• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.93-93
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• 2017

To develop rice cultivars with increased biomass and grain yield, superior lodging resistance is an essential trait. The new breeding approach can be adopted for the improvement of stem lodging resistance by enhancing culm strength. The resistance to breaking type lodging is attributed to bending moment of basal culm (M), which is composed of the section modulus (SM) and bending stress (BS). The resistance to the bending type lodging is attributed to flexural rigidity (FR) of stem, which is composed of the secondary moment of inertia (SMI) and Young's modulus (YM). Starch and cell wall components such as cellulose, hemicellulose and lignin also play a significant role in physical strength of culm, and thus affect lodging. Leaf Star has a superior lodging resistance due to its thick and stiff culm because of its high M and FR compared with Koshihikari. Furthermore, Leaf Star contains high densities of hemicellulose, cellulose and low lignin density in culm compared with Koshihikari. In this study, we performed QTL analysis for these traits associated with culm strength, using 94 recombinant inbred lines (RILs, $F_8$), derived from a cross between Leaf Star and Koshihikari. The SM in the RILs showed a continuous distribution. QTLs for SM were detected on chrs.2, 3 and 10. Leaf Star alleles increased SM on chrs. 2 and 3, but Koshihikari allele increased on chr.10. These QTLs overlapped with those QTLs identified using backcrossed inbred line derived from a cross between Chugoku 117 and Koshihikari, the parents of Leaf Star. The FR in Leaf Star was higher than that in Koshihikari due to the larger SMI and YM. 3 QTLs for SMI were detected on chrs.2, 3 and 10. Leaf Star alleles increased SMI on chrs.2 and 3, and Koshihikari alleles increased on chr.10. One QTL on chr.3 and two QTLs on chr.5 for hollocelulose content were detected with Leaf Star alleles contribution. Moreover, two QTLs were detected for hemicellulose density on chrs.3 and 5. Leaf Star allele increased hemicellulose density on chr.5, and Koshihikari allele increased on chr.3. Furthermore, two QTLs for cellulose density were detected on chr.5, and one QTL on chr.2. For starch content, one QTL on chr.3 and two QTLs on chr.5 with Leaf Star alleles contribution were detected. TULK-6 carrying a chromosome segment of Leaf Star on chr.5 in the Koshihikari genetic background showed higher densities of starch and hemicellulose than those in Koshihikari. These results suggest that the detected QTLs for culm strength could be utilized for the improvement of lodging resistance in rice by marker-assisted selection.

• Korean Journal of Ecology and Environment
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• v.53 no.2
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• pp.165-172
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• 2020

Heavy metals are common pollutants in the freshwater environment and have toxicological effect in habitat organisms. The heavy metals highly accumulated in sediment and organism, and observed various physiological responses. In this study, we investigated the molecular response to heavy metal toxicity (Al, Aluminum; Cr, Chromium; Cu, copper; Mn, Manganese; Zn, Zinc) through expression of heat shock protein 40, 70, 90 (HSP40, 70, 90), cytochrome 450 (CYP450), Glutathione S-transferase (GST) and Serine-type endopeptidase (SP). HSPs showed up-regulation in Cu and Zn exposures. Furthermore, HSPs expression in treated groups tended to be higher than the control group. The tendency of CYP450 and GST mRNA expression was higher for Cr and Cu than for other exposure group. The expression of SP gene was low at Al exposure and other group were measured to be similar to control. These results suggest that heavy metal toxicity in freshwater ecosystem may affect physiological and molecular process. Also, the comprehensive gene expression in the aquatic midge Chironomus riparius give useful information to potential molecular biomarkers for assessing heavy metal toxicity.

• Korean Journal of Environmental Agriculture
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• v.29 no.3
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• pp.287-292
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• 2010

We aimed to investigate the responses of soil organisms to cover plants and to provide information for the selection of proper plant species. We studied the effects of 7 cover plants, including rye, oat, rattail fescue, Chinese milk vetch, red clover, crimson clover, and hairy vetch, on soil organisms in an apple orchard. An increase in the microbial phospholipid fatty acids (PLFA) and in the number of nematodes and microarthropods in the soil under the cover plants reflects elevated activities of soil organisms. A decrease in the level of some marker PLFA, which is an indicator of environmental stress, suggests that cover plants provide favorable environments for soil organisms. The population of fungi and animals that feed on fungi increased in the soil surface under red clover. The population density of nematodes and mites increased in the soil surface under rattail fescue, and that of mites and omnivorous nematodes increased in the soil surface under Chinese milk vetch. The level of microbial PLFA in the soil surfaces under the tested cover plants was higher than that under clean culture system. These results suggest that proper selection of the cover plants can facilitate the creation of favorable environments for soil organisms.

