• Proceedings of the Zoological Society Korea Conference
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• 1996.10a
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• pp.87.1-87
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• 1996

• Journal of Bio-Environment Control
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• v.10 no.3
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• pp.197-206
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• 2001

The depletion of stratospheric ozone is regarded as a major environmental threat to plant growth and ecosystem. The ozone depletion has caused plants to be exposed to an increased penetration of solar ultraviolet-B (UV-B) radiation in the 280-320 nm wavelength range. Enhanced UV-B radiation may have influence on plants biological functions in many aspects including inhibition of photosynthesis, DNA damage, lipid peroxidation, changes in morphology, phenology, and biomass accumulation. To cope with the damage by UV radiation, plants have evolved to have protective mechanisms, such as photorepair, accumulation of UV-absorbing compounds, leaf thickening and activation of antioxidative enzymes. The objective of this review is to address the effects of enhanced UV-B on plant growth, UV-B action mechanisms and protection and protection mechanisms in plants.

• Korean journal of applied entomology
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• v.35 no.3
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• pp.238-242
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• 1996

The second instar milkweed bugs, Oncopeltus fasciatus were exposed to the residue of 6-methoxy-7-ethoxy-2, 2- dimethylchromene(or 7-ethoxy precocene 11, 7-EP-11) with one, two, or four different kinds of synergist(s) deposited as a residue on 9 cm diameter petri dishes. The anti juvenile hormone analog, 7-EP-I1 yielded a 50% effectiveness concentration at 1.18 wg/cmZ. The concentration of 7-EP-I1 and R020-9747 combined gave 0.084 ~*g/cm', as much 14 times more potent than with 7-EP-I1 alone. Most of the other synergists, including geraniol, 4-chalcone oxide, isosafrole, and piperonyl butoxide however, showed comparatively low level synergism with 1.0-4.3 times, depending upon the combinations of the synergist(s). The obtained results were considered that R020-9747, an analog of benzopyran with similar structure to that of 7-EP-I1 inhibited selectively the insect monooxygenase oxidative defense mechanism, in the body except for corpora allata because general antioxidants of piperonyl butoxide, isosafrole, and 4-phenyl chalcone oxide showed relatively mild synergism.

• Journal of Aquaculture
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• v.18 no.1
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• pp.7-12
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• 2005

This study was conducted to investigate antioxidant enzyme activity (catalase and superoxide dismutase) and Heat Shock Protein 70 (HSP70) mRNA variation in hepatopancreas of abalone (Haliotis discus hannai) cultured under several acute water temperatures. Abalones were cultured at 10, 15, 20, 25 and $30^{\circ}C$, for 0, 6, 12, 24 and 48 hours, respectively. The HSP70 mRNA expression in hepatopancreas was more increased at $30^{\circ}C$ compared to those at 10. 15, 20 (control) and $25^{\circ}C$. The superoxide dismutase (SOD) activity was increased in hepato-pancreas at all water temperature conditions compared to the control ($20^{\circ}C$). The SOD activity at high water temperature (25 and $30^{\circ}C$) tended to be increased after 12 hours, and was increased immediately after exposure to low water temperature (10 and $15^{\circ}C$). and then was recovered to starting level after the increase. Also, catalase (CAT) activity in hepatopancreas was increased in all the groups except for at $10^{\circ}C$ than the control ($20^{\circ}C$). Survival rate of abalone was $100\%$ at 10, 15, 20 and $25^{\circ}C$, but $92\%$ at $30^{\circ}C$. Thus, according to our study, when abalone is appeared at $20^{\circ}C$, defense mechanism against stress at low water temperature can be accelerated to be stabilized at about $5^{\circ}C$. In the case of exposure of abalone to high water temperature, antioxidant enzyme and HSP70 expression were increased due to elevated physiological stimulation factor, such as temperature.

• Korean Journal of Weed Science
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• v.31 no.2
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• pp.152-159
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• 2011

The effects of simulated acid rain (SAR) on fatty acid composition and biochemical defense responses of plant was investigated. Garden balsam (Impatiens balsamina L.) was exposed to four pH levels (5.6, 4.0, 3.0, 2.0) of SAR and placed in the growth chambers for 2 weeks. SAR drastically inhibited chlorophyll content of garden balsam. The level of $H_2O_2$ was significantly increased by SAR. As pH levels decreased from 5.6 to 2.0, the ratio of unsaturated to saturated fatty acids of garden balsam was increased. Changes of three major polyamines (putrescine, spermidine and spermine) of garden balsam leaves were observed. All of the polyamine contents were increased with SAR. Catalase activities of the plant affected by SAR were increased as the pH decreased. The results indicate that the application of SAR generates oxidative stresses from the garden balsam and retards the plant growth significantly. A biochemical protect mechanism might be activated to neutralize the oxidative stresses generated through SAR.

• Korean Journal Plant Pathology
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• v.12 no.1
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• pp.1-10
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• 1996

