• 한국환경농학회지
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• 제33권4호
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• pp.344-349
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• 2014

BACKGROUND: Purpose of the study was to establish the extinction coefficients of chlorophyll a and b in N,N-dimethylformamide(DMF) and Dimethylsulfoxide(DMSO) solvents and to find out the conditions of optimal extraction temperature and time in citrus leaves. METHODS AND RESULTS: Chlorophyll a and b standards were dissolved in DMF and DMSO. Extinction coefficients of chlorophyll pigments were determined and their contents were quantified using spectrophotometer. Chlorophyllous pigments of citrus(Citrus unshiu Marc. cv. Okitsu wase) leaves were extracted at 25, 40, 60 and $80^{\circ}C$ for 4, 6, 8, 24 and 48 hours to determine the optimal extraction condition. CONCLUSION: The extinction coefficients of chlorophyll a(Chl a) and chlorophyll b(Chl b) of DMF extracts for high extinction wavelength were 663.8 and 647.2 nm. Similarly, the high extinction wavelength of DMSO extracts were 665.8 and 649.0 nm for chl a and b respectively. Chl a, Chl b and total chlorophyll content of DMF extracts were Chl a = $12.10A_{663.8}-2.74A_{647.2}$, Chl b = $21.94A_{647.2}-5.06A_{663.8}$ and total $Chl=19.193A_{647.2}+7.04A_{663.8}$. Similarly, Chl a, Chl b and total Chl of DMSO extracts were Chl a = $14.53A_{665.8}-5.40A_{649.0}$, Chl b = $26.98A_{649.0}-7.11A_{665.8}$ and total $Chl=21.58A_{649.0}+7.43A_{665.8}$. The chlorophyll extracts of DMF and DMSO were very stable in dark. High chlorophyll contents of citrus leaves were found at $80^{\circ}C$ extraction for 6 hours in DMF and at $80^{\circ}C$ extraction for 24 hours in DMSO. However, the chlorophyll content was decreased significantly after 8 hours in DMF extraction while it was remained up to 30 hours in DMSO extraction.

• 대한화학회지
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• 제26권5호
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• pp.304-309
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• 1982

Chlorophyll-a(chl-a)와 chlorophyll-b(chl-b)를 pyridine을 포함한 실리콘의 dimer, hexamer에 결합시킨 물질은 중합체의 pyridine 농도와 chl-a의 농도의 비가 1:1일 때 가장 큰 에너지 전이를 나타냈으며 chl-b와 실리콘 중합체는 가장 큰 들뜬 에너지를 나타냈다.

• Molecules and Cells
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• 제40권10호
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• pp.773-786
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• 2017

The loss of green coloration via chlorophyll (Chl) degradation typically occurs during leaf senescence. To date, many Chl catabolic enzymes have been identified and shown to interact with light harvesting complex II to form a Chl degradation complex in senescing chloroplasts; this complex might metabolically channel phototoxic Chl catabolic intermediates to prevent oxidative damage to cells. The Chl catabolic enzyme 7-hydroxymethyl Chl a reductase (HCAR) converts 7-hydroxymethyl Chl a (7-HMC a) to Chl a. The rice (Oryza sativa) genome contains a single HCAR homolog (OsHCAR), but its exact role remains unknown. Here, we show that an oshcar knockout mutant exhibits persistent green leaves during both dark-induced and natural senescence, and accumulates 7-HMC a and pheophorbide a (Pheo a) in green leaf blades. Interestingly, both rice and Arabidopsis hcar mutants exhibit severe cell death at the vegetative stage; this cell death largely occurs in a light intensity-dependent manner. In addition, 7-HMC a treatment led to the generation of singlet oxygen ($^1O_2$) in Arabidopsis and rice protoplasts in the light. Under herbicide-induced oxidative stress conditions, leaf necrosis was more severe in hcar plants than in wild type, and HCAR-overexpressing plants were more tolerant to reactive oxygen species than wild type. Therefore, in addition to functioning in the conversion of 7-HMC a to Chl a in senescent leaves, HCAR may play a critical role in protecting plants from high light-induced damage by preventing the accumulation of 7-HMC a and Pheo a in developing and mature leaves at the vegetative stage.

• 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.

