• 원예과학기술지
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• 제31권4호
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• pp.393-399
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• 2013

The effect of solution temperature and nitrogen form on cucumber (Cucumis sativus L.) growth, photosynthesis and nitrogen metabolism was investigated in hydroponic culture. Cucumber plants were grown for 35 days in a greenhouse at three constant solution temperatures ($15^{\circ}C$, $20^{\circ}C$, and $25^{\circ}C$) within a natural aerial temperature ($15-30^{\circ}C$). Four nitrate:ammonium ($NO{_3}^-:NH{_4}^+$) ratios (10:0, 8:2, 5:5, and 2:8 $mmol{\cdot}L^{-1}$) at constant nitrogen (N) concentration of $10mmol{\cdot}L^{-1}$ were applied within each solution temperature treatment. Results showed an increasing solution temperature enhanced plant growth (height, dry weight, and leaf area) in most N treatments. Dry weight accumulation was greatest at the 10:0 $NO{_3}^-:NH{_4}^+$ ratio in the $15^{\circ}C$ solution, the 5:5 ratio in the $20^{\circ}C$ solution and the 8:2 ratio in the $25^{\circ}C$ solution. Photosynthetic rate (Pn) response to solution temperature and $NO{_3}^-:NH{_4}^+$ ratio was similar to that of plant growth. Probably, the photosynthate shortage played a role in the reduced biomass formation. Increasing solution temperature enhanced the nitrate reductase (NR) activity, and further reduced shoots nitrate content. Our results indicate that the optimal ratio of nitrate to ammonium that promotes growth in hydroponic cucumber varies with solution temperature.

• 생물환경조절학회지
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• 제15권1호
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• pp.84-90
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• 2006

This study was conducted to anticipate nitrate reduction state in tree through measurement of nitrate reductase activity (NRA) and investigate the effect of nitrogen concentrations (100, 200, 400, and 600 $mg\;L^{-1}$) on growth, the nitrogen content of various tissue, and NRA of pear (Pyrus pyrifolia cv. Niitaka) seedlings in sand culture. Nutrient solutions used in this experiment were adjusted to pH 6.5 and fixed the ratio of ammonium and nitrate to 1:3 and trickle-irrigated 3 times a day. Tree height and dry weight of various organs in seedlings were higher in low nitrogen concentration (100 and 200 $mg\;L^{-1}$) than in high nitrogen concentration (400 and 600 $mg\;L^{-1}$). The shoot growth in 600 $mg\;L^{-1}$ was extremely poor by nitrogen over supply. Increasing the nitrogen concentration, the concentration of nitrate-N in leaves and roots were insignificantly changed but that of stems increased. The accumulation of total and reduced nitrogen in all organs with increasing concentrations of nitrogen supply were increased at 30 days after treatment but those of all organs at 60 and 90 days after treatment were highest in 600 $mg\;L^{-1}$, whereas there were no significant changes among other nitrogen concentration. The in vivo (${+NO_3}^-$) NRA of all organs did not relate to nitrogen concentration but the in vivo (${-NO_3}^-$) NRA of leaves except roots increased with increasing the nitrogen concentration. Therefore, the proper nitrogen concentration to promote growth and nitrate reduction of pear tree was 200 $mg\;L^{-1}$.

• KSBB Journal
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• 제5권2호
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• pp.151-158
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• 1990

부질소 1-B5 배지에서 단독 배양한 담배 배양세표의 nitrate reductase 활성은 1-B5 배지에서 배양한 담배 배양세포에 비해 50% 이상 감소되었으나 $10^{-4}$ sper-mine 처리구에서는 그 활성이 가장 증가되었으며, N.muscorum파 혼합 배양시 그 활성이 현저히 증가한 반면 polyamine은 거의 영향을 미치지 않았다. Glutamate dehydrogenase 는 혼합 배양시 담배 배양세포플 단독 배양하였플 때보다 약 4배 감소 되었으며, glutamate synthas$\xi$의 활성은 $10^{-4}M$ spermlne 처리구에서 혼합 배양 하였을 때 그 활성이 가장 높았다.

• The Korean Journal of Ecology
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• 제9권1호
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• pp.1-7
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• 1986

plastochron index was used as a measure for the nitrate reductase activity (NRA) in Amaranthus retroflexus, Chenopodium album var. centrorubrum and Glycine max. The material plants treated with $NO_3$-N had higher NRA than those treated with ${NH_4}^+$-N. High NRA were found in young tissues which have low PI or LPI in both A. retroflexus and C. album. These results indicated that this enzyme decreased with increasing plastochron index of the extracted tissues. High level of NRA was detected in Glycine max leaves at PI 4.0. On the other hand, there were no significant differences for PI among $NO_3$-treated, ${NH_4}^+$-treated and control in both stems and roots.

