• Journal of Plant Biology
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• v.35 no.3
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• pp.229-235
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• 1992

Differential expression of the three chlorophyll afb binding (cab) protein gene (cabl, cab2, and cab3) promoters of Arabidopsis thaliana was studied in tobacco plants transformed with cab-CAT (chloramphenicol acetyltransferase) translational fusions. CAT activity was measured to monitor the activities of the cab promoters. The activity of cabi promoter was higher than the other two in transformed tobacco leaves and also in calli and shoots derived from the leaves. Their activities were organ-specific and were the lowest in roots, medium in stems, and the highest in leaves. The relative activity of cabi promoter in stems comparing to it activity in leaves was, however, much higher than the values of cab2 and cab3. When the cab promoter activity was expressed as CAT activity per unit chlorophyll instead of CAT activity per unit protein, the relative cab] promoter activity (stem/leaf) became almost unity. This result suggests that cab2 and cab3 show photosynthetic organ-specificity but cabl does not. Similar result was obtained in the differentiation process of stems and leaves from shoots derived from the transgenic tobacco leaves.leaves.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.4
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• pp.327-335
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• 2002

Effects of available food on growth of commercially cultured Pacific oysters, Crassostrea gigas in Goseong Bay on the south coast were studied using a numerical model. levels of total protein, carbohydrate and lipid in particulate organic matter in the water column as well as chlorophyll a concentration were determined for estimating total available food for oyster growth. Environmental parameters including water temperature, salinity and total suspended solid were also monitored for the model. Oyster growth was also monitored by means of measuring shell length and tissue wet weight increase on a monthly basis. Simulation results from the numerical model indicated that chlorophyll a is not a good representative of available food for the oysters in Goseong Bay. In contrast, available food in the water column measured by filtration of the organic particles and analyzed in terms of total lipids, carbohydrates and protein was well matched with simulated oyster growth in the Bay which is similar to observed growth. The model also suggested that oysters have relatively low retention efficiency of $50\%$ or less. This result indicates that oysters in the bay utilize only a part of food particle available in the water column, as reported in other studies.

• Plant Resources
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• v.8 no.3
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• pp.202-208
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• 2005

Osmotic stress is one of major limiting factors in crop production. In particular, seasonal drought often causes the secondary disease in the field, resulting in severe reduction in both quality and productivity. Recent efforts have revealed that many genes encoding protein kinases play important roles in osmotic stress signal transduction pathways. Previously, the AtSIK (Arabidopsis thaliana Stress Inducible Kinase) mutants have shown to enhance tolerance to abiotic stresses, accompanying with higher expression of abiotic stress-related genes than did the wild-type plants. In this study, we have transformed potato (cv. Taedong Valley) with the AtSIK expression cassette. Both PCR and RT-PCR using AtSIK-specific primers showed stable integration and expression of the AtSIK gene in individual transgenic lines, respectively. Foliar application of herbicide ($Basta^{(R)}$) at commercial application rate (0.3% (v/v)) revealed another evidence of stable gene introduction of T-DNA which includes the bar gene for herbicide resistance. Overexpression of the AtSIK gene under dual CaMV35S promoter increased sensitivity to salt stress (300 mM NaCl), which was demonstrated by the reduction rate of chlorophyll contents in leaves of transgenic potato lines. These results suggest that possible increase of osmotic tolerance in potato plants may be achieved by antisense expression of AtSIK gene.

• Korean Journal of Food Science and Technology
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• v.40 no.3
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• pp.303-310
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• 2008

This study was performed to verify the effects of encapsulation against oil oxidation. Thiobarbituric acid (TBA) values of samples were compared during storage at $60^{\circ}C$, indicating that the encapsulated avocado oil had lower TBA values than the free avocado oil. Microcapsules consisting of a whey protein isolate (WPI)-only wall system had slightly improved oxidative stability; however, spray-dried particles containing a high proportion of maltodextrin (MD) clearly offered better protection from oxidation than the other forms of encapsulation. The chlorophyll (Chl) content of the encapsulated avocado oil was higher than that of the free oil sample. When compared to the control, all wall systems protected the change of the chlorophyll content storage. No large differences were observed between the encapsulated powders according to the various wall materials. The color of the encapsulated oil changed from green to yellowish-green, indicating the formation of pheophytin from chlorophyll. The yellowish color of the oil correlated with a reduced total Chl content. In conclusion, encapsulation with spray drying for avocado oil could lead to improved stability during storage with respect to oxidation and the preservation of chlorophyll.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.67 no.2
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• pp.77-84
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• 2022