• Biotechnology and Bioprocess Engineering:BBE
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• 제6권3호
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• pp.183-188
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• 2001

The deposition behavior and photoelectric response characteristics of chlorophyll a(Chl a) monolayers and multilayers were investigated under various film fabrication conditions. Chl a LB films were deposited onto quartz and pretreated ITO glass substrates under several fabrication conditions, including surface pressure and number of layers. The absorption spectra of Chl a in a solution state and solid-like state (LB films) were fairly consistent with each other, and two absorption peaks were found at 678 and 438nm, respectively. The prepared Chl a LB films were set into an electrochemistry cell equipped with a Pt plate as the counter electrode, and the photoelectric response characteristics were obtained and analyzed relative to the light illumination. By considering the resulting photocurrents, the optimal fabrication conditions for Chl a LB films were determined as 20mN/m of surface pressure and 20 layers. The action spectrum of the Chl a LB films was obtained in the visible region, and was found to be in good agreement with the absorption spectrum. The possible application of the proposed system as a constituent of an artificial color recognition device was suggested based on combining with the photoelectric conversion property of another light-sensitive biological pigment.

• 동아시아식생활학회지
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• 제17권5호
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• pp.671-677
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• 2007

This study examined the relationship between chlorophyll(Chl) and ascorbic acid(ASA) as an index of freshness for vegetables, when the general consumers purchase several kinds of vegetables at the market. The leaves and fruits of several types of vegetables were divided into top, middle, and basal sections. Chl was determined by a spectrophotometer, and ASA was analyzed by high-performance liquid chromatography. For the vegetable sections, we found that Chl and ASA levels were highest in the top sections, followed by the middle, and were lowest in the basal portions. For the relationship between Chl and ASA in vegetables, there were seven classifications including high Chl(above 80mg/100g of fresh weight) and high ASA(above 80 mg/100 g of fresh weight) for mallow, and kail; the second group had high Chl and low ASA(below 80 mg), such as in spinach, burdock, and perilla leaves; the third group contained medium Chl($40{\sim}80mg$) and medium ASA($40{\sim}80mg$) levels, such as for gonddalbee, angelica, pumpkin leaf and coriander; the fourth group had medium Chl and low ASA levels, as in crown daisy and lettuce; the fifth group contained low Chl(below 40 mg) and high ASA, such as in hot peppers and parsley; the sixth group had low Chl and medium ASA levels, and included broccoli, pak choi, and sweet peppers; finally the seventh group contained low Chl and low ASA levels, as in dropwort, young radishes, shallots, cucumbers and swiss chard.

• 생명과학회지
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• 제29권5호
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• pp.509-513
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• 2019

비어 람버트 법칙에 의하면 충분히 묽은 용액에서 주어진 파장에서 측정한 흡광도는 용질의 농도에 비례한다. 반대로 충분히 묽은 용액이란 측정한 흡광도 값이 용질의 농도에 비례관계를 가지는 범위에 있는 용액을 말하지만 실제 확신하기가 어렵다. 본 연구에서는 벼 잎에서 추출한 엽록소 80% 아세톤 용액을 사용하여, 측정한 흡광도 값의 신뢰도를 판단할 수 있는 기준으로서 엽록소 a/b 비례치의 사용 가능성을 4가지 다른 흡광분광분석기(Cary4E, UV-1650PC, Versamax, NanoDrop 100)을 사용하여 조사하였다: 우선 $0.2{\mu}g/ml$의 매우 저농도에서 $200{\mu}g/ml$까지의 다양하게 희석한 엽록소 용액을 사용하여, 645 nm와 663 nm에서 측정한 흡광도 값을 측정한 후, 흡광도 값과 엽록소 농도의 비례관계를 조사하였다. 그 결과, 이 비례관계로 판단한 측정치의 신뢰 범위에서 흡광도로부터 계산한 용액에서의 엽록소 농도와 이미 알고 있는 엽록소 농도 비교적 일치하였다. 그러나, 비례관계의 한계치 안에 있어 신뢰도가 인정된 일부 고농도와 저농도에서의 일부 값이 엽록소 a/b 비례치가 용액의 희석에 변화지 않을 것이라는 판단 기준에 있어 신뢰도가 떨어짐을 알 수 있었다. 그러므로, 본 연구결과는 엽록소 농도결정을 위하여 측정한 흡광도 값의 신뢰 여부는 대상 용액을 희석하여 측정한 흡광도의 비례관계로 본 비어-램버트 법칙의 기준 보다는 엽록소 a/b 비례치가 변하지 않는다는 기준으로 측정치의 신뢰도를 판단하는 것이 더 좋다는 것을 확인할 수 있었다.

• Molecules and Cells
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• 제38권5호
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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.

