• Journal of Plant Biotechnology
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• v.4 no.2
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• pp.83-89
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• 2002

To establish in vitro mass production system of grape anthocyanin pigments through callus and cell suspension culture, the effects of nitrogen amount and the ratio of $NO_3^-$/$NH_4^+$ in the medium on cell growth and anthocyanin production were investigated. Total nitrogen amount and the ratio of $NO_3^-$/$NH_4^+$ in the medium strongly affected anthocyanin production and cell growth. When $NH_4^+$ was fixed, the cell growth was promoted by 50 mM total nitrogen (20 mM $NO_3^-$ : 30 mM $NH_4^+$ ) than other nitrogen combinations, and was strongly inhibited when $NO_3^-$ was lacking (0 mM $NO_3^-$ : 60 mM $NH_4^+$ ) while anthocyanin production was increased. When $NO_3^-$ was fixed, the cell growth was promoted by 70 mM total nitrogen (40 mM $NO_3^-$ : 30 mM $NH_4^+$) than other nitrogen combinations, and was strongly inhibited when $NO_3^-$ was lacking (0 mM $NO_3^-$ : 60 mM $NH_4^+$ ) while anthocyanin production was increased. Cell growth was gradually increased by all nitrogen combinations, but anthocyanin production reached its peak on day 4 in culture. Anthocyanin content increased with decreasing cell density. Sucrose was rapidly hydrolyzed to fructose and glucose within 4 days. Glucose and fructose concentrations in the medium increased and peaked at the 4th day. The anthocyanin content of $NH_4^+$-free 2% sucrose media was 2 times (200 $\mu\textrm{g}$/g) higher than that of 1% sucrose. When $NO_3^-$ was lacking, the highest anthocyanin production was observed at 4% sucrose after 12 days of culture, and increased along with the sucrose concentration.

• 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.

• Korean Journal of Plant Tissue Culture
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• v.21 no.3
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• pp.167-171
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• 1994

This study was carried out to investigate the possibility of plant regeneration through somatic embryogenesis in suspension culture of Aralia elata S. Callus was induced from the explants of leaf and petiole cultured in the MS media containing 2,4-D and TDZ. More embryogenic calli were formed from petiole and with combination treatment of 24-D and TDZ. The quarter strength MS medium was effective for increasing number of somatic embryos. Mannitol supplemented to the quarter strength MS medium, reduced somatic embryo formation but inositol increased. Normal plantlets(86%) were regenerated from mature somatic embryos in MS basal medium and 50% of those survied when transplanted to the vermiculite in greenhouse.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.96.1-96
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• 2003

Serratia plymuthim A21-4 strongly inhibits the mycelial growth, zoospore formation, and cystospore germination of Phytophthor spp and Pythium species. The bacterial isolate produced antifungal substance and chitinase. The bacteria also enhanced to plant growth remarkably in low nutritional condition. The application of cell suspension of A21-4 to pepper seedlings in greenhouse experiments and soil drenching in farmer's field was proved successfully to control the phythophthora blight of pepper. For the effective control, however, relatively high density of cell number(10$\^$9/cfu/$m\ell$) is required. Density effect was similar in plant growth promoting activity of A21-4. Though this investigation we improved the problem with changes of culture condition of bacteria and some nutritional amendment.

• Korean Journal of Weed Science
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• v.15 no.2
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• pp.148-153
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• 1995

Glyphosate (N-[phosphonomethyl]glycine) applied to the assimilate-exporting leaves or sprayed to the whole plants of tomato(Lycopersicon esculentum Mil var. Moneymaker) induced the rapid inhibition of 5-enolpyruvyl skimic acid 3-phosphate synthase(EPSP-synthase). It shows that EPSP-synthase activity precedes chlorophyll loss. There is no difference in EPSP-synthase activity between in vivo tomato meristem and cell suspension culture if glyphosate is not applied. The EPSP-synthase activity is in a range of 4 to 6 nkat per mg protein. The inhibition of EPSP-synthase action is induced within 36 h after glyphosate application while the Chl contents were reduced 48 h after the application. In cell suspension culture of tomato and Corydalis (Corydalis sempervirens), a sublethal concentration of glyphosate retards the fresh weight increase and prolonged lag phase. The fresh weight is reached maximal about 14 days after the subculture in the presence of glyphosate. The inhibitory effect of glyphosate on EPSP-synthase is remarkably induced in lag phase.

