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        검색결과 228

        161.
        2001.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We have studied the nonlinear evolution of a magnetized disk of isothermal gas, which is sustained by its self-gravity. Our objective is to investigate how the Jeans, Parker, and convective instabilities compete with each other in structuring/de-structuring large scale condensations in such disk. The Poisson equation for the self-gravity has been solved with a fourth-order accurate Fourier method along with the Green function, and the MHD part has been handled by an isothermal TVD code. When large wavelength perturbations are applied, the combined action of the Jeans and Parker instabilities suppresses the development of the convection and forms a dense core of prolate shape in the mid-plane. Peripheral structures around it are filamentary. The low density filaments connect the dense core to the diffuse upper region. On the other hand, when small wavelength perturbations are applied, the disk develops into an equilibrium state which is reminiscent of the Mouschovias's 2-D non-linear equilibrium of the classical Parker instability under an externally given gravity.
        3,000원
        163.
        2018.03 KCI 등재 서비스 종료(열람 제한)
        The objective of this study was to determine the mitotic intervals (τ0) of two consecutive cell divisions and synchronous embryonic cleavage in grass puffer, Takifugu niphobles at different water temperatures (18, 20, 22, and 24℃). The color of the fertilized egg was light yellowish. The egg type was demersal and unadhesive. Egg weight was 0.09±0.002 mg. The sizes of unfertilized eggs were smaller than fertilized eggs in major axis and minor axis at 20℃ (p<0.05). The size of the fertilized egg of 18℃ water temperature group at the blastodisc stage was the smallest (p<0.05), but no significant differences were observed in the other water temperatures group except 18℃ water temperature group (p>0.05). The first cleavage stages at 18, 20, 22, and 24℃ were at 75, 90, 105, and 120 mins, respectively. As water temperature was increased, embryonic development and formation time of the first cleavage furrow were accelerated. There were negative correlation between τ0 and water temperature for grass puffer (Y=–1.225X+70.05, R2=0.988, n=10, where Y was τ0 and X was temperature). This study confirmed that successful hatching of grass puffer was related to water temperature. Chromosome manipulation will be helpful for this species using cleavage frequency and τ0.
        164.
        2017.11 KCI 등재 서비스 종료(열람 제한)
        방사선치료에 사용하는 CT 스캐너에 의해 획득된 CT 및 CBCT 전자밀도팬텀의 CT영상부터 CT수 대 물 리적 밀도 변환에 관한 CT 스캐닝 매개변수의 의존성은 실험으로 분석하였다. CT수는 관전류량, 슬라이스 두께, 영상재구성 필터, 시야 그리고 팬텀 용적의 크기에 대해 의존하지 않았다. 그러나 CT수는 관전압과 팬텀 횡단면적 크기에 의존하였다. 결과로서, 물리적 밀도 1이상의 범위에 대하여, 90과 120 kVp 사이의 관 전압에서 관측된 최대 CT수 차이는 27%이었고, 그리고 CT 몸통과 머리 전자밀도팬텀 사이에서 관측된 최대 CT수 차이는 15%이었다.
        165.
        2017.05 서비스 종료(열람 제한)
        Background : Methicillin-Resistant Staphylococcus aureus (MRSA) is a multidrug-resistant (MDR) strain. Especially, MRSA is developing resistance to available antibacterial agents and causing complications in the treatment of infections related to skin, soft tissue, respiratory, bone, joint, and endovascular disorders. Therefore, antibacterial agent combination therapy appears to be a useful option, particularly in developing countries where antibiotic availability is limited. (+)-Usnic acid (UA) is uniquely found in lichens, and is especially abundant in genera such as Usnea and Cladonia. UA has antimicrobial activity against human and plant pathogens. Therefore, UA may be a good antibacterial drug candidate for clinical development. Methods and Results : In search of a natural products capable of inhibiting this multidrug-resistant bacteria, we have investigated the antimicrobial activity of UA against MRSA. In this study, the effects of a combination of UA and permeable agents against MRSA were investigated. For the measurement of cell wall permeability, UA with concentration of Ethylenediaminetetraacetic acid (EDTA) was used. In the other hand, Sodium azide (NaN3) was used as inhibitors of ATPase. These results suggest that the antibacterial effect of UA was potentiated by membrane-binding agents and ABC transporter-inhibiting agents, implying that antibacterial activity is associated with damage of the cell wall and inhibition of ATPase function by UA. Conclusion : UA and in combination with EDTA and NaN3 could lead to the development of new combination antibiotics against MRSA infection. The results of this study appear to be promising, and they are expected to enhance the use of natural products as drugs.
