• Journal of Plant Biotechnology
• /
• v.49 no.3
• /
• pp.240-249
• /
• 2022

Measuring chlorophyll fluorescence (CF) is a useful tool for assessing a plant's ability to tolerate abiotic stresses such as drought, waterlogging and high temperature. Korean ginseng is highly sensitive to water stress in paddy fields. To evaluate the possibility of non-destructively diagnosing waterlogging stress using chlorophyll fluorescence (CF) imaging techniques, we screened 57 ginseng accessions for waterlogging tolerance. To evaluate waterlogging tolerance among the 2-year-old Korean ginseng accessions, we treated ginseng plants with water stress for 25 days. The physiological disorder rate was characterized through visual assessment (an assigned score of 0-5). The physiological disorder rates of Geumjin, Geumsun and GS00-58 were lower than that of other accessions. In contrast, lines GS97-62, GS97-69 and GS98-1-5 were deemed susceptible. Root traits, chlorophyll content and the reduction rates decreased in most ginseng accessions. Further, these metrics were significantly lower in susceptible genotypes compared to resistant ones. All CF parameters showed a positive or negative response to waterlogging stress, and this response continuously increased over the treatment time among the genotypes. The CF parameter Fv/Fm was used to screen the 57 accessions, and the results showed clear differences in Fv/Fm between the susceptible and resistant genotypes. Susceptible genotypes had an especially low Fv/Fm value of less than 0.8, reflecting damage to the reaction center of photosystem II. It is concluded that Fv/Fm can be used as a CF parameter index for screening waterlogging stress tolerance in ginseng genotypes.

• The Korean Journal of Pharmacology
• /
• v.29 no.1
• /
• pp.149-156
• /
• 1993

Intramolecular excimerization of 1,3-di(1-pyrenyl)propane (Py-3-Py) and fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene (DPH) were used to examine the effects of ethanol on the rate and range of lateral diffusion of bulk bilayer structures of plasma membrane vesicles isolated from cultured mouse myeloma cell line Sp2/0-Ag14 (Sp2/0-PMV). In a concentration-dependent manner, ethanol increased the excimer to monomer fluorescence intensity ratio (I'/I) of Py-3-Py in the Sp2/0-PMV and decreased the anisotropy (r), limiting anisotropy $(r_{\infty})$, and order parameter (S) of DPH in the Sp2/0-PMV. This indicates that ethanol increased both the lateral and rotational diffusion of the probes in the Sp2/0-PMV. Selective quenching of DPH by trinitrophenyl groups was utilized to examine the transbilayer asymmetric rotational diffusion of the Sp2/0-PMV. The anisotropy (r), limiting anisotropy $(r_{\infty})$, and order parameter (S) of DPH in the inner monolayer were 0.022, 0.029, and 0.063, respectively, greater than calculated for the outer monolayer of the Sp2/0-PMV. Selective quenching of DPH by trinitrophenyl groups was also utilized to examine the transbilayer asymmetric effects of ethanol on the range of rotational diffusion of the Sp2/0-PMV. Ethanol had a greater fluidizing effect on the outer monolayer as compared to the inner monolayer of the Sp2/0-PMV. It has been proven that ethanol exhibits a selective rather than nonselective fluidizing effect within transbilayer domains of the Sp2/0-PMV.

• Archives of Pharmacal Research
• /
• v.20 no.1
• /
• pp.1-6
• /
• 1997

We determined the microviscosity of synaptosomal plasma membrane vesicles (SPMV) isolated from bovine cerebral cortex and liposomes of total lipids (SPMTL) and phospholipids (SPMPL) extracted from SPMV. Changes in the microviscosity induced by the range and rate of lateral diffusion were measured by the intramolecular excimerization of 1, 3-di(1-pyrenyl)propane (Py-3-Py). The microviscosity values of the direct probe environment in SPMV, SPMTL and SPMPL were 38.17, 31.11 and 27.64 cP, respectively, at$37^{\circ}C$and the activation energies $(E_a)$ of the excimer formation of Py-3-Py in SPMV, SPMTL and SPMPL were 8.236, 7.448 amd 7.025 kcal/mol, respectively. Probe location was measured by polarity and polarizability parameters of the probe Py-3-Py and probe analogues, pyrene, 1-pyrenenonanol and 1-pyrenemethyl-3${\beta}$-hydroxy-22, 23-bisnor-5-cholenate (PMC), incorporated into membranes or solubilized in reference solvents. There existed a good linear relationship between the first absorption peak of the $^1_a$ band and the polarizability parameter $(n^{2}-1)/(2n^{2}+1)$.The calculated refractive index values for SPMV, SPMTL and SPMPL were close to 1.50, which is higher than that of liquid paraffin (n=l.475). The probe location was also determined by using a polarity parameter $(f-1/2f^{I})$. Here f=$({\varepsilon}-1)/(2{\varepsilon}+1)$ is the dielectric constant function and $f^I=(n^2-1)/(2n^2+1)$ is the refractive index function. A correlation existed between the monomer fluorescence intensity ratio and the solvent polarity parameter. The probes incorporated in SPMV, SPMTL, and SPMPL report a polarity value close to that of 1-hexanol $({\varepsilon}=13.29)$. In conclusion, Py-3-Py is located completely inside the membrane, not in the very hydrophobic core, but displaced toward the polar head groups of phospholipid molecules, e.g., central methylene region of aliphatic chains of phospholipid molecules.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.60 no.1
• /
• pp.1-7
• /
• 2015