• Korean Journal of Plant Tissue Culture
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• v.27 no.4
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• pp.245-258
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• 2000

Somatic embryogenesis has become a major tool in the study of plant embryology, as it is possible in culture to manipulate cells of many plant species to produce somatic embryos in a process that is remarkably similar to zygotic embryogenesis. Traditionally, the process has been studied by an examination of the ex vitro factors which influence embryo formation. Later structural, physiological and biochemical approaches have been applied. Host recently, molecular tools are being used. Together, these various approaches are giving valuable information on the process. This article gives an overview of somatic embryogenesis by reviewing information on the morphogenesis, physiology, biochemistry and molecular biology of the process. Topics covered include a brief description of the factors involved in the production of embryogenic cells. Carrot cell suspension is most commonly used, and the development of a high frequency and synchronous system is outlined. At the physiological and biochemical lev-els various topics, including the reactivation of the cell cycle, changes in endogenous growth regulators, amino acid, polyamine, DNA, RNA and protein metabolism, and embryogenic factors in conditioned medium are all discussed. Lastly, recent information on genes and molecular markers of the embryogenic process are outlined. Somatic embryogenesis, the best example of totipotency in plant cells, is not only an important tool in studies in basic biology, but is potentially of equal significance in the micropropagation of economically important plants.

• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.3
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• pp.138-149
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• 2002

Plant cell culture provides a viable alternative over whole plant cultivation for the production of secondary metabolites. In order to successfully cultivate the plant cells at large scale, several engineering parameters such as, cell aggregation, mixing, aeration, and shear sensitivity are taken into account for selection of a suitable bioreactor. The media ingredients, their concentrations and the environmental factors are optimized for maximal synthesis of a desired metabolite. Increased productivity in a bioreactor can be achieved by selection of a proper cultivation strategy (batch, fed-batch, two-stage etc.), feeding of metabolic precursors and extraction of intracellular metabolites. Proper understanding and rigorous analysis of these parameters would pave the way towards the successful commercialization of plant cell bioprocesses.

• Journal of Plant Biotechnology
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• v.31 no.2
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• pp.163-167
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• 2004

The effects of sucrose concentration on the secretion of hGM-CSF, total protein and protease into the medium were investigated in transgenic tobacco cells. The dry cell weight (11.22 g/L), hGM-CSF (181.53 $\mu\textrm{g}$/L) and total protein (66.8 mg/L) were detected as highest at 30 g/L sucrose and protease activity (2660 U/L) was highest at 120 g/L sucrose after 5-day culture. However after 10-day culture, the maximum dry cell weight (28.36 g/L) was found at 60 g/L sucrose while the maximum hGM-CSF (95 $\mu\textrm{g}$/L) was appeared at 150 g/L sucrose. The total protein and protease activity was secreted as 52.28mg/L and 3430 U/L, respectively in the same culture.

• Korean Journal of Plant Tissue Culture
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• v.22 no.2
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• pp.115-120
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• 1995

A method for cryopreservation of suspension cultured embryogenic cells derived from immature zygotic embryos of rice (Korean cultivars, Donggin-byeo and Taebaeg-byeo) was developed. The highest cell regrowth after storage in liquid nitrogen was obtained when Donggin-byeo cells were cryoprotected with a mixture of 2 M DMSO and 0.4 M sucrose and Taebaeg-byeo cells with a mixture of 0.64 M DMSO and 0.4 M sucrose at frequencies of 88% and 90%, respectively, Pretreatment in a high osmotic medium was not necessary. Upon transfer to $N_{6}$ medium suplemented with lmg/L NAA and 5 mg/L kinetin, the regenerated calli gave rise to numerous somatic embryos which subsequently underwent development into plantlets. Among approximately 100 plantlets, 25% of them were albinos.s.

• Korean Journal of Plant Tissue Culture
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• v.27 no.5
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• pp.375-377
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• 2000

It is now generally accepted that a phosphoinositide cycle is involved in the transduction of a variety of signals in plant cells. In animal cells, the hydrolysis of phosphatidyl-4,5-bisphosphate catalysed by phosphatidylinositol - specific phospholipase C yields to D-myo-inositol - 1,4,5-trisphosphate and diacylglycerol, which are well known second messengers. The binding of InsP$_3$to a receptor located on the endoplasmic reticulum triggers a calcium release from the endoplasmic reticulum. We have detected and partially characterised key components of phosphoinositide signaling. First, tobacco microsomal fraction and plasma membrane PI-PLC. Consecutively, using a radioligand binding assay we have identified a $Ca^{2+}$ -dependent high affinity InsP$_3$binding site in microsomal membrane fraction vesicle preparation and then we have measured inositol-1,4,5-trisphosphate induced calcium release from tobacco microsomal fraction. These findings suggest that phosphoinositide signaling system is present and operates in the tobacco suspension culture.e.