• Journal of Crop Science and Biotechnology
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• 제11권1호
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• pp.75-82
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• 2008

Functional stay-green is a beneficial trait that may increase grain yield through the sustained photosynthetic competence during monocarpic senescence in cereal crops. The temporal changes of photosynthesis and related characteristics throughout the grain filling period of a stay-green japonica rice "SNU-SG1" was compared in growth chamber conditions with three high-yielding cultivars(HYVs) and their $F_1$ hybrids with SNU-SG1. SNU-SG1 exhibited a typical characteristic of functional stay-green in terms of chlorophyll degradation and photosynthetic competence during grain filling. According to the photosynthesis-light response curve measured at 10 and 35 d after heading for the flag leaf, SNU-SG1 exhibited higher initial light conversion efficiency and thus higher gross photosynthetic rate at light saturation compared to HYVs. Light saturation point was not different among genotypes, ranging from 1000 to 1500 ${\mu}mol$ photon $m^{-2}s^{-1}$. Net photosynthetic rate at light saturation($P_{max}$) of the upper four leaves in SNU-SG1 was much higher and sustained longer throughout grain-filling than HYVs and $F_1$ hybrids. The sustained high photosynthetic competence of SNU-SG1 during grain filling was ascribed to the longer maintenance of high mesophyll conductance that resulted from not only high chlorophyll content and its delayed degradation but also the slow degeneration of photosystem II(PS II) as judged by chlorophyll fluorescence($F_v/F_m$) of flag leaves. $F_1$ hybrids showed slow degeneration of photosystem II similar to the male parent SNU-SG1 while chlorophyll degradation pattern close to female parents, thus exhibiting a little higher $P_{max}$ than female parents. These results suggest that SNU-SG1 has a typical functional stay-green trait that can be utilized for increasing rice yield potential through the improved dry matter production during grain filling.

• Journal of Microbiology and Biotechnology
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• 제11권2호
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• pp.211-216
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• 2001

The growth of Selenastrum capricornutum in culture was investigated as a function of ionic copper concentrations to verify the toxicity and physiological variation. In a $Cu^{++}$ excess culture (E: $Cu^{++}$ of $130{\mu}g/l$), the growth rate (K)(0.32) was lower than that of the control culture (C: $Cu^{++}$ of $0.065{\mu}g/l$) (0.61) after 8 days and the exponential growth rate ($R_E$) was also found to be lower in culture E (1.1) than culture C (2.9). On the contrary, the K of S. capricornutum in trace $Cu^{++}$ culture ($T_1$ and $T_2$, 0.72) after 6 days tended to be more increased than culture C (0.68). From 8 to 14 days of culture, the amounts of chlorophyllls a and b were increased in culture C (chlorophyll a, $106->126{\mu}g/g$ dry wt; chlorophyll b, $158->208{\mu}g/g$ dry wt; chlorophyll b were decreased in culture E (chlorophyll a, $309->235{\mu}g/g$ dry wt; chlorophyll b, $405->352{\mu}g/g$ dry wt). The amounts of chlorophylls in ionic copper trace culture ($T_1$ and $T_2$) [(chl a/b) of $T_1$: $384/620\;{\mu}g/g$ dry wt; (chl a/b) of $T^2$:$320/467{\mu}g/g$ dry wt] were increased more than the culture C($260/387{\mu}g/g$ dry wt). Howeveer, when photosynthetic rates were normalized to the dry weight of algae, the control culture continued to showed higher values than the treated culture ($T_1$). An appropriate amount of ionic copper ($T_1:\;26\;{\mu}g/l$) stimulated the grwoth of S. capricornutum than the ionic copper content of $13\;{\mu}g/l$ ($T_2$), while the excess amount of ionic copper ($130\;{\mu}g/l$) resulted in the highest toxicity to the growth of S. capricornutum.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• 제1권2호
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• pp.145-155
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• 1997

