• BMB Reports
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• 제38권4호
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• pp.481-485
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• 2005

The response of Spirulina (Arthrospira) platensis to high salt stress was investigated by incubating the cells in light of moderate intensity in the presence of 0.8 M NaCl. NaCl caused a decrease in photosystem II (PSII) mediated oxygen evolution activity and increase in photosystem I (PSI) activity and the amount of P700. Similarly maximal efficiency of PSII (Fv/Fm) and variable fluorescence (Fv/Fo) were also declined in salt-stressed cells. Western blot analysis reveal that the inhibition in PSII activity is due to a 40% loss of a thylakoid membrane protein, known as D1, which is located in PSII reaction center. NaCl treatment of cells also resulted in the alterations of other thylakoid membrane proteins: most prominently, a dramatic diminishment of the 47-kDa chlorophyll protein (CP) and 94-kDa protein, and accumulation of a 17-kDa protein band were observed in SDS-PAGE. The changes in 47-kDa and 94-kDa proteins lead to the decreased energy transfer from light harvesting antenna to PSII, which was accompanied by alterations in the chlorophyll fluorescence emission spectra of whole cells and isolated thylakoids. Therefore we conclude that salt stress has various effects on photosynthetic electron transport activities due to the marked alterations in the composition of thylakoid membrane proteins.

• 한국환경과학회지
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• 제6권4호
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• pp.369-378
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• 1997

The effects of various intensity of W-B on barley seeding were investigated by PS I and II activities and chlorophyll fluorescence. The Inhibitory effect of UV-B radiation on electron transport activity was Increased as the intensity of UV-B Irradiation was increased. Especially, PS I is more sensitive to UV-B radiation than PS I is. By the addition of uncle electron donor, DPC, to the chloroplasts of the barley seedlings treated with UV-B, the photoreduction of DCPIP was recovered by only 1 IBI on electron transport activity. However, the activity of PS II was Inhibited by 45% by the treatment with UV-B, but recovered it only 11% by the addition of DPC. These suggest that other sites besides the oxidation site of PS II may be affected more by UV-B Irradiation. As the intensify of UV-B was Increased, Fo was Increased while Fv was decreased, and thus Fv/Fm was decreased. This means that photochemical efficiency was reduced. With this parameters, it might be that UV-B radiation affected adversely to around PS II.

• 환경생물
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• 제23권1호
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• pp.52-56
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• 2005

8일간 생장한 보리 유식물에 72시간 동안 dimethipin을 처리하면서 엽록소 함량의 변화와 광합성적 전자전달 활성을 측정하였다. 10/sup -3/M dimethipin을 72시간 처리한 경우 엽록소 함량이 33% 감소하였다. 이에 비해 7일간 암소에서 생장시킨 후 dimethipin을 처리한 보리 유식물은 녹화 48시간에 10/sup -4/M에서 대조구에 비해 43% 엽록소 함량이 감소하였으며, 엽록소 a/b 비율이 증가하였다. 24시간의 dimethipin처리는 PSⅡ+PSⅠ활성에 거의 영향을 미치지 않았다. 10/sup -4/M dimethipin처리는 48시간 배양시 10% 그리고 72시간에는 25%의 PSⅡ+PSⅠ 활성을 억제하였다. Water splitting system을 제외한 PSⅡ+PSⅠ 활성은 10/sup -4/M dimethipin을 48시간 처리할 경우 16% 그리고 72시간에는 27% 억제되었다. 10/sup -4/M dimethipin을 24시간 처리할 경우 PSⅡ활성은 8%, 48시간에서는 13% 그리고 72시간에서는 18% 억제되었다. 10/sup -4/M dimethipin을 24시간 처리할 경우 PSⅠ활성은 4%, 48시간에서는 8% 그리고 72시간에서는 10% 억제되었다. 7일간 암소에서 자란 황백화된 보리 유식물을 녹화시간 6, 12, 24와 48시간에 dimethipin을 처리할 경우 PSⅡ+PSⅠ 활성은 5, 10, 10 그리고 11% 억제되었다. 반면에 water splitting system을 제외한 PSⅡ+PSⅠ 활성은 모든 처리시간에서 그 효과가 없었다. 또한 PSⅡ와 PSⅠ의 활성도 대조구와 큰 차이가 없었다. 이와 같이 dimethipin에 의해 야기된 광합성적 전자전달활성의 억제는 엽록체 합성과정에서의 영향보다는 엽록체의 기능에 영향을 주는 것으로 사료되며, 이러한 엽록체 기능의 감소는 dimethipin에 의해 야기되는 30∼40%의 엽록소 함량감소에 의한 것으로 사료된다.

