• Korean Journal of Environmental Biology
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• v.34 no.4
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• pp.304-313
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• 2016

One of the issues currently facing nuclear power plants is how to store spent nuclear waste materials which are contaminated with radionuclides such as $^{134}Cs$, $^{135}Cs$, and $^{137}Cs$. Bioremediation processes may offer a potent method of cleaning up radioactive cesium. However, there have only been limited reports on $Cs^+$ tolerant bacteria. In this study, we report the isolation and identification of $Cs^+$ tolerant bacteria in environmental soil and sediment. The resistant $Cs^+$ isolates were screened from enrichment cultures in R2A medium supplemented with 100 mM CsCl for 72 h, followed by microbial community analysis based on sequencing analysis from 16S rRNA gene clone libraries(NCBI's BlastN). The dominant Bacillus anthracis Roh-1 and B. cereus Roh-2 were successfully isolated from the cesium enrichment culture. Importantly, B. cereus Roh-2 is resistant to 30% more $Cs^+$ than is B. anthracis Roh-1 when treated with 50 mM CsCl. Growth experiments clearly demonstrated that the isolate had a higher tolerance to $Cs^+$. In addition, we investigated the adsorption of $0.2mg\;L^{-1}$ $Cs^+$ using B. anthracis Roh-1. The maximum $Cs^+$ biosorption capacity of B. anthracis Roh-1 was $2.01mg\;g^{-1}$ at pH 10. Thus, we show that $Cs^+$ tolerant bacterial isolates could be used for bioremediation of contaminated environments.

• Horticultural Science & Technology
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• v.32 no.1
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• pp.91-99
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• 2014

The objective of this study is to identify cold-tolerance genes in Brassica rapa. In order to acheive this goal, we analyzed a KBGP-24K oligo chip data [BrEMD (B. rapa EST and Microarray Database)] using B. rapa ssp. pekinensis inbred line 'Chiifu' under cold stress condition ($4^{\circ}C$). Among 23,929 unigenes of B. rapa, 417 genes (1.7%) were primarily identified as cold responsive genes that were expressed over 5-fold higher than those of wild type control, and then a gene which has unknown function and has full length sequence was selected. It was named BrCSR (B. rapa Cold Stress Resistance). BrCSR was transformed using expression vector pSL101 to confirm whether BrCSR can enhance cold tolerance in tobacco plants. $T_1$ transgenic tobacco plants expressing BrCSR were selected by PCR and Southern hybridization analyses, and the function of BrCSR was characterized by expression level analysis and phenotype observation under cold stress condition. The expression level of BrCSR in transgenic tobacco plants increased up to about two folds in quantitative real-time RT-PCR assay and this was very similar to Northern blot hybridization analysis. Analysis of phenotypic characteristics clearly elucidated that transgenic tobaccos expressing BrCSR were more cold tolerant than wild type control under $4^{\circ}C$ treatment. Based on these results, we conclude that the over-expression of BrCSR might be closely related to the enhancement of cold tolerance.

• Journal of Korean Society of Forest Science
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• v.96 no.5
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• pp.551-560
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• 2007