The effect of various supplies of lead singly and in combination with aluminium on growth and chlorophyll biosynthesis was investigated in 7-day-old Vigna angularis seedlings. Expose to 50 uM Pb or more drastically reduced root elongation rate. Significant depressions in root growth was observed within 1 day and no recovery of growth was seen over the duration of treatment period. Root elongation decreased depending on the Pb concentrations. Root growth inhibition was stronger than shoot growth inhibition. The initiation of lateral roots appeared to be more sensitive to Pb than the growth of main roots. Inhibition of root and shoot elongation by Pb was lessened by combined exposure of Pb and Al, suggesting that the presence of Al reverse the inhibitory effect of Pb alone. With the histochemical sodium rhodizonate method the rate of Pb uptake was dependent on the Pb concentration and exposure time of the roots to Pb salts. Pb was first deposited on the root surface and then translocated radially in the root cap cells. During a longer Pb administration (up to 72 h) Pb penetration was nonuniform, with accumulation within the cortex or endodermis. There was drastic reduction in chlorophyll content by Pb. The Pb inhibition of chlorophyll synthesis was concentration dependent. $\delta-Aminolevulinic$ acid dehydratase (ALAD) activity exhibited distinct inhibition from control. Reduction in chlorophyll content was accompanied by proportional changes in ALAD activity. Chlorophyll content and ALAD activity were less affected by combined exposure of Pb and Al, suggesting that Al has a protective effect against the inhibiting action of Pb on photosynthetic activity.

• 한국산림과학회지
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• 제94권4호통권161호
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• pp.264-268
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• 2005

참나무류 임분에 자연 발생한 잣나무와 인공 조림된 잣나무 침엽을 80% acetone과 DMSO(Dimethylsulfoxide)로 추출하여 측정한 엽록소 함량을 비교하였다. 80% acetone에 비해 DMSO로 추출한 총 엽록소 함량은 잣나무 침엽의 모든 연령에서 약 4-6배 높은 값을 나타했다. 또한 DMSO로 추출한 경우 상층 임관을 점유한 인공 조림된 잣나무와 하층에 생육하는 잣나무 간에는 총 엽록소 함량에 차이가 없었으며, 80% acetone으로 추출한 경우에도 역시 두 종류의 잣나무 사이에 연령별 총 엽록소 함량의 차이는 없었다. DMSO로 추출할 경우 자연 발생 잣나무와 인공 조림된 잣나무 침엽 모두 6시간의 추출이 적절한 것으로 판단된다.

• 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.

• 한국식품과학회지
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• 제46권2호
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• pp.127-134
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• 2014

참치유 보강 에멀젼에 첨가된 참기름은 클로로필의 존재 하에 $25^{\circ}C$, 1,700 lux의 빛에서 에멀젼 유지의 광산화를 유의하게 감소시켰다. 또한 참기름의 첨가는 에멀젼의 광산화 중 산성 조건에서 클로로필로부터 전환된 페오피틴의 분해속도를 낮추어 일중항산소 생성이 많았을 가능성에도 불구하고 일중항산소와 라디칼 소거능을 가진 인지방질, 토코페롤, 폴리페놀 화합물을 제공함으로써 참치유 보강 에멀젼 유지의 산화안정성을 개선하였으며 인지방질, 토코페롤에 비해 폴리페놀 화합물이 더 큰 영향을 주었다. 리그난 화합물은 에멀젼의 광산화 중 변화를 보이지 않아 물리적 기전에 의한 일중항산소 소거 작용을 암시하였다.

• 한국수산과학회지
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• 제6권1_2호
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• pp.27-36
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• 1973

The effect of water activity on degradation of pigments in dried lavers, Porphyra tenera Kjellm. was examined when stored at room temperature for fifty days. Chlorophyll pigment was extracted with methanol-petroleum ether mixture solvent(2:1 v/v), partitioned in ether, and analysed spectrophotometrically at 662 nm as chlorophyll a. The degradation products of chlorophyll were isolated on sugar-starch column(85:15 w/w) with n-propanol-petroleum ether solution(1:200 v/v) as a developing solvent. The isolated green colored zones were analysed individually at the wavelengths of 650, 662, and 667 nm as allomerized product, chlorophyll a retained, and pheophytin formed respectively. Carotenoida were also extracted with the methanol mixture solvent, partitioned in ether, and finally redissolved in acetone after the evaporation of ether in a rotary vacuum evaporator. The total carotenoid content was measured as lutein at 450 nm. From the results, it is noted that the rate of chlorophyll degradation reached a minimum at 0.11 to 0.33 water activity while progressively increased at higher moisture levels resulting in rapid conversion of chlorophyll to pheophytin. At lower activity, autocatalysed oxidizing reaction like allomerization seemed prevailing the acid catalysed conversion reaction. The loss of carotenoid pigment was also greatly reduced at the range of 0.22 to 0.34 water activity with much faster oxidative degradation at both higher and extremely lower moisture levels. These two moisture levels indicated above at which the both pigments exhibited maximum stability are considerably higher than the BET monolayer moisture which appeared 7.91 percent on dry basis at Aw=0.10 calculated from the adsorption isothermal data of the sample at $20^{\circ}C$. The rate of pigment loss in heat treated samples at 60 and $100^{\circ}C$ for 2 hours prior to storage somewhat decreased, particularly at higher moisture levels although the final pigment retention was not much stabilized.

