• KOREAN JOURNAL OF CROP SCIENCE
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• v.35 no.1
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• pp.65-72
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• 1990

The mitotic cycle duration and component plase periods of rice (Oryza sativa L. 'Sumjinbyeo and Seokwangbyeo') root merisem cells at 15, 20, and 30$^{\circ}C$ were determined the use of tritiated thymidine, In this work, the time interval between the maxima of sequential mitotic appearances of marked cells was used to estimate the mitotic cycle duration (MCD) of rice, The MCD of rice of the cultivar 'Sumjinbyeo' and 'Seokwangbyeo' at 20. and 30$^{\circ}C$ was 12. and 20hr, respectively. But the MCD of 'Sumjinbyeo' and 'Seokwangbyeo' was 18 and 20hr, at 15$^{\circ}C$. respectively. The MCD decreased with increasing temperature, The duration of component phase of rice cultivar 'Seokwangbyeo' were essentially the same ratio at 20$^{\circ}C$ and 30$^{\circ}C$. but in 'Sumjinbyeo' cultivar the ratio of $G_1$ period was almost doubled while those of $G_2$ and M were decreased by almost two times at 20$^{\circ}C$ and 30$^{\circ}C$. Deoxyribonucleic acid (DNA). Ribonucleic acid (RNA), and protein synthesis were reduced with increasing temperature from 15$^{\circ}C$ to 30$^{\circ}C$ while the MCD was decreased, This result suggest that DNA, RNA and protein synthesis may not affect the MCD from 15$^{\circ}C$ to 30$^{\circ}C$ in rice.

• Korean Journal of Pharmacognosy
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• v.45 no.4
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• pp.326-331
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• 2014

In this study, we investigated pharmacologic activity of rice bran ethyl acetate fraction (RBE), based on their osteoblast enhancing effects. It has been found that REB have a stimulatory effect on the commitment of bi-potential mesenchymal precursor C2C12 cells into osteoblasts in the presence of BMP-2. Furthermore, RBE enhanced the BMP-2-stimulated induction of ALP, an early phase biomarker of osteoblast differentiation. In addition, Western blot analysis showed RBE enhanced the BMP-2-stimulated phosphorylation of p38, but not those of ERK or JNK. These findings show RBE has the potential to enhance the BMP-2-mediated commitment of C2C12 cells into osteoblasts and their differentiation through p38 activation.

• YAKHAK HOEJI
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• v.55 no.6
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• pp.456-461
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• 2011

The aim of the present study is to investigate the anti-inflammatory effect of a Rice Bran Ethanol Extract (RBE). Inflammation, such as a bacterial infection in vivo metabolites, such as external stimuli or internal stimuli to the defense mechanisms of the biological tissue a variety of intracellular regulatory factors deulin inflammatory TNF-${\alpha}$, IL-$1{\beta}$, IL-6, IL-8, such as proinflammatory cytokines, prostagrandin, lysosomal enzyme, free radicals are involved in a variety of mediators. The present study was designed to determine the effect of the RBE on pro-inflammatory factors such as NO, iNOS expression and TNF-${\alpha}$, IL-$1{\beta}$, IL-6 in lipopolysaccharide (LPS) - stimulated RAW264.7 macrophages cells. The cell toxicity was determined by MTS assay. To evaluate of anti-inflammatory effect of RBE, amount of NO was measured using the NO detection kit and the iNOS expression was measured by reverse transcriptase polymerase chain reaction (RT-PCR). And proinflammatory cytokines were measured by ELISA kit. As a result, the RBE reduced NO, iNOS expression and TNF-${\alpha}$, IL-$1{\beta}$, IL-6 production without cytotoxicity. Our results suggest that the RBE may have an anti-inflammatory property through suppressing inflammatory mediator productions and appears to be useful as an anti-inflammatory material.

