon suspension.

• Korean Journal of Medicinal Crop Science
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• v.15 no.5
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• pp.346-351
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• 2007

An efficient somatic embryogenesis and plant regeneration protocol was developed for Schisandra chinensis Baill, using embryogenic cell suspensions and optimized media conditions. Friable embryogenic callus was induced from cotyledonary leaf and hypocotyl explants of 7 days old seedlings on MS agar medium supplemented with 1.0 to $4.0\;mg\;l^{-1}$ of 2,4-dichlorophenoxyacetic acid (2,4-D). Fast growing and well dispersed embryogenic cell suspensions were developed within two months when embryogenic calli were transferred to MS liquid medium containing $1.0\;mg\;l^{-1}\;2,4-D$. One third strength of MS medium was the best for both overall growth and development of somatic embryos in liquid culture. Over 3400 viable somatic embryos were produced from each 150 ml flask with an initial cell density of 30 mg in 30 ml medium. Germinated somatic embryos developed in liquid medium converted into plantlets after transferred to half-strength MS semi-solid medium. Approximately 90% of the converted plantlets were successfully transplanted to soil and grew into fertile plants.

• Korean Journal Plant Pathology
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• v.3 no.3
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• pp.180-186
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• 1987

Cell suspensions of two isolates of Pseudomonas syringae. PS8401 from sweet persimon and PS8402 from tea plant, were active in ice nucleation at -2.5 and $-3.8^{\circ}C$, respectively. Ice nucleation at those temperature was, using micropipette method, detected in suspensions ($10^8$ olony forming unit/ml of distilled water) of cells that had been grown on nutrient agar supplemented with $2.5\%$ glycerol. Using the same method, on the other hand, the freezing temperature of distilled water only was approx. $-21.8^{\circ}C$, and those of various plant saps including corn were lower than $-11.6^{\circ}C$. Corn seedlings sprayed with cell suspensions $(10^8\;cfu/ml)$ of nutrient broth) of PS8401 began to be damaged at $-2^{\circ}C$ and were almost completely damaged at $-4^{\circ}C$, whereas seedlings sprayed with nutrient broth only were not injured until the temperature down to $-9^{\circ}C$. Amounts of frost damage measured 48 hr after application of PS8401 suspensions increased as applied bacterial cell densities were increased. Ice-nucleation activity of the cell suspensions in vitro increased with increasing the number of cells in suspension. The activity also affected by growth-medium composition or growth-temperature. Ice nucleation thus occured at -4.0, -4.4 and $-7.2^{\circ}C$ in suspensions $(10^2\;cfu/ml)$ of PS8401 that had been grown at$25\%$ nutrient agar with $2.5\%$ glycerol, nutrient agar with $2.5\%$ glucose and nutrient agar only, respectively, and occured at -4.0 and $-7.6^{\circ}C$ in suspensions $(10^2\;cfu/ml)$ of PS8401 hat had been grown on nutrient agar with $2.5\%$ glycerol at $15\~25^{\circ}C$ and $30^{\circ}C$, respectively.

• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.301-304
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• 2002

Perfusion culture strategies for high density culture of plant cell suspensions to enhance the productivity of extracellular polysaccharides were investigated. Angelica gigas Nakai cell suspensions were used to produce the extracellular polysaccharide and perfusion parameters were optimized to maximize the production. When the medium exchange was started at the fifth day after inoculation, the maximum cell concentration (23.8 g dry cell weight per liter) was achieved.

• 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 $4^{\circ}C$..