• Journal of Life Science
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• v.19 no.8
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• pp.1039-1046
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• 2009

The cytochrome P450s (P450s) metabolizing natural products are among the most versatile biological catalysts known in plants, but knowledge of the structural basis for their broad substrate specificity has been limited. The activity of p-coumarate 3-hydroxylase (C3H) is thought to be essential for the biosynthesis of lignin and many other phenylpropanoid pathway products in plants however, all attempts to express and purify the protein corresponding C3H gene have failed. As a result, no conditions suitable for the unambiguous assay of the enzyme are known. The detailed understanding of the mechanism and substrate-specificity of C3Hdemands a method for the production of active protein on the milligram scale. We have developed a bacterial expression and purification system for the plant C3H, which allows for the quick expression and purification of active wild-type C3H via introduction of combinational mutagenesis. The modified cytochrome P450 C3H ($C3H_{mod}$) could be purified in the absence of detergent using immobilized metal affinity chromatography and size exclusion chromatography following extraction from isolated membranes in a high salt buffer and catalytically activated. This method makes the use of isotopic labeling of C3H for NMRstudies and X-ray crystallography practical, and is also applicable to other plant cytochrome P450 proteins.

• The Korean Journal of Pesticide Science
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• v.15 no.4
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• pp.350-356
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• 2011

Environment-friendly agro-materials tend to be preferred to chemical insecticides recently. For this reason, many studies were conducted to develop environment-friendly insecticides containing natural materials. The purpose of this study was to assess ecotoxicity for 5 plant essential oils (Thyme white, Clove bud, Cassia, Lavender, Lemon eucalyptus) expected to prevent from pests and be used for agro-materials. Target species used to assess acute toxicity were aquatic invertebrate (Daphina magna), fish (Oryzias latipes), honeybee (Apis mellifera L.) and earthworm (Eisenia fetida). The EC50 value, toxicological responses of thyme white, clove bud, and cassia to Daphina magna were 2.5, 2.8, and $6.9mg\;L^{-1}$ respectively and these values were moderately toxic according to standard of USEPA. $EC_{50}$ of Lavender and lemon eucalyptus were >$10mg\;L^{-1}$ then they were considered as slightly toxicity. In case of acute toxicity test to fish, $LC_{50}$ of thyme white and cassia were 6.7 and $7.5mg\;L^{-1}$ each other. The other plant essential oils indicated $LC_{50}$ >$10mg\;L^{-1}$. Acute contact and oral toxicity test to Honeybee were conducted. As a result, $LD_{50}$ of all essential oils were >$100{\mu}g$ a.i. $bee^{-1}$ in both of tests. In case of acute toxicity test to earthworm, $LC_{50}$ of thyme white, clove bud, cassia, lavender, and lemon eucalyptus were 149, 230, 743, 234, and $635mg\;kg^{-1}$, respectively. In conclusion, if the safety for earthworm is confirmed, 5 plant essential oils are expected to be use for environment-friendly insecticide materials with low risk against ecosystem and contribute to developing environment-friendly agro-materials.

• Journal of Korean Society of Forest Science
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• v.77 no.3
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• pp.259-268
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• 1988

