• 원예과학기술지
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• 제33권5호
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• pp.625-632
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• 2015

Drought is a severe abiotic stress that affects global crop production. A drought model was created for 'Toyonoka' Fragaria ${\times}$ ananassa, and the effects of drought stress on contents of proline, sugars, and antioxidant enzyme activities were investigated. Strawberry transplants with identical growth were chosen for the experiments and the randomized design included four replications (10 plants per block). The experimental sets differed in the moisture level of the culture medium relative to the range of moisture content as follows: control, 70-85%; mild drought stress, 50-60%; moderate drought stress, 40-50%; and severe drought stress, 30-40%. Drought stress was imposed by limiting irrigation. Plants were sampled and physiological parameters w ere measured on 0, 2, 4, 6, 8, and 10 days after the commencement of droughts tress. The water potential of strawberry leaves decreased in the plants under mild, moderate, and severe stress during the course of the water stress treatment and exhibited a significant difference from the control. Strawberry leaves subjected to drought stress had higher accumulation of proline, sugars, and malondialdehyde, and higher activities of superoxide dismutase, peroxidase, and catalase than leaves of control plants. Malondialdehyde levels increased in parallel with the severity and duration of drought stress. By contrast, antioxidant enzyme activity displayed dynamic responses to drought stress, first increasing and subsequently decreasing as the severity and duration of drought stress increased. These results suggest that strawberry plants respond to drought stress by altering the activities of antioxidant enzymes and the levels of osmotically active metabolites. These biochemical response changes may confer adaptation to drought stress and improve the capacity of plants to withstand water-deficit conditions.

• Animal cells and systems
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• 제8권Supplyment
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• pp.23-23
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• 2004

• Journal of Applied Biological Chemistry
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• 제64권1호
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• pp.39-48
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• 2021

가뭄은 작물의 성장과 생산성을 방해하는 비 생물학적 스트레스 중 하나다. 비 생물학적 스트레스에 대응하기 위해서는 식물이 불리한 환경 조건에서 스트레스에 나타내는 분자 조절 네트워크를 이해해야 한다. 비 생물학적 스트레스 (가뭄에 대응)에 대처할 수 있는 조합을 선별하기 위한 실험에서 스트레스 조건에서만 발현되는 5개의 가뭄 스트레스 유도성 프로모터를 선별하였으며, 이 중 36개의 cis-regulatory element를 선별하였다. 그 결과 가뭄 스트레스에서만 발현되는 유전자의 프로모터에서 cis-regulatory element를 새롭게 조합하여 미세 제어 조절을 할 수 있는 2 개의 합성프로모터(BL1, BL2)를 제작하였다. 합성프로모터를 포함한 형질전환식물(BL1-GUS, BL2-GUS)의 분석은 합성프로모터가 건조 조건에서 형질전환식물 내의 GUS 유전자의 발현을 증가시키는 것을 통하여 확인하였다. 또한 Transient activation assay를 통해 DREB1A와 DREB2C에 의해 합성프로모터가 활성화되는 것도 확인하였다. 이러한 결과는 가뭄 특이적인 cis-regulatory element의 조합에 의해 제작한 합성프로모터가 다양한 비 생물학적 스트레스에 반응하고, 식물의 성장 지연을 유발하지 않고 스트레스에 효과적으로 대응할 수 있을 것이라 예상할 수 있다.

• The Plant Pathology Journal
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• 제31권4호
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• pp.323-333
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• 2015

As sessile organisms, plants are exposed to persistently changing stresses and have to be able to interpret and respond to them. The stresses, drought, salinity, chemicals, cold and hot temperatures, and various pathogen attacks have interconnected effects on plants, resulting in the disruption of protein homeostasis. Maintenance of proteins in their functional native conformations and preventing aggregation of non-native proteins are important for cell survival under stress. Heat shock proteins (HSPs) functioning as molecular chaperones are the key components responsible for protein folding, assembly, translocation, and degradation under stress conditions and in many normal cellular processes. Plants respond to pathogen invasion using two different innate immune responses mediated by pattern recognition receptors (PRRs) or resistance (R) proteins. HSPs play an indispensable role as molecular chaperones in the quality control of plasma membrane-resident PRRs and intracellular R proteins against potential invaders. Here, we specifically discuss the functional involvement of cytosolic and endoplasmic reticulum (ER) HSPs/chaperones in plant immunity to obtain an integrated understanding of the immune responses in plant cells.

• 대한안전경영과학회지
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• 제12권4호
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• pp.31-39
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• 2010

The purpose of this study was to examine the effects of stress response on safety behavior and to explore moderating effect of safety climate between stress response and safety behavior. 224 workers were asked to respond to the questionnaires that measured various demographic variables, stress response, safety climates and safety behaviors. A hierarchical regression was conducted to identify variables that had significant relationships with safety behavior and to examine moderating effect of safety climate between stress response and safety behavior. Results indicated that the depression response significantly predicted safety behavior. It was found that the safety climate was also a significant predictor for safety behavior. In addition, safety climate had a moderating effect on the relation between depression and anger responses and safety behavior.