This study aimed to evaluate the growth, yield, and grain quality characteristics of rice varieties that were subjected to water stress during the tillering stage. We also sought to identify whether water stress could be indicated via the plants' response to chlorophyll fluorescence. In this study, we induced water stress by intentionally cutting off water for 30 days, starting 15 days after transplanting the rice varieties to a greenhouse. We analyzed nine rice varieties, including Ilpum, which is the most frequently cultivated variety in Gyeongsangbuk-do, South Korea. The control group was planted in a paddy field where irrigation was entirely dependent on rainfall. Our results revealed that the heading stage of the nine studied varieties occurred approximately ten days earlier in the rain shelter than in the field. Moreover, the rice yield, head rice rate, and palatability score decreased by 18.6%, 17.1%, and 8.3%, respectively, while protein content increased by 20.2% compared with the control group. The Saenuri and Haimi varieties showed the lowest reduction in yield under the water stress conditions, while the Daebo and Samkwang varieties showed the highest reduction in yield. The chlorophyll fluorescence response after re-irrigation was measured between July 30^th and August 17^th. The ratio of variable fluorescence to maximum chlorophyll fluorescence (F_V/F_M) values failed to recover to their baseline values, resulting in either no change or a reduction in fluorescent response, even after re-irrigation of Daebo and Samkwang varieties. These results can be utilized as empirical data for drought-affected farms to select resistant varieties that can respond to spring drought in the southern plains of Gyeongsangbuk-do.

• Journal of Life Science
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• v.16 no.3 s.76
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• pp.510-515
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• 2006

The influence of $N^6-benzyladenine$ (BA) on in vitro growth, chlorophyll, rubisco and rubisco activase were studied in tobacco. After 11 weeks of treatment of various concentrations of BA, the most pronounced effect on in vitro growth and chlorophyll was found at 2 ${\mu}M$ BA. Rubisco content increased with increasing concentrations of BA, but a point at 2 ${\mu}M$ BA was reached beyond which increasing concentrations of BA cause inhibition of this enzyme. Rubisco activity showed patterns of change similar to rubisco content. These data suggest that rubisco activity was associated with an amount of rubisco protein. Under the assumption that effects of BA on rubisco may be related to by rubisco activase, in addition to, its content and activity were determined. The rubisco activase content at 2 ${\mu}M$ BA was more increased than other treatments. A similar change pattern was also observed in activity of rubisco activase. These results suggest that the effects of the activation of rubisco by BA seem to be related with rubisco activase.

• Journal of Photoscience
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• v.7 no.2
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• pp.39-44
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• 2000

To examine the chilling tolerance lipids, we compared the chilling susceptibility of photosystem II of wild type tobacco plants with that of transgenic tobacco plants, in which the sensitivity to chilling had been enhanced by genetic modification of fatty acid unsaturation of chloroplast membrane lipids. The transgenic tobacco plants were found to contain reduced levels of unsaturated membrane fatty acids by being tansformed with cDNA for glycerol-3-phosphate acyltransferase from squash. For the purpose of studying on the functional integrity of photosystem II during low-temperature photoinhibition, the photochemical efficiency was measured as the ration of the maximun fluorescence of chlorophyll (Fv/Fm) of photosystem II. In parallel with an investigation on the transgenic plants, susceptibility of chilling-resistant species, such as spinah and pea, and of chilling-sensitive ones, such as squash and sweet potato, to low-temperature photoinhibition was also compared in terms of room temperature-induced chlorophyll fluorescence from photosystem II. When leaf disks from the two genotypes of tobacco plants were exposed to light at 5$^{\circ}C$, the transgenic plants showed more rapid decline in photochemical activity of photosysytme II than wild-type plants. When they were pretreated with lincomycin, an inhibitor of chloroplast-encoded protein synthesis, the extent of photoinhibition was even more accelerated. More impottantly, they showed a comparable extent of photoinhibition in the presence of lincomycin, making a clear contrast to the discrepancy observed in the discrepancy observed in the absence of lincomycin. Restoration of Fv/Fm during recovery from low-temperature photoinhibition occurred more slowly in the transgenic tobacco plants than the wild-type. These findings are discussed in relation to fatty acid unsaturation of membrane phosphatidylglycerol. It appears that the ability of plants to rapidly regenerate the active photosystem II complex from might explain, in part, why chilling-resistant plants can toleratlow-temperature photoinhibition.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.6
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• pp.555-560
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• 2009