We investigated physiological damages and biochemical alleviation of five species of genus Acer under ozone fumigation in order to assess their tolerant ability against ozone toxicity. At the end of 150 ppb $O_3$ fumigation, photosynthetic characteristics were measured, and chlorophyll contents, malondialdehyde (MDA) and antioxidative enzyme activities were analyzed in the leaves of five maple trees (Acer buergerianum, A. ginnala, A. mono, A. palmatum, and A. palmatum var. sanguineum). The reduction of chlorophyll (chl) a in ozone-exposed plants was 16.8% (A. buergerianum) to 26.7% (A. ginnala) of control plants. For the content of chi b, A. ginnala and A. palmatum var. sanguineum represented the high reduction of 26.3% and 23.6%, respectively. The highest reduction on the chi a:b ratio was observed in the leaves of A. palmatum. The reduction of net photosynthesis in five species varied from 2.4% to 37.6%. Among five species, A. ginnala showed remarkable reduction (37.6%) for net photosynthesis in comparison with control. Carboxylation efficiency differed significantly (P < 0.05) among species and between control and ozone treatment. The reduction of carboxylation efficiency was the highest in the leaves of A. ginnala (44.7%). A. palmatum var. sanguineum showed the highest increase (41.7%) for MDA content. The highest increase of superoxide dismutase (SOD) activity represented in A. palmatum (26.1%) and the increase of ascorbate peroxidase (APX) activity ranged from 16.5% (A. ginnala) to 49.1% (A. palmatum var. sanguineum). A. mono showed the highest increase (376.6%) of glutathione reductase (GR) activity under ozone fumigation and A. buergerianum also represented high increase (42.3%) of GR activity. Catalse (CAT) activity increased in the leaves of A. ginnala, A. palmatun and A. palmatum var. sanguineum under ozone exposure, whereas A. buergerianum and A. mono decreased in comparison with control plants. In conclusion, physiological markers such as chlorophyll content and photosynthesis that responded sensitively to $O_3$ in maple trees were considered as the very important indicators in order to evaluate the tolerance against $O_3$ stress, and parameters were closely related with each other. Among anti oxidative enzymes, SOD and APX might be contributed to alleviate to $O_3$ toxicity through the increase of activity in all maple trees. Therefore, these compounds can be used as a biochemical maker to assess the stress tolerance to $O_3$.

• Korean Journal of Weed Science
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• v.30 no.1
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• pp.17-24
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• 2010

Field study to find appropriate species for phytoremediation and phytomonitoring with higher plants was carried out at four abandoned metalliferous mines. In order to know the tolerant degree of plant resources collected at heavy metal polluted sites, soil and plants were sampled at same sites and metal concentrations were determined. Most serious heavy metal polluted in the sites was As that showed range from 29.1 to 1372.2 mg $kg^{-1}$ in investigated area. The dominant species were Oenothera biennis, Commelina communis, Persicaria senticosa, Conyza annuus, Artemisia princeps, and Erigeron canadensis. These species were predominant species that were proliferated in any survey area. Compared with other sites, vegetational characteristics of Dal-Seong, a mine site abandoned early in 1973, showed higher diversity index and lower dominance index. Distributions of weed species according to life cycle indicated that the proportions of perennial plants were lowered in every investigated site. Although the polluted areas were distant from each other, similarity indices among these vegetation were relatively similar. These results means the vegetations of abandoned mine areas were beginning stage of vegetational succession, and the vegetations were adversely affected by disturbance with heavy-metals and lack of water in soil.

• Journal of Environmental Science International
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• v.24 no.11
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• pp.1501-1511
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• 2015

As essential trace elements, copper and zinc play important roles in many physiological events in plants. In excess, however, these elements can limit plant growth. This study selected a heavy metal-tolerant plant by analyzing seed germination and biomass of alfalfa (Medicago sativa), canola (Brassica campestris subsp. napus var. nippo-oleifera), Chinese corn (Setaria italica), and a sorghum-sudangrass hybrid (Sorghum bicolor ${\times}$ S. sudanense), and determined heavy metal uptake capacity by analyzing biomass, chlorophyll a fluorescence, and heavy metal contents under high external copper or zinc levels. The seed germination rate and biomass of the sorghum-sudangrass hybrid were higher under copper or zinc stress compared to the other three plants. The plant biomass and photosynthetic pigment contents of the sorghum-sudangrass hybrid seedlings were less vulnerable under low levels of heavy metals (${\leq}50ppm$ copper or ${\leq}400ppm$ zinc). The maximum quantum yield of PSII ($F_v/F_m$) and the maximum primary yield of PSII ($F_v/F_o$) decreased with increasing copper or zinc levels. Under high copper levels, the decline in $F_v/F_m$ was caused only by the decline in $F_m$, and was accompanied by an increase in non-photochemical quenching (NPQ). The $F_v/F_m$ declined under high levels of zinc due to both a decrease in the maximum fluorescence ($F_m$) and an increase in the initial fluorescence ($F_o$), and this was accompanied by a marked decrease in photochemical quenching (qP), but not by an increase in NPQ. Accumulations of copper and zinc were found in both aboveand below-ground parts of plants, but were greater in the below-ground parts. The uptake capacity of the sorghum-sudangrass hybrid for copper and zinc reached 4459.1 mg/kg under 400 ppm copper and 9028.5 mg/kg under 1600 ppm zinc. Our results indicate that the sorghum-sudangrass hybrid contributes to the in situ phytoremediation of copper or zinc polluted soils due to its high biomass yield.

