• 한국초지조사료학회지
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• 제17권3호
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• pp.249-256
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• 1997

A pulse-chase labeling of $^{15}N$ on winter rye (Scale cereale) and forage rape (Brassica napus) grown at $15^{\circ}C$ and $25^{\circ}C$ was carried out to determine the effects of low temperature on the uptake exogenous N and the remobilization of endogenous N. The growth rate of leaves and roots depressed at $5^{\circ}C$. AAer 9 days at $5^{\circ}C$, nitrogen content of leaves decreased to 20% on the average while that of roots increased to 12% compared with the plants grown at $25^{\circ}C$. Total content of $NO_3$- uptake 60m medium was 23.0 and 43.5 mg Nlplant, respectively, for winter rye and forage rape grown at $5^{\circ}C$ during 9 days. These values were corresponded to 59.3 and 26.1% lower uptake than those of $25^{\circ}C$. A large part of 1 5 ~ was distributed into leaves throughout time course in both of two species. The content of $^{15}N$ in leaves of winter rye at day 6 increased to 166 and 296 $\mu^{15}$N/plant compared with the initial value (day 0) in the plants grown at $5^{\circ}C$and $25^{\circ}C$ , corresponding to 90 and 163 $\mu$g N of remobilization h m roots into leaves during the fist 6 days. From 7 to 9 days, 75 and 52 $\mu$gN of outflow 6om leaves were occurred at $5^{\circ}C$ and $25^{\circ}C$. However, little remobilization of endogenous N was estimated in forage rape throughout the entire time course regardless of temperature treatment. Comparing two species studied, winter rye was much sensitively influenced by low temperature on the uptake of exogenous N and the remobilization of endogenous N.

• 한국육종학회지
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• 제43권5호
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• pp.349-359
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• 2011

Agriculture plays a vital role in the sustenance of human society and is the fundamental of developing economies. Nitrogen is one of the most critical inputs that define crop productivity. To ensure better value for investment as well as to minimize the adverse impacts of the accumulative nitrogen species in environment, improving nitrogen use efficiency of crop plants is of key importance. Efforts have been made to study the genetic and molecular biological basis as well as the biochemical mechanisms involved in nitrogen uptake, assimilation, translocation and remobilization in crops and model plants. This review gives an overview of metabolic, enzymatic, genetic and biotechnological aspects of nitrogen uptake, assimilation, remobilization and regulation. This review presents the complexity of nitrogen use efficiency and the need for an integrated approach combining physiology, quantitative trait genetics, system biology, soil science, ecophysiology and biotechnological interventions to improve nitrogen use efficiency.

• Journal of Plant Biology
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• 제36권4호
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• pp.363-370
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• 1993

예취 후 재생시 저장질소의 재이동과 재생기관으로서의 전이를 양적 평가하고 xylem을 통한 환원유기질소의 이동형태를 규명하기 위해 알팔파(Medicago sativa L. cv. Europe)를 수경재배하였다. 근류균을 형성하지 않은 알팔파에 예취 전 $^{15}N$ labeling을 실시하여 재생기간 중 각 기관내 분포된 $^{15}N$ dmlexcess를 분석하고 xylem sap을 채취하여 아미노산의 조성 및 함량을 분석하였다. 예취 후 잔여기관내의 $^{15}N$ 함량은 재생이 진행됨에 따라 유의적으로 감소하였고, 감소된 $^{15}N$은 질소의 전이에 의해 새로 재생되는 잎과 줄기에서 발견되었다. 저장기관으로부터 전이된 $^{15}N$의 약 2/3가 잎으로, 나머지가 줄기로 분포되어 잎이 줄기보다 저장질소에 대한 수용력(sink strength)이 높았다. 예취 후 재생초기 10일 동안 잎과 줄기의 재생에 이용된 무기질 질소의 함량은 낮은 반면, 이 기간동안 총 저장질소의 약 72%가 잎과 줄기로 전이되었다. 재생이 진행됨에 따라 무기질 질소의 이용율은 점차 증가하였다. 재생초기 10일 동안 뿌리조직(주근과 지근)의 아미노산태 및 단백질태 질소함량은 유의적으로 감소하였다. 주근과 지근에서 공히 단백질태 질소함량이 아미노산태 질소함량 보다 높았으나, 재생 10일 동안 전이된 비율은 아미노산태가 월등히 높았다. 이는 저장질소는 아미노산태로 우선적으로 이동하여 재생에 이용된다는 것을 보여준다. Asparagine이 xylem sap내 총 아미노산의 75%로서 환원태 유기질소의 주요 이동형태였다. 재생 10일 동안 asparagine의 상대적 함량은 59%까지 감소하였는데, 이러한 감소는 asparatate의 glutamine의 상대적 함량의 보충적 증가를 동반하였다.

