• Journal of Life Science
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• v.19 no.3
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• pp.343-348
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• 2009

Magnaporthe oryzae, a major cause of rice blast, is one of the most destructive plant fungal pathogens. Secretion of reactive oxygen species (ROS) during the infection phase of plant pathogenic fungus plays a key role in the defense mechanism of a plant. ROS causes oxidative damage and functional modification to the proteins in a pathogenic fungus. Methionine, especially, is a major target of ROS, which oxidizes it to methionine sulfoxide. To survive from the attack of ROS, plant pathogenic fungus has antioxidative systems - one example would be methionine sulfoxide reductase B (MSRB), which reverses the oxidative alteration of methionine to methionine sulfoxide. In the present study, identification and molecular characterization of the MSRB gene in M. oryzae KJ201 were investigated. The MSRB gene was amplified by PCR from the M. oryzae KJ201 genomic DNA. The copy number of MSRB in the genome of M. oryzae KJ201 was identified by Southern blot analysis, which revealed that the gene exists as a single copy. To study the molecular function of an MSRB gene, the expression level of the MSRB gene was assayed with hydrogen peroxide treatment by Northern blot analysis and RT-PCR. The expression of the MSRB gene was increased by treatment of hydrogen peroxide, without significant correlation to hydrogen peroxide concentrations. These results indicate that the MSRB gene in M. oryzae KJ201 could contribute to protection against plant defense compounds such as ROS and offer a novel strategy for the control of rice blast.

• Journal of Plant Biotechnology
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• v.29 no.4
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• pp.229-233
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• 2002

Ferritin is ubiquitous in bacteria, animals and plants. Ferritin is thought to play two main roles in living cells to provide iron for the synthesis of iron protein such as ferretoxin and cytochromes and to prevent damage from radicals produced by iron/dioxygen interaction. To enhance the resistance of potato to Erwinia carotovora, the soybean ferritin gene was introduced into the potato either under CaMV 35S or hsr203J promoter. Potato transgenic plants were screened by PCR analysis using specific primers to the ferritin gene. Expression of ferritin gene under CaMV 35S and hsr203J promoter in potato transgenic plants was confirmed by northern blot analysis. hsr203J promoter known to pathogen inducible in tobacco drives the induction upon Phytophthora infestan in potato and the transcript level of ferritin gene was extremely high after 24 hours post inoculation. One of transformants under CaMV 35S promoter was increased 2.5 fold than untransformant. Each one of transgenic potato containing gene promoter CaMV 35S and hsr203J-ferrtin fusion exhibited tolerance against potato soft rot.

• Journal of Life Science
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• v.27 no.7
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• pp.849-856
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• 2017

The ${\beta}$-D-fructofuranosidase (EC 3.2.1.26) is an important enzyme from a historical point of view, discovered by French biologist Berthelot in 1860 and was first used to study enzymology. ${\beta}$-D-fructosfuranosidase catalyzes the hydrolysis of sucrose into D-glucose and D-fructose. Four biochemical subgroups of ${\beta}$-D-fructofuranosidase have been investigated in plants. There are vacuolar (soluble acid), cytoplasmic (soluble alkaline), membrane-bound (insoluble alkaline), and cell wall-bound (insoluble acid) ${\beta}$-D-fructofuranosidase by purification. Their biochemical characteristics are distinct. It suggested that those enzymes might be different gene products. The contribution of each of these enzymes to sucrose management in the plant is likely to be correlated with their localization. Common localization in developing cells in tissues from a range of developmental stages and plant parts suggests that all of the isoforms may be closely involved in nutrient transport. The ${\beta}$-D-fructofuranosidases were most commonly found associated with maturing tissues in developing fruits, leaves, and roots. The ${\beta}$-D-fructofuranosidase activity varies in the relationship between growth and expansion through cell division, development of storage organs and tissues, and the relationship of plant defense responses. It is necessary to summarize more researches in order to know the definite physiological function.