        166.
        2016.12 KCI 등재 서비스 종료(열람 제한)
        This study was conducted to investigate the antibacterial, antioxidant, and in vitro greenhouse gas mitigation activities of fermented Scutellaria baicalensis Georgi extract. Seven starter cultures were used, comprising four of lactic acid bacteria and three of Saccharomyces cerevisiae. Ten grams of S. baicalensis Georgi powder was diluted in 90 mL autoclaved MRS broth. Each seed culture was inoculated with 3-10% (v/v) S. baicalensis Georgi MRS broth and incubated at 30℃ for 48 h. Among the starter cultures used, only Lactobacillus plantarum EJ43 could withstand the fermentation conditions. This fermentation broth was dried and extracted with ethanol to assess its antibacterial, antioxidant, and in vitro methane mitigation activities. The extract of S. baicalensis Georgi fermented by L. plantarum EJ43 (SBLp) showed higher antibacterial activity (bigger clear zone) compared to the unfermented S. baicalensis Georgi extract (SB0). SBLp also presented 1.2 folds higher antioxidant activity than SB0. During in vitro rumen fermentation, SBLp showed reduction in methane production compared to SB0 or the control. In conclusion, fermentation by L. plantarum EJ43 may enhance antibacterial and antioxidant activities of S. baicalensis Georgi and decrease enteric methane production.
        167.
        2016.12 KCI 등재 서비스 종료(열람 제한)
        The aim of this paper is to investigate the syntactic structure of the so-called transparent relative clause. What in the standard free relative clause has been treated as a unit including a head NP and a relative pronoun together. In the case of transparent free relatives, however, a what-clause reveals some peculiar characteristics different from standard relative clauses. To explain those characteristics, many linguists have suggested several different analyses. The analyses can be categorized into three groups: Backward Deletion, Shared Structure analysis, (Rightward) Movement and Deletion analysis. Because of their drawbacks, I have suggested Leftward Movement and Deletion analysis, and adopted Winkler's(2005) D(rivational)-Model of Grammar to explain the interactions between the PF deletion and LF interpretation.
        168.
        2016.12 서비스 종료(열람 제한)
        The study aimed to evaluate the usability of sterile bag collection (SBC) urinalysis and urine culture for diagnosing urinary tract infections (UTI). Urine culture is key for diagnosing UTI, and transurethral catheterization (TUC) or suprapubic aspiration is recommended for non-toilet-trained children. Although urine testing using SBC is non-invasive and easy, UTI can be diagnosed only if other criteria including clinical symptoms and positive urinalysis results are met. This study included 228 infants who were hospitalized for unexplained fever from October 2015 to June 2016. TUC culture, SBC urinalysis, and urine culture were performed for all patients. UTI was diagnosed when the TUC culture results met the criterion of ≥104 colony-forming units (CFU)/mL. When UTI diagnosis was made based on SBC urine colony counts ≥105 CFU/mL, the false-positive and false-negative rates were 6.3% and 70.0%, respectively. When the criterion was set as ≥104 CFU/mL, they were 23.7% and 30.0%, respectively. When both the criteria of ≥105 CFU/mL and positive urinalysis results were met, the false-positive rate was 2.4%, and the false-negative rate was 80%. Our results suggest that diagnosing UTI using SBC urinalysis and urine culture is not useful in infants with unexplained fever.
