• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.1
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• pp.54-58
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• 2014

Climate change may result in greater risk of yield reduction of waxy corn due to drought stress and maize is one of the sensitive crops to the soil moisture shortage. While irrigation is the most effective practice to reduce the drought damage, farmers are unable to apply water due to limited water resource and irrigating facilities. The study was conducted to investigate the application effect of salicylic acid and abscisic acid on reducing drought stress of waxy corn (Zea mays L.). Drought stress was imposed by withholding irrigation from 9 days before anthesis to 14 days after anthesis. Salicylic acid or abscisic acid was applied on tasseling date at concentration of 0.5 mM and 0.1 mM, respectively. Drought stress increased anthesis-silking interval (ASI) by 3.0~3.3 days and decreased plant height, ear length, ear diameter, number of rows in ear, and yield by 47~51 cm, 4.6~5.0 cm, 4.4~5.3 mm, 1.5~2.0, and 2.4~2.5 Mg/ha, respectively. Application of salicylic acid and abscisic acid did not significantly reduced the drought injuries of waxy corn. Pretreatment of the plant growth regulators before water deficit stress or divided application at low concentration may be required to obtain the reduction effect on drought stress of waxy corn.

• Journal of Life Science
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• v.14 no.3
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• pp.396-399
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• 2004

This study was investigated the changes of root length, tissue structure of root tip, and dry matter production of a Dongjinbyeo (DJ) cultivar subjected to 0.4 % agar medium with various concentration of NaCl (salt stress)- and polyethylene glycol 6000 (PEG, drought stress). Root length and dry weight of DJ plant were declined along the high concentration of PEG and NaCl in rice plants. To elucidate the changes of tissue structure in root tip to PEG- and NaCl-treatments, we examined the microscopic observation of root tip in NaCl- and PEG-treated rice plants using Toluidine blue O. By Toluidine blue O staining, methyl-lignin accumulation was found in the epidermis and outer cortex of the elongation zone at an early stage of PEG treatment, whereas was found only the outer cortex of the elongation zone of NaCl-treated root tip. The epidermis of NaCl-treated root tip became soften instead of methyl-lignin accumulation. TR ratio was increased along the high concentration in PEG- and NaCl-treated rice plant as a result of inhibited root elongation under PEG- and NaCl-treatment. From these morphological changes in root stimulated by drought and salt stress, we suggest that agar medium is useful to identify tolerant variety in germination stage under stressful environments.

• Journal of Life Science
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• v.13 no.1
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• pp.110-117
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• 2003

A thermotolerant yeast strain, Saccharomyces cerevisiae KNU5377 (abbreviated as KNU5377, was exposed to inorganic acids including sulfuric, nitric and hydrochloric acid. As a stressor, each inorganic acid is very easily dissociated in water, resulting in lowering environmental pH. When compared with a reference S. cerevisiae ATCC24858, KNU5377 could overcome such a severe condition containing a final 0.4% concentration of sulfuric acid or nitric acid to grow at the overnight culture, but this reference could not. Additionally, this strain showed a surprisingly strong tolerance by surviving despite of exposure to the regime of 0.35% of hydrochloric acid for over 90 min and also to 0.6% of sulfuric acid for 30 min. On the contrary, both strains could not survive against a final 0.45% concentration of nitric acid. This strain KNU5377 could produce ethanol of 3% in 2 days by using the fermentation medium containing a final 0.3% concentration of sulfuric arid. Moreover, change into a final 0.2% concentration of sulfuric acid caused this strain to enhance fermentation productivity up to about 4.5% even at $40^{\circ}C$. In exposure to a final 0.2% of sulfuric acid for 60 min, trehalose was most accumulated within 30 min in KNU5377, and this suggested a cellular defense system led by this disaccharide was profitable for this strain to lead to no morphological changes.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.7 no.2
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• pp.203-212
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• 1996

In this thesis, we investigate the psychosocial variables within the family environments of Attention Deficit Hyperactivity Disorder with (ADHD+CD/ODD) or without (ADHD) externalizing symptoms. The subjects in this research were 86 boys and girls(aged range 6 to 14 years) consisted of 20 ADHD, 22 comorbid ADHD(ADHD+CD/ODD) and 44 normal control group(NC). We have collected data on children and their mothers. The psychosocial variables included in the analysis are socioeconomic status, parent's educational level, life stress event, and the rate of psychiatric disorders in relatives. The self-reported questionnaires marital discord(MAS), parenting stress(PSI), and parenting attitute(MBRI) completed by mothers. The results indicated that ADHD+CD/ODD is supposed to have higher level of family adversity suggested by the lower SES, lower parental educational level, higher life stress events, and more psychic disorders in relatives compared with ADHD or normal control group. In MAS, ADHD+CD/ODD group has significantly the lowest scores on each factor of the measure of marital adjustment. Parents of ADHD+CD/ODD are much more likely to have positive parenting stress when compared with the parents of ADHD. Especially, mothers of ADHD+CD/ODD have the lowest tendency in the mean score on affective, accepted attitudd. In an inapropriate parenting attitude perceived by children, father of ADHD+CD/ODD have the most negative, contradictory attitude and mothers of ADHD+CD/ODD have the most restrictive, negative and contradictory attitude.

