• Korean Journal of Plant Tissue Culture
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• v.24 no.5
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• pp.295-303
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• 1997

To investigate the response on feeder cell cultures, protoplasts isolated from cell suspensions initiated from mature seed scutellum-derived callus of the Japonica rice variety Taipei 309, were cultured on filter membranes under various conditions. The effects of various factors, such as gelling agents, feeder cell and protoplast densities, species of feeder cells and heat shock treatment, have been investigated to improve protoplast plating efficiencies on filter membranes. Maximum protoplast plating efficiencies were obtained when protoplasts were cultured on KPR medium semi-solidified with Sea Plaque agarose at a density of $5\;\times\;10^{5}\;ml^{-1}$ protoplasts in the presence of Lolium multiflorum as feeder cells (0.5 ml pcv per 10 ml of protoplast culture medium). Pre-culture heat shock treatments for 1 min. and 5 min. to the protoplasts did not give any appreciable increase on the plating efficiency of protoplasts in the presence of feeder cells. Maltose-supplemented medium was superior for plant regeneration from protoplast-derived colonies compared with medium containing only sucrose. The plants were transferred to the glasshouse, flowered and were fertile.

• Korean Journal of Plant Tissue Culture
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• v.25 no.1
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• pp.7-11
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• 1998

Protoplasts were isolated from the parenchyma supension cultured cells of Streptanthus tortus using hydrolytic enzymes, 0.03% cellulase + 0.02% pectinase. Phloem cells and companion protoplasts were isolated from differentiated suspension cultured cells using hydrolytic enzymes, 0.2% macerase + 0.03% cellulase + 0.02% pectinase + 0.025% rohamet PC. Isolated parenchyma -and companion- protoplasts transported glucose into the cells, but not transported sucrose at all. On the other hand, isolated phloem cells transported sucrose into the cells actively, but not transported glucose. These results show for the first time that loading of sucrose into the phloem cells without nucleus was possible without contributing of companion cells and companion cells had not the ability to transport sucrose directly because of lack of sucrose carriers in the membrane. The sucrose transport into the isolated phloem cells depend on metabolic energy.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2005.04a
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• pp.92.1-92.1
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• 2005

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2002.04b
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• pp.146-146
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• 2002

• Proceedings of the Plant Resources Society of Korea Conference
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• 2001.11b
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• pp.71-71
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• 2001

• Journal of Plant Biotechnology
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• v.1 no.1
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• pp.61-68
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• 1999

Rapid accumulation of reactive oxygen species (ROS) and their toxic reaction products with lipids and proteins significantly contributes to the damage of crop plants under biotic and abiotic stresses. We have identified several stress activated alfalfa genes, including the gene of the alfalfa ferritin and a novel NADPH-dependent aldose/aldehyde reductase enzyme. Transgenic tobacco plants that synthesize alfalfa ferritin in vegetative tissues-either in its processed form in chloroplast or in the cytoplasmic non-processed form-retained photosynthetic function upon free radical toxicity generated by paraquat treatment and exhibited tolerance to necrotic damage caused by viral and fungal infections. We propose that by sequestering intracellular iron involved in generation of the very reactive hydroxyl radicals through a Fenton reaction, ferritin protects plant cells from oxidative damage. Our preliminary results with the other stress-inducable alfalfa gene (a NADPH-dependent aldo-keto reductase) indicate, that the encoded enzyme may play role in the stress response of the plant cells. These studies reveal new pathways in plants that can contribute to the increased stress resistance with a potential use in crop improvement.

• Journal of Plant Biology
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• v.39 no.2
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• pp.107-112
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• 1996