The photochemical characteristics were analyzed in the context of sowing time and different levels of fertilized nitrogen during the maize (Zea mays L.) growth. When maize was early sawn, the fluorescence parameters related with electron-transport, in photosystem II (PSII) and PSI, were effectively enhanced with the higher level of fertilized nitrogen. Highest values were observed in maize leaves grown in double N-fertilized plot. The photochemical parameters were declined in the progress of growth stage. In early growth stage, the fluorescence parameters were highest, and then reduced to about half of the parameters related with electron transport on PSII and PSI at middle and late growth stages. In 1/2 N plot, the photochemical energy dissipation was measured to 13% in term of active reaction center per absorbed photon resulting in decrease in performance index and driving force of electron. This decrease induced to lower the photochemical effectiveness. In 2 N plots, the electron transport flux from $Q_A$ to $Q_B$ per cross section and the number of active PSII RCs per cross section were considerably enhanced. It was clearly indicated that the connectivity between photosynthetic PSII and PSI, i.e. electron transport, was far effective.

• Journal of Forest and Environmental Science
• /
• v.37 no.4
• /
• pp.315-322
• /
• 2021

The aim of this study was to investigate the sensitivity to environmental stress, and changes in the photosynthesis capacity in Abies koreana seedlings by age and to suggest the most effective age for restoration. To identify these physiological characteristics of A. koreana, the chlorophyll fluorescence and photosynthetic capacity of 1-, 2-, 3-, 5- and 6-year-old A. koreana seedlings were observed from June 2020 to June 2021. The maximum quantum efficiency of Photosystem II (Fv/Fm), a chlorophyll fluorescence measurement parameter, was strongly positively correlated with the monthly average temperature (1-year-old seedling: r=0.8779, 2-year-old seedling: r=0.8605, 3-year-old seedling: r=0.8697, 5-year-old seedlings: r=0.8085, and 6-year-old seedlings: r=0.8316). The Fv/Fm values were the lowest in winter (November 2020-March 2021). In addition, the Fv/Fm values of 1-, 2-, and 3-year-old seedlings in winter were lower than that of 5- and 6-year-old seedlings, while the Fv/Fm values in summer were relatively higher than those in winter. Further, the Fv/Fm values of seedlings of all ages decreased in August 2020, when the monthly average temperature was the highest. In particular, 1-year-old to 3-year-old seedlings showed Fv/Fm values less than 0.8. Further, the photosynthetic capacity measured in August 2020 increased with increasing seedling age. The analysis of variance results for summer Fv/Fm values showed significant differences in age-specific averages (p<0.05), and Duncan's multiple range test showed significant differences between 5- and 6-year-old seedlings and 1-, 2-, and 3-year-old seedlings (p<0.05). These results suggested that the 5- and 6-year-old seedlings were less sensitive to environmental stress and showed better photosynthetic capacity than the 1-, 2-, and 3-year-old seedlings. Therefore, 5-year-old or older A. koreana seedlings can be used as restoration materials because they can show increased adaptability and stable growth during transplantation due to their relatively high environmental resistance and photosynthetic capacity.

• Analytical Science and Technology
• /
• v.22 no.5
• /
• pp.422-431
• /
• 2009

The analytical results of wear metals such as Na, Mg, Al, Si, P, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Mo, Ag, Cd, Sn, Ba, Pb in oil samples are compared by portable and bench-top XRF methods as a basic study for the development of portable X-ray fluorescence spectrometer. The instrumental parameters such as measurement time of portable and bench-top XRF were optimized using certified reference materials of hydrocarbon oil with 20 wear metals in concentration range from 10 to 900 mg/kg. The analytical results of 20 wear metals in certified reference materials and new/used engine oil samples were compared by empirical and fundamental parameter methods.

