• Journal of Plant Biology
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• v.39 no.4
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• pp.309-314
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• 1996

Developmental of photosynthetic pigments and changes in chlorophyll fluorescence of dark-grown rice seedlings were studied during greening. Light-illumination stimulated accumulations of total chlorophylls and carotenoids in leaves of etiolated seedlings, accompanied by a decrease in the ratio of chlorophyll a to chlorophyll b. When the composition of carotenoids was analyzed, violaxanthin level was shown to increase up to 24 h after the beginning of light illumination, followed by a subsequent decline. In contrast to this, zeaxanthin level increased consistently with progress of deetiolatin. The role of zeaxanthin is discussed in relation to chlorophyll fluorescence quenching. A study on chlorophyll fluorescence kinetics of the rice seedlings being deetiolated showed a time-dependent increase in Fv/Fm (yield of variable fluorescence/maximum yield of fluoresecnece) ratios, indicating that greening is responsible for the activation of photochemical reaction centers of the photosystem. When chlorophyll fluorescence quenching was examined, qNP (nonphotochemical quenching) and qE (energy-dependent quenching) exhibited a time-dependent decline with progress of greening. The presented results indicate that greening-induced development of the photosynthetic machinery is associated the conversion of the carotenoid violaxanthin to zeaxanthin, suggesting that zeaxanthin synthesized in the illuminated leaves may provide the protection from the damage when etiolated plants are exposed to light.

• Proceedings of the Zoological Society Korea Conference
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• 2001.10a
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• pp.228.2-228
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• 2001

No Abstract, See Full Text

• Ocean Science Journal
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• v.41 no.4
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• pp.301-313
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• 2006

Abundance and distribution of phytoplankton in seawater at southwestern East/Japan Sea near Gampo were investigated by HPLC analysis of photosynthetic pigments during summer of 1999. Detected photosynthetic pigments were chlorophyll a, b, $c_{1+2}$ (Chl a, Chl b, Chl $c_{1+2}$), fucoxanthin (Fuco), prasinoxanthin (Pras), zeaxanthin (Zea), 19'-butanoyloxyfucoxanthin (But-fuco) and beta-carotene (B-Car). Major carotenoid was fucoxanthin (bacillariophyte) and minor carotenoids were Pras (prasinophyte), Zea (cyanophyte) and But-fuco (chrysophyte). Chl a concentrations were in the range of $0.16-8.3\;{\mu}g/land$ subsurface chlorophyll maxima were observed at 0-10m at inshore and 30-50 m at offshore. Thermocline and nutricline tilted to the offshore direction showed a mild upwelling condition. Results from size-fraction showed that contribution from nano+picoplankton at Chl a maximum layer was increased from 18% at inshore to 69% at offshore on average. The maximum contribution from nano+picoplankton was found as 87% at St. E4. It was noteworthy that contribution from nano+picoplanktonic crysophytes and green algae to total biomass of phytoplankton was significant at offshore. Satellite images of sea surface temperature indicated that an extensive area of the East/Japan Sea showed lower temperature ($<18\;^{\circ}C$) but the enhanced Chi a patch was confined to a narrow coastal region in summer, 1999. Exceptionally high flux of low saline water from the Korea/Tsushima Strait seemed to make upwelling weak in summer of 1999 in the study area. Results of comparisons among Chi a from SeaWiFS, HPLC and fluorometric analysis showed that presence of Chi b cause underestimation of Chi a about 30% by fluorometric analysis but overestimation by satellite data about 30-75% compared to HPLC data.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.37 no.3
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• pp.215-225
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• 2004