• Toxicological Research
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• v.17 no.3
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• pp.187-194
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• 2001

The oxidative stress causes the cell damage and death and thereby, stimulates membrane lipid peroxidation. In this study, the correlation between the lipid peroxidation product and the parameter of liver fibrosis (cirrhosis) was investigated in cholestasis induced rats. The Sprague-Dawley rats were divided into 3 groups (sham: sham operation, BDL/S-I and BDL/S-II : bile duct ligation/scission) and were observed for 2 or 4 weeks. After observation period, the organs were weighed and the ratio of organ weight/body weight was calculated. Sera and liver tissue were used for the measurement of malondealdehyde (MDA), parameter of clinical biochemistry, total collagen content and the staining. The ratio of organ weight/body weight in BDL/S-I and BDL/S-II was significantly increased compared to sham operated group. Serological parameters (Alanine transaminase, Aspartate transaminase, Alkaline phosphatase and Total bilirubin) in BDL/S-I and BDL/S-II group were significantly higher than those in sham operated group. Concentration of MDA in BDL/S-I (261%) and BDL/S-II(790%) was significantly increased compared to MDA in sham operated group. And the content of hydroxyproline (hyp) in BDL/S-I and BDL/S-II group was significantly increased 2~4 times than in sham operated group. The good correlations between hyp in liver tissue and MDA in sera of sham operated group and all operated group were found (r=0.825). The significantly higher value of MDA, hyp and serological parameters in BDL/S-I and BDL/S-II group suggests the stimulation of lipid peroxidation and chronic liver damage. Especially the activation of lipid peroxidation and the stimulation of liver fibrosis was stronger in BDL/S-II group than in BDL/S-I group. The stronger fibrosis, portal-portal septum formation, the more massive bile duct proliferation in portal triads and stroma, and hepatocytes swelling were observed in liver tissue of and BDL/S-II group compared to BDL/S-I group. Conclusively, a good correlation between MDA as a lipid peroxidation marker and hyp as a liver fibrotic parameter could be connected with the process of liver fibrosis. Moreover, cholestasis condition may cause jaundice, activation of lipid peroxidation, and collagen accumulation in liver. Additionally, optimal observation period of bile duct obstruction for the screening of antioxidant and antifibrotic effect in rats would be four weeks.

• Toxicological Research
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• v.30 no.1
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• pp.7-11
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• 2014

Malondialdehyde (MDA), used as an oxidative stress marker, is commonly assayed by measuring the thiobarbituric acid reactive substances (TBARS) using HPLC, as an indicator of the MDA concentration. Since the HPLC method, though highly specific, is time-consuming and expensive, usually it is not suitable for the rapid test in large-scale environmental epidemiologic surveys. The purpose of this study is to develop a simple and rapid method for estimating TBARS levels by using a multiple regression equation that includes TBARS levels measured with a microplate reader as an independent variable. Twelve hour urine samples were obtained from 715 subjects. The concentration of TBARS was measured at three different wavelengths (fluorescence: ${\lambda}-_{ex}$ 530 nm and ${\lambda}-_{em}$ 550 nm; ${\lambda}-_{ex}$ 515 nm and ${\lambda}-_{em}$ 553 nm; and absorbance: 532 nm) using microplate reader as well as HPLC. 500 samples were used to develop a regression equation, and the remaining 215 samples were used to evaluate the validity of the regression analysis. The induced multiple regression equation is as follows: TBARS level (${\mu}M$) = -0.282 + 1.830 ${\times}$ (TBARS level measured with a microplate reader at the fluorescence wavelengths ${\lambda}-_{ex}$ 530 nm and ${\lambda}-_{em}$ 550 nm, ${\mu}M$) -0.685 ${\times}$ (TBARS level measured with a microplate reader at the fluorescence wavelengths ${\lambda}-_{ex}$ 515 nm and ${\lambda}-_{em}$ 553 nm, ${\mu}M$) + 0.035 ${\times}$ (TBARS level measured with a microplate reader at the absorbance wavelength 532 nm, ${\mu}M$). The estimated TBARS levels showed a better correlation with, and are closer to, the corresponding TBARS levels measured by HPLC compared to the values obtained by the microplate method. The TBARS estimation method reported here is simple and rapid, and that is generally in concordance with HPLC measurements. This method might be a useful tool for monitoring of urinary TBARS level in environmental epidemiologic surveys with large sample sizes.