        169.
        2016.10 서비스 종료(열람 제한)
        Background : Despite the presence of various bioactive compounds in ginseng, there is lack of study on the variations of bioactive compounds in ginseng according to the cultivation of soil and the applied fertilizer types (or amount). Therefore, this study aims to examine the variations of 37 fatty acids (FA) and 8 vitamin E (Vit-E) vitamers in 6-year-old ginseng root cultivated in different soil types with different fertilizers regimes. Methods and Results : The profiling of 37 FAs and 8 Vit-E vitamers in 6-year-old ginseng roots was measured by gas chromatography coupled with a flame ionization detector, and then these results were statistically analyzed with chemometrics. The FA and Vit-E content in ginseng roots varied significantly with respect to soil cultivation conditions due to organic fertilizer types and amounts used. Unsaturated FA in ginseng is approximately 2.7 fold higher than the saturated FA. Linoleic, palmitic, and oleic acids were the most abundant FAs found in the ginseng roots. Also, the major Vit-E vitamer found in ginseng root is α -tocopherol. In particular, the application of rice straw compost or food waste fertilizer was increased to create nutritionally-desirable FAs and bioactive Vit-E in ginseng root. In addition, phytonutrient profiling coupled with chemometrics can be used to discriminate the cultivation conditions of ginseng. Conclusion : This preliminary study extends our understanding about the variations of FA and Vit-E in ginseng root depending on cultivation conditions. Hence, these results can be useful as basic information for reliable ginseng production containing high amounts of phytonutrients in a paddy-converted field.
        170.
        2016.10 서비스 종료(열람 제한)
        Background : Recently, ginseng (Panax ginseng C.A. Meyer.) berry has been used as a health-promoting supplements. Also, Mulberries (Morus alba L.) fruit have been used in traditional herbal medicine to treat and prevent diabetes. In this study, we measured the cytotoxicity after fermentation of the extracts in Panax Ginseng Berry and Mulberry Fruit. Methods and Results : The extracts were prepared by decoction for 3 hours in distilled water (100 g/L). The dried extract was then dissolved in phosphate-buffered saline (PBS) in preparation for use. Cell viability was examined by an MTT assay. RAW 264.7 cells were seeded at 1 × 104/mL densities in 96-well plates. Each grouping had a non-treated group as the control. The extracts were added to each well and incubated for 24 hours at 37°C and 5% CO2. The MTT solutions (5 mg/mL) were added to each well, and the cells were cultured for another 2 hours. The supernatant was then discarded, and 100 μL of dimethyl sulfoxide was added to each well. The optical density was read at 540 nm. Conclusion : Probiotics and prebiotics modulate the composition of human and domestic animal gut microbiota. The beneficial effects may result from suppression of harmful microorganisms or stimulation of organisms which contribute in a positive way to the nutrition and health of human and domestic animal. Recently, fermentation using microorganisms for the production of more effective compounds has been extensively studied. In particular, the novel pharmacological effects of a new compound generated by fermentation have been reported. Some previous studies have demonstrated that Fermented herbal medicine extract showed better bioactivity than normal herbal Plants extract when used at the same concentration.
        171.