• Human Ecology Research
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• 제57권2호
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• pp.295-305
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• 2019

This study examined the effects of social comparison orientation and stress coping styles on job-seeking stress experienced by university students. The participants of this study were 324 junior and senior students (151 males and 173 females) from six universities located in Seoul who were preparing for employment. They were asked to respond to a written questionnaire to measure research variables for the Job-Seeking Stress Scale, the Social Comparison Orientation Scale, and the Ways of Coping Checklist. The data were analyzed by means of descriptive statistics and a hierarchical multiple regression. The major findings of this study were as follows. First, social comparison orientation had a positive effect on job-seeking stress of university students, revealing that students with a high level of social comparison orientation were more likely to experience job-seeking stress. Second, both emotion-alleviation coping style and wishful thinking coping style increased level of job-seeking stress. In addition, problem-focused coping style had a negative influence on job-seeking stress, whereas social support seeking coping style had no significant effect on it. The results suggested that it would be possible to reduce job-seeking stress of university students by changing either social comparison or stress coping style.

• Human Ecology Research
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• 제52권3호
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• pp.313-324
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• 2014

This study investigated the effects of acculturative stress and resilience on the depression of university students from North Korea, and examined the moderating effect of resilience on the relation between acculturative stress and depression. The participants of this study were 116 university students from North Korea (53 males and 63 females) aged between 20 and 35 years. The participants were asked to respond either to a written questionnaire or to an online survey system designed to measure research variables. The data were analyzed by using descriptive statistics and a hierarchical regression. The moderating effect of resilience was examined by means of a hierarchical regression. The major findings were as follows: first, an increase in the level of acculturative stress increased that of depression, whereas an increase in the level of resilience decreased that of depression. Second, the moderating effect of resilience on the relation between acculturative stress and depression was statistically significant. That is, the negative influence of acculturative stress on depression was greater when the level of resilience was low, compared to when it was high. In summary, both acculturative stress and resilience had significant effects on the depression of university students from North Korea. Moreover, resilience buffered the detrimental effect of acculturative stress on their depression.

• BMB Reports
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• 제33권4호
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• pp.344-348
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• 2000

The logarithmically growing Schizosaccharomyces pombe cells were subjected to high heat ($40^{\circ}C$), hydrogen peroxide, and heavy metals such as mercuric chloride and cadmium chloride. Then, the stress responses of catalase, glutathione S-transferase and thioltransferase were investigated. The high heat and cadmium chloride enhanced the catalase activity. The glutathione S-transferase activity of S. pombe cells was increased after treatments with heavy metals. The thioltransferase activity of S. pombe cells was completely abolished by mercuric chloride. Hydrogen peroxide caused no effect on the activities of glutathione S-transferase and thioltransferase. These results suggest that the response of S. pombe cells against oxidative stress is very complicated.

• Molecules and Cells
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• 제37권6호
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• pp.435-440
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• 2014

Hemodynamic shear stress, the frictional force acting on vascular endothelial cells, is crucial for endothelial homeostasis under normal physiological conditions. When discussing blood flow effects on various forms of endothelial (dys)function, one considers two flow patterns: steady laminar flow and disturbed flow because endothelial cells respond differently to these flow types both in vivo and in vitro. Laminar flow which exerts steady laminar shear stress is atheroprotective while disturbed flow creates an atheroprone environment. Emerging evidence has provided new insights into the cellular mechanisms of flowdependent regulation of vascular function that leads to cardiovascular events such as atherosclerosis, atherothrombosis, and myocardial infarction. In order to study effects of shear stress and different types of flow, various models have been used. In this review, we will summarize our current views on how disturbed flow-mediated signaling pathways are involved in the development of atherosclerosis.

• Journal of Microbiology and Biotechnology
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• 제25권1호
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• pp.50-56
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• 2015

During pretreatment of lignocellulosic biomass, a variety of fermentation inhibitors, including acetic acid and vanillin, are released. Using DNA microarray analysis, this study explored genes of the budding yeast Saccharomyces cerevisiae that respond to vanillin-induced stress. The expression of 273 genes was upregulated and that of 205 genes was downregulated under vanillin stress. Significantly induced genes included MCH2, SNG1, GPH1, and TMA10, whereas NOP2, UTP18, FUR1, and SPR1 were down regulated. Sequence analysis of the 5'-flanking region of upregulated genes suggested that vanillin might regulate gene expression in a stress response element (STRE)-dependent manner, in addition to a pathway that involved the transcription factor Yap1p. Retardation in the cell growth of mutant strains indicated that MCH2, SNG1, and GPH1 are intimately involved in vanillin stress response. Deletion of the genes whose expression levels were decreased under vanillin stress did not result in a notable change in S. cerevisiae growth under vanillin stress. This study will provide the basis for a better understanding of the stress response of the yeast S. cerevisiae to fermentation inhibitors.