• Journal of Plant Biotechnology
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• v.41 no.2
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• pp.73-80
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• 2014

Pretreatment of chinese cabbage leaves with $100{\mu}M$ sodium nitroprusside (SNP), a nitric oxide (NO) donor, effectively improved their tolerance to subsequent $2{\mu}M$ paraquat (PQ)-induced oxidative damage. The fresh weight, and chlorophyll and protein contents in primary leaves treated with PQ alone were noticeably reduced over 24 h light incubation. However, these leaf injury symptoms were significantly alleviated with $100{\mu}M$ SNP pretreatment for 3 h prior to PQ exposure. In additions, the increase of the contents of malondialdehyde (MDA) and $H_2O_2$ due to PQ exposure were significantly inhibited by SNP pretreatment. Together with the protective effects of SNP against PQ toxicity in leaves, the changes of ascorbate-glutathione cycle enzymes activities were examined. In the PQ alone treatment, the activities of APX, DHAR, and GR after 6 h incubation were rapidly reduced and showed 19%, 50% and 39% respectively, compared with those of the control. However, the decreases in these enzyme activities were significantly inhibited by SNP pretreatment. As a result, their activities were higher than those of PQ alone treatment by 5 times, 2 times, and 1.5 times, respectively, at 6 h incubation. Thereafter, these enzymes decrease their activities gradually showing high levels than those of PQ alone. Based on the above results, it can be assumed that the activation of ascorbate-glutathione cycle by SNP pretreatment in chinese cabbage leaves exposed to PQ can prevent $H_2O_2$ accumulation, thereby leading to protection against PQ-induced oxidative stress. Also, these results indicate that NO acts as an protectant against PQ stress in the leaves of chinese cabbage.

• Journal of Applied Biological Chemistry
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• v.61 no.2
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• pp.109-117
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• 2018

Recently, cancer incidence in modern society is increasing sharply. DNA damage is caused by intrinsic or extrinsic factors in the human body, cells protect themselves by defense mechanism against DNA damage. Also, Aberrant DNA and deficient DNA repair are closely associated with various diseases, including aging and cancer. Researchers are interested in search for proper materials to inhibition for DNA damage. As knew the side effects of synthetic antioxidant, some researches have been conducted about cancer prevention materials derived from nature. Root of Smilax china, in Liliaceae, is used detoxification and tumor treatments traditionally. However, studies on the inhibitory effect of DNA damage haven't progressed. In this study, antioxidant activity and protective effects on oxidative DNA damage of S. china root were confirmed, relationship between those activities and contents of phenolic compounds in plants were established. S. china root effectively removed 1,1-diphenyl-2-picryl-hydrazyl radicals and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid radicals. The quantification and identification of phenolic compounds were confirmed by high performance liquid chromatography analysis, its antioxidant activity was associated with some phenolic compounds. In addition, protective effects against hydroxyl radicals and ferrous ion-induced oxidative DNA damage were confirmed in plasmid DNA. In the cellular levels, S. china root suppressed the expression of ${\gamma}$-H2AX and p53 protein in NIH 3T3. Besides, S. china root suppressed H2AX and p53 mRNA levels. In conclusion, S. china root had the effect on DNA protection and antioxidant.

• Proceedings of the Korean Journal of Food and Nutrition Conference
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• 2003.07a
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• pp.82-82
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• 2003