        2016.10 서비스 종료(열람 제한)
        Background : Some of invasive plants, which were introduced from foreign countries, have caused problems in Korea. Invasion of these invasive plants in the ecosystem threatens the habitat of endemic species, reducing biodiversity, and causing a disturbance in the ecological system. Hypochaeris radicata L. (Asteraceae), the most invasive plants in Korea, particularly in Jeju Island, invade farmland, and autochthonous forest, establishing monocultures and modifying the ecosystem structure. This invasive species has become a serious environmental problem because they displace the indigenous plant species. This study was conducted to evaluate the antioxidantive effects of ethanolic extracts from different parts (root, stem, seed and leaf) of the invasive exotic species Hypochaeris radicata L. Methods and Results : The aim of present study was to estimate the total phenolic and flavonoid contents and to investigate in vitro antioxidant potential of ethanolic leaf, root, seed, and stem extracts of the Hypochaeris radicata. Antioxidant activity was assessed by using 2,2-diphenyl-1-picryl-hydrazyl (DPPH) assay, reducing power activity, [2,2-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid)] ABTS+ assay and ferrous ion chelating activity. The total phenolic and flavonoid contents were also determined and expressed in gallic acid and quercetin equivalent respectively. The results of the study indicate that the ethanolic extracts of the leaf, root, seed, and stem of H. radicata posses significant scavenging activity against DPPH (21.25% for leaf, 34.98% for root, 60.76% for seed and 45.25% for stem at 250 μg/ml each) and ABTS+ radical scavenging activity (14.85% for leaf, 17.40% for root, 35.91% for seed and 24.70% for stem at 250 μg/ml each), reducing power activity (0.178 absorbance at 300 μg/ml for leaf, 0.211 absorbance at 300 μg/ml for root, 0.447 absorbance at 300 μg/ml for seed, 0.276 absorbance at 300 μg/ml for stem). The free radical scavenging and antioxidant activities may be attributed to the presence of adequate phenolic (gallic acid content is 361.92.98 μg/g in leaf, 356.59μg/g in root, 719.72 μg/g in seed and 512.08 μg/g stem) and flavonoid compounds (219.52 μg/g in leaf, 75.67μg/g in root, 281.39 μg/g in seed and 215.66 μg/g stem). This study revealed that the ethanolic extracts of both leaf, root, seed and stem of H. radicata has demonstrated significant antioxidant activity. Conclusion : In conclusion, the present study has demonstrated that Hypochaeris radicata seed ethanol extracts are rich in phenolics and have a strong antioxidant activity and a radical-scavenging action in all of the tested methods. This suggests that Hypochaeris radicata is a good source of natural antioxidants.
        172.
        2016.10 서비스 종료(열람 제한)
        Background : More than 1250 bamboo species, belonging to 75 genera, are distributed all over the world. Sasa quelpaertensis Nakai is a type of bamboo grass widely distributed in Halla mountain, Jeju Island, which has been used as antidiabetic, anti-cancer and anti-inflammatory drugs. In this study, we investigated the antioxidant and antimicrobial activities of Sasa quelpaertensis Nakai leaf extracted with different ethanol concentration and demonstrated the potent bioactivities of the extracts suitable to be used as natural antioxidant compounds or pharmaceutical supplements. Methods and Results : Antioxidant and anti-microbial activities of Sasa quelpaertensis Nakai extracts were studied. At first, different ethanol concentrations (0, 20, 40, 60 and 80%) were compared for determining of the best solvent for extraction of phenolic compounds from Sasa quelpaertensis Nakai. Forty percent Ethanol extract with 990.01±28.9 (mg of gallic acid equivalents/g sample) were the best solvent in the extraction of phenolic compounds. But, 60% ethanolic extracts were highest antioxidant activity appeared such as DPPH radical scavenging (IC50 21.20±0.42 μg/ml), ABTS radical scavenging (IC50 49.85±1.27 μg/ml) and reducing power. However, 80% ethanol extracts showed the strongest SOD like activity. The anti-microbial capacity was screened against Gram positive and Gram negative bacteria, and yeast. Sixty percent and 80% ethanol extracts inhibited the growth of Gram positive bacteria; Bacillus cereus was the most susceptible one with MIC of 125 μ g/ml and 250 μg/ml for the 60% and 80% extracts, respectively. Conclusion : The results of this study show that the extract of Sasa quelpaertensis Nakai can be used as easily accessible source of natural antioxidants and as a possible food supplement or in pharmaceutical industry. However, the components responsible for the antioxidant and antimicrobial activities of both extracts of Sasa quelpaertensis Nakai are currently unclear. Therefore, it is suggested that further works should be performed on the isolation and identification of the antioxidant components in Sasa quelpaertensis Nakai.