• Korean Journal of Environmental Agriculture
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• v.20 no.1
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• pp.44-49
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• 2001

To study whether the secondary toxic substances such as ethylene and reactive oxygen species(ROS) are induced by air pollutants in foliage plants, $SO_2$ was fumigated to Pachira aquatica, Spathiphyllum patinii, and Hedera helix. $SO_2$ was controlled to $1\;{\mu}L/L$ and then fiumigated to plants for 2 days(8 hrs/day). It resulted in visible injury in P. aquatica and H. helix while no symptom appeared in S. patinii. Photosynthetic rate and water use efficiency were most remarkably reduced in P. aquatica compared to other two species whereas least in S. patinii. Two days after $SO_2$ fumigation, ethylene evolution was quantified to 23.56, 10.43 and 4.79 nL/g/h in P. aquatica, H. helix and S patinii, respectively. On the other hand, antioxidative enzymes were clearly activated by $SO_2$ treatment in all tested plant species implying ROS production. In conclusion, we could suggest that ethylene and ROS have been intimately related to the defense mechanism against $SO_2$ and their induction degree increased with plant susceptibility to $SO_2$. Furthermore, it was found that S. patinii was tolerant and P. aquatica sensitive to $SO_2$ on the basis of antioxidative enzyme activity and ethylene evolution.

• Weed & Turfgrass Science
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• v.3 no.3
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• pp.225-231
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• 2014

Benzobicyclon induces phytotoxicity to Tongil type rice, although it is an efficient herbicide in paddy. This study was performed to figure out the benzobicyclon-induced phytotoxicity responses of whole crop forage rice genotypes that have the genetic background similar to Tongil type rice, under wet-seeded and transplanted conditions. Mogwoo demonstrated whitening symptom at all the temperatures in both wet-seeding and transplanting by the application of standard and double rates of benzobicyclon. Nokyang, Mogyang and Suweon560 exhibited no or negligible whitening and their plant heights were not reduced at standard rate of benzobicyclon. But in double rate application in wet-seeding, the three genotypes showed 0-8% of white plants at all temperature treatments and reduction in plant height was comparatively larger at $27^{\circ}C$. In transplanting, the double rate application of benzobicyclon at 24 and $27^{\circ}C$ induced 0-32% of whitening plants depending on genotypes while no whitening plants were observed at 18 and $21^{\circ}C$ in all genotypes. Reduction in biomass by double rate of benzobicyclon at 24 and $27^{\circ}C$ was greater than at 18 and $21^{\circ}C$. It is concluded that Mogwoo is extremely sensitive to benzobicyclon and Nokyang, Mogyang and Suweon560 are tolerant to the standard rate of benzobicyclon.

• Applied Biological Chemistry
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• v.19 no.3
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• pp.172-183
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• 1976