• 한국수산과학회지
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• 제18권1호
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• pp.63-66
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• 1985

동해와 남해 동부연안에서 1983년 가을 중 식물플랑크톤이 함유한 클로로필-a 양을 세포의 크기 별로 구분하여 조사하였다. 1. 가을철 동해 해수중의 세포의 크기 $300{\mu}m$이하 전체의 식물플랑크톤이 함유한 클로로필-a 양은 $0.202{\sim}1.350mg/m^3$(평균과 표준편차는 $0.597{\pm}0.287\;mg/m^3$)이었다. 표층수중에 포함된 양이 심층수 50m층까지)에서의 양에 비해 약간 많았다. 그리고, 수표면 $1m^2$하 수주의 클로로필-a 양은 St.에 따라 큰 차이 없이 평균 $17.013\;mg/m^2$이었다. 2. 세포의 크기 $60{\mu}m$이하의 미세플랑크톤이 함유한 클로로필-a 양은 $0.100{\sim}0.855\;mg/m^3$(평균 및 표준편차는 $0.372{\pm}0.201\;mg/m^3$)로서 표층수에서의 양이 심층수에 비해 약간 많았다. 이를 미세플랑크톤이 전체 식물플랑크톤 현존량에 차지하는 율은 클로로필-a 양으로 $25.4{\sim}83.3\%$로써 평균 $62.2\%$이었고 이 율 역시 표층수에서 약간 높았다.

• 한국식품과학회지
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• 제28권2호
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• pp.220-225
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• 1996

꽈리고추의 저장중 저장조간에 따fms 중량, 부패율, 비타민 C, chlorophyll, 유리당 및 매운맛 성분 등 품질 변화를 측정하여 꽈리추의 적정 저장조건을 밝히고자 하였다. 중량 감소율은 상온에서 저장한 꽈리고추에서 급격히 증가하나 저온에서 저장한 꽈리고추의 중량 감소는 크게 나타나지 않았다. 부패율은 상온에서 저장 7일부터 크게 증가하였으며, 저온에서는 저장 21일부터 급격히 증가하였다. Capsaicin 및 dihydrocapsaicin 함량은 상온에서 저장시간기 경과합에 따라 급격히 감소하였고, 저온의 경우 저장시간이 경과함에 따라 완만하게 감소하였다. Ascorbic acid 함량은 저장초기에 많이 감소하였고 낮은 온도에서 보다 높은 온도에서 감소폭이 크게 나타났으나 온도에 따른 변화는 거의 없었다. 유리당은 저장기간이 경과함에 따라 점진적으로 감소하였으며, $25^{\circ}C$ 저장 꽈리고추는 $3^{\circ}C$에 비하여 유리당의 감소가 현저하였다. chlorophyll 함량은 저장기간이 경과함에 따라 완만하게 감소하는 경향이었으며, 저장온도에 관계없이 chlorophyll a, b의 비율은 대체로 3 : 1을 나타났다. 꽈리고추의 씨는 저장시간이 경과함에 따라 갈변이 진행되었으나, 과피는 거의 갈변되지 않았다.

• 한국산림과학회지
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• 제98권3호
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• pp.331-338
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• 2009

본 연구에서는 상수리나무 용기묘와 노지묘를 대상으로 시비처리에 따른 광합성 특성, 엽록소 형광반응, 엽록소 함량 및 생장 특성을 조사 분석하였다. 상수리나무 용기묘와 노지묘 모두 시비 처리별 광합성 능력 및 광화학 효율은 1,000배액 시비 처리구에서 가장 높았으며, 엽록소 함량도 1,000배액 시비 처리구에서 가장 많았다. 생장특성에서는 1,000배액 시비 처리구에서 높은 상대생장률과 물질생산량을 보였으며 엽면적도 같은 경향을 보였다. 모든 시비 처리구에서 전반적으로 용기묘가 노지묘보다 우수한 광합성 능력과 광화학 효율, 엽록소 함량 및 생장을 보였다.