• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.49 no.1
• /
• pp.12-18
• /
• 2004

Activity of senescence-induced antioxidant enzymes in the detached rice seedlings (Oryza sativa L. cv. Dongjin) was examined. The levels of $\textrm{H}_2\textrm{O}_2$ content and peroxidase (POD) activity were gradually increased during leaf senescence, whereas catalase activity was decreased. The activity of superoxide dismutase (SOD) was increased, and ascorbate peroxidase (APX) and glutathione reductase (GR) were slightly increased until 3d and 4d of dark induced-senescence, and thereafter were decreased. The activation of all SOD isoforms showed a significant decrease after 6d and 7d. After 4d to 7d of dark senescence, there was a significant effect in enhancing the activity of APX-12 and -13 isoforms as compared with light, despite similar levels in total APX activity. GR-8 and -10 isoforms were more effective in leaf senescence at 4d to 7d, particularly with respect to dark-induced senescence. These results suggest that the metabolism of active oxygen species such as $\textrm{H}_2\textrm{O}_2$ is dependent on various functionally interrelated antioxidant enzymes such as catalase, peroxidase, SOD, APX and GR.

• Journal of Microbiology and Biotechnology
• /
• v.22 no.3
• /
• pp.407-415
• /
• 2012

An endophytic bacterium, Bacillus thuringiensis GS1, was isolated from bracken (Pteridium aquilinum) and found to have maximal production of chitinase (4.3 units/ml) at 5 days after culture. This study investigated the ability of B. thuringiensis GS1 to induce resistance to Rhizoctonia solani KACC 40111 (RS) in cucumber plants. Chitinase activity was greatest in RS-treated plants at 4 days. ${\beta}$-1,3-Glucanase activity was highest in GS1-treated plants at 5 days. Guaiacol peroxidase (GPOD) activity increased continuously in all treated plants for 5 days. Ascorbate peroxidase (APX) activity in RS-treated plants was increased 1.5-fold compared with the control at 4 days. Polyphenol oxidase (PPO) activity in RS-treated plants was increased 1.5-fold compared with the control at 3 days. At 5 days after treatment, activity staining revealed three bands with chitinase activity (Ch1, Ch2, and Ch3) on SDS-PAGE of cucumber plants treated with GS1+RS, whereas only one band was observed for RS-treated plants (Ch2). One GPOD isozyme (Gp1) was also observed in response to treatment with RS and GS1+RS at 4 days. One APX band (Ap2) was present on the native-PAGE gel of the control, and GS1- and GS1+RS-treated plants at 1 day. PPO bands (Po1 and Po2) from RS- and GS1+RS-treated plants were stronger than in the control and GS1-treated plants upon native-PAGE at 5 days. Taken together, these results indicate that the induction of PR proteins and defense-related enzymes by B. thuringiensis GS1 might have suppressed the damping-off caused by R. solani KACC 40111 in cucumber plants.

• Applied Biological Chemistry
• /
• v.42 no.3
• /
• pp.246-251
• /
• 1999

This experiment was carried out to elucidate and investigate the changes in the content of antioxidants and the activities of antioxidant enzymes in the leaves of soybean subjected to water stresses. The results obtained were as follows; Leaves of soybeans subjected to water stresses have showed the differences in the activities of the antioxidant enzymes. In eunhakong, the activity of APOX was increased within a few days, but that of GR was decreased, whereas the activities of APOX and GR were gradually decreased in eunhakong. The activity of MDHAR of the leaves of eunhakong subjected to drought stress was gradually increased within 4days, whereas that of flooding was increased within 2days. We are supposed that the activities of APOX and MDHAR are coupled to maintain ascorbate concentration. In eunhakong, the relative activity of DHAR subjected to flooding was higher than that of drought. These results imply that DHAR is the only enzyme participating in the regeneration of ascorbate when the activity of MDHAR was limited by the deficiency of NADPH. The contents of ascorbate and reduced glutathione subjected to drought stress decreased continually, whereas those subjected to flooding stress recovered after five days of treatment.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
• /
• v.22 no.3
• /
• pp.20-35
• /
• 2009

Objective : The present study designed this study to investigate anti-oxidative effects of EF on HaCaT keratinocyte. Method : The present study measured the amount of polyphenoics and flavonoids, and also measured the levels of catalase, Ascorbate peroxidase (APX), SOD like activities and DPPH free radical scavenging activity. Then the effects of SB on viability and prolferation rates, and protective effects against oxidative stress induced by chemicals such as hydrogen peroxide and rotenone were also investigated. Results and conclusion : EF showed protective effect against cell death of HaCaT keratinocyte induced by rotenone and SNP significantly. In conclusion, these results suggest that EF may have anti-oxidantic action in human skin and also suggest that EF can be used as anti-aging agent.