• Journal of Life Science
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• v.23 no.7
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• pp.904-912
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• 2013

This study aimed to evaluate the protective effect of cordycepin-increased Cordyceps militaris strain on carbon tetrachloride ($CCl_4$)-induced hepatotoxicity and oxidative stress in rats. Male Sprague-Dawley rats were randomly divided into five groups (n=6) based on six dietary categories: normal (N), $CCl_4$ control (C), $CCl_4$ plus Paecilomyces japonica (CPJ) (3%, w/w), $CCl_4$ plus C. militaris (CCM) (3%, w/w), and $CCl_4$ plus cordycepin-increased C. militaris ($CCM{\alpha}$) (3%, w/w). The activities of the liver marker enzymes ALT, AST, and LDH and the levels of lipid peroxidation were increased in the $CCl_4$-treated groups, but these parameters were significantly decreased in the $CCM{\alpha}$ group. The TBARS content in the liver homogenate, microsome, and mitochondrial fractions of the C group was significantly elevated compared with the N group. However, in the $CCl_4$-treated groups, $CCM{\alpha}$ group was significantly lowered in the TBARS levels of hepatic homogenate and microsomal fractions. The C group showed a significant decrease in the levels of plasma and hepatic glutathione, whereas they were significantly increased in the $CCM{\alpha}$ group. Accordingly, cordycepin-increased C. militaris may be an ideal animal model for studying hepatoprotective effects.

• Journal of Life Science
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• v.15 no.4 s.71
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• pp.607-612
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• 2005

Heat shock protein 70 (HSP70) is a multigene family composed of constitutively expressed members(Hsc70) and stress-inducible members (Hsp70). In the mammalian nervous system, a considerable amount of HSPs is also synthesized under normal conditions suggesting that they play an important role in the metabolism of unstressed cells. In this study we examined the expression of Hsp70 in the synapses of rat cerebellar neurons. Immunohistochemistry using specific antibodies revealed that both Hsp70 and Hsc70 are expressed in the cerebellar tissue, with strongest expression in Purkinje cells followed by granule cells. Neurons in deep cerebellar nuclei were also intensely stained by Hsp70 antibody. Immunocytochemical stainings of cultured cerebellar cells showed that Hsp70 is expressed in both Purkinje and granule cells. The expression was punctate in the soma and along dendritic trees, and the punctae were colocalized with those of PSD95, a postsynaptic marker. Immunoblotting also indicates that Hsp70 is associated with the postsynaptic density fraction. Taken together, our results indicate that the Hsp70 is expressed in cerebellar neurons in normal conditions, and that some are localized in the synapses.

• Journal of Applied Biological Chemistry
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• v.64 no.2
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• pp.165-170
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• 2021

In this study, the antioxidant effects of mineral-containing deep sea water (DSW) on kidney function was confirmed using a cell model. DSW samples were prepared with different mineral concentrations including calcium and magnesium-the main minerals found in DSW-to derive the following sample groups: trace minerals (TM), high magnesium (HM), high magnesium, low salt (HMLS) and high magnesium, high calcium (HMHC). The purpose of this preparation was to determine the optimal calcium/magnesium ratio in DSW. Human embryonic kidney (HEK293) cells were exposed to sodium chloride (NaCl) for 2 h to induce release of reactive oxygen species (ROS). Thereafter, the cells were treated with the respective DSW samples before ROS concentrations, as well as antioxidant enzyme activity and protein levels, were measured. Among the water samples, HMLS showed the most protective effect against ROS, whereas the intracellular glutathione content was highest in cells from the HMLS- and HMHC-treated groups. However, TM- and HMHC-treated cells showed similar tendencies to the control group, in terms of mRNA expression of antioxidant genes. These results suggested that DSW may aid in preventing renal oxidative stress caused by excessive sodium intake. Furthermore, it was determined that HMLS and HMHC water samples displayed good antioxidant effects in the kidney cell model, based on the combined results of ROS concentration and antioxidant marker measurements.

