• Korean Journal of Fisheries and Aquatic Sciences
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• v.57 no.3
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• pp.227-238
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• 2024

This study aimed to evaluate the effects of polyethylene microplastic (PE-MPs) via measuring the growth performance, hematological parameters, and antioxidant responses in Korean rockfish Sebastes schlegelii exposed to waterborne polyethylene microplastic with dimensions of 22-71 ㎛. S. schlegelii (mean weight, 34.55±5.82 g; mean length, 12.59±0.79 cm) were exposed to PE-MPs at concentrations of 0, 400, 800, 1,600 and 3,200 ㎍/L for 10 and 20 days. PE-MPs significantly affected growth performance, hematological parameters, plasma components, and antioxidant responses in a concentration-dependent manner. At a concentration ≥1,600 ㎍/L, PE-MPs significantly decreased body weight gain and specific growth rate, and significantly increased the hepatosomatic index. Hematological parameters showed a significant decrease in total red blood cell count and hemoglobin levels. Plasma components showed a significant increase in glucose, aspartate aminotransferase, and alanine transaminase levels, whereas total protein, calcium, and magnesium levels significantly decreased. Exposure to ≥1,600 ㎍/L PE-MPs also induced reactive oxygen species generation in the gill and liver, significantly increasing superoxide dismutase and catalase activity. These findings suggest that exposure to ≥1,600 ㎍/L PE-MPs could significantly change growth performance, hematological parameters, plasma components, and antioxidant responses, resulting in physiological toxicity.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.2
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• pp.122-128
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• 2014

The present study was performed to examine the contraction and relaxation responses of the smooth muscles, and search for antimicrobial and antioxidant activities in the tissues, of the starfish Asterina pectinifera. Frozen samples were extracted with distilled water containing 1% acetic acid. Extracts from all tissues showed potent antimicrobial activity against Escherichia coli D31. Relatively high levels of antimicrobial activity were also detected in the body extracts. Liver, tube feet, and body extracts caused contraction responses in the dorsal retractor muscles (DRM) of the starfish. In contrast, all tissues examined exhibited contractile activity in the esophagus of squid Todarodes pacificus. In addition, liver and gonad extracts caused contraction responses upon application to the intestine of the puffer fish Takifugu pardalis. Relaxation effects on the DRM of starfish were identified in most of the extracts, while no relaxant activity was detected in body extracts. Extracts from all tissues examined also exhibited antioxidant activities. The results of this study suggest that starfish are a potential source of novel bioactive compounds.

• Proceedings of the Botanical Society of Korea Conference
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• 2002.04a
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• pp.101-101
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• 2002

• Fisheries and Aquatic Sciences
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• v.24 no.2
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• pp.89-98
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• 2021

The accumulation of ammonia, a consequence of intensive aquaculture activity, can damage cultured animals. We analyzed the survival rates, growth, antioxidant responses, and immune responses of abalones, Haliotis discus hannai (mean shell length 70.2 ± 4.9 mm; mean body weight 36.9 ± 3.6 g), biweekly for four weeks, to determine the accumulated concentrations of ammonia (0, 0.1, 0.2, 0.4, 0.8, and 1.6 mg/L). In our biweekly measurements, a survival rate of ≥ 95% was observed for all concentrations of ammonia. The specific growth rate (SGR) decreased at ≥ 0.8 mg/L (p < 0.05), but the daily increment in shell length (DISL) showed no significant change (p < 0.05). Regarding antioxidant responses, the superoxide dismutase (SOD) activity of the hepatopancreas was increased at ammonia concentrations over 0.8 and 0.2 mg/L (p < 0.05) at two and four weeks, respectively, and the SOD activity of the gills increased at concentrations over 0.4 and 1.6 mg/L (p < 0.05) at four weeks. The catalase (CAT) activity of the hepatopancreas and gills increased at ammonia concentrations > 0.8 mg/L (p < 0.05). Phenoloxidase (PO) activity increased at ammonia concentrations over 0.8 mg/L (p < 0.05), and Lysozyme (LZM) increased at concentrations over 0.8 and 0.4 mg/L (p < 0.05). Overall, our findings indicated that ammonia concentrations over 0.8 mg/L in seawater might damage the SGR, antioxidant responses, and immune responses in H. discus hannai. Our findings suggest the necessity of improvement or reinstallation for abalone aquaculture systems and can be used to assess the toxic effects of ammonia on H. hannai.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.1
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• pp.79-88
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• 2023

A 12-week feeding trial was conducted to evaluate the effect of different stocking densities on the growth, body composition, stress, antioxidant status, and immune responses of juvenile rainbow trout Oncorhynchus mykiss. Juvenile rainbow trout (32.2±0.5 g) were randomly placed in eight experimental tanks, each containing 2,000 L of water, at stocking densities of 150, 300, 600, and 1,200 individual/m³. The trout were assigned to four treatments (2.4, 4.8, 9.7, and 19.4 kg/m³) in duplicates. Following after the feeding trial, the fish cultured in the less dense group showed significantly higher growth and survival (P<0.05). In terms of proximate composition, the whole body crude protein and lipid contents were lower in the denser group (19.4 kg/m³). Regarding the antioxidant and immune responses, the fish reared in the relatively denser group exhibited lower lysozyme, immunoglobulin M, and superoxide dismutase levels. The stress indicators, glucose and cortisol, were significantly lower in the less dense group (2.4 kg/m³), while the denser group (19.4 km/m³) exhibited higher AST and ALP levels(P<0.05). The results showed that denser stocking has a crowding stress effect and negatively impacts growth and immune responses.