• Mycobiology
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• v.47 no.2
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• pp.250-255
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• 2019

In the present study, we aimed to determine the cause of surface film formation in three rice vinegars fermented using the traditional static fermentation method. The pH and total acidity of vinegar were 3.0-3.3 and 3.0-8.7%, respectively, and acetic acid was the predominant organic acid present. Colonies showing a clear halo on GYC medium were isolated from the surface film of all vinegars. Via 16S rDNA sequencing, all of the isolates were identified as Acetobacter pasteurianus. Furthermore, field-emission scanning electron microscopy analysis showed that the bacterial cells had a rough surface, were rod-shaped, and were ${\sim}1{\times}2{\mu}m$ in size. Interestingly, cells of the isolate from one of the vinegars were surrounded with an extremely fine threadlike structure. Thus, our results suggest that formation of the surface film in rice vinegar was attributable not to external contamination, to the production of bacterial cellulose by A. pasteurianus to withstand the high concentrations of acetic acid generated during fermentation. However, because of the formation of a surface film in vinegar is undesirable from an industrial perspective, further studies should focus on devising a modified fermentation process to prevent surface film formation and consequent quality degradation.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.188-188
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• 2017

Rice (Oryza sativa L.) is one of the major crops that is seriously impacted by global soil salinization. Rice is among those crops where most of the high-yielding cultivars are highly sensitive to salinity. The key to a plant survival under NaCl salt stress is by maintaining a high $K^+/Na^+$ ratio in its cells. Selection for salinity tolerance genotypes of rice based on phenotypic performance alone is less reliable and will delay in progress in breeding. Recent advent of molecular markers, microsatellites or simple sequence repeats (SSRs) were used to find out salt tolerant rice genotypes. In the current experiment phenotyping and genotyping studies were correlated to differentiate different rice accessions for salinity tolerance. Eight rice accessions along with check plant Dongjin were screened by physiological studies using Yoshida solution with 50mM NaCl stress condition. The physiology studies identified four tolerant and four susceptible accessions based on their potassium concentration, sodium concentration, $K^+/Na^+$ ratio and biomass. 17 SSR markers were used to evaluate these rice accessions for salt tolerance out of which five molecular markers were able to discriminate tolerant accessions from the susceptible accessions. Banding pattern of the accessions was scored comparing to the banding pattern of Dongjin. The study identifies accessions based on their association of $K^+/Na^+$ ratio with molecular markers which is very reliable. These markers identified can play a significant role in screening large set of rice accessions for salt tolerance; these markers can be utilized to improve salt tolerance of commercial rice varieties with marker-assisted selection (MAS) approach.

• Animal cells and systems
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• v.8 no.4
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• pp.281-288
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• 2004

The change in relationships between methane production and sulfate reduction was investigated in reclaimed rice field soils at different time points after reclamation of tidal flat in Korea. Sulfate concentrations of soils in the ca. 60-year-old and 26-year-old reclaimed rice fields were much lower than that in a natural tidal flat. During 60 d of anaerobic incubation, total methane production and sulfate consumption of the soil slurries were 7.0 ${\mu}$mol $CH_4$/g and 8.2 ${\mu}$mol $SO_4^{2-}$/g in the 60-year-old rice field, 5.6 ${\mu}$mol $CH_4$/g and 12.7 mmol $SO_4^{2-}$/g in the 26-year-old rice field, and ca. 0 mmol $CH_4$/g and 22.4 ${\mu}$mol $SO_4^{2-}$/g in a natural tidal flat. Relative percent electron flow through sulfate reduction in the 60-year-old rice field was much lower (50.8%) compared with the 26-year-old rice field (69.3%) and the tidal flat (99.9%). The addition of an inhibitor of methanogenesis (2-bromoethanesulfonate) had no effect on sulfate reduction in the soil slurries of the reclaimed rice fields. However, instant stimulation of methane production was achieved with addition of an inhibitor of sulfate reduction (molybdate) in the soil slurries from the 26-year-old reclaimed rice field. The specific inhibitor experiments suggest that the relationship of methanogenesis and sulfate reduction might become mutually exclusive or syntrophic depending on sulfate content in the soil after reclamation. Sulfate, thus sulfate reduction activity of sulfate-reducing bacteria, would be an important environmental factor that inhibits methane production and determines the major pathway of electron and carbon flow in anaerobic carbon mineralization of reclaimed rice field soils.