오디는 옛부터 보혈자음(補血滋陰), 생진윤조(生津閏操), 현훈이명(眩最耳鳴), 심계실면(心悸失眠), 수발조백(鬚髮早白) 등을 치료하는 효능을 가진다고 알려져 있다. 상심자(桑 子)라 하여 뽕나무 열매로서 한방에서 상심(桑 ), 상실(桑實), 오심(烏 ), 흑심(黑 ) 등으로 지칭되며, 뽕나무과(Moraceae)에 속하는 뽕나무(Morus alba L)의 성숙한 과실로 취화과(聚花果)에 속하며 작은 수과(瘦果)가 많이 모여 이루어진 장원형으로 길이 1 내지 2 cm, 지름 0.5 내지 0.8 cm이며 황갈색, 갈홍색 또는 암자색을 띠고 짧은 줄기가 있다. 작은 수과(瘦果)는 난원형으로 조금 납작한 편이며, 길이는 약 2 mm, 너비는 약 1 mm 이고 육질의 화편(花片) 4개가 둘러싸고 있다. 그러나 아직까지는 오디에 대하여 자연과학적인 연구방법을 이용하여 구체적으로 연구된 바가 많지 않다. 또한 이의 생리활성 성분에 대해서도 그 작용과 연관지어 보고된 바가 많지 않다. 뇌졸중 가운데 뇌조직으로 가는 혈액 공급의 감소 혹은 차단으로 발생되는 허혈성 뇌졸중(ischemic stroke)은 전체 뇌졸중 환자의 약 80%정도를 차지하고 있으나 아직까지 뇌신경세포 손상기전의 복잡성 등으로 뇌졸중으로 발생하는 뇌신경세포의 손상을 보호해 줄 수 있는 물질이 개발되어 있지 못한 실정이다. 한편, 천연물로부터 뇌허혈 보호작용을 가지는 물질의 도출은 주로 한방에서 처방을 중심으로 이루어지고 있으며, 따라서 처방으로부터 신경보호작용을 가지는 물질의 도출은 그 처방에 함유되어 있는 각종 생약이 갖는 다양한 활성으로 인해 어려운 점이 있으며, 비록 효과가 있다고 하더라도 과학적인 입증자료가 매우 미비한 실정이다. 이에 본 연구에서는 위에 언급된 자료를 토대로 오디추출물이 뇌허혈에 효과가 있을 것이라는 가정하에 in vitro system을 이용하여 오디추출물의 신경보호작용기전을 검색하고자 DPPH radical 의 생성억제효과, PC12 cell line을 이용한 산화적 스트레스에 의한 오디추출물의 방어효과, LSP에 의하여 활성화된 BV-2 cell에 미치는 영향 등을 검색하였다. 오디의 DPPH 소거활성은 단일화랍물인 bacicalein과 유사한 효과를 나타냈으며 PC12 cell line을 이용한 산화적 스트레스에 의한 오디의 방어 효과는 LDH activity를 행한 결과 농도 의존적으로 LDH 유리 량을 감소시켰다. 뇌손상시에 오디추출물의 염증방어 효과를 관찰하기 위하여 microglial cell line인 BV2 세포주를 선택하여 배양한 후 LPS로 자극을 준 후 일차적인 염증지표인 NO양을 측정한 결과 BV2 cell에 LPS 100 ng/ml을 처리하는 경우 nitrite량이 유의적으로 증가하였는데 이때 오디추출물을 1, 5, 10 ug/ml의 용량으로 처리하는 경우 역시 저농도에서 NO생성량을 감소시켰다. 정리해보면 뽕나무과 식물인 오디는 신경보호효과가 있는 것으로 사료되는데 이러한 효과는 아마도 오디의 항산화효과에 기인한 것으로 추정된다.

• Korean Journal of Environmental Biology
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• v.39 no.3
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• pp.354-361
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• 2021

Understanding the phytotoxic mechanism of methyl bromide (MB), an essential fumigant during the quarantine and pre-shipment process, is urgently needed to ensure its proper use and reduce international economic losses. In a previous study, two main MB-induced toxic mechanisms such as reactive oxygen species (ROS) and auxin distribution were selected by analyzing transcriptomic analysis. In the study, a 3-week-old A. thaliana was supplied with 1 mM ROS scavengers [N-acetyl-L-cysteine (NAC) or L-glutathione (GSH)] and 1µM indole-3-acetic acid(IAA) three times every 12 h, and visual and gene expression assessments were performed to evaluate the reduction in phytotoxicity by supplements. Phytotoxic effects on the MB-4h exposed group were decreased with GSH application compared to the other single supplements and a combination of supplements at 7 days post fumigation. Among these supplements, GSH at a concentration of 1, 2, and 5mM was suppled to A. thaliana with MB-fumigation. During a long-term observation of 2 weeks after the fumigation, 5 mM GSH application was the most effective in minimizing MB-induced phytotoxic effects with up-regulation of HSP70 expression and increase in main stem length. These results indicated that ROS was a main key factor of MB-induced phytotoxicity and that GSH can be used as a supplement to reduce the phytotoxicity of MB.

