• 한국잡초학회지
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• 제30권2호
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• pp.111-121
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• 2010

Protoporphyrinogen oxidase(Protox) 저해형 제초제인 oxyfluorfen에 대한 내성차이는 동일 개체내의 호박 엽령에서 관찰되었다. 엽위별 oxyfluorfen에 내성기작을 구명하기 위해 잎의 피해정도, 세포내 구성물질의 누출, 포르피린 생합성 경로의 tetrapyrrole 중간물질 축적량 및 항산화효소 활성을 포함한 생리적 반응을 조사하였다. 중앙애호박의 1, 2 및 3엽에 대한 oxyfluorfen에 내성은 4엽에 비해 각각 >10,000, 1,286 및 1.6배 높았고, 신토좌의 1, 2 및 3엽에 대한 oxyfluorfen에 내성은 4엽에 비해 각각 725, 366, >0.6배 높았다. 그러나 oxyfluorfen과 작용기작이 다른 paraquat 처리에서는 oxyfluorfen 처리의 결과와 다르게 두 품종 모두 상위엽인 4엽이 하위엽인 1, 2 및 3엽에 비해 훨씬 피해가 적었다. Oxyfluorfen 처리에 따른 전해물질의 누출은 처리 후 광노출 기간이 경과할수록 상위엽(4엽)에서 하위엽(1, 2, 3엽) 보다 많았다. Oxyfluorfen 처리에 의한 tetrapyrrole 중간물질 protoporphyrin IX(Proto IX), Mg-Proto IX 및 Mg-Proto IX monomethyl ester의 축적량은 감수성인 4엽이 내성인 1엽에 비해 많았다. 따라서 oxyfluorfen 처리에 대한 호박 엽령별 반응 차이는 tetrapyrrole 중간물질의 과다한 축적에 의해 기인되는 것으로 생각된다. Tetrapyrrole 중간 물질 축적량의 결과와 다르게 항산화효소 superoxide dismutase, catalase, peroxidase, ascorbate peroxidase 및 glutathione reductase 활성은 무처리 및 oxyfluorfen 처리 후 4엽이 1엽에 비해 높았다. 그러나 4엽에서 항산화효소 활성 유도는 Protox 저해제 oxyfluorfen의 독성효과를 극복하는데 충분하지 않아 결국 4엽은 고사하게 되는 것으로 생각된다.

• 원예과학기술지
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• 제19권1호
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• pp.87-91
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• 2001

본 연구는 수경재배 바실의 MA 저장시 적정 저장 온도를 선정하고 기능성 배가를 위해 양액 내 첨가한 Se이 바실의 저장성에 미치는 영향을 조사하고자 수행하였다. 바실은 European Vegetable R & D Center에서 개발한 허브 배양액 1배액을 사용하여 담액 순환식으로 재배하였으며, Se을 sodium selenate($Na_2SeO_4$)의 형태로 수확 3주 전 2, 4, 6, $8mg{\cdot}L^{-1}$의 농도로 양액 내 첨가하였다. 바실의 MA 저장 시 $5^{\circ}C$에서는 저온장해가 발생하여 전해질 용출량이 크게 증가하였다. 그러나 Se 처리에 의해 저장기간을 무처리구에 비해 3일간 연장시킬 수 있었다. $10^{\circ}C$ 저장 시 $5^{\circ}C$보다 생체중 감소율이 적었으며, 비타민 C 함량도 더 높았다. Se 처리는 작물 내 비타민 C 함량을 증가시키고 전해질 용출량은 감소시켰다. 작물 내 Se 함량은 Se 처리 농도에 따라 증가하였으며 저장 전 $2mg{\cdot}L^{-1}$ 처리구에서는 $67{\mu}g{\cdot}g^{-1}DM$, $8mg{\cdot}L^{-1}$ 처리구에서는 $423{\mu}g{\cdot}g^{-1}DM$을 함유하였다. 이상에서 바실의 MA 저장 시 저온장해를 줄이고 여러 가지 내적 품질을 유지하기 위해서는 $10^{\circ}C$ 저장 온도가 적합하다. 또 보다 안전하게 Se 함유 바실을 섭취하기 위한 적정 Se 처리농도는 $Na_2SeO_4\;2mg{\cdot}L^{-1}$ 이하가 효과적이라고 생각된다.

• Journal of Plant Biotechnology
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• 제5권3호
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• pp.173-179
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• 2003

The combination of a radiation technique with an in vitro culture system was appiled to develop submergence tolerant rice. The 3,000 $M_3$ lines with an average 80 percent of fertile grain were utilized for the selection of submergence tolerance. Salt tolerant lines were selected based on high plant height, root length and root number after submergence in plastic pots. Of the lines tested, the tolerant line (403-6) showed a dramatic difference in morphological traits under submergence compared to its original variety (Dongjinbyeo). It was suggested that genetic variations between the original variety and $M_3$-403-6 did exist. The levels of $\alpha$-amylase and alcohol dehydrogenase activities were significantly increased in the mutant line compared to its original variety. The mutant with greater tolerance showed less electrolyte leakage indicating a greater membrane integrity and better survival. Also, this line was much more resistant to a salt stress of $1.25\%$ than the original variety. The proline level of the line was significantly (p<0.01> higher than that of the original variety. The relationships between the inhibition of growth caused by stress and the physiological changes in the plant cell were discussed.

