• 생명과학회지
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• 제27권7호
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• pp.826-833
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• 2017

대기의 이산화탄소의 농도 증가는 해양산성화와 지구온난화를 유발하는 것으로 알려져 있다. 해마는 해양생태계 및 수산자원생물로서 중요한 종으로 알려져 있지만, 최근 해양산성화로 인하여 개체수가 감소되고 있는 실정이다. 따라서 본 연구에서는 멸종 위기 종인 복해마(Hippocampus kuda)에 미치는 생리적 영향을 조사하기 위해서 사육수의 산성조건인 pH 6.0, 6.5, 7.0 및 자연해수(pH 8.0)의 환경에서 복해마(H. kuda)를 15일 동안 사육 후 체내 조성 변화 및 항산화 효소 활성 변화에 대하여 조사를 실시하였다. 복해마(H. kuda)의 크기 및 성장은 대조군인 pH 8.0을 제외한 실험군에서는 pH가 저하함에 따라 감소하는 경향을 나타내었다. 체내 조성성분인 회분, 조지방 및 조단백 또한 pH 저하에 따라 농도의존적으로 감소하는 것이 관찰되었다. SOD, CAT 및 GSH와 같은 항산화 효소의 분석 결과, SOD활성의 경우, pH 저하에 따라 농도의존적으로 감소하지만, 이와 상반되게 CAT 및 GSH에서는 pH저하에 따라 활성이 농도의존적으로 증가하는 결과가 나타내었다. 이것은 복해마(H. kuda)가 사육수의 pH 저하에 따른 체내 항상성을 유지하는 과정 중 스트레스가 야기되어 에너지 대사가 손상된 것으로 추정된다. 항산화효소는 일반적으로 산성화 스트레스에 민감하게 작용하는데 본 연구에서도 사육수의 pH 변화에 따라 항산화 효소작용이 유의하게 변화하였다. 이러한 결과로 복해마(H. kuda)에 있어서 산성화 노출을 통한 생리학적 스트레스가 항산화 반응 및 체내 성분과 성장을 저해하는 것으로 여겨진다.

• 생명과학회지
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• 제23권4호
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• pp.487-494
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• 2013

T-DNA가 표지된 집단에서 AlaAT 유전자가 깨어진 돌연변이체(alaat)를 분리하고, AlaAt1 특이 프라이머를 이용하여 유전자형을 결정하였다. Alaat의 표현형은 대조구와 비교해서 생장의 감소를 보였고, 종자 역시 작고 생산성의 감소를 보였다. 돌연변이체의 AlaAT 활성은 거의 검출되지 않았다. 고염 스트레스 하에서 alaat의 반응을 엽록소 형광과 항산화 효소들의 활성 및 RT-PCR을 이용하여 대조구와 비교하였다. 고염, 건조 및 저온과 같은 모든 비생물적 스트레스에 대한 Fv/Fm은 대조구와 alaat 둘 다 감소를 보였으며, 비생물적 스트레스에 대한 엽록소 형광은 거의 유사하였다. 항산화 효소인 peroxidase (POX)의 활성은 고염 스트레스에 의해 대조구는 증가하나 alaat에서는 오히려 감소하였다. RT-PCR에 의한 cAPX, POX 및 AlaAT mRNA의 수준을 분석한 결과, 효소 활성과 마찬가지로 AlaAt mRNA는 alaat에서 나타나지 않았고, POX2 mRNA는 대조구는 약간의 증가를 보이나 alaat는 거의 검출할 수 없었다. cAPX mRNA는 대조구와 alaat 모두 고염 스트레스에 의해 크게 증가하였다. 이 같은 결과는 AlaAT 유전자 기능의 상실은 염 스트레스 하에서 벼 식물의 생장에 대해 광합성능 보다는 항산화 효소, 특히 POX 활성 및 합성을 변화시킬 수 있음을 제안한다.