RNA, DNA and other phosphorus fractions were determined in the leaf and root of soybean plants different in phosphorus sensitivity grown in $NH_4-N,\;NO_3-N$ and urea medium. The phosphorus sensitive cultivars contained higher ASIP (acid soluble inorganic phosphorus) than the tolerant cultivars with all nitrogen sources. ASIP was highest in the urea treated plants and lowest in the nitrate treated plants. Total phosphorus content was mostly affected with increase in ASIP. When ASIP increased, acid solsuble organic phosphorus(ASOP), phospholipids (L-P), RNA-P, residual phosphorus (R-P) tended to increase, while DNA-P showed little change. The percent RNA-P or DNA-P of total phosphorus in the nitrate treated plant was twice that in the ammonium treated plant, which were also higher in tolerant cultivars regardless of nitrogen sources. The percent ASOP in total acid soluble phosphorus $(ASOP/ASP{\times}100)$ decreased as phosphorus sensitivity decreased. Indications are that phosphorus sensitivity depends on the relative sizes of phosphorus metabolic pools. Total dry matter yield was negatively correlated with total phosphorus (r=0.84 significant at 0.01P), ASIP (0.84 significant at 0.01P) and residual phosphorus (0.69 significant at 0.05P). ASOP showed positive correlation with L-P, RNA-P and DNA-P but negative with R-P. RNA-P was significanly correlated only with L-P (0.63 at P=0.01). There was significant interaction (0.01) among nitrogen sources, cultivars and phosphorus metabolic pools. Phosphorus sensitivity and ammonium toxicity appear to be same in view of energy metabolism, that is, the former inhibits the conversion of ATP to ADP (energy releasing) through phosphate potential while the latter inhibits ATP formation (energy storing).

• Journal of the Korean Institute of Landscape Architecture
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• v.42 no.5
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• pp.81-87
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• 2014

Heavy metal pollution is a widespread global problem causing serious environmental concern. Heavy metals such as Cd, Pb, and Zn can induce toxicity in all organisms if the soil levels of contaminants reach critical values. The aim of the present study was to examine the application of Liriope platyphylla, an ornamental Korean native plant with great potential for contaminated soil in urban areas, to determine tolerance for Cd, Pb, and Zn. Plants were grown in amended artificial soil with Cd, Pb, and Zn at 0, 100, 250, and $500mg{\cdot}kg^{-1}$ for 7 months. The length of leaf, width of leaf, total leaf number, dead leaf number, new leaf number, chlorophyll contents, and ornamental value were monitored from May to August, during growth the period. The relative leaf length and leaf width displayed rapidly decreasing tendencies with an increasing Cd concentration beginning from 4 months after planting. The same decreasing tendency was observed in total leaf number, new leaf number, chlorophyll contents, and ornamental values showed a trend of Control> $Cd_{100}$ > $Cd_{250}$ > $Cd_{500}$. In Pb concentration treatments, the relative leaf length and leaf width were significantly lower in plants grown at $250mg{\cdot}kg^{-1}$ and $500mg{\cdot}kg^{-1}$ as compared to the Control, $100mg{\cdot}kg^{-1}$. The total leaf number, new leaf number, and dead leaf number did not show significant difference among treatments in Control and $Pb_{100}$ but chlorophyll contents and ornamental value decreased with increasing Pb supply concentration treatments. However, in Zn supply treatments, the relative leaf length was higher at $100mg{\cdot}kg^{-1}$ than the Control, $250mg{\cdot}kg^{-1}$, $500mg{\cdot}kg^{-1}$, but the relative leaf width decreased compared to the Control, $Zn_{100}$, $Zn_{250}$, and $Zn_{500}$. The total leaf number, dead leaf number, new leaf number, and ornamental value showed the lowest value in plants grown in $Zn_{500}$ treatment but no significant differences were found among other treatments.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.5
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• pp.487-498
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• 2010

This article presents an effect of deicer such as $CaCl_2$(calcium chloride) and EFD(Eco-Friendly Deicer) composed by organic acids on the survival and growth of plant. Pine and bush clover which are main natural species on the road side, and young radish and kidney bean which are cultivation species used in this test that responses of survival and growth were analyzed as grade concentration of deicers. Bush clover showed the most sensitive survival response among 4 species to the deicer. Pine growth didn't have statistical significance as the kind of deicers and concentration variation, but growths of bush clover and kidney bean showed growth inhibition in concentration more than 3% of $CaCl_2$ and EFD1. The results of survival and growth for $CaCl_2$(calcium chloride) demonstrated that young radish and pine are tolerant species and bush clover and kidney bean are sensitive species. Although EFD1 manufactured by chemical showed the negative effect on the survival and growth of plants, EFD2 made with waste compost was confirmed that it has the positive influence to the survival and growth of the both sensitive and tolerant plant species for chloride.