• 한국토양비료학회지
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• 제6권4호
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• pp.231-237
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• 1973

Phytotron을 사용(使用) 열대형질(熱帶形質)인 IR667 계통(系統)(수원 213 및214)과 기존장려품종(진흥(振興) 및 팔달(八達))의 생육(生育) 시기별(時期別)(묘대말기(苗代末期), 최분기(最分期), 출수기(出穗期))로 저온처리(低溫處理)($15^{\circ}C$, $20^{\circ}C$, $25^{\circ}C$, 3일(日) 및 7일간(日間))를 하여 엽록소(葉綠素), 질소(窒素) 및 가리(加里) 함량(含量)의 변화(變化)를 상부제(上部第) 2엽신(葉身)에서 조사(調査)하였다. 1. chl. 함량이 $25^{\circ}C$ 에서는 IR667계통(系統)이 장여품종(奬勵品種)보다 크나 $20^{\circ}C$이하(以下)에서는 그 반대(反對)였으며 chi. a/b 값은 장려품종(奬勵品種)이 언제나 큰 경향이다. 2. 엽록소함량(葉綠素含量)은 생육(生育)에 따라 감소(減少)하며 chl.a가 b 보다 저온(低溫)에 의(依)한 감소(減少)가 크고 묘대기(苗代期)가 저온(低溫)의 영향(影響)을 가장 심히 받았다. 3. chl. 함량(含量)이 증가(增加)할수록 chl. a/b 값도 증가(增加)하는데 장해(障害)를 받으면 chi.당(當) a/b. 비율(比率) 증가(增加)가 감소(減少)하며 저온(低溫)에 약(弱)한 IR667이 장려품종보다 더욱 감소(減少)한다. 4. Chl. 잔존율(殘存率)로 보아 IR667계통(系統)이 장려품종(奬勵品種)보다 저온장해(低溫障害)를 크게 받는다. 5. 전질소(全窒素) 및 methanol 가용질소(可溶窒素)(S-N)는 저온(低溫)에 의(依)하여 감소(減少)하는 경향(傾向)이다. 6. chl. (a+b)/S-N 값은 생육(生育)에 따라 감소하며 온도(溫度)에 크게 영향(影響)받지 않으며 장려품종(奬勵品種)이 언제나 큰 경향(傾向)이다. 7. 저온(低溫)에 의하여 K함량(含量)은 감소(減少)하는 경향(傾向)이며 methanol 가용(可溶)K가 증가(增加)하면 chlorophyll 함량(含量)도 증가(增加)하는 경향(傾向)이다. 8. IR667이 고온(高溫)에서 생체당(生體當) chlorophyll 함량(含量)이 많은 것은 이의 다수성(多收性)의 한 원인(原因)이며 chl. /S-N가 적은것은 엽신(葉身)의 저온(低溫)이나 비절(肥切)에 의(依)한 적변(赤變)의 한 원인(原因)이 될 것으로 보였다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2022년도 학술발표회
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• pp.27-27
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• 2022

본 연구는 본 연구에서는 내륙에 위치한 하천(백제보)과 호소(남양호)를 대상으로 수체반사도를 활용하여 유역특성에 따른 반사도의 변화를 확인하고 Chlorophyll-a(Chl-a)의 농도를 추정하고자 하였다. 각 유역별 특성분석을 위해 제원자료, 토지피복도 및 11개(수소이온농도, 용존산소, BOD, COD, 부유물질, 총질소, 총인, 수온, 전기전도도 및 Chlorophyll-a)의 수질인자 자료를 구축하였다. 백제보는 2016-2017년 유인항공기에 탑재된 초분광센서를 이용하여 반사도를 측정하였고, 남양호는 2020-2021년 초분광센서가 탑재된 Drone과 Sentinel-2 MSI영상으로부터 반사도를 측정하였으며 두 유역 모두 촬영 범위에 대하여 현장샘플링을 실시하였다. 유역특성, 수질인자간 상관성 및 밴드별 상관성 분석을 실시하였다. 수질인자 간 상관성 분석 결과 Chl-a와 광학적 특징이 있는 SS, TOC가 상관성이 높게 나타났으며, 반사도의 경우 Chl-a가 고농도일수록 Near-Infrared, Blue 파장과 상관성이 높게 나타났다. 해당 분석결과를 기반으로 각 유역에 대해 Chl-a Machine-learning 기법과 원격탐사자료를 이용하여 Chl-a의 농도를 산정하였으며 백제보, 남양호 각각 결정계수(R²) 0.80, 0.88의 성능을 보였다. 추후 고해상도 광학위성영상을 통해 유역특성을 고려한 광범위한 지역 규모의 Chl-a의 시공간적 분석이 가능할 것으로 판단된다.