• Journal of Photoscience
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• 제3권1호
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• pp.1-7
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• 1996

When cucumber (Cucumis sativus L.) cotyledon discs were floated on $\delta$-aminolevulinic acid, oxyfluorfen, or rose bengal solution under light condition following 20 h dark incubation, rapid electrolyte leakage from the tissues occurred. The electrolyte leakage from the tissues was dependent on the compounds treated, their concentrations, and the duration of light exposure to the tissues. Dark incubation before exposure to continuous white light enhanced electrolyte leakage from the tissues treated with the compounds and reduced lag period for the activity of the compounds. Electrolyte leakage from the treated tissues was greatly influenced by the light intensity to which they were exposed. Higher light intensities stimulated electrolyte leakage and reduced lag period. Porphyrin biosynthesis inhibitors, gabaculine and 4,6-dioxoheptanoic acid, completely inhibited electrolyte leakage from the oxyfluorfen-treated tissues. Protection against the activity of $\delta$-aminolevulinic acid from electrolyte leakage was complete with 4,6-dioxoheptanoic acid, but not with gabaculine. However, gabaculine and 4,6-dioxoheptanoic acid gave no such protection against rose bengal activity. In summary, our results indicate that $\delta$--aminolevulinic acid, oxyfluorfen, and rose bengal exert their effects by causing electrolyte leakage from the treated tissues in a similar manner, except that oxyfluorfen has an apparent lag period for its action on electrolyte leakage increase. All above compounds require preincubation of treated tissues in darkness and subsequent light exposure with a high intensity for their maximal activities. Our results also support that in the presence of light, $\delta$-aminolevulinic acid and oxyfluorfen cause cellular damage through the indirect generation of singlet oxygen from accumulated tetrapyrroles of porphyrin pathway, whereas rose bengal causes cellular damage through the direct generation of singlet oxygen.

• Journal of the Korean Data Analysis Society
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• 제20권6호
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• pp.2721-2731
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• 2018

This study purposes to derive the predictive model for the cold tolerance of Brassica napus, using the data collected in the Tree Breeding Lab of Gyeongsang National University during July and August of 2016. Three Brassica napus samples were treated at each of low temperatures from $4^{\circ}C$ to $-12^{\circ}C$ by decrement of $4^{\circ}C$, step by step, and electrolyte leakage levels were measured at each stage. Electrolyte leakages were observed tangibly from $-4^{\circ}C$. We tried to fit the six nonlinear regression models to the electrolyte leakage data of Brassica napus: 3-parameter logistic model, baseline logistic model, 4-parameter logistic model, (4-1)-parameter logistic model, 3-parameter Gompertz model, and (3-1)-parameter Gompertz model. The baseline levels of the electrolyte leakage estimated by these models were 4.81%, 4.07%, 4.19%, 4.07%, 4.55%, and 0%, respectively. The estimated median lethal temperature, LT50, were $-5.87^{\circ}C$, $-6.31^{\circ}C$, $-6.05^{\circ}C$, $-6.35^{\circ}C$, $-4.98^{\circ}C$, and $-5.15^{\circ}C$, respectively. We compared and discussed the measures of goodness of fit to select the appropriate nonlinear regression model.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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• pp.382-382
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• 2009

In this study, we prepared electrodes containing ionic liquid for high temperature polymer electrolyte fuel cells. Effects of ILs on electrochemical properties of the electrodes were investigated carrying out measurement of cyclic voltammograms of the various electrodes with the content of IL in a strong supporting electrolyte. As the ILs content increased in electrodes, electrochemical surface area(ESA) decreased due to the leakage of ILs from Nafion ionomer. In addition, two case of cyclic voltammograms under two simulated environment, i.e. IL leakage from Nafion ionomer in I) electrode and ii) polymer electrolyte, were investigated. As a result, IL leakage from polymer electrolyte showed worse results in electrochemical properties of the electrode.

• 원예과학기술지
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• 제32권2호
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• pp.241-251
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• 2014