• Journal of Plant Biology
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• 제33권2호
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• pp.111-118
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• 1990

In order to characterize the chloroplasts of Korean ginseng as a semi-shade plant and radish as a sun plant, effects of growth light intensity on photosynthetic electron transport (PS) activity in chloroplasts and superoxide (O2.-) production in thylakoid membrane by irradiation were investigated. High-light chloroplasts of both plants showed higher PS activities than those grown under ow growth light intensity. High PS II and low PS I activities in ginseng chloroplasts (ratio of PS II/PS I : 1.1) were observed, but radish chloroplasts showed low PS II and high PS I activities (ratio of PS II/PS I : 0.3). PS II activity of both plants was little affected by temperature in range of 15-35$^{\circ}C$. Activities of whole -chain (PS II+I) in ginseng and PS I in radish were increased at high temperature (4$0^{\circ}C$). Preincubation of chloroplasts at 4$0^{\circ}C$ during 30 min, as a mild heat stress, caused rapid decrease in PS II and PS II+I activities of both plants. However PS I activity was not decreased in ginseng and rather increased in radish. O2.- production (NBT reduction) in Mehler reaction in the thylakoid membrane was inhibited by DCMU in both plants. DMBIB inhibited O2.- production in ginseng, but radish was insensitive to DMBIB. Electron flow system in ginseng thylakoid membrane was more susceptible to damage of photooxidation than that of radish.

• 미생물학회지
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• 제29권2호
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• pp.92-96
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• 1991

The soluble cytochrome c-551 of photosynthetic bacterium, Rhodopseudomonas gelatinosa ATCC 17013 was purified through a sequene of four step chromatography including CM-cellulose ion-exchange chromatography, DEAE-Sephacel chromatography, Sephacryl s-200 gel permeation chromatography, and HPLC (SP-5PW). The molecular weight of the purified cytochrome c-551 was 14, 600 Da, and this protein shows the absorption peak at 551 nm, 522 nm, and 417 nm as the reduced form, and at 412 nm as the oxidized form. The cytochrome c-551 seems to be a substrate for the terminal oxidase in the electron transport chain.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVI)
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• pp.18-18
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• 2005

Photoinduced electron transport process in nature such as photoelectric conversion and long-range electron transfer in photosynthetic organisms are known to occur not only very efficiently but also unidirectionally through the functional groups of biomolecules. The basic principles in the development of new functional devices can be inspired from the biological systems such as molecular recognition, electron transfer chain, or photosynthetic reaction center. By mimicking the organization of the biological system, molecular electronic devices can be realized $artificially^{1)}$. The nano-fabrication technology of biomolecules was applied to the development of nano-protein chip for simultaneously analyzing many kinds of proteins as a rapid tool for proteome research. The results showed that the self-assembled protein layer had an influence on the sensitivity of the fabricated bio-surface to the target molecules, which would give us a way to fabricate the nano-protein chip with high sensitivity. The results implicate that the biosurface fabrication using self-assembled protein molecules could be successfully applied to the construction of nanoscale bio-photodiode and nano-protein chip based on electrical detection.

• 한국작물학회지
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• 제38권3호
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• pp.245-252
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• 1993

광합성 전자전달 억제물질에 대한 빠른 검색 방법을 모색하기 위하여 녹색배양 세포인 광학적 자가 영양세포(PA)를 이용하여 실용화된 제초제 및 4종의 잡초 추출액으로 부터 PA세포의 반응을 조사하였다. 녹색배양 세포인 담배 및 우산이끼 PA세포는 타가 영양세포에 비하여 광합성 전자전달 저해형 제초제들은 700배 이상 높은 감수성을 나타내었으며 호르몬 작용형 제초제인 2, 4-D는 감수성의 차가 8배로 낮게 나타났다. 우산이끼 PA세포는 약제 농도간의 범위(0.01～0.9${\mu}$M)가 좁아 약제선발시 타 배양 세포에 비하여 좋은 재료임을 암시하였으며, 광합성 전자전달 저해약제에 대해서 힐(hill)반응과 동일하게 광합성 산소발생 억제정도인 PI$_{50}$에서 강한 활성을 나타내었다. 잡초 중 여뀌 추출액 10% 처리시 PA배양 세포의 엽록소 함량이 가장 낮았고, 광합성 산소발생 억제율이 가장 높았다. 수용 및 MeOH액으로 추출한 10% 여뀌 추출액을 반응용액 3ml에 300${\mu}$l 반응시 우산이끼 PA배양세포에 대해 각각 60%, 100% 광합성 산소발생 억제효과가 있었다. 이상의 결과에서 PA세포들은 광합성 전자전달 저해형 약제에 대하여 빠르고 민감한 검색수단으로서 좋은 재료가 될 수 있다고 생각한다.다.