Biomass and community composition of microphytobenthos in the Saemankeum tidal flat were studied by HPLC analysis of the photosynthetic pigments from November 2001 to November 2002. The environmental factors of sediment were also investigated to examine the relationship between microphytobenthos biomass and sedimentary environments. The detected photosynthetic pigments of microphytobenthos were chlorophyll a, b, c, fucoxanthin, 19'-hexanoyloxyfucoxanthin, violaxanthin, diadinoxanthin, alloxanthin, diatoxanthin, zeaxanthin+lutein, peridinin and beta-carotene. Pheophytin a, the degradation product of chlorophyll a, was also detected. The results of pigmen analysis suggest the presence of diatom (fucoxanthin), euglenophytes (chlorophyll b), chlorophytes (chlorophyll b + lutein), cyanobacteria (zeaxanthin), cryptophytes (alloxanthin), chrysophytes (fucoxanthin + violaxanthin), prymnesiophytes (19'-hexanoyloxyfucoxanthin) and dinoflagellates (peridinin). Chlorophyll a concentration in the top 0.5 cm of sediment was in the range of $0.24\;mg{\cdot}m\^{-2}\;-32.11\;mg{\cdot}m\^{-2}$ in the study area. The increase of chlorophyll a concentration in the spring indicates the occurrence of a microphytobenthic bloom. In the summer, there was a sharp decrease of the chlorophyll a concentration which was probably due to high grazing activity by macrobenthos. The annual mean chlorophyll a concentration in the study area was low compared to that in most of other tidal flat areas probably due to active resuspension of microphytobenthos and high grazing activity by macrobenthos. There was no clear relationship between microphytobenthos biomass and sedimentary environments because of a large variety of physical, chemical and biological factors, Pigment analysis indicated that while diatoms were dominated in the microphytobenthic community of the Geojon tidal flat, euglenophytes and/or chlorophytes coexisted with diatoms in the Mangyung River tidal flat.

• Korean Journal of Ecology and Environment
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• v.52 no.3
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• pp.202-209
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• 2019

The primary productivity and production rate of photosynthetic pigment of periphyton and phytoplankton were estimated using a $^{13}C$ stable labeling technique in May 2011, in the waterfront of Lake Paldang. Primary productivity of periphyton ($28.15mgC\;m^{-2}\;d^{-1}$) was higher than phytoplankton production ($0.14mgC\;m^{-2}\;d^{-1}$). The net production rates of photosynthetic pigments(Chl a and Fucoxanthin) of periphyton were $2.53ngC\;m^{-2}\;d^{-1}$ and $0.12ngC\;m^{-2}\;d^{-1}$, respectively. On the other hand, the net production rate of pigments on phytoplankton (Chl a : $0.023ngC\;m^{-2}\;d^{-1}$, Fucoxanthin: $0.002ngC\;m^{-2}\;d^{-1}$) was lower than that of periphyton. Specific production rates of individual pigments of phytoplankton to the total primary productivity indicate the predominance of diatom (Fucoxanthin) species in phytoplankton assemblage in Lake Paldang. The net individual production rate of pigments by $^{13}C$ tracer was a useful tool to estimate the contribution of each phytoplankton class for total primary productivity, and it is possible to calculate the seasonal contribution of each phytoplankton class to the total primary productivity in the aquatic ecosystems. This study is the first report on photosynthetic pigment production rates of periphyton and phytoplankton.

• Journal of Photoscience
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• v.12 no.1
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• pp.33-39
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• 2005

Plants possess the ability to dissipate the excitation energy for the protection of photosynthetic apparatus from absorbed excess light. Heat dissipation is regulated by xanthophyll cycle in thylakoid membranes of chloroplasts. We investigated the mechanistic aspects of xanthophyll cycle-dependent photoprotection against low-temperature photoinhibition in plants. Using barley and rice as chilling-resistant species and sensitive ones, respectively, chilling-induced chlorophyll fluorescence quenching, composition of xanthophyll cycle pigments and mRNA expression of the zeaxanthin epoxidase were examined. Chilled barley plants exhibited little changes in chlorophyll fluorescence quenching either of photochemical or non-photochemical nature and in the photosynthetic electron transport, indicating low reduction state of PS II primary electron acceptor. In contrast to the barley, chilled rice showed a marked decline in those parameters mentioned above, indicating the increased reduction state of PS II primary electron acceptor. In addition, barley plants were shown to have a higher capacity to elevate the pool size of xanthophyll cycle pigments in response to cold stress compared to rice plants. Such species-dependent regulation of xanthophyll cycle activity was correlated with the gene expression level of cold-induced zeaxanthin epoxidase. Chilled rice plants depressed the gene expression of zeaxanthin epoxidase, whereas barley increased its expression in response to cold stress. We suggest that chilling-induced alterations in the pool size of xanthophyll cycle pigments related to its capacity would play an important role in regulating plant's sensitivity to chilling stress.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.189-192
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• 2000