본 연구는 남부 지방에서 널리 사용되고 있는 상록활엽수인 돈나무의 내한성 예측을 위한 편리하고 신뢰성 있는 평가 모델 개발을 목적으로 전해질 용출법을 통한 내한성 평가에서 나타나는 실험방법 상의 오차를 최소화하는 내한성 평가 모델을 도출하고자 수행되었다. 평가 모델링은 저온 처리된 식물체에 대한 재생검사와 전해질 용출 평가로 구성되었고, 전해질 용출법에서 표본조직 선택, 최대 전해질 용출 측정을 위한 온도 처리법, 치사 온도 예측을 위한 통계 분석법에 의한 방법적 조합들로부터 예측된 치사 온도들이 재생검사 결과와 비교되었다. 재생 검사 결과 돈나무의 저온 치사 온도는 50% 미만의 생존율을 보이는 최고온도인 $^-10{\circ}C{\sim}-5^{\circ}C$로 분석되었고, 이 결과를 바탕으로 전해질 용출법에 의해 예측된 저온 치사 온도를 분석한 결과, 잎을 표본 조직으로 하여 냉각치사법으로 최대 전해질 용출을 측정한 방법적 조합에서 재생 검사 결과와 가장 근접한 예측 저온 치사 온도가 나타났다. 저온 치사온도 예측을 위한 통계 모델 평가에서는 선형보간법이 비선형회귀에 비하여 내한성을 과대평가하는 경향이 상대적으로 높았다. 결론적으로 돈나무 내한성 예측을 위한 내한성 평가 모델은 잎을 표본 조직으로 사용하고, 최대 전해질 용출 측정을 위한 온도 처리 방법으로 냉각치사법을 적용하며, 치사온도 예측을 위한 통계 분석 기법으로 비선형회귀를 활용하는 방법적 구성이 가장 적합한 것으로 나타났다.

• Journal of Microbiology and Biotechnology
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• 제19권8호
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• pp.810-817
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• 2009

The effect of cryoprotectants (maltodextrin+glycerol) and cryoprotectants+antioxidant [ascorbic acid and/or butylated hydroxytoluene (BHT)] mixtures on the survival, electrolyte leakage, and lipid degradation of freeze-dried Weissella paramesenteroides LC11 during storage was investigated and compared with that of the control (cells without additives) over a 90-day storage period at 4 or $20^{\circ}C$ in glass tubes with water activity ($a_w$) of 0.23. The survival, electrolyte leakage, and lipid degradation were evaluated through colony counts, electrical conductivity, and thiobarbituric acid reactive substances (TBARS) content, respectively. The fatty acids composition was determined by gas chromatography, in both the total lipid extract and the polar lipid fraction, and compared with that of the control after the 90-day storage period. As the storage proceeded, increases in leakage value and TBARS content, as well as a decrease in viability, were observed. After 90 days of storage, the major fatty acids found in both the total lipid extract and the polar lipid fraction were palmitic (16:0), palmitoleic (16:1), stearic (18:0), oleic (18:1), linoleic (18:2), and linolenic (18:3) acids. The survival, leakage value, TBARS content and 18:2/16:0 or 18:3/16:0 ratio were the greatest for the protected strain held at $4^{\circ}C$. Cells with the cryoprotectants+BHT mixture showed the highest percentage of survival and 18:2/16:0 or 18:3/16:0 ratio in both lipid extracts, as well as the lowest leakage value and TBARS content after the 90-day storage period. Drying cells with the cryoprotectants+BHT mixture considerably slowed down polar lipid degradation and loss of membrane integrity, resulting in improved viability during storage.

• 한국작물학회지
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• 제47권2호
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• pp.116-122
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• 2002

Dehydrins (LEA Dll proteins) are one of the typical families of plant proteins that accumulate in response to dehydration, cold stress, abscisic acid, or during seed maturation. A 1.3-kb cDNA was cloned from a cDNA expression library of 5-day-old germinating maize scutellums under drought stress. The deduced protein sequence indicated a dehydrin gene encoding SK$_3$ LEA protein typically expressed during cold acclimation, but not by drought stress in barley and wheat. Thus, it was named maize DEHYDRIN2 (ZmDhn2). It accumulates rapidly and highly in drought-stressed scutellum and leaf tissues at any stage, but not under cold stress. ZmDhn2 gene was transformed into Arabidopsis thaliana for functional analysis under drought condition. From electrolyte leakage test, no significant difference showed between wild type and transformants under normal growth condition, but the leakage level of electrolyte in wild type plants was about 3 times as high as that in the transformed plants under drought stress. It suggests that ZmDHN2 playa role in increasing drought tolerance.