• Korean Journal of Plant Resources
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• v.14 no.2
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• pp.116-123
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• 2001

The non-enzymatic antioxidants and antioxidant enzyme from the extracts of Parthenocissus tricuspidata PLANCH. were examined in order to utilize natural product for cerchemopreventive agents. The antioxidant potential and enzyme activities on plant positions in the extracts of Parthenocisuss tricuspidata PLANCH. showed considerable differences. The antioxidant activity of the leaf extracts by Ethyl acetate fractions of Parthenocisuss tricuspidata PLANCH. was the highest among three positions ($7.57\mu\textrm{g}/m\ell$). The highest activities showed in S-5 (in leaf), S-4 (in stem) and S-3 (in root) fraction by Silicagel column chromatography and the antioxidant activity showed, in purified extract of each positions, $7.06\mu\textrm{g}/m\ell$ (in leaf), $6.99\mu\textrm{g}/m\ell$ (in stem) and $12.39\mu\textrm{g}/m\ell$ (in root) respectively. The activities of DPPH by LH-20 column chromatography revealed much higher than those by silica-gel column chromatography. These were identified as the phenolic compounds known as antioxidant compounds such as Benzoic acid(Gallic acid), 1-methyl-3-(2-phenylethen) benzene, phloroglucinol and 1,2-dihydroxy-4-(1-propyl)benzene by GC/MS. POD activities in the stem and root were higher than in the leaf. SOD activity was highest in the leaf, stem and root activity was comparatively low. Especially, SOD activity in leaf was over 2 times higher than root.

• Journal of Life Science
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• v.16 no.3 s.76
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• pp.522-526
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• 2006

To investigate the effects of UV-B on fatty acid composition, lipid peroxidation and biochemical defense responses of plant, kidney bean (Phaseolus vulgaris L.) was subjected to enhanced UV-B irradiation [daily dose : 0.02.(No UV-B) and 11.36 (enhanced UV-B) $kJ\;m^{-2};UV-B_{BE}$] for 3 weeks. UV-B drastically inhibited both height and dry weight of kidney bean. The content of malondialdehyde significantly increased by about 50% after 3 weeks of UV-B irradiation. The ratio of unsaturated to saturated fatty acids of kidney bean was increased by UV-B irradiation. Three major polyamines of kidney bean leaves : putrescine, spermidine and spermine, were observed. All of the polyamine contents were increased with UV-B irradiation. These results suggested that enhanced UV-B radiation caused oxidative stress on lipids and biochemical protection responses might be activated to prevent from damaging effects of oxidative stress generated by UV-B irradiation.

• Journal of Radiation Protection and Research
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• v.25 no.2
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• pp.67-73
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• 2000

The effects of combined irradiation of neutrons and ${\gamma}$-rays were analysed by means of Tradescantia stamen hair (TSH) assay. Potted plants were irradiated with $0{\sim}2$ Gy of ${\gamma}$-rays. For the combined treatments, the plants were irradiated with neutrons from $^{252}Cf$ 24 hours before or after ${\gamma}$-irradiation. The slopes of dose-response curves were 5.98, 6.17 and 7.48, in ${\gamma}$-rays, ${\gamma}$-rays+neutrons, and neutrons+${\gamma}$ -rays irradiated groups, respectively. The biological efficacy of radiations in the induction of pink mutations increased by 25% in neutrons+${\gamma}$-rays irradiated group, while it increased by 12% in ${\gamma}$-rays+neutrons irradiated group. The combined irradiation with two kinds of radiations results in the different efficacy of radiation depending on the order of irradiations, which is of great importance in the related fields such as sterilization and radiotherapy.