To study the compensatory aspect of putrescine biosynthetic enzyme n tobacco suspension cultured cells, we examined the contents of the cellular polyamines and the activities of arginine decarboxylase (ADC, EC 4.1.1.19) and ornithine decarboxylase (ODC, EC 4.1.1.17) in the tobacco suspension cells treated with $\alpha$-difluoromethyl arginine (DFMA) or $\alpha$-difluoromethyl ornithine (DFMO). In the untreated cells, the content of the cellular putrescine was decreased during the first 3 hours and then subsequently increased. However, the content of the cellular spermidine and spermine remained constant during the incubation time. While ADC activity increased after 6 hours, ODC activity decreased following the rapid increase until 6 hours. DFMA induced the decrease in the contents of putrescine and spermidine, and the increase in that of spermine. It also caused the inhibition of ADC and ODC activities throughout the incubation time. DFMO produced the stimulation of ADC activity about 2 times of untreated cells and the decrease in the content of putrescine about 50% of them at 12 hour. The application of putrescine or cycloheximide prevented the increase of ADC activity by DFMO but that of actinomycin-D did not show any detectable effect. The stimulation of ADC activity by DFMO in tobacco suspension cultured cells was probably due to the enhancement of de novo synthesis for ADC protein, which might be regulated in the translation step by the content of the cellular putrescine.

• Journal of Plant Biology
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• v.35 no.4
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• pp.359-364
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• 1992

The vascular cambium in Ginkgo biloba seedling began to differentiate in the cotyledonary node, and then the differentiation proceeded bidirectionally from the cotyledonary node toward the stem and root. In tangential view, procambium at the early developmental stage was a homogeneous structure consisted of almost similar cells in shape, and at the later stage the procambium became a heterogeneous one consisted of long cells and short cells. Such a differentiation pattern in the cotyledonary node was similar to that in the stem. However, it was different from that in the root. Fusiform initials and ray initials consisting the vascular cambium were originated from the long cells and the short cells, respectively. The long cells and the fusiform initials in the cotyledonary node were shorter and wider than those in the first internode.ernode.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.04a
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• pp.92-92
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• 2018

Solanum nigrum L. (SNL), generally known as black nightshade, is traditionally used as medicine to reduce inflammation caused by several diseases like asthma, chronic bronchitis and liver cirrhosis. In this study, anti-inflammatory effects of SNL extract were examined and possible molecular mechanisms of the anti-inflammatory effects were investigated. The inhibitory effects of SNL extract on nitric oxide (NO), pro-inflammatory cytokines ($TNF-{\alpha}$, IL-6) and Matrix metallopeptidase 9 (MMP-9) productions were dissected using lipopolysaccharide (LPS) stimulated murine macrophage-like cell line Raw264.7 cells and human microglial cell line BV2 cells. We further investigated whether SNL extract could suppress the phosphorylation of ERK1/2, JNK, and p38 and the nuclear expression of nuclear factor $NF-{\kappa}B$ p65 in LPS-stimulated Raw264.7 cells and BV2 cells. As a result, we showed that the SNL extract significantly decreased the production of pro-inflammatory cytokines, NO, and MMP-9. In addition, the SNL strongly inhibited the phosphorylation of ERK1/2, JNK, p38 and nuclear translocation of $NF-{\kappa}B$ p65 in activated cells. We confirmed that the extracts of SNL effectively inhibits the anti-inflammatory and may be used as a therapeutic to various inflammatory diseases.

• International Journal of Oral Biology
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• v.42 no.1
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• pp.9-15
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• 2017

Microglia have multiple functions in regulating homeostasis of the central nervous system. Microglia cells have been implicated as active contributors to neuron damage in neurodegenerative disorders. In this study, medicinal plant extracts (MPEs) were used to evaluate the cell-death induction effect in microglia BV-2 cells. Among 35 MPEs tested in this study, 4 MPEs showed less than a 30% cell survival after 24 hours of incubation. These were Foeniculi Fructus, Forsythiae Fructus, Zingiberis Rhizoma and Hedera Rhombea. The concentration showed that 50% cell death ($IC_{50}$) occurred with 33, 83, 67 Ed highlight: Please confirm wording, and $81{\mu}/ml$, respectively. For further study, we chose Zingiberis Rhizoma (ZR) which showed a reasonably low $IC_{50}$ value and an induction of cell death in a relatively narrow range. Western blot analysis showed that ZR-treated cells showed activation of caspase-3 and cleavage of PARP Ed highlight: When an acronym is first presented it needs to be spelled out in both dose- and time-dependent manners. However, the level of Bcl-2 and Bax were not changed by ZR-treatment in BV-2 cells. These results suggest that ZR-induced apoptosis in BV-2 cells occured through caspase-3 activation. The results also suggested that ZR may be useful in developing treatments for neurodegenerative diseases.