• 환경생물
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• 제19권1호
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• pp.43-48
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• 2001

구상나무 침엽의 엽록소형광과 생육지의 환경요인의 일변화를 계절별로 조사하여 환경요인의 변화에 따른 구상나무의 환경 적응성을 규명하였다. 광계 II의 광화학적 효율, 즉 Fv/Fm은 겨울에는 0.19-0.36으로 매우 낮은데 반하여 여름에는 0.8-0.86으로 높았다. 낮시간의 Fv/Fm이 겨울에는 아침, 저녁보다 상대적으로 높아서 겨울철 한낮의 환경조건이 구상나무 잎의 광합성기구에 우호적으로 작용을 하는 것으로 판단된다. 여름에는 낮시간에 광억제가 다소 일어나지만 Fv/Fm이 전반적으로 높아 낮시간의 환경 조건이 구상나무에 광피해를 야기하지는 않는 것으로. 해석되었다. 비광화학적 엽록소형광 소멸 능력, 즉 NPQ는 겨울에는 0-0.01로 밤과 낮의 차이가 없이 매우 낮았고, 여름에는 낮시간에 0.76으로 높았다. 따라서 구상나무는 여름철 환경 스트레스로부터 광계 II를 보호하는 조절 기구가 잘 발달한 것으로 판단되었다. 겨울에는 Fv/Fm이 온도, 광량, 상대습도와 모두 정의 상관관계를 보였으나 NPQ는 환경요인 모두와 상관성이 없는 것으로 나타났다. 여름에는 Fv/Fm이 온도와 광량과는 음의 상관관계를 나타낸 반면에 상대습도와는 정의 상관관계를 보였다. 따라서 구상나무 생육지의 조건하에서 겨울에는 온도, 광량, 상대습도의 증가는 모두 광합성 효율을 증가시키는 반면에 여름에는 높은 온도와 광량이 광억제를 야기할 수 있는 것으로 사료된다.

• Journal of Plant Biology
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• 제39권4호
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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.

• Fisheries and Aquatic Sciences
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• 제1권1호
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• pp.122-128
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• 1998

Characteristic changes in chlorophyll fluorescence from thalli of red alga, Porphyra, under high salt stress and during subsequent recovery were investigated, and the differences in the sensitivity to the stress among four species of Porphyra with different intertidal distributions were compared. By the treatment of NaCl with $9\%$ or higher concentrations, photochemical efficiency (Fv/Fm) decreased in a biphasic pattern: a rapid decrease was observed within 1­3 h and followed by a slow decline. The decrease of Fv/Fm was mainly due to the increase of Fo without significant increases of Fm. When the thalli treated with $15\%$ NaCl for 6 h were returned to natural sea water for recovery, the increase of Fv/Fm also showed a biphasic pattern: a rapid increase of Fv/Fm was observed within 2 h and followed by a slow increase. Differences in the sensitivity to salt stress among the four species could be found during recovery after the treatment of severe salt stress. After the treatment of $20\%$ NaCl for 6 h, Fv/Fm decreased below 0.3 in all of the four Porphyra species, and the species living in upper parts of the intertidal zone (P. suborbiculata and P. pseudolinearis) could recover better compared with the species in lower parts of the intertidal zone (P. seriata and P. yezoensis), during recovery for 24 h. The species collected from the coast of the South Sea seemed to be more tolerant than those in the East Sea.

• 한국환경과학회지
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• 제22권6호
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• pp.705-715
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• 2013

The response of the freshwater microalga Chlorella vulgaris to mercuric ion ($Hg^{2+}$) stress was examined using chlorophyll a fluorescence image analysis and O-J-I-P analysis as a way to monitor the toxic effects of mercury on water ecosystems. The levels of photosynthetic pigments, such as chlorophyll a and b and carotenoids, decreased with increasing $Hg^{2+}$ concentration. The maximum photochemical efficiency of photosystem II(Fv/Fm) changed remarkably with increasing $Hg^{2+}$ concentration and treatment time. In particular, above $200{\mu}M\;Hg^{2+}$, considerable mercury toxicity was seen within 2 h. The chlorophyll a fluorescence transient O-J-I-P was also remarkably affected by $Hg^{2+}$; the fluorescence emission decreased considerably in steps J, I, and P with an increase in $Hg^{2+}$ concentration when treated for 4 h. Subsequently, the JIP-test parameters (Fm, Fv/Fo, RC/CS, TRo/CS, ETo/CS, ${\Phi}_{PO}$, ${\Psi}_O$ and ${\Phi}_{EO}$) decreased with increasing $Hg^{2+}$ concentration, while N, Sm, ABS/RC, DIo/RC and DIo/CS increased. Therefore, a useful biomarker for investigating mercury stress in water ecosystems, and the parameters Fm, ${\Phi}_{PO}$, ${\Psi}_O$, and RC/CS can be used to monitor the environmental stress in water ecosystems quantitatively.

