• Korean Journal of Plant Tissue Culture
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• v.25 no.6
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• pp.477-485
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• 1998

To underatand in vitro regulation of differentiation, the effects of growth regulators and nitrogen source on metabolism of cell wall polysaccharides in suspension culture of kidney bean (Phaseolus vulgaris L.) were investigated. The suspension cells (cell clusters) were directly induced from the epicotyl segments of the seedlings, which were cultivated in MS medium supplemented with 1.0mg/L of 2,4-D and 0.5 mg/L of kinetin. When compared with cell wall sugar contents of the epicotyl segments, the cellulose content of the suspension-cultured cells decreased; while the pectin and hemicellulose content increased; suggesting increases of rhamnogalacturonan I and arabinogalactan IIduring the dedifferentiation, respectively, The effects of growth regulators(2,4-D, 1.0mg/L and kinetin, 0.5mg/L) and nitrogen source (potasium nitrate, 19.0mg/L and ammonium nitrate, 16.5 g/L) in the medium on the proliferation and the turnover of the cell wall polysaccharides were investigated for 30 days. In the medium with growth regulators and without nitrogen source, the proliferation rate was extremely high (16 folds). Growth regulators and nitrogen source increased the pectin content. Analysis of neutral sugar composition of pectin fraction showed that nitrogen source enhanced rhamnose level remarkably, suggesting that rhamnogalacturonan I was the one most likely synthesized. In hemicellulose fraction, growth regulators reduced arabinose level, suggesting that arabinogalactan II was degraded. And nitrogen source reduced galactose level, suggesting that xyloglucan was also degraded.

• Microbiology and Biotechnology Letters
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• v.26 no.2
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• pp.130-136
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• 1998

An Immunostimulating polysaccharide was produced from the suspension culture of Angelica gigas H4, plant cells. In order to enhance the polysaccharide production by the A. gigas cell culture, medium composition and physical conditions were optimized. Schenk and Hildebrandt (SH) medium was selected as an optimal basal medium for the growth of A. gigas. The maximum cell and polysaccharide concentration obtained in SH medium were 15.8 g DCW/l and 0.85 g polysaccharide/l, respectively, at $25^{\circ}C$ under dark condition. For the enhanced polysaccharide production, a polysaccharide production medium (PPM) was established by modifying Gamborg B5 medium with optimized carbon sources, growth regulators, organic and inorganic elements. Optimal initial pH and temperature were 6.0-6.6 and $20^{\circ}C$, respectively, and the dark condition was better than the light condition. The maximum polysaccharide concentration of 1.5 g/l could be obtained through the optimization of the medium composition and physical conditions.

• Applied Biological Chemistry
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• v.35 no.6
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• pp.443-448
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• 1992

To investigate the production of monoterpenoids by Mentha pipperita cells in suspension culture, effects of media formulation, plant growth hormones, initial pH of the media, and cold stress on the production of essential oil and menthol were analyzed. Among the media employed, Lin-Staba medium resulted in the best essential oil production. Addition of 100 mg/l of yeast extract to the Lin-Staba medium induced the cells to produce large amount of essential oil and high content of menthol (0.39 g/l and 19.6%, respectively). In the effect of plant growth hormone, auxine were more effective than cytokinins. At initial pH of 4.7, oil production was good but menthol content was low. However at pH 5.7 the trend was reversed. When the culture temperature was lowered from $27^{\circ}$ to $10^{\circ}$ during 6 hour-dark period, growth was not changed much but essential oil production and menthol content was increased and reached to 528 mg/l and 21%, respectively.

• Journal of Life Science
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• v.6 no.2
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• pp.94-103
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• 1996

To understand effect of inoculum size, cell density, sucrose concentration and concentrations of MS basal on suspension culture and protoplast isolation of wild viola(Viola patrinii DC.) callus from petiole segments this experiment was conducted. In the lot of 30 mesh inoculum size, two observations were; One was that a considerable increase in the fresh and dry weight of callus was determined. Another was that the callus mass was relatively compact compared with others. A recommendable cell density was 0.4g for 20ml culture medium and the higher sucrose concentration, the higher fresh and dry weight were obtained. The dilution of MS basal salt was differently affected on fresh and dry weight; the highest fresh weight was found in 1x MS salt, while the higest dry weight was in 1/3x dilution.The addition of casein hydrolysate(3g/L) was more effective to increase of both fresh and dry weight. THe contents of protein was great in the inoculum lots with larger inoculum sizeand higher concentration of MS basal salts contenting 3g/L of casein hydrolysate and higher sucrose compared with others. The greatest protoplasts were isolated from the lot of 10 mesh size treated with 1%pectinase SE-150 and 2% cellulase YC. In general, for optimal protoplast isolation the followingconditions were recommended; 1) Use of smaller cell size cultured for 2-5 weeks, and 2) more than 5 hours incubation using the combined mixture of the enzymes with proper concentrations.