To identify the food characteristics of seven melania snail species in Korea, the detailed proximate, fatty/amino acid, mineral composition and chlorophyll contents were investigated. The content ranges of moisture, crude protein, crude lipid and ash were 70.1-81.0%, 11.6-16.9%, 0.4-1.6% and 1.9-3.4%, respectively. K. nadifila showed the significant mineral contents Fe, P, Ca than other species. Total Chlorophyll level was highest in K. globus ovalis ($1.2\pm0.2$ mg/g). The major fatty acids were 16:0, 22:1, 20:1, 18:1, 20:5 and 22:6 were identified as small amounts (1.0-3.3%) of total fatty acids. Citrulline was shown to be the major free amino acids (20.4-53.1%).

• Environmental Analysis Health and Toxicology
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• v.13 no.3_4
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• pp.133-142
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• 1998

Effects of phosphorous (P) and methylglyoxal (MG) on the cell number, dry weight, chlorophyll content, photosynthetic and respiratory rate, phosphate uptake and protein content of green algae (Scenedesrnus obliquus) were studied. The algal cell number from the medium treated with 0.5-1.0 mM of MG at 1/2 P or 1/4 P concentration was significantly lower than those of algae treated :with full strength of phosphrous in medium. The inhibitory effect of MG on algal cell division was enhenced at low concentration of phosphorous in medium. At the beginning of logrithmic phase of algal growth, the mean dry weight of algae from the medium without MG-treatment in 1/2 P media was significantly higher than that of algae treated with MG. After logrithmic phase of growth cycle, the mean dry weight of algae from the medium with 1.0 mM of MG-treatment in 1/4 P media was significantly lower than that of algae treated with or without MG. At logrithmic phase of algal growth, there were significant differences in the chlorophyll content among all groups of tested algae with various concentrations of P and MG. At 15 days after inoculation, the mean chlorophyll content per algal cell from the media without MG-treatment in 1/2P was significantly higher than that of other cells from MG-treated media. The adverse effect of MG at concentration of 0.5-1.0mM in 1/2 and 1/4 P media on photosynthetic rate was observed. The mean photosynthetic rate of algal cell without P and MG treatment at 15 days after inoculation was significantly higher than that of MGtreated algae. After logarithmic phase, the algal cell treated with 0.5mM of MG with full strength of phosphorous showed significantly high respiratory rate than that of other cell groups. There were significant differences in mean phosphate uptake rate among all groups of Scenedesmus obliquus at logarithmic phase. At 12 days after inoculation, phosphate uptake rate per each algal cell from the basic media without MG and P treatment was rapidly reduced which shows early introduction to stationary phase.

• Biotechnology and Bioprocess Engineering:BBE
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• v.8 no.2
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• pp.94-100
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• 2003

We studied the effect of cadmium on chlorophylls and rubisco activation in Canavalia ensiformis L. leaves. Chlorophyll levels were reduced by 5.0 ${\mu}$M Cd. Rubisco activity at 5.0 ${\mu}$M Cd was significantly smaller than that at no treatment. Rubisco Content showed patterns of change similar to rubisco activity. These data suggest that rubisco activity was associated with an amount of rubisco protein, and that the activation and induction of rubisco is inhibited by Cd. The degree of intensity of 50 and 14.5 kD polypeptides identified as the large and small subunit of rubisco by SDS-PAGE analysis at 5.0 ${\mu}$M Cd was significantly lower than that at control, indicating Cd had a e f-fect on both subunits. Under the assumption that effects of Cd on rubisco may be r elated to rubisco activase, in addition to, its activity and content we re determined . The rubisco activase activity at 5.0 ${\mu}$M Cd was more decreased than the control. A similar change pattern was also observed in content of rubisco activase. Remarkable differences in the intensitiy of both the 45 kD and 41 kD band were found between at control and Cd-treatment. These results suggest that the change in the levels of rubisco activase leads to a subsequent alter action of rubisco levels.