• Korean Journal of Ecology and Environment
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• v.34 no.4 s.96
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• pp.277-284
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• 2001

Since a substantial part of the total planktonic primary production is due to the activity of the picoplankton, seasonal change of chlorophyll a in the picoplankton, nanoplankton and microplankton was determined at four locations in Daechung Reservoir from September in 1998 to September in 1999. Chlorophyll a concentration (<$200\;{\mu}m$) was $0.7{\sim}36.9\;{\mu}g/l$ In TAE (Taejeon site), $0.5{\sim}23.5\;{\mu}g/l$ in MAN (Man site), $1.9{\sim}20.1\;{\mu}g/l$ in HOE (Hoenam site), and $0.5{\sim}17.4\;{\mu}g/l$ in DAM (Dam site). Generally it was observed the highest concentration of chlorophyll a was in September and the lowest in April to June. The relative contribution of chlorophyll a of each fraction was changed dramatically through the year. Relative contribution of chlorophyll a of microplankton was high from June to October, and low in March in all locations except HOE. However chlorophlyll a concentration of picoplankton fraction was $2.0{\sim}24.3%$ of total chlorophyll a (<$200\;{\mu}m$) through the year and did not show any dramatic changes at all locations.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.6 no.1_2
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• pp.27-36
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• 1973

The effect of water activity on degradation of pigments in dried lavers, Porphyra tenera Kjellm. was examined when stored at room temperature for fifty days. Chlorophyll pigment was extracted with methanol-petroleum ether mixture solvent(2:1 v/v), partitioned in ether, and analysed spectrophotometrically at 662 nm as chlorophyll a. The degradation products of chlorophyll were isolated on sugar-starch column(85:15 w/w) with n-propanol-petroleum ether solution(1:200 v/v) as a developing solvent. The isolated green colored zones were analysed individually at the wavelengths of 650, 662, and 667 nm as allomerized product, chlorophyll a retained, and pheophytin formed respectively. Carotenoida were also extracted with the methanol mixture solvent, partitioned in ether, and finally redissolved in acetone after the evaporation of ether in a rotary vacuum evaporator. The total carotenoid content was measured as lutein at 450 nm. From the results, it is noted that the rate of chlorophyll degradation reached a minimum at 0.11 to 0.33 water activity while progressively increased at higher moisture levels resulting in rapid conversion of chlorophyll to pheophytin. At lower activity, autocatalysed oxidizing reaction like allomerization seemed prevailing the acid catalysed conversion reaction. The loss of carotenoid pigment was also greatly reduced at the range of 0.22 to 0.34 water activity with much faster oxidative degradation at both higher and extremely lower moisture levels. These two moisture levels indicated above at which the both pigments exhibited maximum stability are considerably higher than the BET monolayer moisture which appeared 7.91 percent on dry basis at Aw=0.10 calculated from the adsorption isothermal data of the sample at $20^{\circ}C$. The rate of pigment loss in heat treated samples at 60 and $100^{\circ}C$ for 2 hours prior to storage somewhat decreased, particularly at higher moisture levels although the final pigment retention was not much stabilized.

• Korean Journal of Plant Resources
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• v.12 no.4
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• pp.253-259
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• 1999

In this study, three simple methods were established to confirm the transgenic potato plants. The leaf disc was used in the first method. After leaf discs of transgenic and non-transgenic potato were transfered into the liquid MS medium with bialaphos 5mg/l, 25 days, the chlorosis occurred in the non-transgenic leaf discs while it could not find in the transgenic leaf discs, In the second method, shoot tips of potato were transferred into MS medium supplemented with 0.5mg/l bialaphos and 0.6% agar. After 7-10 days, a lot of roots developed from the transgenic shoot tip, but the non-transgenic shoot tip was dead. The third method was using chlorophyll contents. Leaf discs were transferred into the liquid MS medium with bialaphos 0.5 mg/l. After 15 days, the content of chlorophyll A in transgenic plant was at least 2.5 times higher than in non-transgenic plant. In addition, the PAT enzyme activity were detected in the transgenic potato, but not detected in normal potato.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.693-695
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• 2004

This study is a comparative analysis of chlorophyll a retrievals in the JES from SeaWiFS and MODIS/Terra. SeaWiFS and MODIS/Terra data over period from 2000 through 2003 were compared. The chlorophyll concentration from the SeaWiFS was generally higher than that from MODIS during the period. There are some possible causes for such discrepancy: differences in the sensor sensitivity, chlorophyll algorithms, and atmospheric correction algorithms. We checked some of these possibilities. We also compared the data from other regions. The deviation between the two data sets was highly correlated with chlorophyll concentrations Atmospheric corrections seem the major cause of the discrepancy.