For the purpose of examining the effects of simulated acid rain on nutrient contents of plant tissues in Pintos densiflora seedlings and Forsythia koreana rooted cuttings, the experimental design of randomized block arrangement with three replications was implemented in the experimental field of Yesan National Agricultural Junior College. One-year-old Pinus densiflora seedlings and Forsythia koreana cuttings were planted in the pots filled the mixed soils(nursery soil : forest soil of siliceous sandy loam=1 : 1 v/v) in the early spring of 1986. The regime of artificial acid rain, in terms of spray frequency per month and spray amount at single treatment per plot, was simulated on the basis of climatological data averaged from 30 years records. Simulated acid rain(pH 2.0, pH 4.0, and pH 5.5 as control) containing sulfuric and nutric acid in the ratio of 3 : 2(chemical equivalant basis) diluted with ground water were treated on the experimental plants under condition of cutting off the natural precipitation with vinyl tunnel, during the growing season(May 1 to August 31) in 1986. The results obtained in this study were as follow : (1) As for the nitrogen contents in plant tissues, P. densiflora increased significantly in one-year-old stembranch and root tissues, and F. koreana increased significantly in leaf and root tissues, as the pH levels of acid rain decreased. (2) The available phosphate contents in root tissues of P. densiflora, and in leaf and root tissues of F. koreana were significantly decreased, as the pH levels of acid rain decreased. (3) $K_2O$, CaO and MgO contents in plant tissues were significantly decreased in the both species as the pH levels decreased. And the effects of acid rain on F. koreana were higher than those of P. densiflora. (4) Sulfur contents of plant tissues in the both species were increased at pH 2.0 treatment. There were significant differences among three acid rain treatments in leaf and root tissues of P. densiflora, and in all parts of F. koreana. (5) In the effects of simulated acid rain on the both species and the tested soils, in general, F. koreana revealed higher sensitiveness than P. densiflora, and the lower pH levels of simulated acid rain were treated, the more sharp reaction was showed.

• Journal of Practical Agriculture & Fisheries Research
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• v.24 no.4
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• pp.18-29
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• 2022

Five species of plants (Clerodendrum trichotomum Thunb., Angelica dahurica (Fisch. ex Hoffm.) Benth. & Hook. f. ex Franch. & Sav., Caryopteris incana (Thunb. ex Houtt.) Miq., Lonicera japonica Thunb., and Parasenecio auriculatus var. matsumurana Nakai) native to the clean area of Mt. Jiri were selected. The collection period was from May to September 2021, and the five species plants were collected in their native habitats with flowers in full bloom. The collected plants were extracted with 70% EtOH, and 17 kinds of polyphenol components were analyzed. Next, flowers, leaves, stems, and roots were separated from plants, extracted with 70% EtOH for each part and experiments were conducted on DPPH, ABTS, total polyphenols, and total flavonoids. The results are as follows. 1. It was found that there were a total of 8 kinds of polyphenols contained in 5 species of plants that are native to Mt. Jiri. Among the polyphenol components, chlorogenic acid was contained in 4 species of plants, and caffeic acid was contained in 2 species of plants. 2. As a result, the DPPH radical scavenging activity was the best in the stem of P. auriculata and the C. trichotomum was good regardless of the specific part. It was found that the activity-scavenging activity was good in the flowers of A. dahurica and the leaves of L. japonica. 3. The highest ABTS radical scavenging activity was C. trichotomum Thunb., whose EC₅₀ value was 38.73~66.28ppm. Next, the leaves and stems of L. japonica Thunb., A. dahurica and P. auriculata, and the leaves and stems of C. incana appeared in that order. 4. The highest total polyphenol content was 154.83mg GAE/g in the leaves of C. trichotomum, followed by about 130mg GAE/g in the flowers of C. trichotomum and P. auriculata. The lowest was 26.27mg GAE/g in the stems of A. dahurica.

• The Korean Journal of Pesticide Science
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• v.17 no.4
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• pp.435-439
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• 2013

