• Journal of Ginseng Research
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• v.15 no.2
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• pp.139-143
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• 1991

This study investigated the relations between the photosynthetic rate and the activities of antioxidatile enzymes, glutathione reductase, ascorbate free radical reductase, ascorbate peroxidase, glutathione peroxidase, and ascorbate oxidase, in the leaves of Panax ginseng. Under the normal cultivation condition, Panax in showed lower g1utathione reductase and ascorbate free radical reductase activities the Glycine max. But P ginseng showed higher 91utathione Peroxidase, ascorbate Peroxidase, and ascorbate oxidase activities than C. Panax. Therefore, P. ginseng showed weak activities of reductases for the reduction of the oxidized antioxidants. Under the light intensity of 25 KLux, the reductases showed a decrease of over 75% after 24 hours. But the peroyoxidases decreased about 40%. These results showed that the decrease of reductases acitivities was consistent with the decrease of photosynthetic rate. Therefore, we consider that the regulation of antioxidative enzymes or the application of exogenous antioxidants will be effective means for the protection of photodamage in p. ginseng.

• Journal of The Korean Society of Grassland and Forage Science
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• v.22 no.2
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• pp.101-106
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• 2002

This study was conducted to obtain the transformed tobacco (Nicotiana tubacum) plants with cytosolic ascorbate peroxidase gene(ApxSC7) using Agrobacterium tumefaciens LBA4404. A cDNA encoding the cytosolic ascorbate peroxidase of strawberry, ApxSC7, was introduced into tobacco plants via Agrobacterium-mediated gene transfer system. The expression vector, pIG-AP8, harboring ApxSC7 gene was used for production of transgenic tobacco plants. A large number of transgenic plants were regenerated on a medium containing hygromycin. Integration of ApxSC7 gene was confirmed by PCR and Southern blot analyses with genomic DNA. Northern blot analyses revealed that the pIGap8 gene was constitutively expressed.

• Plant Resources
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• v.8 no.3
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• pp.194-201
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• 2005

A cytosolic ascorbate peroxidase, hydrogen peroxide-scavenging enzyme, was characterized from Codonopsis lanceolata. The cytosolic ascorbate peroxidase cDNA (CAPX) was 983 nucleotides long and possess an open reading frame of 753 bp with 251 amino acids (MW 27.9 kDa) with pI 5.61. The deduced amino acid sequence of CAPX shows high homology to other known cytosolic APXs ($78{\sim}83%$), but the CAPX was clustered independently from compared ten plant APXs. The CAPX gene was highly expressed in leaf and stem tissues, but not in root. When Codonopsis leaves cut using scalpel were soaked in 1 mM hydorgen peroxide, the expression of CAPX gene was suppressed.

• Proceedings of the Botanical Society of Korea Conference
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• 2001.04a
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• pp.13-13
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• 2001

• Current Research on Agriculture and Life Sciences
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• v.15
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• pp.93-100
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• 1997

Plants are exposed to wide range of different stresses. As plants have only limited mechanism for stress avoidance, they require flexible means for adaption to changing environmental conditions. This study was carried out to reasearch the changes of antioxidant enzymes activities as caused by water stress in four lettuceUactuca sativa) lines. Four lettuce lines exposed to water stress showed premature senescence as evidenced by the consistenent reduction in the content of total soluble protein and total lipid. Water stress also caused decreased activities of superoxide dismutase, catalase, ascorbate peroxidase, but decrease rates were different. Catalase activity was decreased much more than that of ascorbate peroxidase that suggest catalase reacted with hydrogenyperoxide directly not with ascorbate peroxidase.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2002.11b
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• pp.67-67
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• 2002

아열대성 식물 4종 (문주란, Crinum asiaticum var. japonicum; 박달목서, Osmanthus insularis; 죽절초, Chloranthus glaber; 파초일엽, Asplenium antiquum)을 대상으로 자연 환경요인의 변화에 의한 항산화 효소 (superoxide dismutase, peroxidase, catalase, ascorbate peroxidase)의 활성과 isoenzyme 패턴의 변화를 전기영동으로 조사하였다. 그 결과, peroxidase의 활성과 isoenzyme 패턴이 식물종이나 환경조건에 따라 가장 다양하게 나타났다. Peroxidase는 4종 모두에서 여름철보다 겨울철에 활성이 높았고 문주란, 박달목서, 파초일엽에서는 겨울철에 특이적으로 발현되는 isoenzyme들도 관찰할 수 있었다. Catalase는 문주란, 박달목서, 파초일엽에서 검출되었다. 문주란 잎에서는 겨울철에 비해 여름철에 다소 높은 활성을 보였으며, 박달목서와 파초일엽에서는 겨울철에 높은 활성을 나타내었다. 그리고 문주란과 박달목서에서는 겨울철에 새벽이나 밤보다 낮시간에 높은 활성을 보였는데 파초일엽에서는 낮시간의 catalase 활성이 낮았다. Superoxide dismutase는 문주란, 박달목서, 파초일엽에서 검출되었으며, 특히 박달목서에서는 겨울철에 높은 활성을 보였다. Ascorbate peroxidase는 문주란과 파초일엽에서 관찰되었으나 계절적으로 큰 차이가 없었으며, 겨울철에는 isoenzyme 패턴의 일주기적 변화가 관찰되었다. 이상의 결과, 종별로는 문주란, 파초일엽에서 4종의 항산화효소가 모두 검출되었고, 박달목서에서는 ascorbate peroxidase가, 죽절초에서는 peroxidase를 제외한 모든 항산화 효소가 검출되지 않았다. 식물종에 따라 또는 환경요인의 변화에 따라 항산화효소의 활성 또는 isoenzyme 패턴의 차이를 보이고 있지만 항산화효소의 계절적 그리고 일주기적 변화가 관찰되어, 본 연구에서 조사된 4종의 아열대성 식물이 자연환경 조건 하에서도 산화적 스트레스에 처하고 있는 것으로 보인다.