• The Plant Pathology Journal
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• v.30 no.4
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• pp.355-366
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• 2014

In this study, resistance responses were investigated during the interaction of Botrytis fabae with two faba bean cultivars expressing different levels of resistance against this pathogen, Nubaria (resistant) and Giza 40 (susceptible). Disease severity was assessed on leaves using a rating scale from 1 to 9. Accumulation levels of reactive oxygen species (ROS), lipid peroxidation and antioxidant enzymes (superoxide dismutase, catalase and ascorbate peroxidase) were measured in leaf tissues at different times of infection. The expression profiles of two pathogenesis-related proteins (PRPs) encoded by the genes PR-1 and ${\beta}$-1,3-glucanase were also investigated using reverse transcription RT-PCR analysis. The accumulation of these defense responses was induced significantly in both cultivars upon infection with B. fabae compared with un-inoculated controls. The resistant cultivar showed weaker necrotic symptom expression, less ROS accumulation, a lower rate of lipid peroxidation and higher activity of the enzymatic ROS scavenging system compared with susceptible cultivar. Interestingly, ROS accumulated rapidly in the resistant leaf tissues and peaked during the early stages of infection, whereas accumulation was stronger and more intense in the susceptible tissues in later stages. Moreover, the response of the resistant cultivar to infection was earlier and stronger, exhibiting high transcript accumulation of the PR genes. These results indicated that the induction of oxidant/antioxidant responses and the accumulation of PRPs are part of the faba bean defense mechanism against the necrotrophic fungus B. fabae with a different intensity and timing of induction, depending on the resistance levels.

• BMB Reports
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• v.37 no.5
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• pp.618-624
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• 2004

All members of R. glutinosa show the unique characteristic of intrinsic tolerance to paraquat (PQ). Antioxidant enzymes have been proposed to be the primary mechanism of PQ resistance in several plant species. Therefore, the antioxidant enzyme systems of R. glutinosa were evaluated by comparatively analyzing cellular antioxidant enzyme levels, and their responses of oxidative stresses and hormones. The levels of ascorbate peroxidase (APX), glutathione reductase (GR), non-specific peroxidase (POX), and superoxide dismutase (SOD) were 7.3-, 4.9-, 2.7- and 1.6-fold higher in PQ-tolerant R. glutinosa than in PQ-susceptible soybeans. However, the activity of catalase (CAT) was about 12-fold higher in the soybeans. The activities of antioxidant enzymes reduced after PQ treatment in the two species, with the exception of POX and SOD in R. glutinosa, which increased by about 40%. Interestingly, the activities of APX, SOD and POX in R. glutinosa, relative to those in soybeans, were further increased by 49, 67 and 93% after PQ treatment. The considerably higher intrinsic levels, and increases in the relative activities of antioxidant enzymes in R. glutinosa under oxidative stress support the possible role of these enzymes in the PQ tolerance of R. glutinosa. However, the relatively lower levels of SOD versus PQ tolerance, and the mixed responses of antioxidant enzymes to stresses and hormones, suggest a possible alternative mechanism(s) for PQ tolerance in R. glutinosa.

• Journal of The Korean Society of Grassland and Forage Science
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• v.39 no.4
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• pp.298-302
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• 2019

Acidic soil significantly reduces crop productivity mainly due to aluminum (Al) toxicity. Alfalfa (Medicago sativa L.) roots were exposed to aluminum stress (Al₃⁺) in calcium chloride (CaCl₂) solution (pH4.5) and root growth, physiological and antioxidant enzyme responses were investigated. The root growth (length) was significantly inhibited after 48 h of aluminum stress imposition. Histochemical staining with hematoxylin indicated significant accumulation of aluminum in Al stress-treated root tissues. Histochemical assay were also performed to detect superoxide anion, hydrogen peroxide and lipid peroxidation, which were found to be more in root tissues treated with higher aluminum concentrations. The enzymatic activity of CAT, POD and GR in root tissues was slightly increased after Al stress treatment. The result suggests that Al stress alters root growth in alfalfa and induces reactive oxygen species (ROS) production, and demonstrates that antioxidant enzymes involved in detoxification of Al-mediated oxidative stress.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.6
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• pp.750-755
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• 2017

Flatfish Paralichthys olivaceus raised in biofloc system (mean length $27.6{\pm}3.1cm$, mean weight $280.4{\pm}26.5g$) were exposed for to different concentrations of ammonia (0, 8, 16, 32, and $64mg\;{NH_4}^+/L$) for 7 days. Following ammonia exposure, hematological parameters such as hemoglobin and hematocrit were significantly reduced. Plasma components such as magnesium, glucose, aspartate aminotransferase (AST), and alanine aminotransaminase (ALT) were significantly altered by ammonia exposure, whereas there were no significant changes in calcium, cholesterol, or total protein. Antioxidant responses, such as superoxide dismutase (SOD) and catalase (CAT) levels were significantly elevated following ammonia exposure. The results of this study indicate that ammonia exposure induces significant changes in hematological parameters and antioxidant responses in biofloc-reared Paralichthys olivaceus as a toxic response.

• Journal of Korean Society of Forest Science
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• v.96 no.4
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• pp.470-476
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• 2007

This study is conducted to identify responses of plants to low $O_3$ concentration, Five species, Liriodendron tulipifera, Cornus officinalis, Ginkgoba biloba, Zelkova serrata, and Acer palmatum, were exposed to low ozone concentration from June 9 to July 8 in the phytotron, We measured chlorophyll contents, leaf diffusion resistance, leaf transpiration, and antioxidant enzyme activities; ascorbate peroxidase(APX), Especially, Liriodendron tulipifera and Cornus officinalis showed sensitive responses to ozone treatment as visible injuries, while other four species relatively showed tolerant responses. However, we noticed that almost all species under ozone treatment were lower physiological activities such as chlorophyll contents, leaf diffusion resistance, leaf transpiration, and antioxidant enzyme activities with time even without any visible injury.