• Geosciences Journal
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• 제22권6호
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• pp.921-938
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• 2018

The Motzfeldt intrusions in the Gardar Province, southern Greenland, split into syenitic plutonic and hypabyssal rocks, in which the latter include ring dykes and sheet intrusions. Sheet intrusions, considered as the source for rare earth elements (REE) and high field strength elements (HFSE), comprise sheets of peralkaline microsyenite (SPM), syenitic pegmatite (SP), and peralkaline microsyenite (PM). SP exhibits extremely high concentrations of REE and HFSE, which are positively correlated with increasing alkalinity from early towards late intrusion, caused by magmatic processes. In contrast, some of the SPM and PM are also significantly enriched in REE and HFSE, caused by post-magmatic fluids. The REE- and HFSE-rich phases in SP consist mainly of zircon and allanite with smaller amounts of pyrochlore in pseudomorph from the inferred eudialyte, whereas some of the PM and SPM consist of pyrochlore, REE-carbonate, and zircon in the matrix. The zircon grains in the Motzfeldt Sø Formation (MSF) syenite occur in interstitial spaces, exhibiting an association with magnetite and a bipyramidal form in texture. They are characterized by a highly fractured and embayed rim. Zircons from PM and SP are clearly enriched in Fe, Al, Ca, Na, Y, P, Hf, Y, P, Nb, Ta, and REE, and are depleted in Zr and Si in comparison with magmatic zircon. They also show a clear trend of higher LREE/HREE and $Eu/Eu^{\star}$ ratios, and lower $Ce/Ce^{\star}$ ratios, which define them as typical hydrothermal zircons. In contrast, zircons from the MSF syenite show a relatively lower LREE/HREE ratio and Eu and Ce anomalies of a similar magnitude compared with those from SP and PM. The occurrence and mineral composition of the zircon suggest that post-magmatic fluids have played an important role in the remobilization of REE and HFSE as well as the primary concentration of REE and HFSE, caused by magmatic processes.

• 한국초지조사료학회지
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• 제39권2호
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• pp.75-80
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• 2019

Oilseed rape is known to crop having low nitrogen use efficiency (NUE) but requires high levels of N fertilizer. NUE is associated with N remobilization from source to sink organ, consequently affects seed yield. Remobilization of leaf N is also related to transport of C/N metabolites in phloem. However, interaction between seed yield and phloem transport was not fully documented. In response to seed yield, N and C metabolites and their transport into seed from bolting to pod filling stage investigated in two contrasting genotypes (Capitol and Pollen) cultivated under ample (HN) or limiting nitrate (LN) supply. Seed yield was significantly reduced in N limitation and its reduction rate was much lower in Capitol than in Pollen compared to HN treated plants. Amino acid and protein content was higher in Capitol than in Pollen at bolting stage. They gradually decreased during plant development but not significant between two cultivars and/or two treatments. Glucose, fructose and sucrose content were 1.8-,1.6- or 1.25-fold higher in LN condition than in HN condition, respectively. Amino acid and sucrose content in phloem were largely higher in Capitol than in Pollen under LN condition. These results indicate that the higher seed yield might be related to greater transport ability of amino acid and sucrose in phloem under LN condition.

• Journal of Plant Biology
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• 제37권3호
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• pp.357-363
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• 1994

An expreiment with non-nodulating alfalfa (Medicago sativa L.) plants was designed to investigate the changes in protein contents and the activities of proteolytic enzymes during a regrowth period of 24 d. Shoot removal caused a depression of root growth and significantly reduced protein contents in roots. An initial decline of root proteins for the first 10 d was followed by a rapid recovery from d 11 to 24. The major increase of regrowing shoot weight occurred also from d 11. The activities of aminopeptidase and endoprotease slightly decreased in regrowing leaves, while protein contents remains stable after shoot removal. Roots exhibited source behaviour with a rapid increase of endoprotease activities for the first 10 d of regrowth; about a 370% increase over the initial level was observed. Increase in endoprotease activity in roots coincided with the time of protein remobilization after shoot removal, indicating the important role of endoproteases in protein degradation.

• Animal cells and systems
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• 제9권3호
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• pp.127-133
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• 2005

We investigated expression of cucumber senescence-associated genes (SAGs) from developing cotyledons and flower petals. Several cucumber SAGs have been reported in earlier reports. This is an extension of the previous findings. Semi-quantitative RT-PCR revealed that most of the cucumber SAG transcripts were consistently produced until the organ senescence. These results imply that many cucumber senescence-related genes are still active during the final development stage, playing some executive biological roles, possibly in remobilization of nutrients to the other parts of tissues or organs. These results were used to search for possible functions of senescence-related genes during organ development.