• 한국작물학회지
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• 제47권5호
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• pp.341-351
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• 2002

In order to examine the mechanistic basis for differential sensitivities to chilling and subsequent recovery between two rice (Oryza sativa L.) cutivars, a chilling-tolerant japonica type (Ilpumbyeo) and a chilling-susceptible indica type (Taebaekbyeo), changes of physiological responses and antioxidant enzymes were investigated. Both cultivars at 3 leaf stage were exposed at a low temperature of $5^{\circ}C$ for 3 days and subsequently recovered in a growth chamber at a $25^{\circ}C$ for 5 days with 250 mmol $m^{-2}$ $s^{-1}$. Physiological parameters such as leaf fresh weight, relative water content, cellular leakage, lipid peroxidation, and chlorophyll a fluorescence showed that the chilling tolerant cultivar had a high tolerance during chilling. However, the chilling-susceptible cultivar revealed severe chilling damages. The chilling-tolerant cultivar was also faster in recovery than the chilling-susceptible cultivar in all parameters examined. We analyzed the activity and isozyme profiles of four antioxidant enzymes which are: superoxide dismutase (SOD), caltalase (CAT), ascorbate peroxidase (APX), and glutation reductase (GR). We observed that chilling-tolerance was due to a result of the induced or higher antioxidant enzyme system, CAT and APX in leaves and SOD, CAT, APX, and GR in roots. Especially, we observed the most significant differences between the chilling-tolerant cultivar and -susceptible cultivar in CAT and APX activity. Also in isozyme profiles, CAT and APX band intensity in the chilling-tolerant cultivar was distinctively higher than in the chilling-susceptible cultivars during chilling and recovery. Thus, the cold stability of CAT and APX are expected to contribute to a tolerance mechanism of chilling in rice plants. In addition, the antioxidative enzymes activity in roots may be more important than in that of leaves to protect chilling damage on rice plants.

• 한국환경농학회지
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• 제24권2호
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• pp.159-163
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• 2005

도시의 화단 및 꽃길 조성용으로 많이 이용되고 있는 만수국을 대상으로 산성비에 의한 식물 피해 양상을 조사하고, 산성비 처리가 활성산소 생성에 의한 산화 스트레스를 일으키는지를 조사함과 동시에 산성비에 대한 식물의 생화학적 방어반응을 조사하기 위하여 여러 농도의 인공 산성비(pH 2.0, 3.0, 4.0, 5.6)를 제조하여 실험을 수행하였다. 산성비의 pH가 낮을수록 생육 피해는 심하게 나타났으며 pH 3.0 이하의 처리에 의해 암회색 또는 적갈색의 괴사 반점이 생성되었다. MDA 함량은 pH 2.0 처리에서 약 2배 정도의 증가를 나타내었다. 산성비의 $H^+$ 부하량 증가에 따라 DHA/AsA 및 GSSG/GSH의 비율이 증가하였다. SOD, AP, GP 등의 항산화효소 활성도 산성비의 $H^+$ 부하량의 증가에 따라 크게 증가하는 것으로 나타났다. 이상의 결과로 볼 때 산성비는 만수국 식물에 활성산소 생성에 의한 산화스트레스가 일으키며, 이를 무독화하기 위해 식물의 생화학적 방어반응이 작용하는 것으로 사료된다.

• Fisheries and Aquatic Sciences
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• 제16권1호
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• pp.7-14
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• 2013

A 10-week feeding trial was conducted to examine the effects of dietary spirulina and quercetin on growth, innate immunity, disease resistance and dietary antioxidant capacity in the juvenile olive flounder. Triplicate groups of fish (initial body weight, $2.9{\pm}0.01g$) were fed one of isonitrogenous (48% crude protein) and isocaloric (17.4 MJ/kg DM) experimental diets containing 0% spirulina (as a control), 3.4% spirulina, or 6.8% spirulina with or without supplementation of 0.5% quercetin (designated as CON, SP3.4, SP6.8, and SP6.8 + Q, respectively) at a rate of 3% body mass twice daily. Higher dietary antioxidant capacity was found with spirulina supplementation, and the highest value (P < 0.05) was obtained with SP6.8 + Q diet. At the end of the feeding trial, no significant effects were observed on growth performance, body composition and disease resistance against Edwardsiella tarda. Lysozyme activity was significantly increased by spirulina supplementation (P < 0.05), and the highest value was observed in the group fed SP6.8 + Q diet. Also, significantly higher respiratory burst activity (P < 0.05) was found in SP3.4 group. According to the results of this study, dietary supplementation of 3.4% spirulina may enhance innate immunity of olive flounder.