• Horticultural Science & Technology
• /
• v.33 no.6
• /
• pp.829-838
• /
• 2015

Garlic (Allium sativum L.), one of the oldest cultivated crops, is the most widely used Allium species belonging to the family Lilliaceae. In this study, growth characteristics, photosystem II activity, and antioxidative enzyme activity were investigated in five temperatures ($10-30^{\circ}C$) during early growth stage of garlic to determine the optimum temperature for cultivation and assess the effects of high temperature on early growth of garlic. Vegetative growth (e.g., shoot height, number of leaves) of garlic plants was greater in the temperature ranges of $15-25^{\circ}C$. However, dry weight (of shoot, bulb, and total plant) of garlic was significantly greater at $20^{\circ}C$, compared to either below or above $20^{\circ}C$. $F_v/F_o$ and $F_v/F_m$ values were highest at $15-20^{\circ}C$, and decreased above $25^{\circ}C$. The chlorophyll a fluorescence induction OKJIP transient was also considerably affected by high temperature; the fluorescence yields $F_i$ and $F_P$ decreased considerably above $25^{\circ}C$, with the increase of $F_k$ and $W_k$. Activities of catalase and superoxide dismutase in leaves and peroxidase in roots were high in $20-25^{\circ}C$, and decreased significantly in $30^{\circ}C$. These results indicate that a growth temperature of $30^{\circ}C$ inhibits early growth of garlic and that it is desirable to culture garlic plants near $20^{\circ}C$. Fluorescence parameters such a $F_v/F_o$, $F_v/F_m$, $F_k$, $ET_o/CS_m$, and $PI_{abs}$ were significantly correlated with dry weight of whole garlic plants (p < 0.01), indicating that these fluorescence parameters can be used for early assessment of high temperature effects even though the damage to the plant is not very severe.

• Bulletin of the Korean Chemical Society
• /
• v.29 no.1
• /
• pp.127-129
• /
• 2008

EPR spectroscopic technique was applied for a quantitative analysis of Eu(II) for a speciation of europium in a LiCl-KCl eutectic melt. By adopting the first absorption line of each isotopes (151Eu and 153Eu), a calibration plot was obtained. The calibration of the EPR intensity shows a good linearity according to the amount of Eu(II). The EPR intensity was identified to increase proportionally with a decrease of the attenuation parameter for EPR microwave power. The fluorescence technique was used qualitatively to find whether either of Eu(II) or Eu(III) ions exists in a molten salt sample. The ICP-AES technique was also adopted to determine the total concentration of europium in the sample, since EPR is only sensitive for detecting the Eu(II) ion. The extent of the reduction of Eu(III) in the LiCl-KCl eutectic melt at 723 K was determined by using this technique.

• Journal of environmental and Sanitary engineering
• /
• v.13 no.1
• /
• pp.185-194
• /
• 1998

Laboratory-scale investigation into initial anaerobic biofilm development was carried out by circulating mixed liquor from a steady-state anaerobic reactor through silicone tubing and then rerurning the mixed liquor to the reactor. The wall of the silicone tubing was the surface upon which anaerobic biofilm accumulation or development was monitored. Methanogenic bacteria accumulation was monitored by F$_{420}$ fluorescence (picomoles F$_{420}$/cm$^{2}$) of the extracted biofilm material. Biofilm accumulation was measured by the increase in COD of the extracted material ($\mu $g COD/cm$^{2}$). Experiments were conducted for 25 days, and biofilm analyses were performed at 5 days intervals. The results indicated that the initial rates of methangen and anaerobic biofilm accumulation increased with increasing organic loading rate and higher initial rates were observed for 15 days than 15 day liquid HRT or SRT. When the initial rates were plotted against the corresponding mixed liquor volatile suspended solids the difference between the results at the two HRT's became much less significant. Thus, the concentration of mixed liquor volatile suspended solids was found to be a very important parameter affecting initial anaerobic biofilm development. The ratio of methanogens to anaerobic biofilm was also investigated. The results showed that the ratio remained constant through the 25 days of each experiment and for high organic loading rates. Based on the results of this research, a reduction, a reduction of start-up period of anaerobic fixed film reactors might be achieved by maintaining a high organic loading and a large concentration of anaerobic microorganisms in the mixed liquor during the start-up period.

• Journal of Mechanical Science and Technology
• /
• v.19 no.12
• /
• pp.2253-2262
• /
• 2005

The focus of this work is placed on the analysis of the mixture formation mechanism under the evaporative diesel spray of impinging and free conditions. As an experimental parameter, ambient gas density was selected. Effects of density variation of ambient gas on liquid and vapor-phase inside structure of evaporation diesel spray were investigated. Ambient gas density was changed between ${\rho}a=5.0\;kg/m^3$ and $12.3\;kg/m^3$. In the case of impinging spray, the spray spreading to the radial direction is larger due to the decrease of drag force of ambient gas in the case of the low density than that of the high density. On the other hand, in the case of free spray, in accordance with the increase in the ambient gas density, the liquid-phase length is getting short due to the increase in drag force of ambient gas. In order to examine the homogeneity of mixture consisted of vapor-phase fuel and ambient gas in the spray, image analysis was conducted with statistical thermodynamics based on the non-dimensional entropy (S) method. In the case of application of entropy analysis to diesel spray, the entropy value always increases. The entropy of higher ambient density is higher than that of lower ambient gas density during initial injection period.