• International Journal of Industrial Entomology and Biomaterials
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• v.7 no.1
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• pp.45-49
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• 2003

Foliar treatment with different concentrations of potassium chloride (KCl) to mulberry plants resulted in higher level of total chlorophyll, total sugars, soluble protein, in vivo nitrate reductase activity (NRA), net photosynthetic rate (NPR), pWUE and leaf yield. Optimal concentration was found to be 10.0 mM KCl with limited irrigation provided in the mulberry plantation planted in 90 ${times}$ 90 cm spacing. The deleterious effect of soil moisture stress condition has been found to be overcome by KCl foliar spray twice at 15 days interval. Regression and correlation coefficients were analyzed, and a strong positive correlation was found between chlorophyll and total sugars, soluble protein and in vivo nitrate reductase activity, leaf dry weight and net photosynthetic rate and pWUE and net photosynthetic rate.

• BMB Reports
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• v.29 no.4
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• pp.327-334
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• 1996

In this study, the origin of the monovinyl chlorophyll a carboxylic biosynthetic route was investigated in barley (Hordeum vulgare L.) and com (Zea mays L.). Protoporphyrin IX accumulated in vivo or in vitro was found to be all of the divinyl form. Furthermore, the conversion of divinyl protoporphyrin IX to monovinyl protoporphyrin IX in vitro was not observed. In contrast, the biosynthesis and accumulation of monovinyl Mg-protoporphyrin IX and its methyl ester occurred in etiolated leaves and divinyl Mg-protoporphyrin IX was convertible to monovinyl Mg-protoporphyrin IX in vitro. These results suggest that the monovinyl chlorophyll ${\alpha}$ carboxylic biosynthetic route in plants may originate from the divinyl Mg-protoporphyrin IX pool.

• Molecules and Cells
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• v.38 no.5
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• pp.390-395
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• 2015

Degradation of chlorophyll (Chl) by Chl catabolic enzymes (CCEs) causes the loss of green color that typically occurs during senescence of leaves. In addition to CCEs, STAYGREEN1 (SGR1) functions as a key regulator of Chl degradation. Although sgr1 mutants in many plant species exhibit a staygreen phenotype, the biochemical function of the SGR1 protein remains elusive. Many recent studies have examined the physiological and molecular roles of SGR1 and its homologs (SGR2 and SGR-LIKE) in Chl metabolism, finding that these proteins have different roles in different species. In this review, we summarize the recent studies on SGR and discuss the most likely functions of SGR homologs.

• BMB Reports
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• v.50 no.7
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• pp.343-344
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• 2017

Plants are able to recognize even small changes in surrounding temperatures to optimize their growth and development. At warm temperatures, plants exhibit diverse architectural adjustments, including hypocotyl and petiole elongation, leaf hyponasty, and reduced stomatal density. However, it was previously unknown how such warm temperatures affected the early stages of seedling development. In our recent study, we demonstrated that the RNA-binding protein, FCA, is critical for sustaining chlorophyll biosynthesis during early seedling development, which is a prerequisite for autotrophic transition at warm temperatures. FCA plays a dual role in this thermal response. It inhibits the rapid degradation of protochlorophyllide oxidoreductases (PORs) that mediate chlorophyll biosynthesis. In addition, it induces the expression of POR genes at the chromatin level, which contributes to maintaining functional enzyme levels. Our findings provide molecular basis for the thermal adaptation of chlorophyll biosynthesis during the early stages of seedling development in nature.

• Journal of Life Science
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• v.11 no.3
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• pp.197-202
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• 2001

This study was conducted to investigate the effect of simulated acid solution(SAS) on acid buffering capacity, chlorophyll content and butrient leacking in 4 herb species(Petunia hybrida Vilm, Gomphrena globosa L. Celosia cristat L. Salvia officinallis L) . The acid buffering capacity in the leves was increased in the treatment of pH 3.0 in Celosia L., whereas it was increased at pH 4.0 in Petunia Petunia hybrida Vilm. and Gomprean globosa L.. But, the acid buffering capacity of the leaves did not work at ph 2.0 treatment in 4 herb species. With decreasing pH level, the chlorophyll content of Petunia hybrida Vilm. and Gomphrena globosa L. Was markedly decreased than that of Gelosia cristata L. and Savia officinalis L. As the pH levels decreased from 5.6 to 2.0 the nutrient leaching from leaves was significantly increased in 4 herb species. In pH 4.0 and 5.6, the concentrations of nutrient leaching from leaves were higher in Perunia hybrida Vilm. and Gomphrean globosa L. than Gelosia cristata L. and Salvia officinalis L., Based on the results, there was a great differences in response to SAS among the 4 herb species. Im general, Gelosia cristata L. and Salvia officinalis L. represented a higher tolerance to SAS Petunia hybrida Vilm, and Gomphrena globosa L..

• Journal of Ginseng Research
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• v.11 no.2
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• pp.101-110
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• 1987

This study was investigated and analyzed the physiological reaction mechanisms and the factors of the chlorophyll bleaching phenomenon on leaf burning-disease of the Ginseng (Panax ginseng C.A. Meyer). Chlorophyll bleaching phenomenon was mainly caused by the photooxidation of singlet oxygen and the autooxidation of hydrogen peroxide($H_2O_2$) accumulation resulted from inactivation of catalase and peroxidase. Chlorophyll bleaching phenomenon was remarkably accelerated by addition of saponin.