Bacillus amyloliquefaciens M27 was selected as a control agent for the biological control of cucumber powdery mildew. The new mixture of B.amyloliquefaciens M27 and plant (Eucalytus) extract was developed to improve the control activity of B.amyloliquefaciens M27 against cucumber powdery mildew. The mixed formulation showed the high preventive and curative control effect against cucumber powdery mildew when it was diluted at 500 times and foliar-sprayed. Its control effect was higher in preventive spraying than curative spraying. When 500-fold diluted solution of the formulation was sprayed preventively four times at five-day intervals, three times at seven-day intervals and twice at ten-day intervals, the diseased leaf area was shown to be 4.4%, 8.0%, 27.9%, respectively; Whereas the diseased leaf area in the control plot was 45.4%. When the 500-fold diluted formulation was sprayed curatively four times at five-day intervals, three times at seven-day intervals and twice at ten-day intervals after occurred cucumber powdery mildew, the diseases leaf area was 11.5%, 25.2%, 51.8%, respectively; whereas in the control plot, the diseases leaf area was 64.3%. When the 500-fold diluted formulation was treated four times at five-day intervals in the plastic house, its control effect was higher than that treated three times at seven-day intervals and twice at ten-day intervals. As the results, the mixed formulation of B.amyloliquefaciens M27 and plant extract could be a promising candidate of bio-fungicides for the environment-friendly control of powdery mildew of cucumber.

• Research in Plant Disease
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• v.14 no.3
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• pp.187-192
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• 2008

Five environment-friendly farm materials including $Chitomate^{(R)}$, $Diegyun^{(R)}$, IC-$66D^{(R)}$, Gold $Bordo^{(R)}$, and $Biospot^{(R)}$ were examined for their growth inhibition effect of the 7 fungal pathogens of grape in vitro. $Diegyun^{(R)}$, being composed of natural ingredients which are extracted from a plant, was the most effective in suppression of mycelial growth of the fungi. $Diegyun^{(R)}$ inhibited the mycelial growth of all of fungi over 75% at $2,500{\mu}g{\cdot}mL^{-1}$ on potato dextrose agar(PDA) except Colletotrichum gloeosporioides 04-159. Growth inhibition effect of $Chitomate^{(R)}$, being composed of the chitosan, varied depending on the fungal pathogens on PDA. It inhibited the mycelial growth of the Botrytis cinerea 06-063 at the rate of 75.8% at $40,000{\mu}g{\cdot}mL^{-1}$ on PDA while it inhibited the mycelial growth of the C. gloeosporioides 04-159 at the rate of 6.5%. IC-$66D^{(R)}$ and Gold $Bordo^{(R)}$ are two different formula of the Bordeaux mixture, showed different control effects on mycelial growth inhibition. Except of Acremonium sp. the growth inhibition of IC-$66D^{(R)}$ was a little higher than Gold $Bordo^{(R)}$. $Biospot^{(R)}$, a chlorine formula, showed the strongest growth inhibition on C. gloeosporioides 04-159 among the farm materials used. Inhibition of spore germination of $Chitomate^{(R)}$, $Biospot^{(R)}$ and Gold $Bordo^{(R)}$ was higher than mycelial growth inhibition for Pseudocercospora vitis 04-152. The results suggest that the different types of environment-friendly farm materials are needed for different disease control in organic grape farm.

• Korean Journal of Plant Resources
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• v.24 no.2
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• pp.253-259
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• 2011

In this studies, contents and activities of antioxidative substances in the fruits of a pear cultivar and five Korean wild pear lines were investigated. The content of total phenolic compounds was highest with Pyrus pyrifolia var. culta "Shingo" (7.68 $mg{\cdot}g^{-1}$, D.W.) while total flavonoids was highest with P. ussuriensis var. acidula (5.66 $mg{\cdot}g^{-1}$, D.W.). The contents of total polyphenols and flavonoids varied according to plant species, but in general pyrifolia lines had higher total polyphenols than total flavonoids whereas in ussuriensis lines total flavonoid contents were higher than total polyphenols. The scavenging effects of DDPH radicals was highest with highest with P. ussuriensis var. seoulensis ($RC_{50}$=1.45 $mg{\cdot}mL^{-1}$) and that of ABTS radicals was highest with P. ussuriensis var. acidula ($RC_{50}$=0.69 $mg{\cdot}mL^{-1}$). A pear cultivar "Shingo" showed highest total polyphenol content, but scavenging activity of DDPH and ABTS radicals was lowest. The fruits of P. ussuriensis var. seoulensis contained low level of phenolic compounds, but their scavenging effects on two radicals was superior. Ferrous ion chelating effect was high in P. pyrifolia var. culta (98.93%), and in P. ussuriensis var. sinensis (68.71%), but two species had low scavenging activity. The content of phenolic compounds in wild pears was not always directly proportional to the radical scavenging activity. Neither radical scavenging activity was to ferrous ion chelating activity. In conclusion the fruits of P. ussuriensis var. acidula, P. ussuriensis var. seoulensis, and P. ussuriensis var. sinensis had great potential for the development of new antioxidative functional food because their antioxidative activity is higher or at least similar to P. pyrifolia var. culta. However, due to their different levels of antioxidative effects, the development of methods of using them jointly, not singly, to obtain maximum level of antioxidants is recommended.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.3
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• pp.393-400
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• 2011