• Journal of Plant Biology
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• 제26권2호
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• pp.91-99
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• 1983

The formation of chlorophyll-protein complexes (CP-complexes) during the greening of rape cotyledons (Brassica napus cv. Yongdang) was investigated by the SDS-polyacrylamide gel electrophoresis. The total chlorophyll content and Chl a/b ratio were also determined. In addition, the effects of dark treatment on the CP-complex patterns during greening have been examined with respect to their photosynthetic electron transport activity. Greening has brought about the increasein total chlorophyll content and the decrease in Chl a/b ratio, but there have been no changes in Chl a/b ratio after 24 hrs of greening. The light-harvesting chlorophyll a/b-protein complex (LHCP-complex0 was predominant during the initial greening period. Thereafter, the amout of chlorophyll a-protein complex (CP I-complex) was gradually increased. Twenty-four-hr dark treatment immediately after illumination for 6 hrs and 12 hrs resulted in the increase of the Chl a/b ration and the CP I complex, otherwise the decrease of the LHCP-complex. The LHCP/CP I ratio was gradually decreased with further greening, and appeared no change after 48 hrs illumination. The investigation of the photosynthetic electron transport activity indicated that photosystem (PS) II activity (H2Olongrightarrowp-PD*＋FeCy**) did not change, but the activity of PS I was increased suddenly due to the dark treatment. The data suggests that the increase of CP I-complex may result in that of P-700, that is, the increase of PS I activity.

• 환경생물
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• 제30권3호
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• pp.210-218
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• 2012

일반적으로 많이 양식되는 방사무늬김(Porphyra yezoensis Ueda)에 대하여 방사무늬김 엽체의 형태적 특성, 탄소 및 질소 성분의 농도, 안정동위원소 비값, 광합성 효율을 방사무늬김 양식이 이루어 지고 있는 남서해역에서 조사를 하였다. 방사무늬김의 형태적 특성에 대해서 살펴보면 평균 엽장은 11.6~16.3 (13.8) cm, 평균 엽폭은 4.6~6.3 (5.4) cm이었고, 단위면적당 방사무늬김 엽체의 평균 엽중량은 $1.1{\sim}2.6(1.86)g\;DW\;m^{-2}$이었다. 단위면적당 Chl a 농도는 2.18~17.77 (평균 9.65) mg DW Chl a $m^{-2}$이었다. 방사무늬김의 탄소 농도는 $201{\sim}317(240)mg\;DW\;g^{-1}$이었고, 질소 농도는 $39.8{\sim}50.0(43.5)mg\;DW\;g^{-1}$이었으며, C/N비는 5.0~6.7 (5.5)이었다. 방사무늬김의 방사성 안정동위원소비 중에서 탄소 안정동위원소 비는 ${\delta}^{13}C$=-25.6‰ 에서 ${\delta}^{13}C$=-24.0‰ (평균 -24.7‰)의 값을 보였고, 질소 안정동위원소 비는 ${\delta}^{15}N$=1.3‰ 에서 ${\delta}^{15}N$=4.1‰ (평균 2.1‰)의 값을 보였다. PAM에 의한 해조류의 광합성 특성은 광합성 활동의 지시자로서 사용될 수 있다. 우리는 Diving-PAM을 이용하여 각 정점 해조류인 방사무늬김의 광합성율을 분석하였다. 최대양자수율은 0.46~0.55 (평균 0.52)로서 최대 양자수율의 변동은 정점간 큰 차이는 없었다. 최대상대전자전달률은 4.71~5.84 (평균 5.33) ${\mu}mol\;electrons\;m^{-2}\;s^{-1}$ 로서 최대양자수율과 비슷한 분포를 보였다. 기울기 (${\alpha}$)는 0.027~0.045 (평균 0.036)을 보였고, 전자전달을 위한 포화광은 지역에 따라서 일부 차이를 보였으나 $139{\sim}180(156){\mu}mol\;photons\;m^{-2}\;s^{-1}$이었다. 남서해역 방사무늬김 엽체의 탄소 및 질소 농도와 광합성 효율은 지역에 따른 큰 차이는 보이지 않았다. 광합성 특성은 낮은 최대양자수율과 최대 상대전자전달률로 인한 낮은 광합성 효율이 나타났다.

• ALGAE
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• 제25권2호
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• pp.89-97
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• 2010

To test the feasibility of using chlorophyll ${\alpha}$ fluorescence to assess the establishment success of seagrass transplants, photosynthetic characteristics of eelgrass Zostera marina transplants were measured using a Diving-pulsed amplitude modulation fluorometer in Jindong Bay on the southern coast of Korea. Maximum quantum yield ($F_v/F_m$), photosynthetic efficiency ($\alpha$), saturating irradiance ($E_k$) and maximum electron transport rate ($ETR_{max}$) of transplants and reference plants in a nearby transplant site were measured using the fluorometer for 5 months. Additionally, shoot morphology, individual shoot weight and productivity of transplants and reference plants were also monitored. Shoot height, leaf weight and productivity of transplants were significantly reduced during the first two or three months after transplantation compared to those of reference plants, and then increased to the levels of reference plants Characteristics of chlorophyll a fluorescence, including $F_v/F_m$, $\alpha$, $E_k$ and $ETR_{max}$ of transplants were also significantly reduced in the initial period, but recovered slightly sooner than shoot morphology or leaf productivity. These results indicated that after transplantation, Z. marina transplant photosynthesis recovered faster than shoot morphology, biomass or productivity. Thus, chlorophyll a fluorescence can be used as an indicator for early assessment of the status of eelgrass transplants without destructive sampling.