• 한국연초학회지
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• 제4권1호
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• pp.1-5
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• 1982

The metabolic enzymes, nitrate reductase, amylase and peroxidase and the Photorespiratory enzyme, Slycolate oxidise in Nicotiana tabacum varieties were studied at various growth stages. The enzyme activities of young leaves with rapid growth were different from those of old ones with stationary growth. In young leaves, activity of nitrate reductase was higher than that in mature ones and amylase activity was fairly constant in all stages. Activities of glycolate oxidise and peroxidase were found to be significantly lower in young leaves than in mature ones. Activity of glycolate oxidase in mature middle leaves was 2.45 times higher than that of young ones and inhibited by 36% when the enzyme was treated with 0.16 mM isonicotinic hydrazide.

• 대한환경공학회지
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• 제28권7호
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• pp.752-756
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• 2006

최근 수계의 총질소(T-N) 규제가 강화되면서 기존 BAF 공정의 개선을 위해 독립적인 무산소조가 추가로 도입되었다. 본 연구에 사용된 공정은 유기물과 질산화 중심으로 개발 된 기술인 $Biobead^{(R)}$공법으로 상용화된 상향류의 BAF공정의 하나이다. 독립적인 무산소조의 도입의 타당성을 검토하기 위해 분자생물학적 방법의 하나인 PCR-DGGE기법이 수행되었다. 두 가지 type의 nitrite reductase genes를 통해 진행되었는데, nirS로 암호화된 cytocrome $cd_1$ nitrite reductase gene과 nirK로 암호화된 Cu를 함유한 nitrite reductase gene이다. 이러한 탈질 기능유전자를 이용하여 PCR-DGGE를 통해 탈질 목적으로 순화된 독립적인 무산소조의 탈질미생물의 군집을 해석하였다. PCR 증폭결과, 탈질을 수행하는 무산소조 내에서는 nirS와 nirK유전자 가운데 nirS유전자만 검출되었고, DGGE 분석결과, 최초 식종원으로 이용된 활성슬러지에서는 상대적으로 많은 band들이 검출되는 반면, 무산소조 내에서는 운전일수와 nitrate 부하량이 증가할수록 단일 band로 우점화 하는 경향을 나타내었다. DGGE band에 대한 염기서열 분석결과, 식종 슬러지의 경우 다양한 uncultured bacteria가 나타났으나, nitrate 제거율이 높은 안정화된 무산소조에서는 alcaligenes faecalis 등 특정 탈질미생물이 우점화 되는 것으로 확인되었다. 결론적으로 이러한 탈질미생물 군집특성을 가지는 무산소조의 도입은 96%이상의 안정적인 탈질을 가능하게 하였으며, BAF 공정 개선을 위한 독립적인 무산소조의 도입은 적절한 것으로 판단되었다.

• BMB Reports
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• 제45권6호
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• pp.342-347
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• 2012

Plant mitochondria possess alternative respiratory pathways mediated by the type II NAD(P)H dehydrogenases and alternative oxidases. Here, E3 SUMO ligase was shown to regulate alternative respiratory pathways and to participate in the maintenance of carbon and nitrogen balance in Arabidopsis. The transcript abundance of the type II NAD(P)H dehydrogenases NDA2 and NDB2 and alternative oxidases AOX1a and AOX1d genes was low in siz1-2 mutants compared to that in wild-type. The addition of nitrate or ammonium resulted in a decrease or an increase in the expression of the same gene families, respectively, in both wild-type and siz1-2 mutants. The amount of free sugar (glucose, fructose and sucrose) was lower in siz1-2 mutants than that in wild-type. These results indicate that low nitrate reductase activity due to the AtSIZ1 mutation is correlated with an overall decrease in alternative respiration and with a low carbohydrate content to maintain the carbon to nitrogen ratio in siz1-2 mutants.