This study investigates the effects of a hangover beverage (MIX) that contains minerals (highly-salty mineral water, HSMW) and several medicinal plant extracts, on antioxidant and alcohol-metabolizing enzymes in alcohol administered Sprague-Dawley rats. HSMW is pumped from below the sedimentary rock layer of Dadaepo, Busan, South Korea, which is 1,050 m below the land surface; it tastes salty, like sea water. In terms of medicinal plant extracts, the total phenolic and flavonoid contents of Rubus coreanus and Cornus officinalis were measured as being significantly higher than those in Curcuma longa. The results suggest that treatment with MIX significantly increases superoxide dismutase (SOD) activity and DPPH radical scavenging activity. In the 10% HSMW-, for MIX- and company product (CP)-treated groups, the concentration of blood alcohol was significantly reduced 1~5 hr after alcohol loading, compared to that in the control group. In hepatic alcohol-metabolizing enzyme activities, alcohol dehydrogenase (ADH) activity was found to be higher in the MIX- and CP-treated groups than in controls, whereas acetaldehyde dehydrogenase (ALDH) activity was significantly higher in the CP-treated groups than other groups. This study concludes, therefore, that MIX (HSMW) minerals, like as Zn, Ca, Mg, Mn, and others stimulate alcohol-metabolizing enzymes, while the antioxidants of plant extracts prevent the damage otherwise incurred by alcohol toxicity. These results suggest that the hangover beverage (MIX) alleviates alcohol hangover symptoms by stimulating activities related to hepatic alcohol-metabolizing enzymes and antioxidant effects.

• Journal of Korean Society of Forest Science
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• v.99 no.3
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• pp.267-276
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• 2010

This study was performed to obtain basic data about vegetation structure and site environment of rare and endangered plant, viola websteri in five natural habitats. The dominant species of Hongcheon habitat were Pyrus pyrifolia (tree layer), Morus bombycis (subtree layer), Pyrus pyrifolia (shrub layer) and Isodon inflexus (herb layer). Mt. Yeonin habitat were dominated by Quercus mongolica (tree layer), Morus bombycis (subtree layer), Philadelphus schrenckii (shrub layer) and Viola websteri (herb layer). Mt. Yumyung habitat were dominated by Cornus controversa (tree layer), Morus bombycis (subtree layer), Fraxinus rhynchophylla (shrub layer) and Adenocaulon himalaicum (herb layer). Mt. Daebu habitat were dominated by Acer mono (tree layer), Staphylea bumalda (subtree layer), Staphylea bumalda(shrub layer) and Dryopteris crassirhizoma (herb layer). And the dominant species of Mt. Worak habitat were Larix leptolepis (tree layer), Fraxinus rhynchophylla (subtree layer), Alangium platanifolium var. macrophylum (shrub layer) and Adenocaulon himalaicum (herb layer). It was found out that the average acidity of soil pH was 5.23; 0.30ds/m for electron conductivity; 12.6% for organic matter content; 0.68% for total nitrogen; 21.66 ppm for available phosphorous; and 23.45 cmol(+)/kg for CEC. Interchangeable cation was decreased in order of $Ca^{2+}$ > $Mg^{2+}$ > $K^{2+}$. Viola websteri had positive association with Polygonatum odoratum var. pluriflorum and Geranium thunbergii but negative association with Poa sphondylodes. Species diversity index(H'), maximum Species diversity index (H' max), evenness(J') and dominance (1-J'), of investigated sites ranged 0.6816 (Mt. Worak)~0.9656 (Mt. Daebu), 1.0000 (Mt. Yeonin)~1.3010 (Hongcheon, Gangwon), 0.5330 (Mt. Worak)~0.8947 (Mt. Daebu) and 0.1053 (Mt. Daebu)~0.4670 (Mt. Worak) in woody layer and 1.0414 (Mt. Yumyung)~1.3295 (Mt. Worak), 1.4314 (Mt. Yumyung)~1.6435 (Mt. Daebu), 0.6984 (Hongcheon, Gangwon)~0.8356 (Mt. Worak) and 0.1644 (Mt. Worak)~0.3016 (Hongcheon, Gangwon) in herb layer, respectively.