• BMB Reports
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• v.29 no.6
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• pp.564-568
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• 1996

Bursts of ethylene production occurred in twice at an early exponential (EEP) and prestationary (PSP) phases, respectively, during growth of callus tissue isolated from the root of soybean seedlings. The second burst of ethylene production at PSP was smaller in magnitude than the earlier one at EEP, but was followed by increases in both guaiacol peroxidase (GuPOX) and ascorbate peroxidase (AsPOX). The increase in AsPOX activity was also preceded by an increase in lipoxygenase (LOX) activity. Treatment of the tissue with the ethylene antagonist 2,5-norbonadiene (NBD) resulted in substantial reduction in LOX and AsPOX activities during this period. GuPOX activity was reduced only slightly, if any, by NBD. Role of ethylene in the sequential induction of LOX and AsPOX in senescing callus tissue is discussed.

• Korean Journal of Plant Tissue Culture
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• v.22 no.2
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• pp.71-76
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• 1995

The effects of light on the activities of several antioxidative enzymes, catalase (CAT), superoxide dismutase(SOD), ascorbate oxidase(AO), and peroxidase(POD) were examined in the hairy root cultures of Phytolacca esculenta van Houtte induced by Agrobacterium tumefaciens $A_4$T. Activities of CAT, SOD, and AO were significantly decreased with incresing light intensity (500-2,000 lx). The activity of AO under high light condition (2,000 lx)was decreased by 92% compared to the dark condition. The activities of glutathoine peroxidase (GPO), ascorbate peroxidase (APO) and general POD were increased under lower light intensify below 500 lx. The activity of GPO under 2,000 lx was decreased by 85% compared to the dark condition. The activities of antioxidative enzymes were more decreased in blue light (400-500nm). The activities of antioxidative enzymes in blue light intensity were increased in lower light intensity below 30 lx, but decreased 21-70% under 200 lx. The activity of AO was decreased by 70% under 200 lx with increasing blue light intensity. Our results suggest that the activities of antioxidative enzymes in hairy roots might be inhibited by endogenous oxidants generated under the high blue light conditions.

• Journal of Life Science
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• v.20 no.8
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• pp.1173-1180
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• 2010

We investigated changes in photosynthesis and activity of ascorbate peroxidase (APX) that scavenges ROS as responses to oxidative stress induced by salinity in rice (Oryza sativa L.). Photosynthetic efficiency of rice leaves, monitored in terms of Fv/Fm, declined with the increase of salt concentration (100-300 mM NaCl). Salinity caused an increase of $H_2O_2$ in leaves of rice, with an increase of APX activity. Among total APX isoforms, an isoform of stromal-APX 1 in leaves of rice was completely inactivated by 300 mM NaCl, but was not affected by chilling or drought. The results suggest that salt stress acts in quite a different mechanism in relation to the activity of stromal-APX from that of other stresses such chilling and drought. We carried out RT-PCR for analysis of genes expression of APX isoforms as affected by salt stress. The expression of cytosolic APX/thylakoid-bound APX genes in leaves of rice exposed to salt stress was increased, while stromal APX gene expression rapidly declined.

• Journal of Ginseng Research
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• v.41 no.3
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• pp.307-315
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• 2017

Background: Red-skin root disease has seriously decreased the quality and production of Panax ginseng (ginseng). Methods: To explore the disease's origin, comparative analysis was performed in different parts of the plant, particularly the epidermis, cortex, and/or fibrous roots of 5-yr-old healthy and diseased red-skin ginseng. The inorganic element composition, phenolic compound concentration, reactive oxidation system, antioxidant concentrations such as ascorbate and glutathione, activities of enzymes related to phenolic metabolism and oxidation, and antioxidative system particularly the ascorbate-glutathione cycle were examined using conventional methods. Results: Aluminum (Al), iron (Fe), magnesium, and phosphorus were increased, whereas manganese was unchanged and calcium was decreased in the epidermis and fibrous root of red-skin ginseng, which also contained higher levels of phenolic compounds, higher activities of the phenolic compound-synthesizing enzyme phenylalanine ammonia-lyase and the phenolic compound oxidation-related enzymes guaiacol peroxidase and polyphenoloxidase. As the substrate of guaiacol peroxidase, higher levels of $H_2O_2$ and correspondingly higher activities of superoxide dismutase and catalase were found in red-skin ginseng. Increased levels of ascorbate and glutathione; increased activities of $\text\tiny L$-galactose 1-dehydrogenase, ascorbate peroxidase, ascorbic acid oxidase, and glutathione reductase; and lower activities of dehydroascorbate reductase, monodehydroascorbate reductase, and glutathione peroxidase were found in red-skin ginseng. Glutathione-S-transferase activity remained constant. Conclusion: Hence, higher element accumulation, particularly Al and Fe, activated multiple enzymes related to accumulation of phenolic compounds and their oxidation. This might contribute to red-skin symptoms in ginseng. It is proposed that antioxidant and antioxidative enzymes, especially those involved in ascorbate-glutathione cycles, are activated to protect against phenolic compound oxidation.