• Journal of Life Science
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• v.13 no.5
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• pp.658-667
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• 2003

Antioxidative enzymes (superoxide dismutase; SOD, ascorbate peroxidase; APX, glutathione reductase; GR) play major roles in scavenging mechanism of reactive oxygen species which were involved in various stress conditions including salt. In order to investigate the relation between their growth responses (dry weight) and the changes of antioxidative enzymes activity, salt-tolerant spinach beet having 15cm of shoot length were treated with various salt levels (0, 50, 200, 1000 mM NaCl) for 24 hours. Spinach beet exhibited an increase in the activity of antioxidative enzymes by salt, the maximal activity at 200 mM NaCl and the lowest activity at 50 mM NaCl in 2 hrs. after treatments. As a result of PAGE, it has been confirmed that spinach beet contained 3 isoforms (Fe-SOD, CuZn-SOD and Mn-SOD) of SOD and main isoform was CuZn- SOD form. In case of APX, isoforms of the low molecular weight(No. 7, 8) were showed strong expression especially at 200 and 400 mM NaCl treatment. Meanwhile, GR did not show specific pattern of isoforms among the salt treatments. Especially, in case of 50 mM treatment, plant showed the lowest activity of SOD with the best growth, a low enzyme activity was induced by inactivation of the Mn-SOD. Therefore, we suggested that the decrease of SOD activity at a low salt level (50 mM NaCl) or the increase of enzyme activity at a high salt level (200 mM NaCl) may be related to expression of the Mn-SOD isoform. These antioxidative enzymes showed the increase of activity in a short time by salt addition. So, it is considered that spinach beet copes effectively with a stressful condition such as salt by operating effective antioxidative defense mechanism rapidly under high salt level.

• Journal of Plant Biotechnology
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• v.43 no.2
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• pp.231-239
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• 2016

To study the transcript levels of epigenetically regulated genes in tobacco, we have developed a transgenic line OX1 overexpressing NtROS2a gene encoding cytosine DNA demethylation and a RNAi plant line RNAi13. It has been reported that salt- and $H_2O_2$-stress tolerance of these transgenic lines are enhanced with various phenotypic characters (Lee et al. 2015). In this paper, we conducted microarray analysis with Agilent Tobacco 4 x 44K oligo chip by using overexpression line OX1, RNAi plant line RNAi 13, and wild type plant WT. Differentially expressed genes (DEGs) related to metabolism, nutrient supply, and various stressed were up-regulated by approximately 1.5- to 80- fold. DEGs related to co-enzymes, metabolism, and methylation functional genes were down-regulated by approximately 0.03- to 0.7- fold. qRT-PCR analysis showed that the transcript levels of several candidate genes in OX1 and RNAi lines were significantly (p < 0.05) higher than those in WT, such as genes encoding KH domain-containing protein, MADS-box protein, and Zinc phosphodiesterase ELAC protein. On the other hand, several genes such as those encoding pentatricopeptide (PPR) repeat-containing protein, histone deacetylase HDAC3 protein, and protein kinase were decreased by approximately 0.4- to 1.0- fold. This study showed that NtROS2a gene encoding DNA glycosylase related to demethylation could regulate adaptive response of tobacco at transcriptional level.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.6
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• pp.1215-1219
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• 2001

The present study was conducted to investigate effect of powdered herb of Aster scaber Thunb. (chamchwi) on antioxidant system in ethanol-administrated rats. Four week-old Sprague Dawley male rats which had initial body weights of 97.10$\pm$4.50 g were randomly divided into three groups: control (ethanol treated, vitamin E-deficient group); 5% chamchwi (ethanol-treated, 5% chamchwi powder-supplemented group): 10% chamchwi (ethanol-treated, 10% chamchwi powder-suplemented group). Three groups of rats were suplemented with three experimental diets for 4 weeks and orally administrated 10% ethanol (v/v) daily via drinking water in the last experimental week. Contents of TBARS (thiobarbituric acid reactive substance). glutathione in liver and kidney and serum albumin were determined. The activities of superoxide dismutase (SOD), catalase and glutathione peroxidase (GSH-px) in liver and kidney were also analyzed. Relative weight of liver and spleen to body in chamchwi groups was lower than that in control group (p<0.05). The most remarkable result was that liver TBARS contents in chamchwi groups (5% chamchwi group, 46 $\mu\textrm{g}$ in MDA value; 10% chamchwi group, 35 $\mu\textrm{g}$) were significantly lower (p<0.05) than that in control group (66 $\mu\textrm{g}$). The supplement of chamchwi powder lowered the activity of manganese- superoxide dismutase (Mn-SOD), catalase in liver and GSH-px in kidney. The levels of glutathione in liver and kidney and serum albumin were not significantly different in all experimental groups (p<0.05). These results indicate that powdered herb of Aster scaber decreases lipid peroxidation and acitvity of Mn-SOD increased by alcohol-induced oxidative stress in liver of rats.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.41 no.1
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• pp.9-20
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• 2015