• Molecules and Cells
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• v.45 no.3
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• pp.134-147
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• 2022

The anti-oxidant enzyme heme oxygenase-1 (HO-1) is known to exert anti-inflammatory effects. From a library of pyrazolo[3,4-d]pyrimidines, we identified a novel compound KKC080096 that upregulated HO-1 at the mRNA and protein levels in microglial BV-2 cells. KKC080096 exhibited anti-inflammatory effects via suppressing nitric oxide, interleukin1β (IL-1β), and iNOS production in lipopolysaccharide (LPS)-challenged cells. It inhibited the phosphorylation of IKK and MAP kinases (p38, JNK, ERK), which trigger inflammatory signaling, and whose activities are inhibited by HO-1. Further, KKC080096 upregulated anti-inflammatory marker (Arg1, YM1, CD206, IL-10, transforming growth factor-β [TGF-β]) expression. In 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridinetreated mice, KKC080096 lowered microglial activation, protected the nigral dopaminergic neurons, and nigral damage-associated motor deficits. Next, we elucidated the mechanisms by which KKC080096 upregulated HO-1. KKC080096 induced the phosphorylation of AMPK and its known upstream kinases LKB1 and CaMKKbeta, and pharmacological inhibition of AMPK activity reduced the effects of KKC080096 on HO-1 expression and LPS-induced NO generation, suggesting that KKC080096-induced HO-1 upregulation involves LKB1/AMPK and CaMKKbeta/AMPK pathway activation. Further, KKC080096 caused an increase in cellular Nrf2 level, bound to Keap1 (Nrf2 inhibitor protein) with high affinity, and blocked Keap1-Nrf2 interaction. This Nrf2 activation resulted in concurrent induction of HO-1 and other Nrf2-targeted antioxidant enzymes in BV-2 and in dopaminergic CATH.a cells. These results indicate that KKC080096 is a potential therapeutic for oxidative stress-and inflammation-related neurodegenerative disorders such as Parkinson's disease.

• Asia Marketing Journal
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• v.15 no.3
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• pp.15-29
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• 2013

Shopping is considered a 'must-do' activity for most people on travel. One of the major parts of tourist shopping is the purchasing of souvenirs. Souvenirs are universally associated with tourism as a commercially produced and purchased object to remind the purchaser of the experience. Recently, Korea becomes one of the most popular destinations that many Asian tourists like to visit. Among those Asian tourists, the number of Thai tourists bound for Korea shows an incredible rapid growth. Thai people pick Korea and Seoul as their favorite country and city to visit for three consecutive years since 2009. One of the major reasons why Thais are choosing to tour Korea is the enthusiasm for Korean pop culture. That is, 'Hallyu' has influenced Thais' decision to visit Korea and purchase Korean products. The primary objective of the current research is to explore the shopping experiences of Thai tourists, specifically their souvenir shopping. It adopts a reflexive interpretive approach to bring light to the various meanings Thai tourists attach to the souvenirs they purchase in Korea. In order to accomplish the objective, the individual interviews were conducted. A total of 12 Thais who have experienced traveling in Korea participated in the study. Four themes were identified through interview text analysis. First, the research participants almost always purchase souvenirs in Korea because the souvenirs represent their identities as tourists. Especially, they purchase the souvenirs as gifts for others, including family members, friends, and colleagues. The souvenirs as gifts show love and thanks to others, and they cement the social relationship. However, purchasing souvenirs for others is more like the moral obligations which evoke the psychological stress. Secondly, the research participants feel closer to Korea while shopping souvenirs around. Thirdly, they obtain imaginative experiences and pleasure through souvenirs related to the Korean pop culture. Souvenirs provide them to visually extraordinary experiences. Lastly, souvenirs purchased in Korea act as visible status marker when they go back to Thailand. They show the socioeconomic status and lifestyles. Tourists themselves and others place special value to souvenirs that were purchased out of Thailand. The findings of this study are of both academic and practical importance. Souvenirs are among the most pervasive elements of the travel experience. However, souvenir shopping is the complicated consumer behavior within tourism both from business and social science perspectives. Along the same line, it needs strategic approaches in order to maximize the economy effects. It concludes by suggesting how further research could offer unique insights into how the souvenirs are positioned both in the context of tourism academics and industry.