• Journal of Plant Biology
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• 제34권4호
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• pp.253-260
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• 1991

Spirodela polyrhiza and Lemna aequinoctialis often occurred at the sites of high ammonium concentration and at the sites of high nitrate concentration, respectively. We investigated the different distribution between two species in relation to the type of nitrogen sources and their concentrations. Our experiments showed that L. aequinoctialis grew faster than S. polyrhiza in nitrate media with lower than 15 mM concentration. The nitrate uptake was also faster in L. aequinoctialis than in S. polyrhiza. However, neither differences in growth nor in uptake patterns between these two species were observed in ammonium media. Glutamine synthetase (GS), glutamate dehydrogenase (GDH) and glutamate synthetase (GOGAT) activities were higher in L. aequinoctialis. In particular, nitrate reductase activity (NRA) in L. aequinoctialis was 12.1 times as high as that in S. polyrhiza. These results showed that the two species responded varyingly to the types of nitrogen sources and their concentrations. Therefore, the difference in geographic distribution between the two species appeared to reflect the interspecific differences in enzyme activities and, subsequently, nitrogen absorption abilities.

• 생명과학회지
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• 제32권8호
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• pp.659-665
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• 2022

Chlorella vulgaris는 인간과 동물에서 주요한 식품의 원료로 이용되는 수 조류이다. 최근 클로렐라는 어류 양식, 생물연료 및 영양물질과 치료용 단백질의 생산을 위한 이용 가능성과 관련하여 많은 관심을 받고 있다. 최근 본 연구실에서는 빠른 성장, 배양의 용이성, 암 조건에서의 배양성을 특징으로 하는 새로운 C. vulgaris PKVL7422균주를 분리하였으나, 이 균주의 질소 이용에 관련된 유전자에 대하여는 보고된 바가 없다. 본 연구에서는 cDNA 말단의 신속 증폭과 genome walking을 이용하여 C. vulgaris PKVL7422의 질산환원 효소(nitrate reductase, NR)를 동정하였다. C. vulgaris PKVL7422 NR 유전자는 약 8 kb이며, 18개의 인트론과 877개의 아미노산을 암호화 하는 19개의 엑손으로 되어 있다. 기존의 알려진 NR 단백질과의 비교 분석 결과 C. vulgaris PKVL7422 NR 단백질은 식물의 NR에 존재하는 5개의 도메인과 다수의 비변이성 아미노산 잔기를 가지고 있는 것으로 확인되었으며, 이러한 결과는 조류 NR 유전자의 분자생물학적 구조에 대한 새로운 정보를 제공한다.

• 한국토양비료학회지
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• 제20권1호
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• pp.43-53
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• 1987

전보(前報)에 이어 토양별(土壤別) 토착대두근류균(土着大豆根瘤菌)의 분포(分布), 질소고정효율(窒素固定效率) 및 Nitrate reductase 특성(特性)을 비롯하여 동일(同一)한 토양조건(土壤條件)에서 토착대두근류균(土着大豆根瘤菌)과 대두품종별(大豆品種別) 친화성(親和性)을 조사(調査)한 결과(結果)는 다음과 같다. 1. 토착근류균(土着根瘤菌) 중 대두근류(大豆根瘤)를 형성(形成)할 수 있는 토착대두근류균(土着大豆根瘤菌)은 $0.9{\sim}42.4{\times}10^3\;cells/g$ soil 범위(範圍)로서 토양간(土壤間)에 상이(相異)하였고 특(特)히 석회암토양(石灰岩土壤)에서 균밀도(菌密度)가 높았다. 2. 토양별(土壤別) 질소고정효율(窒素固定效率)은 대두연속재배지(大豆連續栽培地) 및 석회암토양(石灰岩土壤)에서 높았으며, 토착근류균수(土着根瘤菌數)가 많았던 토양(土壤)에서 질소고정효율(窒素固定效率)도 많은 경향(傾向)이있다. 3. 대두근류(大豆根瘤)의 bacteroid에서 질소고정효소(窒素固定酵素)와 질산환원효소(窒酸還元酵素)와의 상호관계(相互關係)에서 TNA와 NRA간(間)에는 유의(有意)한 부(負)의 상관관계(相關關係)($r=-0.52^*$)를 보였으나 SNA와 NRA과는 대두근류(大豆根瘤)의 분리원간(分離源間)에 2개군(個群)으로 구분(區分)되었다. 4. 동일(同一)한 토양조건(土壤條件)에서 토착대두근류균(土着大豆根瘤菌)과 대두품종간(大豆品種間) 친화성(親和性)은 품종간(品種間)에 상이(相異)하였으며 질소고정효율(窒素固定效率)이 높았던 품종(品種)은 장엽(長葉) 및 광교(光敎)로 나타났다.