• Fisheries and Aquatic Sciences
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• 제17권3호
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• pp.345-353
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• 2014

Copper has been widely used to control algae and pathogens in fish culture ponds. However, its toxic effects on fish depend not only on its concentration in the water but also on the water quality. A laboratory experiment was conducted to assess copper toxicity in the black rockfish Sebastes schlegeli using a panel of antioxidant enzymes, including glutathione (GSH), glutathione S-transferase (GST), glutathione peroxidase (GPx), glutathione reductase (GR) and superoxide dismutase (SOD), at different levels of copper at three water temperatures (WT, 18, 23, $28^{\circ}C$) for 4 days. After exposure to two copper concentrations (100 and $200{\mu}g/L$), GSH levels and GST activities increased significantly, depending on WT (P < 0.05) in the liver, gill, and kidney of the black rockfish. GPx and SOD activities decreased significantly with both increasing WT and copper treatment in the organs of black rockfish (P < 0.05). These changes can be seen as initial responses to temperature stress and as a sustained response to copper exposure. This also indicates that GSH and related enzymes activities were sensitive indexes to stress by toxicants such as copper. The present findings suggest that simultaneous stress due to temperature change and copper exposure can accelerate changes in enzymes activities in the black rockfish. This provides another example of synergism between environmental temperature and pollutants, which may have important implications for the survival of fish in polluted environments during seasonal warming and/or global climate change.

• Plant Biotechnology Reports
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• 제2권2호
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• pp.113-122
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• 2008

Nitric oxide (NO) affects the growth and development of plants and also affects plant responses to various stresses. Because NO induces root differentiation, we examined whether or not it is involved in increased ROS generation. Treatments with sodium nitroprusside (SNP), an NO donor, 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (PTIO), a specific NO scavenger, and $N{\omega}-nitro-{\text\tiny{L}}-arginine$ methyl ester hydrochloride (${\text\tiny{L}}-NAME$), an NO synthase (NOS) inhibitor, revealed that NO is involved in the adventitious root growth of mountain ginseng. Supply of an NO donor, SNP, activates NADPH oxidase activity, resulting in increased generation of $O_2{^{{\cdot}-}}$, which subsequently induces growth of adventitious roots. Moreover, treatment with diphenyliodonium chloride (DPI), an NADPH oxidase inhibitor, individually or with SNP, inhibited root growth, NADPH oxidase activity, and $O_2{^{{\cdot}-}}$ anion generation. Supply of the NO donor, SNP, did not induce any notable isoforms of enzymes; it did, however, increase the activity of pre-existing bands of NADPH oxidase, superoxide dismutase, catalase, peroxidase, ascorbate peroxidase, and glutathione reductase. Enhanced activity of antioxidant enzymes induced by SNP supply seems to be responsible for a low level of $H_2O_2$ in the adventitious roots of mountain ginseng. It was therefore concluded that NO-induced generation of $O_2{^{{\cdot}-}}$ by NADPH oxidase seems to have a role in adventitious root growth of mountain ginseng. The possible mechanism of NO involvement in $O_2{^{{\cdot}-}}$ generation through NADPH oxidase and subsequent root growth is discussed.

