• Journal of Applied Biological Chemistry
• /
• v.43 no.1
• /
• pp.5-11
• /
• 2000

Three cDNA clones encoding rice calmodulin (CaM) isoforms (OsCaM-1, OsCaM-2, and OsCaM-3) were isolated from a rice cDNA library constructed from suspension-cultured rice cells treated with fungal elicitor. The coding regions of OsCaM-1 and O.sCaM-2 were 89% homologous at DNA Ievel, whereas the 5' and 3' untranslated regions were highly divergent. The polypeptides encoded by OsCaM-1 and OsCaM-2 was identical except two conservative substitution at position 8 and 75. The coding region of OsCaM-3 was consist of a typical conserved CaM domain and an additional C-terminal extension. The amino acid sequence of conserved CaM domain of OsCaM-3 shared only 86% identity with that OsCaM-1. The OsCaM-3 cDNA is belongs to a novel group of calmodulin gene due to its C-terminal extension of 38 amino acids, a large number of which are positively charged. The extension also contains a C-terminal CaaX-box prenylation site (CVlL). Genomic Southern analysis revealed at least six copies of CaM or CaM-related genes, suggesting that calmodulin may be represented by a small multigene family in the rice geneme. Expression of OsCaM gene was examined through Northern blot analysis. Transcript level of OsCaM-3 was increased by treatment with a fungal elicitor, whereas the OsCaM-1 and OsCaM-2 genes did not respond to the fungal elicitor. The expression of OsCaM-3 gene was remarkable inhibited in the rice cells treated with cyclosporine A, calcinurin inhibitor.

• The Plant Pathology Journal
• /
• v.36 no.3
• /
• pp.289-296
• /
• 2020

Type VI secretion system (T6SS) is a contact-dependent secretion system, employed by most gram-negative bacteria for translocating effector proteins to target cells. The present study was conducted to investigate T6SS in Xanthomonas oryzae pv. oryzae (Xoo), which causes bacterial blight in rice, and to unveil its functions. Two T6SS clusters were found in the genome of Xoo PXO99^A. The deletion mutants, Δhcp1, Δhcp2, and Δhcp12, targeting the hcp gene in each cluster, and a double-deletion mutant targeting both genes were constructed and tested for growth rate, pathogenicity to rice, and inter-bacterial competition ability. The results indicated that hcp in T6SS-2, but not T6SS-1, was involved in bacterial virulence to rice plants. However, neither T6SS-1 nor T6SS-2 had any effect on the ability to compete with Escherichia coli or other bacterial cells. In conclusion, T6SS gene clusters in Xoo have been characterized, and its role in virulence to rice was confirmed.

• Molecules and Cells
• /
• v.40 no.11
• /
• pp.828-836
• /
• 2017

Eukaryotic cells consist of a complex network of thousands of proteins present in different organelles where organelle-specific cellular processes occur. Identification of the subcellular localization of a protein is important for understanding its potential biochemical functions. In the post-genomic era, localization of unknown proteins is achieved using multiple tools including a fluorescent-tagged protein approach. Several fluorescent-tagged protein organelle markers have been introduced into dicot plants, but its use is still limited in monocot plants. Here, we generated a set of multicolored organelle markers (fluorescent-tagged proteins) based on well-established targeting sequences. We used a series of pGWBs binary vectors to ameliorate localization and co-localization experiments using monocot plants. We constructed different fluorescent-tagged markers to visualize rice cell organelles, i.e., nucleus, plastids, mitochondria, peroxisomes, golgi body, endoplasmic reticulum, plasma membrane, and tonoplast, with four different fluorescent proteins (FPs) (G3GFP, mRFP, YFP, and CFP). Visualization of FP-tagged markers in their respective compartments has been reported for dicot and monocot plants. The comparative localization of the nucleus marker with a nucleus localizing sequence, and the similar, characteristic morphology of mCherry-tagged Arabidopsis organelle markers and our generated organelle markers in onion cells, provide further evidence for the correct subcellular localization of the Oryza sativa (rice) organelle marker. The set of eight different rice organelle markers with four different FPs provides a valuable resource for determining the subcellular localization of newly identified proteins, conducting co-localization assays, and generating stable transgenic localization in monocot plants.