Ultraviolet radiation (UV) is a major cause of skin photoaging, and effective UV protecting agents are needed for the skin health and beauty. This study was undertaken to examine the effects of Bambusae caulis in Taeniam extract (BCTE) on UVB-induced cell death, oxidative stress and matrix metalloproteinase 1 (MMP1) expression in cell-based assays. HaCaT human keratinocytes were exposed to UVB in the presence of BCTE at different concentrations and resulting changes in cell viability and biochemical events were determined. The results showed that BCTE enhanced the viabilities of UVB-exposed cells, and attenuated apoptotic events such as cleavage of procaspase 3 to its active form, and the increase of Bax to Bcl-2 ratios. BCTE also attenuated the reactive oxygen generation and lipid peroxidation in cells exposed to UVB. Additionally, it attenuated the expression of matrix metalloproteinase 1 and the phosphorylation of c-Jun N-terminal kinase stimulated by UVB. Conclusively, the present study demonstrated that BCTE pro tected skin cells from the UVB-induced cell death, oxidative stress and MMP1 expression, suggesting its potential use as a cosmetic ingredient mitigating some features of the skin photoaging.

• Stress
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• v.26 no.4
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• pp.305-311
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• 2018

Background: The purpose of the study was to explore whether the effect of Huanglian-jie-du granule depends on the baseline heart rate variability in patients with Hwa-byung. Methods: We used the supplementary data from a randomized, double-blind, placebo-controlled trial of Huanglian-jie-du granule for Hwa-byung patients. Study drugs were taken orally three times per day for one week. Heart rate variability was measured three times; before the treatment, after the treatment, and month follow-up period. Spearman's rho test was done to explore the role of the baseline heart rate variability to the effect of Huanglian-jie-du granule. Results: Baseline low frequency power of heart rate variability was negatively correlated with the reduction of the insomnia severity index in experimental group (r=-0.493 p=0.02). Also, Huanglian-jie-de granule significantly decreased the low frequency power of heart rate variability in patients with Hwa-byung compared to placebo (mean difference 266 [95% CI: 29~503], p=0.028). In Hwa-byung symptoms, stuffy, pushing up in the chest, and flush of anger were correlated with low frequency power of heart rate variability (p=0.010, p=0.000, and p=0.016, respectively). Conclusions: The effect of the Huanglian-jie-de granule for insomnia seems to be lower when the baseline low frequency power of heart rate variability is higher in Hwa-byung patients. Also, Huanglian-jie-de granule is likely to decrease the sympathetic activity in patients with Hwa-byung. Measurement of heart rate variability may be the useful to understand the state of Hwa-byung patients.

• Journal of Korean Home Economics Education Association
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• v.32 no.4
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• pp.67-79
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• 2020

The purpose of the study were to analyze the patterns of adolescent suicide attempts, and to explore the effects of personal psychology (subjective depression, subjective stress), health status (BMI, subjective health perception), and subjective academic performance on the types of youth suicide attempts. For this research, data of 'The 15th Korea Youth Risk Behavior Survey' were analyzed employing a hierarchical logistic regression analysis. The findings are as follows. First, out of 1,731 youth suicide attempts 156 (9%) were impulsive and 1,575 (91%) were planned. Girls(67.3%) attempted suicide more than boys (32.5%), and middle school students (62%) attempted suicide more than high school students (38%). Second, the variables that significantly affect suicide attempt types were subjective depression, subjective stress, and subjective health perception, after controlling for gender, grade level, school type, and SES. The rate of planned suicide attempts was higher among those who experienced depression than among those who did not. In the case of subjective stress, adolescents who felt stressed were likely to commit planned suicide attempts. Those who attempted impulsive suicide showed 1.32 times higher subjective health perception scores than those who attempted planned suicide, indicating adolescents who perceived they were not healthy were more likely to attempt planned suicide. BMI and subjective academic performance did not have a significant effect on the types of youth suicide attempts. These findings suggested the necessity of systematic intervention in Home Economics classes or extra-curricular programs, to prevent potential youth suicide attempts.