• Journal of Photoscience
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• 제8권2호
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• pp.61-66
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• 2001

Using maize green- and white-leaf tissue, we have examined the effect of various chemicals on cytoplasmic leakage with respect to the light requirement or chloroplast targeting for their activities. Oxyfluorfen, oxadiazon, diuron, and paraquat, which are known as representative herbicides acting on plant chloroplasts, caused the electrolyte leakage only in the green tissues, whereas 2, 4-dinitrophenol, rose bengal (singlet oxygen producing chemical) and methyl-jasmoante (senscence-stimulating chemical) play a role both in green- and white-tissue. Benzoyl(a) pyrene, generating superoxide radical upon light illumination, functions only in white tissues. Tralkoxydim, metsulfuron-methyl and norflurazon showed no effect in two tested plant samples. In terms of light requirement in electrolyte leakage activity, diuron, oxyfluorfen, oxadiazon, rose bengal, and benzoyl(a) pyrene absolutely require the light for their functions, but other chemicals did not. based on these results, we could classify into four different response types according to whether chemicals require light or chlroplasts for their action. This classification is likely to be applied to simply and rapidly identify the requirement of light and chlroplasts for the actions of chemicals, thereby it makes easy to characterize many new herbicides that their action mechanisms are unclear, and to elucidate the mode of action of them.

• 전기화학회지
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• 제16권1호
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• pp.30-38
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• 2013

In this study, a catalyst slurry was prepared with a Pt/C catalyst, Nafion ionomer solution as a binder, an ionic liquid (IL) (1-butyl-3-methylimidazolium tetrafluoroborate), deionized water and ethanol as a solvent for the application to polymer electrolyte fuel cells (PEFCs) at high-temperatures. The effect of the IL in the electrode of each design was investigated by performing a cyclic voltammetry (CV) measurement. Electrodes with different IL distributions inside and on the surface of the catalyst electrode were examined. During the CV test, the electrochemical surface area (ESA) obtained for the Pt/C electrode without ILs gradually decreased owing to three mechanisms: Pt dissolution/redeposition, carbon corrosion, and place exchange. As the IL content increased in the electrode, an ESA decrement was observed because ILs leaked from the Nafion polymer in the electrode. In addition, the CVs under conditions simulating leakage of ILs from the electrode and electrolyte were evaluated. When the ILs leaked from the electrode, minor significant changes in the CV were observed. On the other hand, when the leakage of ILs originated from the electrolyte, the CVs showed different features. It was also observed that the ESA decreased significantly. Thus, leakage of ILs from the polymer electrolyte caused a performance loss for the PEFCs by reducing the ESA. As a result, greater entrapment stability of ILs in the polymer matrix is needed to improve electrode performance.

• 원예과학기술지
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• 제30권2호
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• pp.158-161
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• 2012

The influence of lysophosphatidylethanolamine (LPE) on anti-senescence of melon leaves and the change in fruit quality during the storage at low temperature were studied. In most of the crops, freshness of leaves is important factor for characteristics of fruits, such as sugar contents, color, and firmness. Melon ($Cucumis$ $melo$ L. cv. Prince) plants were sprayed with LPE at 5 and 3 weeks before commercial harvest. In upper part, LPE treatment showed slight high number of fresh leaf compared to no treatment (None). However, in lower part, LPE resulted in apparent inhibition effect on senescence, showing that lower side of melon plant kept fresh upon LPE application up to about 30%. The SSC of melon treated with LPE was similar to that of fruit from None at harvest. There was no change in soluble solids content (SSC) for all treatment during the storage at $7^{\circ}C$. There were no significant differences in firmness of mesocarp from melons given different treatments at harvest. The firmness of mesocarp from melon treated with LPE was higher than none after 2 weeks storage. The electrolyte leakage means for melon treated with LPE did not differ significantly from the means at initial storage after 2 weeks storage among the treatments. None increased 57% from its initial electrolyte leakage during storage. These results suggest that the application of LPE may have potential to inhibit senescence of leaves and maintain fruit quality during the storage in melon.

• 한국환경과학회지
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• 제25권1호
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• pp.173-179
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• 2016

Leaf water and osmotic potential, chlorophyll content, photosynthetic rate, and electrolyte leakage were measured to evaluate tolerance to water stress in wild-type (WT) and transgenic tobacco plants (TR) expressing copper/zink superoxide dismutase (CuZnSOD) and ascorbate peroxidase (APX) in chloroplasts. Leaf water potential of both WT and TR plants decreased similarly under water stress condition. However, leaf osmotic potential of TR plants more negatively decreased in the process of dehydration, compared with WT plants, suggesting osmotic adjustment. Stomatal conductance (Gs) in WT plants markedly decreased from the Day 4 after withholding water, while that in TR plants retained relatively high values. Relatively low chlorophyll content and photosynthetic rate under water stress were shown in WT plants since $4^{th}$ day after treatment. In particular, damage indicated by electrolyte leakage during water stress was higher in WT plants than in TR plants. On the other hand, SOD and APX activity was remarkably higher in TR plants. These results indicate that transgenic tobacco plants expressing copper/zink superoxide dismutase (CuZnSOD) and ascorbate peroxidase (APX) in chloroplasts improve tolerance to water stress.