• Journal of Industrial and Engineering Chemistry
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• 제68권
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• pp.355-363
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• 2018

There are serious issues with the application of surfactant flooding as a third recovery method, such as surfactant slug losses. In this study,the impact of the salinity gradient on the remobilization of oiltrapped in Berea sandstone was investigated by emphasizing the surfactant adsorption gradient and phase behavior to determine the optimal salinity of the chosen surfactant concentration for investigating the salinity gradient. Three salinity-gradient schemes were applied to six cores saturated with light and heavy oils. The positive salinity gradient provided the best recovery results with an in situ microemulsion formation that could be observed in the fluid collector.

• 자원환경지질
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• 제35권1호
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• pp.75-95
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• 2002

안동심성암체는 3개 암상으로 구분되는 동원성 마그마로부터 유래되었다. 이 암체는 전체적으로 중앙부에 각섬석 흑운모 토날라이트가 노출되고 이의 연변부에 흑운모 화강섬록암이 놓이며, 상단부(복동부)에 반상 흑운모 화강암이 놓인다. 결과적으로 이들은 토날라이트를 중심으로 하는 동심원상 분포를 하며, 중앙부에 고온 광물군의 고철질 암석이 우세하고 연변부와 상단부로 갓수록 보다 저온 광물군의 규장질 암석이 우세한 역누대를 나타낸다. 이 암체의 모드 및 화학 자료는 중앙부에서 연변부, 상단부 순으로 역누대 조성변화를 보여준다. 이 조성변화는 인접하는 암상간에서 매우 점이적으로 변화한다. 각섬석과 흑운모 등의 고철질 광물은 중앙부의 토날라이트에서 가장 풍부하고 연변부로 갈면서 감소하고 상단부로 갈수록 더욱 감소한다. 석영과 K-장석 등의 규장질 광물은 이와 반대로 변화한다. 화학적으로도 고철질 광물을 지배하는 원소들은 중앙부에서 최고치이고 이로부터 연변부와 상단부로 갈수록 점차 감소되는 양상을 보이며, 반면에 규장질 광물을 주로 지배하는 원소들은 이와 반대 양상을 나타낸다. 이 역누대 심성암체는 열중력확산작용과 분별결정작용에 의해 수정된 마그마챔버의 상부 규장질 부분 속으로 하부의 더 고철질 부분이 재이동(소생)된 결과이다. 진화의 초기 단계에 , 이 마그마챔비는 하부에 토날라이트질, 중부에 화강섬록암질, 상부에 화강암질 마그마를 갖는 화학적 조성누대를 이룬 암석화학계이었다. 후기 단계에 챔버 기저에서 더 고철질 마그마의 유입에 의해 하부의 토날라이트질 조성대가 상부의 규장질 조성대 속으로 재이동을 야기시켰다.

• 자원환경지질
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• 제19권spc호
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• pp.163-173
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• 1986

Black and graphite slates from the Okcheon metamorphic belt contain enriched values of uranium (average 200~250ppm) and molybdenum (average 150~200ppm). Uranium mineralization is closely associated with quartz and sulfide veinlets which are formed diagenetically in graphite slate. The uranium minerals were concentrated in outer part of graphite nodules. The ${\delta}^{13}C$ values of organic carbon from the metasediments including uranium bearing graphite slate range from -15.2 to -26.1‰ with a mean of -23.5‰. Meanwhile, ${\delta}^{13}C$ values of coal and coaly shale from some Paleozoic coal fields of South Korea vary from -19.4 to -23.9‰ with an average of -22.5‰. Isotopic compositions of vein calcite in uranium bearing slate range from -13.4 to -15.4‰ in ${\delta}^{13}C$ and +11.3 to +15.1‰ in ${\delta}^{18}O$ could indicate a reduced organic carbon source isotopically exchanged with a graphite of biogenic origin. Metamorphic temperature determined by a calcite-graphite isotope geothermometer was 383~$433^{\circ}C$ which corresponded to greenschist facies by Miyashiro (1973) and is consistent with metamorphic facies estimated by mineral assemblages (Lee, et al., 1981, and Kim, 1971). The fixation of uranyl species by carbonaceous matter in marine epicontinental environment, and remobilization of organouranium by diagenetic processes have attributed to the enrichment of uranium and heavy metals in the graphite slate of Okcheon metamorphic belt.