• Nutrition Research and Practice
• /
• v.10 no.3
• /
• pp.251-258
• /
• 2016

BACKGROUND/OBJECTIVES: Several pharmacological properties of red rice extract have been reported including anti-oxidant, anti-tumor, and reduced cancer cell invasion. This study was conducted to evaluate the anti-inflammatory effects of red rice extract on the production of inflammatory mediators in lipopolysaccharide (LPS)-induced Raw 264.7 macrophages. MATERIALS/METHODS: Pro-inflammatory cytokines including tumor necrosis factor-${\alpha}$ and interleukin-6 were determined by ELISA and cyclooxygenase-2 and inducible nitric oxide synthase expression was evaluated using western blot analysis. In addition, the signaling pathway controlling the inflammatory cascade such as nuclear factor kappa B ($NF-{\kappa}B$), activator proteins-1 (AP-1), and mitogen-activated protein kinase (MAPK) was determined. RESULTS: Our results showed that red rice polar extract fraction (RR-P), but not non-polar extract fraction, inhibited interleukin-6, tumor necrosis factor-${\alpha}$, and nitric oxide production in LPS-induced Raw 264.7 cells. RR-P also reduced the expression of inflammatory enzymes, inducible nitric oxide synthase, and cyclooxygenase-2. In addition, activation of AP-1 and $NF-{\kappa}B$ transcription factor in the nucleus was abrogated by RR-P. RR-P inhibited the phosphorylation of extracellular signaling-regulated kinase 1/2, c-Jun NH2-terminal kinase, and p38 MAPK signaling responsible for the expression of inflammatory mediators in LPS-stimulated Raw 264.7 cells. Based on chemical analysis, high amounts of proanthocyanidin and catechins were detected in the RR-P fraction. However, only proanthocyanidin reduced $NF-{\kappa}B$ and AP-1 activation in LPS-activated Raw 264.7 cells. CONCLUSION: These observations suggest that the anti-inflammatory properties of RR-P may stem from the inhibition of pro-inflammatory mediators via suppression of the AP-1, $NF-{\kappa}B$, and MAPKs pathways.

• Microbiology and Biotechnology Letters
• /
• v.5 no.1
• /
• pp.24-28
• /
• 1977

For the production of microbial cells from cellulosie materials by cellulore-assimilating bacteria, Cellulomonas flavigena GFB 24-1, isolated by authors, utilization of this organism on some microbiological properties was investigated. The results of these studies were summarized at follows; 1. When the organism was incubated in the growth medium at pH 7.0 for 50 hours, its growth was the most effective and the level of excreted total protein in the menstruum increased continuously during the stationary phase of cell growth. 2. The optimal enzyme activity was observed in the pH region of 5 to 7 and culture period of 40 to 50 hours. 3. The microbial degestibility of cellulosic wastes such as sawdust, rice hull, rice straw, peanut hull and used newspaper was less than 30％, whereas that of cellulose powder was 47.1％ and rice straw was digested 77％ by NaOH treatment. 4. Bacterial cells incubated in the growth medium were increased up to 8％ of sustrate concentration and showed a decrease on further concentration. 5. The production of microbial cells from NaOH treated rice straw was obtained 10.6mg/ml of culture medium.

• Preventive Nutrition and Food Science
• /
• v.19 no.4
• /
• pp.353-357
• /
• 2014

Phytic acid (myo-inositol hexakisphosphate) or phytate is considered an anti-nutrient due to the formation of precipitated complexes that strongly reduces the absorption of essential dietary minerals. In this study, brown rice with reduced phytate was made by inoculation with Lactobacillus sakei Wikim001 having high phytase activity. The effects of brown rice extract treated with L. sakei Wikim001 (BR-WK) on osteoblast differentiation and osteoclast formation were investigated. The proliferation of SaOS-2 cells was measured by the MTT assay. Treatment with BR-WK increased cell proliferation by 136% at a concentration of $100{\mu}g/mL$. The Alkaline phosphate activity in SaOS-2 cells was 129% higher when BR-WK was processed at a concentration of $100{\mu}g/mL$. The proliferation of bone marrow macrophages decreased by nearly 60% in response to treatment with BR-WK. In addition, BR-WK reduced the number of tartrate-resistant acid phosphatase-positive ($TRAP^+$) multinucleated cells from bone marrow macrophages. These results indicate that BR-WK stimulates bone formation through its positive action on osteoblast differentiation and function and furthermore, decreases osteoclast differentiation.