• Applied Biological Chemistry
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• v.47 no.2
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• pp.222-227
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• 2004

Effects of the extracts from bran part of the pigmented rices on inflammation was evaluated by determining their inhibitory action on the production of nitric oxides, histamines and matrix metalloproteinase(MMP) from inflammatory leukocytes. Effects on the production of nitric oxides in a macrophage cell line, RAW264.7 cells, were determined, demonstrating that any significant difference was not detected between the normal rice and the pigmented rice extracts. Inhibitory effects on the histamine-release from a basophilic cell line, RBL-2H3, were examined, showing 3.6 to 5.4-fold increase in the inhibitory activity compared to that of the normal rices. Among the pigmented rice cultivars tested, especially, inhibitory activity of LK1-3-6-12-1-1 was the greatest. Using RAW264.7 cells, we examined the effect of the pigmented rice extracts on the MMP activity. The results showed that the enzyme activity increased with the increasing concentration of the normal rice extract. However, the pigmented rice extracts, except LK1A-2-12-1-l, acted to decrease the MMP activity with their increasing concentrations. The results described above showed the superiority of the pigmented rice extracts in inhibition on release of histamine and MMP, pivotal factors for causing inflammatory responses, from the leukocytes.

• Journal of Photoscience
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• v.11 no.1
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• pp.25-28
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• 2004

The kinetics of the loss of leaf fresh weight during incubation of barley and rice leaves in 9% or 15% NaCl solutions were biphasic, indicating the existence of a controlling mechanism for water transport. The first rapid phases reached their plateaus within 1 and 2 h in the case of rice and barley leaves, respectively. When barley leaves were fed with sodium fluoride, an inhibitor of phosphatase inhibitor, through their epicotyls for 3 h in darkness, prior to the treatment of NaCl, the biphasic pattern shown during NaCl treatment was disappeared resulting in linear decreases in the relative fresh weights. The results suggest that NaF accelerates salt-induced water efflux from plant cells, possibly by inhibiting the protection mechanism that may act in NaF-untreated leaves. The linear water loss can be explained in terms of phosphorylation of aquaporin by blocking its dephosphorylation in the presence of the phosphatase inhibitor to keep aquaporin in a phosphorylated form. However, the effect of NaF shown in barley leaves were not observed in rice. These results suggest that the regulation of water transport depends on plant species, and the mechanism for the controlling water transport in rice is different from that of barley.

• Mycobiology
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• v.30 no.4
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• pp.213-218
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• 2002

The induction of NAD(P)H: quinone oxidoreductase(QR), glutathione S-transferase(GST), and glutathione(GSH) levels in hepa1c1c7 cells(murine hepatoma) by waxy brown rice cultured with Phellinus igniarius to induce anticarcinogenic enzymes were measured. In addition, the inhibition of polyamines metabolism was tested with the growth of Acanthamoeba castellanii. The result shows that QR, GST activities, and GSH levels of experimental animals were increased much more by feeding the methanol extract of waxy brown rice cultured with Phellinus igniarius than those of the rats received the ethanol of uncultured brown rice. The growth of A. castellanii was inhibited mostly at 40 mg/3 ml concentration of methanol extract of waxy brown rice cultured with P. gniarius. The results suggested that waxy brown rice cultured with P. igniarius possess chemopreventive activity by inducing anticarcinogenic enzymes and inhibiting polyamine metabolism.

• Molecules and Cells
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• v.37 no.7
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• pp.532-539
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• 2014

We isolated a rice (Oryza sativa L.) WRKY gene which is highly upregulated in senescent leaves, denoted OsWRKY42. Analysis of OsWRKY42-GFP expression and its effects on transcriptional activation in maize protoplasts suggested that the OsWRKY42 protein functions as a nuclear transcriptional repressor. OsWRKY42-overexpressing (OsWR KY42OX) transgenic rice plants exhibited an early leaf senescence phenotype with accumulation of the reactive oxygen species (ROS) hydrogen peroxide and a reduced chlorophyll content. Expression analysis of ROS producing and scavenging genes revealed that the metallothionein genes clustered on chromosome 12, especially OsMT1d, were strongly repressed in OsWRKY42OX plants. An OsMT1d promoter:LUC construct was found to be repressed by OsWRKY42 overexpression in rice protoplasts. Finally, chromatin immunoprecipitation analysis demonstrated that OsWRKY42 binds to the W-box of the OsMT1d promoter. Our results thus suggest that OsWRKY42 represses OsMT1d-mediated ROS scavenging and thereby promotes leaf senescence in rice.