• Korean Journal of Heritage: History & Science
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• v.52 no.1
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• pp.272-287
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• 2019

The Korean Demilitarized Zone (DMZ) was established in 1953 by the Korean War Armistice Agreement. It extends from the estuary of the Imjin River, in the west, to the coast of the East Sea. It is 4 km in width and 148 km in length. However, the ecosystems of the civilian control zone (CCZ) located between the southern border of the DMZ and the civilian control line (CCL) and the CCZ in the estuary of the Han River and the Yellow Sea are similar to those in the DMZ, and, therefore, the ecosystems of the DMZ and the CCZ are collectively known as the "ecosystems of the DMZ and its vicinities." The flora in the DMZ and its vicinities is composed of 1,864 species, which accounts for about 42% of all the vascular plant species on the Korean Peninsula and its affiliated islands. Conducting a detailed survey on the vegetation, flora, and fauna in the DMZ is almost impossible due to the presence of landmines and limitations on the time allowed to be spent in the DMZ. However, to assess the environmental impact of the Munsan-Gaesong railroad reconstruction project, it was possible to undertake a limited vegetation survey within the DMZ in 2001. The vegetation in Jangdan-myeon, in Paju City within the DMZ, was very simple. It was mostly secondary forests dominated by oaks such as Quercus mongolica, Q. acutissima, and Q. variabilis. The other half of the DMZ in Jangdan-myeon was occupied by grassland composed of tall grasses such as Miscanthus sinensis, M. sacchariflorus, and Phragmites japonica. Contrary to the expectation that the DMZ may be covered with pristine mature forests due to more than 60 years of no human interference, the vegetation in the DMZ was composed of simple secondary forests and grasslands formed on former rice paddies and agricultural fields. At present, the only legal protection system planned for the DMZ is the Natural Environment Conservation Act, which ensures that the DMZ would be managed as a nature reserve for only two years following Korean reunification. Therefore, firstly, the DMZ should be designated as a site of domestic legally protected areas such as nature reserve (natural monument), scenic site, national park, etc. In addition, we need to try to designate the DMZ as a UNESCO Biosphere Reserve or as a World Heritage site, or as a Ramsar international wetland for international cooperation. For nomination as a world heritage site, we can emphasize the ecological and landscape value of the wetlands converted from the former rice paddies and the secondary forests maintained by frequent fires initiated by military activities. If the two Koreas unexpectedly reunite without any measures in place for the protection of nature in the DMZ, the conditions prior to the Korean War, such as rice paddies and villages, will return. In order to maintain the current condition of the ecosystems in the DMZ, we have to discuss and prepare for measures including the retention of mines and barbed-wire fences, the construction of roads and railroads in the form of tunnels or bridges, and the maintenance of the current fire regime in the DMZ.