• 아시안잔디학회지
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• 제25권1호
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• pp.112-117
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• 2011

본 시험은 뽕나무 숯이 염해의 내성에 미치는 영향에 대해 알아보고자 한지형 잔디인 Kentucky bluegrass를 공시하여 수행하였다. 잔디의 생체중과 건물중 등의 생육은 NaCl 400 mM의 처리에 의해 크게 억제되었으며 NaCl처리에 의해 엽록소 농도의 저하와 전해질의 누출상승 등 생리적 장해를 초래하였다. 이러한 생육의 억제와 생리적 장해는 뽕나무 숯의 전처리에 의해 크게 경감될 수 있었다. 뽕나무 숯의 전처리는 K이온의 흡수를 도와 Na이온을 체외로 배출시키는 것을 확인하였다. 본 시험의 결과 뽕나무 숯의 처리는 염해에 약한 잔디류의 간척지 및 염류가 높은 토양에서 식생조성이 가능할 것으로 사료되었다.

• 식품저장과 가공산업
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• 제3권1호
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• pp.42-46
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• 2004

Quality of fresh-cut tomato slices was compared during cold storage under various modified atmosphere packaging conditions. Chilling injury of slices in containers sealed with Film A was higher than with Film B; these films had oxygen transmission rates of 87.4 and 60.0 ml h-1 m-2 nun-1 at $5^{\circ}C$ and $99\%$ RH, respectively. While slices in containers with an initial atmospheric composition of air, $4\%$ CO2 + 1 or $20\%\;O_2, \;8\%\;CO_2+1$ or $20\%\;O_2$, or $12\%\; CO_2+\;20\%\;O_2$ showed fungal growth, slices in containers with $12\%\;CO_2 +\;1\%\;O_2$ did not. Low ethylene in containers enhanced chilling injury. Modified atmosphere packaging provided good quality tomato slices with a shelf-life of 2 weeks or more at $5^{\circ}C$. Experiments were conducted to compare changes in quality of slices of red tomato (Lycopersicon esculentum Mill. 'Sunbeam') fruit from plants grown using black polyethylene or hairy vetch mulches under various foliar disease management systems including: no fungicide applications (NF), a disease forecasting model (Tom-Cast), and weekly fungicide applications (WF), during storage at $5^{\circ}C$ under a modified atmosphere. Slices were analyzed for firmness, soluble solids content (SCC), titratable acidity (TA), pH, electrolyte leakage, fungi, yeasts, and chilling injury. With both NF and Tom-Cast fungicide treatments, slices from tomato fruit grown with hairy vetch (Vicia villosa Roth) mulch were firmer than those from tomato fruit grown with black polyethylene mulch after 12 days storage. Ethylene Production of slices from fruit grown using hairy vetch mulch under Tom-Cast was about 1.5- and 5-fold higher than that of slices from WF and NF fungicide treatments after 12 days, respectively. The percentage of water-soaked areas (chilling injury) for slices from tomato fruit grown.

• 농업과학연구
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• 제41권2호
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• pp.75-83
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• 2014

Recently, a quick drop of air temperature in plastic film houses by adverse weather conditions leads to the occurrence of low temperature damages to growing crops. Chilling injury, defined as a variety of growth restriction occurring below the optimal temperature, is one of environmental factors strongly affecting crop growth and yield. Low temperature causes the restricted evapotranspiration, reduced mineral uptake (P > K > $NO_3{^-}$), and an increase in electrolyte leakage such as K. Despite being different with plant species, an accumulation of soluble carbohydrates such as glucose, fructose, sucrose and starch under chilling condition is well known. A variety of environmental stresses are known to cause oxidative damage to plants either directly or indirectly by triggering an increased level of production of reactive oxygen species (ROS), and, to combat the oxidative damage, plants have the antioxidant defense systems comprising of enzymes, SOD, POD, CAT, GPX and APX, and non-enzymes, ascorbate, gluthathione, ${\alpha}$-tocopherol, phenolic compounds, carotenoid and flavonoids. The aim of this review is to provide basic information to build chilling-indicators and optimal nutrition management under adverse temperature conditions as broadly considering mineral uptake, carbohydrate metabolism and antioxidative defense system.