• Biomolecules & Therapeutics
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• 제26권2호
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• pp.175-181
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• 2018

Carbon monoxide (CO) is well-known as toxic gas and intrinsic signaling molecule such as neurotransmitter and blood vessel relaxant. Recently, it has been reported that low concentration of CO exerts therapeutic actions under various pathological conditions including liver failure, heart failure, gastric cancer, and cardiac arrest. However, little has been known about the effect of CO in neurodegenerative diseases like Parkinson's disease (PD). To test whether CO could exert a beneficial action during oxidative cell death in PD, we examined the effects of CO on 6-hydroxydopamine (6-OHDA)-induced cell death in C6 glioma cells. Treatment of CO-releasing molecule-2 (CORM-2) significantly attenuated 6-OHDA-induced apoptotic cell death in a dose-dependent manner. CORM-2 treatment decreased Bax/Bcl2 ratio and caspase-3 activity, which had been increased by 6-OHDA. CORM-2 increased phosphorylation of NF-E2-related factor 2 (Nrf2) which is a transcription factor regulating antioxidant proteins. Subsequently, CORM-2 also increased the expression of heme oxygenase-1 and superoxide dismutases (CuZnSOD and MnSOD), which were antioxidant enzymes regulated by Nrf2. These results suggest that CO released by CORM-2 treatment may have protective effects against oxidative cell death in PD through the potentiation of cellular adaptive survival responses via activation of Nrf2 and upregulation of heme oxygenase-1, leading to increasing antioxidant defense capacity.

• Journal of Microbiology
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• 제41권1호
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• pp.28-33
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• 2003

Pycnogenol (PYC) is believed to have potential as a therapeutic agent against free radical-mediated oxidative stress. It is important, therefore, to understand the interactions between PYC and cellular defenses against oxidative stress. Toward this end, we analyzed the survival rates on the gene expression responses of E. coli sod katG mutants to PYC after pre-treatment of PQ or H$_2$O$_2$-mediated stress under aerobic conditions. We identified SOD induced by PYC, but not HP1 in sod hate mutants. A striking result was the PYC induction of SOD with antioxidant property in single katG mutant cells, particularly MnSOD and CuZnSOD. These inductions were further increased with oxidative stress, while HP1 was not induced in these conditions. The effects of pycnogenol treatment on these cells depend in part on its concentration on the stress response. Protective effects of PYC exposure which affected gene expression in cells were consistent with cell survival rates. Our results demonstrate that pycnogenol may alter the stress response gene expression in a specific manner such as SOXRS because PYC induction of single mutant only worked under increased PQ stress. All together our data indicate that SOD activity is essential for the cellular defense against PQ-mediated oxidative stress, suggesting that PYC may not be effective as an antioxidant in only oxidative stress conditions. On the other hand, it was expected that PYC may play a role as a pro-oxidant and if it is available for use, it should be evaluated carefully.

• Journal of Plant Biotechnology
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• 제37권4호
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• pp.529-538
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• 2010

Proline accumulates in plants under environmental stresses including saline stress and alkaline stress. Here, we investigated the responses to two different stresses, saline stress (200 mM NaCl) and alkaline stress (100 mM $Na_2CO_3$) in two Leymus chinensis (Trin.) genotypes, LcWT07 and LcJS0107, and effects of exogenous proline on the activities of antioxidant enzymes. Both saline stress and alkaline stress significantly induced the accumulation of proline in leaves of the two genotypes after 96 h, and alkaline stress caused a transient and significant increase in LcJS0107 plants at 6 h. A reduction in the activities of catalase (CAT, EC 1.11.1.6) and ascorbate peroxidase (APX, EC 1.11.1.11), but not in the activity of superoxide dismutase (SOD, EC 1.15.1.1), was detected in plants exposed to saline and alkaline stresses. Remarkable decrease in relative water contents (RWC) was found in 144 h stressed plants. However, lipid peroxidation estimated by malonyldialdehyde (MDA) content in leaves remained relatively stable. With the addition of exogenous proline, it did not cause changes of proline levels in two genotypes, but combined with saline or alkaline stress, the exogenous application of proline significantly induced proline accumulation after even short treatment periods. Combined with salt stress, the exogenous application also increased the activities of CAT and APX. These results indicated that exogenous proline not only increases proline levels in vivo as a osmotic adjustment under stress, but mitigates the detrimental effects of saline and alkaline stresses by increasing the activities of antioxidant enzymes.