• 한국작물학회지
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• 제46권4호
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• pp.296-302
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• 2001

Winter cereals are acclimated during wintering, and thereafter their freezing resistance is increased. In order to analyze inheritance and heritabilities for photoinhibition of photosynthesis by high light intensity under low temperature, and to evaluate the relationship between low temperature-induced photoinhibition and winter survival, 4 parental half diallel crosses were used. The detached leaves of 7-8cm long from plants grown for 35 and 55 days were placed on wet filter paper and placed in trays at 5$^{\circ}C$ cold room with 1,200 $\mu$mol $m^{-2}$ $s^{-1}$ PPFD. Chlorophyll fluorescence was measured with a chlorophyll fluorescence system after dark adaptation for 30 min. The Fv/Fm of 35day old plants was reduced from 0.714 in the control leaves to 0.409 and 0.368 following photoinhibitory treatment of 6h and 8h and the CVs were increased from 0.8% to 22.2-22.3%. The Fv/Fm of 55-day old plants was reduced from 0.775 in the control leaves to 0.485 and 0.439 following photoinhibitory treatment of 10h and 12h, respectively. According to half diallel cross analysis, Reno and Dongbori 1 (highly resistant to photoinhibition) was dominant, but Oweolbori (susceptible to photoinhibition) was recessive, and photoinhibition showed partial dominance with highly additive gene action. Dongbori 1 showed the greatest GCA effects for photoinhibition, and GCA/SCA ratios (8.7-22.3 times) indicated that the additive variance for the character was more important. Winter survival in barley crosses was positively correlated with resistance to photoinhibition and significantly fitted by linear regression ($R^2$=0.751$^{**}$-0.779$^{**}$). The chlorophyll fluorescence measured by Fv/Fm has been found to be highly inheritable and very useful in evaluating relative levels of freezing resistance in barley.ley.

• 한국작물학회지
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• 제45권5호
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• pp.322-327
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• 2000

For the stable production of high quality tea, the freezing resistance is a very important character. Most of the farmers have planted out-pollinated seeds that are not genetically pure. So, with small sample, a quick and simple method is required to test freezing resistance of lots of germ-plasm and early generation of hybrids. The absorbances(A530 nm) of TTC reduction solution at -5$^{\circ}C$ were positively correlated with resistance to photoinhibition of PSII in 6 hour photoinhibitory treatments, being significantly fitted by simple linear regression ($R^2$=${0.64}^{**}$). Chlorophyll fluorescence measured by Fv/Fm was found to be very useful in evaluating the relative levels of freezing resistance in tea.

• Journal of Photoscience
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• 제5권1호
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• pp.17-22
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• 1998

Changes of chlorophyll fluorescence and xanthophyll cycle pigment contents in maize leaves were investigated dunng desiccation in darkness or in the light. In darkness, a drastic dehydration of detached maize leaves down to 50% relative water content (RWC) affected photochemical efficiency of photosystem II (Fv/Fm) and pht)tochemical quenching (qP) only slightly. In contrast, desiccation in the light with a moderate intensity led to a pronounced reduction in Fv/Fm with a Fo quenching when RWC was greater than 70%. This reduction in Fv/Fm could be recovered in darkness under hutrod condition. In leaves with RWC below 70%, significant reduction in Fv/Fm was accompanied by an increase of Fo, which could not be reversed within 5 h in darkness under humid condition. The nonphotochemical quenching increased during desiccation in the light with a concomitant rise in zeaxanthin at the expense of violaxanthin. Pretreatment with dithiothreitol (DTT), an inhibitor of zeaxanthin synthesis, inhibited the development of nonphotochemical quenching and prevented the xanthophyll interconversion during desiccation in the light. These results suggest that even light with a moderate intensity becomes excessive under dehydration and zeaxanthin-associated photoprotection of photosynthetic apparatus against photodamage is involved, but the protection is not complete against severe desiccation.

• Journal of Forest and Environmental Science
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• 제37권4호
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• pp.315-322
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• 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.

• Journal of Plant Biology
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• 제38권4호
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• pp.399-407
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• 1995

보리(Hordeum vulgare L.) 유식물의 녹화시기에 따라 오존이 엽록체의 광합성 활성에 미치는 영향을 알아보기 위하여 황백화된 보리 유산물을 녹화하는 중에 오존(0.5 ppm과 1.0 ppm)을 4시간 동안 처리하여 엽록소 함량, 광계 I과 II 활성 및 엽록소 형광을 측정하였다. 녹화를 시작하므로 엽록체가 발달되는 초기에 오존이 미치는 영향은 24시간 녹화구에서 엽록소 함량을 많이 감소시켰으나 48시간 녹화한 경우에는 대조구와 유사하였다. 24시간 녹화구에서는 처리한 오존의 농도가 0.5 ppm에서 1.0 ppm으로 증가함에 따라 Fo, Fv, Fm 및 qE가 급격히 감소하였으나 Fv/Fo와 qPsms 감소하지 않았으며, 48시간 녹화구에서는 Fo, Fv, Fm 및 qE가 많이 회복되었다. 엽록체의 발달 증가에 오존이 미치는 영향은 오존의 농도가 0.5 ppm에서 1.0 ppm으로 증가함에 따라 광계 II 활성을 감소시켰으며 광계 I활성은 감소시키지 않았고, Fv와 Fv/Fm 비가 크게 감소하였으며, 형광 소멸 분석에서는 qP와 qR이 특히 많이 감소하였다.

• 환경생물
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• 제22권1호
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• pp.233-241
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• 2004

겨울철 저온에 의한 식물의 반응 및 생리적 상태를 확인하기 위해 문주란(Crinum asiaticum var. japonicum)을 대상으로 엽록소형광과 항산화효소 찬성의 변화를 조사하였다. O-J-I-P곡선을 분석한 결과 겨울철에 J, I, P-단계에서의 형광세기가 현저하게 간소하였다. 문주란 잎의 광계II의 광화학적 효율, 즉 Fv/Fm은 겨울철의 온도변화 추이와 유사하게 낮은 값을 나타내어 겨울철 저온이 스트레스 요인으로. 작용하는 것으로 보인다. 그리고, 겨울철에 superoxide dismutase, ascorbate peroxidase, peroxidase 활성 이 다소 증가하였으나 catalase 활성은 여름철에 비하여 크게 낮았다. 이러한 결과는 겨울철의 Fv/Fm의 감소와 함께 문주란이 겨울철 저온에 의해 산화적 스트레스에 처해 있게되며 세포사멸이 일어나는 것으로 해석된다.