Xanthomonas campestris pv. vesicatoria의 감염으로 토마토 잎조직에 $\beta$-1, 3-Glucanases와 chitinases가 합성, 축적되었다. 그러나 접종되지 않은 건전한 잎에서는 위의 두 가지 가수분해 효소는 매우 낮은 수준으로 유지되었고, 이 두 가지 효소는 친화적 상호작용에서보다는 불친화적 상호작용에서 더욱 높은 수준으로 존재하였다. 이것은 $\beta$-1, 3-glucanases와 chitinases가 X. c. pv. vesicatoria의 생육에 대한 방어기작으로서 중요한 역할을 한다는 것을 시사해 주고 있다. Native PAGE 젤 상에서 $\beta$-1, 3-glucanases를 분리한 결과, 병징 발현이나 저항성 발현에 중요한 역할을 하는 것으로 생각되는 산성 isoform Ga 1과 염기성 isoform Gb 1의 isoform bands만 확인되었다. Isoelectric focusing을 이용하였을 때, 적어도 pI 6.4와 pI 8.6을 지닌 두 개의 $\beta$-1, 3-glucanases의 isoform을 확인할 수 있었고, 특히 불친화적 상호작용에서 더욱 뚜렷하게 유도되었다. 이것은 병 진전과정에서 X. c. pv. vesicatoria에 대해 저항성 발현에 관여한다는 것을 나타내고 있다. 산성 chitinase isoform인 Ca 1의 활성은 병원균의 감염이 진전되는 동안 감소하였다. 또한 다섯 개의 염기성 chitinase isoform이 감염된 토마토 잎 조직에서 발견되었는데, 특히 토마토의 방어기작에 관여하여 병원화적 균주 Bv5-4a에 감염된 잎에서만 유도, 축적되었다. Isoelectric focusing(IEF)을 이용한 후 적어도 2개의 산성과 4개의 염기성 chitinase isoform이 감염된 토마토 잎 추출액에서 확인되었다. Native PAGE 젤에서 isoform Cb 1에 해당되는 pI 9.5를 지닌 chitinase isoform은 오직 불친화적 상호작용에서만 확인되었다. 이온이 제거된 Triton X-100을 처리하여 renaturation 시킨 후에 SDS-PAGE 젤 상태에서 23 kDa과 26 kDa을 지닌 2개의 chitinase isoform을 확인하였다.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.317-317
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• 1994

생체에 영향을 줄 수 있는 다양한 환경성 물질들 (이하 약물로 칭함)은 세포내에서 일련의 대사과정을 받아 수용성으로 전환되어 체외로 배설된다. 생체내에서의 지용성 약물에 대한 생화학적 방어체계중 대사적 방어기구는 약물대사의 phase I활성화 과정인 독성화 과정과 약물대사의 phase II 포합과정인 해독화 과정이 상호균형을 이루어 생체내의 향상성을 유지하도록 방어기능을 수행한다고 할 수 있다. 이러한 약물대사는 생체내 여러 장기에서 일어날 수 있으나 주로 대부분이 간에서 이루어진다. 즉, 간에서 약물의 약리학적 알성의 시작과 종료가 이루어진다는 관점에서 간은 약물대사, 약물의 독성 및 해독작용에 대한 연구의 중요한 대상이라 할 수 있다. 그러므로 약물대사의 기초연구는 물론 신물질 개발에 있어서 개발약물에 대한 간세포의 손상을 측정하기 위하여 보다 효과적인 간독성 평가방법이 개발되어야 할 필요가 절실히 요구된다.

• Korean journal of applied entomology
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• v.21 no.1 s.50
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• pp.23-26
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• 1982

The present study was carried out to investigate the change of peroxidase activity of soybean seed infected with Cerrospora kikurhii. The protein content, polyphenol oxidase activity and peroxidase isozyme pattern in health and infected soybean seed were also compared. 1. The peroxidase activity was substantially higher in the infected soybean seeds than that in the healthy seeds either cracked or not. No significant differences in protein content were recognized among the seeds tested. 2. No significant differences in peroxidase activities and protein contents were notified between healthy and infected seeds from the measurements on each parts of dissected seeds, cotyledon and seedcoat, however the peroxidase activity in the seed coat of the stained seed was 2.5 times to healthy seed. 3. The activities of polyphenel oxidase were undectable in both healthy and diseased seeds. 4. The electrophoretic Patterns of the Peroridase isozyme were the same between healthy and in footed seed. 5. Therefore, the increase of peroxidase activity in infected soybean seedcoat was mainly due to the biochemical reaction against the pathogen.

• Journal of fish pathology
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• v.27 no.2
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• pp.115-125
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• 2014

The effects of waterborne arsenic (As) exposure on antioxidant defense were studied in liver and gills of tilapia, Oreochromis niloticus under thermal stress. Tilapia were exposed to different As concentrations (0, 200 and $400{\mu}g/L$) at three water-temperatures (WT; 20, 25 and $30^{\circ}C$) for 10 days. In antioxidant response, glutathione (GSH) levels, glutathione reductase (GR), glutathione peroxidase (GPx) and glutathione S-treansferase (GST) activities were significantly decreased depend on WT in the gills after As exposure. Also, the range of fluctuation in these enzymes activities was most significantly increased at $30^{\circ}C$ in the liver of tilapia exposed to As. The present findings suggest that a simultaneous stress by temperature change and As exposure could accelerate the alteration in antioxidant enzymes activities of tilapia.

• Korean Journal of Environmental Agriculture
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• v.12 no.3
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• pp.264-280
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• 1993

The environmental pollutions were a serious problem in Korea recently. So many researcher have studied the effect of environmental pollution on plants and agro-ecosystem, but the basic mechanisms of environmental stresses were various. One of the important mechanisms was oxidative stress caused by active toxic oxygen. The toxic oxygen was generated by several stresses, abnormal temperature, many xenobiotics, air pollutants, water stress, fugal toxin, etc. In the species of toxic oxygen which is primary inducer of oxidative stresses, superoxide, hydrogen peroxide, hydroxyl radical and singlet oxygen were representative species. The scavenging systems were divided into two groups. One was nonenzymatic system and the other enzymatic system. Antioxidants such as glutathione, ascorbic acid, and carotenoid, have the primary function in defense mechanisms. Enzymatic system divided into two groups; First, direct interaction with toxic oxygen(eg. superoxide dismutase). Second, participation in redox reaction to maintain the active antioxidant levels(eg. glutathione reductase, ascorbate peroxidase, etc.).