• 한국수소및신에너지학회논문집
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• 제22권4호
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• pp.488-494
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• 2011

Gasket plays an important role on sealing of the polymer electrolyte membrane fuel cell (PEMFC) stack. Stack requires gaskets in each cell to keep the hydrogen and air/oxygen within their respective regions. The failure of the gasket creates the problems of fuel leakage, mixing, damage on parts and can be a direct reason for the degrading the efficiency of fuel cell. The purpose of this paper researches on how mechanical properties of EPDM gasket in PEMFC are changed after long-term operations. The EPDM (ethylenepropylene-diene monomer) gaskets are obtained from the stack after long-term operations. DMA (dynamic mechanical analysis) is conducted to access the change of mechanical properties of the EPDM gasket. SEM/EDS (scanning electron microscope/energy dispersive spectroscopy) was used to show the surface topography and chemical characterization on the sample surface.

• 농업과학연구
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• 제40권3호
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• pp.197-202
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• 2013

This study was aimed to find the storage potential of low temperature adapted shiitake mushroom under freezing temperature ($-3^{\circ}C$). Fresh shiitake mushroom was harvested at late Feb. and cooled to target temperature, $-3^{\circ}C$ in the cooling room for 24 hr. Cooled mushroom were then placed in plastic boxes, wrapped with plastic film ($30{\mu}m$), and stored at $-3^{\circ}C$ for 2 months. Weight loss of mushroom was ranged from 2.1 to 3.2%. Dry weight per unit fresh weight, however, was slightly increased because of moisture loss. Firmness of fruit body increased from $0.95kg/cm^{-2}$ (before storage) to $1.13kg/cm^{-2}$ (after 2 month storage). About half amount of starch was lost during 2 month storage. The amount of total and reducing sugars remained relatively constant. After storage, freshness of mushroom was recovered by thawing treatment. When recovered mushroom were packaged with styrofoam tray and PVC wrapping, and exposed to ambient and $10^{\circ}C$, respectively, brown spot on the gill of fruit body was found and slight decay symptom was also found at ambient temperature only but not at $10^{\circ}C$. Results indicated that low temperature adapted shiitake mushroom has a storage potential under freezing temperature ($-3^{\circ}C$). Freezing storage technology of fresh shiitake mushroom will contribute the increase of storability up to 2 months.

• Molecules and Cells
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• 제39권3호
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• pp.250-257
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• 2016

Abiotic stresses such as drought and low temperature critically restrict plant growth, reproduction, and productivity. Higher plants have developed various defense strategies against these unfavorable conditions. CaPUB1 (Capsicum annuum Putative U-box protein 1) is a hot pepper U-box E3 Ub ligase. Transgenic Arabidopsis plants that constitutively expressed CaPUB1 exhibited drought-sensitive phenotypes, suggesting that it functions as a negative regulator of the drought stress response. In this study, CaPUB1 was over-expressed in rice (Oryza sativa L.), and the phenotypic properties of transgenic rice plants were examined in terms of their drought and cold stress tolerance. Ubi:CaPUB1 T3 transgenic rice plants displayed phenotypes hypersensitive to dehydration, suggesting that its role in the negative regulation of drought stress response is conserved in dicot Arabidopsis and monocot rice plants. In contrast, Ubi:CaPUB1 progeny exhibited phenotypes markedly tolerant to prolonged low temperature ($4^{\circ}C$) treatment, compared to those of wild-type plants, as determined by survival rates, electrolyte leakage, and total chlorophyll content. Cold stress-induced marker genes, including DREB1A, DREB1B, DREB1C, and Cytochrome P450, were more up-regulated by cold treatment in Ubi:CaPUB1 plants than in wild-type plants. These results suggest that CaPUB1 serves as both a negative regulator of the drought stress response and a positive regulator of the cold stress response in transgenic rice plants. This raises the possibility that CaPUB1 participates in the cross-talk between drought and low-temperature signaling pathways.

• Journal of Ecology and Environment
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• 제29권5호
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• pp.479-484
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• 2006

Ecophysiological parameters of non-transgenic sweetpotato (NT) and transgenic sweetpotato (SSA) plants were compared to evaluate their resistance to multiple environmental stresses. Stomatal conductance and transpiration rate in NT plants decreased markedly from Day 6 after water was withheld, whereas those values in SSA plants showed relatively higher level during this period. Osmotic potential in SSA plants was reduced more negatively as leaf water potential decreased from Day 8 after dehydration treatment, while such reduction was not shown in NT plants under water stressed condition. SSA plants showed less membrane damage than in NT plants. As water stress and high light stress, were synchronously applied to NT and SSA plants maximal photochemical efficiency of PS II ($F_v/F_m$) in NT plants markedly decreased, while that in SSA plants was maintained relatively higher level. This trend of changes in $F_v/F_m$ between SSA plants and NT plants was more conspicuous as simultaneously treated with water stress, high light and high temperature stress. These results indicate that SSA plants are more resistive than NT plants to multiple environmental stresses and the enhanced resistive characteristics in SSA plants are based on osmotic adjustment under water stress condition and tolerance of membrane.