The objective of this study was to investigate the effect of high content of light-absorbing pigments on overall photosynthetic efficiency in high density microalgal cultures. The light harvesting complex II (LHC II) regulating gene of Rhodobacter sphaeroides, photosynthetic purple bacterium, was removed to construct a mutant strain that had less pigment content. The mutant and wild type strains were cultured under various light intensity by adjusting the distance from the light source. The productivity of the mutant strain was higher at high light intensity (over 118 ${\mu}E/m^2/s$) compared with one of the wild type , and was lower at low light intensity (34 ${\mu}E/m^2/s$). Especially, the concentration of LHC II mutant strain was 56% higher at 118 ${\mu}E/m^2/s$. The reduction of per cell pigment contents in the mutant strain lessened the degree of the mutual shading and thus enhanced the overall photosynthetic efficiency.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2003.04a
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• pp.104-104
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• 2003

• Korean Journal of Agricultural and Forest Meteorology
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• v.12 no.3
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• pp.173-182
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• 2010

This study was conducted to investigate ozone sensitivity of physiological indicators and the difference in ozone tolerance of 8 families of Sophora japonica seedlings on the basis of the standardized physiological indicators. After ozone treatment, photosynthetic parameters, photosynthetic pigments and malondialdehyde (MDA) content, and antioxidative enzyme activities were analyzed from the leaves of S. japonica seedlings. Ozone tolerance indices among 8 families were calculated with the standardized physiological parameters. In addition, the reduction of carboxylation efficiency and apparent quantum yield were observed in the leaves of seven families, except for family No. 6 and 7, respectively. The apparent quantum yield varied from -27% to -61% of the control seedlings. Photosynthetic pigment content differed significantly among 8 families, but was not affected significantly by ozone treatment. Superoxide dismutase (SOD) activity increased from 7% to 64% after ozone exposure, and significant difference existed among 8 families. Ascorbate-peroxidase (APX) activity of 8 families increased by ozone treatment, and the activity of family No. 7 showed the highest increase (218%) in comparison to their respective control plants. On the basis of the standardized indices, family No. 6 showed the lowest tolerance by indicating higher reduction of both photosynthetic parameters and pigment content and lower increase of antioxidative enzyme activities. On the contrary, family No. 7 showed the highest tolerance as indicated by lower reduction of photosynthetic parameters, higher amounts of photosynthetic pigments, and higher enzyme activity.

• Journal of Forest and Environmental Science
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• v.40 no.1
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• pp.43-52
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• 2024

Cadmium (Cd) is non-essential heavy metal that negatively affects plant metabolism. Nitric oxide (NO) is an increasingly important molecule for plant metabolism that makes signaling. In this study, it was aimed to investigate the alleviating effect of sodium nitroprusside (SNP) application as NO donor in white poplar (Populus alba) under Cd stress conditions. SNP and without SNP treatments increased the Cd accumulation in root tissue. While photosynthetic pigments (Chl a, Chl b, Chl a+b, and carotenoid) content decreased by only Cd application, SNP+Cd application decreased the rate of photosynthetic pigments reduction. When the results of Cd and Cd+SNP applications were evaluated for mineral (Fe, Zn, Mn and Cu) uptake, it was found that the positive effect of SNP was heterogeneously affected. Depending on SNP application, it was found that malondialdehyde (MDA) amount decreased in leaf in 100 µM Cd applications while hydrogen peroxide (H₂O₂) amount decreased in 100 and 500 µM Cd applications. When antioxidant enzyme activities were examined, it was found that catalase (CAT) and ascorbate peroxidase (APX) enzyme activities increased with 100 µM SNP applications under all Cd applications. As a result, it was found that SNP application under Cd stress generally supports physiological processes positively in white poplar, suggesting that NO molecule plays important alleviating roles in plant metabolism.