• Journal of Plant Biotechnology
• /
• v.36 no.1
• /
• pp.45-52
• /
• 2009

In order to understand the molecular interactions that occur between rice and the rice blast fungus during infection, we previously identified a number of rice blast fungal elicitor-responsive genes from rice (Oryza sativa cv. Milyang 117). Here, we report the cloning and characterization of the rice fungal elicitor-inducible gene Oshin1 (GenBank Accession Number AF039532). Sequence analysis revealed that the Oshin1 cDNA is 1067 bp long and contains an open reading frame encoding 205 amino acid residues. The Oshin1 gene shows considerable sequence similarity to the tobacco hin1 and hin2 genes. The predicted Oshin1 protein has a cysteine-rich domain at the N-terminus and is rich in leucine, serine, and alanine residues. Southern blot analysis suggests that Oshin1 gene is a member of a small gene family in the rice genome. To examine the expression of Oshin1, Northern blot analysis was conducted. Expression of the Oshin1 transcript is rapidly induced in suspension-cultured rice cells treated with fungal elicitor, salicylic acid or hydrogen peroxide. In addition, Oshin1 transcript levels are rapidly increased by treatment with $Ca^{2+}$/A23187. The expression of Oshin1 was also elevated in 3-week old leaf tissues upon ethephon application or fungal elicitor treatment. Our results suggest that the Oshin1 gene is involved in plant defense responses to environmental stresses.

• Molecules and Cells
• /
• v.21 no.2
• /
• pp.192-196
• /
• 2006

Salt tolerance was evaluated at the young seedling stage of rice (Oryza sativa L.) using recombinant inbred lines (MG RILs) from a cross between Milyang 23 (japonica/indica) and Gihobyeo (japonica). 22 of 164 MG RILs were classified as tolerant with visual scores of 3.5-5.0 in 0.7% NaCl. Interval mapping of QTLs related to salt tolerance was conducted on the basis of the visual scores at the young seedling stage. Two QTLs, qST1 and qST3, conferring salt tolerance, were detected on chromosome 1 and 3, respectively, and the total phenotypic variance explained by the two QTLs was 36.9% in the MG RIL population. qST1 was the major QTL explaining 27.8% of the total phenotypic variation. qST1 was flanked by Est12~RZ569A, and qST3 was flanked by RG179~RZ596. The detection of new QTLs associated with salt tolerance will provide important information for the functional analysis of rice salt tolerance.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.37 no.5
• /
• pp.397-404
• /
• 1992

The mitotic cycle duration(MCD) and component phase periods of rice(Oryza sativa L.) root meristem cells on the different salt concentrations were investigated by using of tritiated thymidine. The time interval between the maxima of sequential mitotic appearances of marked cells was used as criteria in measuring the MCD of rice. The MCD of rice cultivars 'Seomjinbyeo and Chilseongbyeo' at 0.0%, 0.3%, and 0.6% of salt concentrations appeared the same period as 12hr. The durations of component phase of rice cultivar 'Seomjinbyeo' were the almost same periods at 0.1%, 0.3%, and 0.6% of salt, but in 'Chilseongbyeo' cultivar the G1 and G2 periods were shorter while the S period was longer at 0.3% and 0.6% of salt. Deoxyribonucleic acid(DNA) and protein synthesis were increased while ribonucleic acid(RNA) synthesis was decreased with increasing salt concentrations at Chilseombyeo roots. In Seomjinbyeo roots, DNA and RNA synthesis were decreased while protein synthesis was increased with increasing salt concentrations. These results suggest that DNA, RNA, and protein synthesis may not affect the MCD in rice, but the increase of protein synthesis may be related to the salt tolerance of rice.

• Journal of Life Science
• /
• v.30 no.4
• /
• pp.352-358
• /
• 2020

Red yeast rice has been extensively used as a food and traditional medicine for thousands of years in Korea. Monascus produces many secondary metabolites during its growth, including pigments, monacolins, and γ-aminobutyric acid. Some metabolites, specifically monacolin K, γ-aminobutyric acid, and dimerumic acid, have been reported to lower cholesterol and blood pressure because of certain antioxidant effects. This study investigated the total phenolic content of ethanol extract from red yeast rice fermented with Monascus sp. BHN-MK and its anti-inflammatory effect on LPS-stimulated RAW 264.7 macrophage cells. To assess its anti-inflammatory effect, the inhibitory activity of the ethanol extract on LPS-induced NO production and expression levels of iNOS and COX-2 proteins in macrophage cells were measured. Its total polyphenol content was higher than that of ordinary non-fermented rice. Its NO production inhibition activity was comparable to that of the negative control group treated with LPS at a concentration of 400 ㎍/ml. Western blot revealed a significant decrease in the inhibition of iNOS and COX-2 protein expression at concentrations of 400 and 800 ㎍/ml, respectively. Red yeast rice ethanol extracts exerted the strongest anti-inflammatory effects. The results indicate that red yeast rice could be used as a functional cosmetic and anti-inflammatory material.