• The Korean Journal of Ecology
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• v.20 no.3
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• pp.169-173
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• 1997

The measurement of cell death constant in Anabaena flos-aquae was tested by the Live/Dead BacLight Viability kit(Molecular Probes Co., Seatle, WA). When the Live/Dead BacLight Viability kit was applied to Anabaena flos-aquae, the cells with intact cell membranes(live cells) stained fluorescent green, while the cell with damaged membranes(dead cells) stained fluorescent red and the background remained virtually nonfluorescent. The rations of live : dead cells in the cell suspension were controlled artifically and Live/Dead BacLight Viability kit was applied to them. The ratios of green:red fluorescent cells in the cell suspension were the same as those of live : dead cells controlled artifically. It was also approved by the fluorescence emission. The cell death constant was measured in the P-limited Anabaena flos-aquae chemostal culture in the N-fixing and $KNO_3-supplied$ conditions. The culture in N-fixing chemostat had a dead cell proportion of 1.2% at the growth rate of 0.7/day and increased to 2.6% at the growth rate of 0.3/day. The cell death constant of N-fixing culture was 0.008/day.There was a same trend in the $KNO_3-supplied$ chemostat culture. The proportion of dead cell was 1.6% of dead cell proportion at the growth rate of 0.7/day and increased to 4.3% at the growth rate of 0.3/day.

• Korean Journal of Plant Tissue Culture
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• v.27 no.3
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• pp.233-238
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• 2000

To obtain a basic information of the development of Genus Viola, morphological and histological observation of in vitro calli and cells in Viola culture cells were investigated. There were two callus types obtained by long term subculture of wild viola (Viola partrinii DC. ) petiole callus. One was friable callus - soft and pale green in color and small cells in size, and the other was compact callus - compact and deep bluish green in color, large cells in size. In scanning electron microscopic observation, friable callus was composed of voculated cell around small. cell clump, while compact callus was composed of cells filled with protoplasm Somatic embryogenesis was observed from suspension culture of the compact callus.

• Journal of Plant Biotechnology
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• v.1 no.2
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• pp.117-121
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• 1999

Effects of jasmonic acid treatment, UV-B and white light treatment on the anthocyanin biosynthesis and cell growth were investigated using the cell suspension culture system of grape (Vitis vinifera L.). Cell growth was not affected by white light irradiation, while it was remarkably suppressed by UV-B irradiation from 8 to 32 h. Anthocyanin accumulation dramatically increased after 16 h from irradiation of UV-B. Simultaneous treatment of jasmonic acid and UV-B increased anthocyanin accumulation by 10-fold. The cell division was restored when anthocyanin was abundantly accumulated after 32 h from UV-B irradiation. Optimum concentration of jasmonic acid was found to be 5 uM for maximum accumulation of anthocyanin. Application of jasmonic acid to grape suspension cells rapidly induced the expression of CHS gene after 2 h from treatment and showed maximum level at 32 h. Simultaneous treatment of jasmonic acid and light also induced CHS gene expression after 2 h, but the maximum level of CHS transcript was observed at 16 h with white light and 8 h with UV-B exposure. The synergistical effects could be explained by the defense mechanism that UV irradiation is mediated in part by alterations in JA and its signaling pathway.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.329-333
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• 2003

Human granulocyte-macrophage colony-stimulating factor (hGM-CSF) is a glycoprotein that stimulates the production of granulocytes, macrophages and white blood cells. hGM-CSF secreted by transgenic Nicotiana tabacum suspension cells was unstable in the culture medium and rapidly degraded by extracellular preteases. In order to reduce extracellular pretense activity, culture temperature was lowered. Then, the production of hGM-CSF by transgenic plant suspension cell cultures could be enhanced by reduced degradation of hGM-CSF at low temperature.

• KSBB Journal
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• v.19 no.5
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• pp.374-380
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• 2004

Production of therapeutic proteins by transgenic plant cell suspension cultures is an attractive system alternative to the other expression system. However, plant cell cultures have shown low expression level of foreign proteins and decreased cell viability by the changes of culture conditions. Therefore, it is necessary to enhance cell viability during the culture period. In this study, a quantitative analysis technique was designed to measure relative cell viability for plant suspension cells which have cell wall and aggregates. It was found that the programmed cell death of plant cells by apoptosis was essentially linked with the apoptotic pathway of animal cells. Therefore, effects of nicotinamide, 3-aminobenzamide and antioxidants on cell viability and apoptosis were examined in transgenic Nicotiana tabacum cells producing hGM-CSF. With those additives, cell viability could be maintained and apoptosis could be redued. In the result, the extracellular production of hGM-CSF could be enhanced 2.5 fold. It was also found that the supplementation of glutathione and ascorbic acid suppressed both the cold stress-induced decrease in cell viability and the increase of total genomic DNA fragmentation.

• Molecules and Cells
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• v.23 no.1
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• pp.100-107
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• 2007

The moss Physcomitrella patens has two life cycles, filamentous protonema and leafy gametophore. A modified from of suppression subtractive hybridization (SSH), mirror orientation selection (MOS), was applied to screen genes differentially expressed in the P. patens protonema. Using reverse Northern blot analysis, differentially expressed clones were identified. The identified genes were involved mainly in metal binding and detoxification. One of these genes was an AP2 (APETALA2) domain-containing protein (PpACP1), which was highly up-regulated in the protonema. Alignment with other AP2/EREBPs (Ethylene Responsive Element Binding Proteins) revealed significant sequence homology of the deduced amino acid sequence in the AP2/EREBP DNA binding domain. Northern analysis under various stress conditions showed that PpACP1 was induced by ethephon, cadmium, copper, ABA, IAA, and cold. In addition, it was highly expressed in suspension-cultured protonema. We suggest that PpACP1 is involved in responses to metals, and that suspension culture enhance the expression of genes responding to metals.