• Journal of Korean Society of Forest Science
• /
• v.95 no.2
• /
• pp.183-187
• /
• 2006

This study investigated concentrations of the several air pollutants and compared antioxidative enzyme activities on Platanus occidentalis because this tree species is one of the widespread street trees in Korea. This species has been emerging the ambient air pollutants during its growing periods. The purpose of this study was to identify the relationship between air pollution on the tree species and antioxidant enzyme activities on the trees. $O_3$, $NO_2$, CO and $SO_2$ concentrations of several cities in Korea were compared for last decades. Among the air pollutants, $O_3$ and $NO_2$ concentrations in six big cities in Korea showed similar increasing trends during this period. In contrast, $SO_2$ and CO concentrations in the same cities dramatically decreased between 1994 and 2005. Platanus occidentalis trees were controlled to investigate, ascorbate peroxidase (APX) and glutathione reductase (GR) activity. Ozone exposure generally increased APX and GR activities of tree seedlings. It is a typical compensatory strategy of stressed trees.

• The Korean Journal of Ecology
• /
• v.27 no.2
• /
• pp.107-114
• /
• 2004

Tomato (Lycopersicon esculentum) seedlings exposed to various concentrations of $CdC1_2$ (0∼100 $\mu$M) in the nutrient solution for up to 9 days were analyzed with the seedling growth, $H_2O_2$ production, glutathione levels and activity changes of enzymes related to $H_2O_2$ removal. The growth of seedlings was inhibited with over 50 $\mu$M Cd, whereas the levels of $H_2O_2$ and glutathione were enhanced with Cd exposure level and time. Meanwhile, Cd exposure increased the activities of catalase (CAT) and glutathione reductase (GR) but decreased the activities of dehydroascorbate acid reductase (DHAR) and ascorbate peroxidase (APX) in both leaves and roots. These results suggest that the altered activities of antioxidant enzymes particularly involved in the $H_2O_2$ removal and the subsequent $H_2O$$_2$ accumulation could induce the Cd-induced phytotoxicity.

• Journal of the Korean Society of Physical Medicine
• /
• v.1 no.1
• /
• pp.139-146
• /
• 2006

Purpose : This study is to understand the reactive oxygen which is expected to be a causative factor of aging condition including dementia, atherosclerosis, even cancer. Methods : The reactive oxygen is generated usually when people do very hard exercise or is under severe stressful situation or in unhealthy environment and as a protective reaction to reactive oxygen, human body releases antioxidant enzyme systems like superoxide dismutase (SOD), catalase, glutathione peroxidase (GPX), glutathion-S-transferase (GST) and non-enzymetic antioxidant systems like glutathione, ascorbate, $\beta$-carotene, vitimin E. Results : Nowadays, we are getting more interested in the generation of reactive oxygen especially in the area of physical education, food and nutrition, alternative medicine etc. Conclusion : The study of reactive oxygen in patients with musculoskeletal disease is also required and among various physical therapeutic approaches, the method of general coordinative manipulation is considered more necessary.

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

• Journal of Ecology and Environment
• /
• v.30 no.3
• /
• pp.257-264
• /
• 2007

Over-expression of a copper/zinc superoxide dismutase (Cu/ZnSOD) resulted in substantially increased tolerance to cadmium exposure in Arabidopsis thaliana. Lower lipid peroxidation and $H_2O_2$ accumulation and the higher activities of $H_2O_2$ scavenging enzymes, including catalase (CAT) and ascorbate peroxidase (APX) in transformants (CuZnSOD-tr) compared to untransformed controls (wt) indicated that oxidative stress was the key factor in cadmium tolerance. Although progressive reductions in the dark-adapted photochemical efficiency (Fv/Fm) and quantum efficiency yield were observed with increasing cadmium levels, the chlorophyll fluorescence parameters were less marked in CuZnSOD-tr than in wi. These observations indicate that oxidative stress in the photosynthetic apparatus is a principal cause of Cd-induced phytotoxicity, and that Cu/ZnSOD plays a critical role in protection against Cd-induced oxidative stress.

• Journal of Life Science
• /
• v.1 no.1
• /
• pp.15-23
• /
• 1991

노화현상에 관련된 가설은 프로그램설, 세포손상축적설 등 다양하나 증거와 연구자료가 아직은 불충분하고 미흡하다. 현재 상당한 주목을 받고 있고 또 일견 설득력이 있는 것으로 수용되고 있는 oxygen species에 의한 세포손상축적 가설은 시험관 또는 생체 내에서의 실험과 관측을 통해 연구에 상당한 진전이 있음에도 노화현상을 해석하는 또 다른 실마리에 불과하다. Oxygen radical이 세포내의 거대분자들 중 DNA에 손상과 변이를 일으키거나, 우리기를 수반하지 않는 다른 기작에 의해 조직손상이 일어나면서 세포내의 유리기반응에 이차적 장애가 유도되어 세포내의 분자들이 훼손되거나 변화됨으로서, 이들 손상물이 시간과 더불어 축적하여 신체기능의 퇴행을 수반한 질병과 노화현상이 나타나게 된다는 것이다. 유리기에 대한 효과를 가지는 SOD, catalase, glutathione, peroxidase, metal-chelator와 chain-breaking 효과를 가진 alpha-tocopherol, beta-carotere, urate, ascorbate, ubiquinone, glutathione, protein-thiol 등 항산화물질의 적용과 섭취의 중요성이 인식되었다.