        173.
        2016.05 서비스 종료(열람 제한)
        Backgrounds : Pomelo (Citrus grandis Osbeck) is the kind of citrus fruit which is Dicotyledoneae belongs to Rutaceae and special product in Jeju island. According to the previous researches, coumarin, eliocitrin, naringin are identified and these kinds of constituents revealed to be effective as anticancer, antioxidant, and antidiabetic. Until recently, there are many investigations about its functional properties were reported, but investigation about biological activities depend on extraction conditions are not sufficient. Methods and Results : 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity was performed by the method of Blois with minor modification. After adding DPPH radical to each sample solutions, the mixtures were incubated in 30 minutes at aphotic place. Then, the degree of scavenging activity was recorded by microplate reader at 490 nm. The scavenging activity was expressed by RC50, which is the concentration of sample solution necessitated to scavenge 50% DPPH radical against negative control. For α-glucosidase inhibitory activity, the method using p-nitrophenyl-α-D-glucopyranoside (pNPG) was applied. To each samples, α-glucosidase and pNPG were mixed and incubated, consequently, Na2CO3 was added to terminate the reaction. Finally, absorbance was read at 450 nm. The same as DPPH radical scavenging activity, the inhibition was explicitly expressed by the amount of sample solution to inhibit 50% α-glucosidase, IC50. The 80% MeOH extract demonstrated the highest radical scavenging activity with 74.32±8.45 μg/ml. α-Glucosidase inhibitory activity was carried out to evaluate the inhibitory activity of sugar digestion and absorption and 60, 80% MeOH extract exhibited 416.35±11.07 μg/ml and 336.57±2.03 μg/ml, respectively. Conclusion : The DPPH radical scavenging and α-glucosidase inhibitory activity were evaluated in this study. The highest DPPH radical scavenging activity was seen in 80% Citrus grandis Osbeck MeOH extract, following 60% MeOH extract exhibited the second highest scavenging activity. Also, 80% MeOH extract showed 336.57±2.03 μg/ml, which was the highest α-glucosidase inhibition among all extracts.
        174.
        2016.05 서비스 종료(열람 제한)
        Background : This study aimed to investigate the antioxidant and anti-inflammatory activities of water chestnut (Trapa japonica Flerow) extract. Methods and Results : The antioxidant and anti-inflammatory activities of 100% methanol extract of water chestnut were investigated. The methanol extract was evaluated for its total phenolic and flavonoid content, DPPH•(1,1-diphenyl-2-picrylhydrazyl) free-radical scavenging activity,reducing power, andeffect on nitric oxide (NO) production and cell viability using real-time polymerase chain reaction (qPCR). The total phenolic content was 438.31 ㎍ allic acid equivalent (GAE)/㎎ extract and the total flavonoid content was 61.40 ㎍ quercetin equivalent (QE)/㎎ extract. In addition, results revealed the extract possessed antioxidant activity (DPPH• free-radical scavenging activity) with IC50 value of 5.28 ㎍㎖ The reducing power of the extract was assayed spectro photometrically and showed Abs of 0.71 at 100 ㎍㎖ Furthermore, extracts of water chestnut exhibited no cytotoxicity in RAW 264.7 cells. In addition, the NO assay revealed that LPS-induced NO production was significantly inhibited following treatment with water chestnut extracts. The expression of pro-inflammatory proteins such as inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 decreased in a concentration-dependent manner. The water chestnut extract also decreased tumor necrosis factor α (TNF-α) release. Conclusion : Therefore, the present findings provide scientific evidence for the nutritional potential, chemical composition, and biological activities of Trapa japonica Flerow anddemonstrate its potential use as a functional food forapplication in the pharmaceutical industry
        175.
        2016.05 서비스 종료(열람 제한)
        Background : Curcuma longa L., in the family Zingiberaceae, is distributed in tropical and/or sub-tropical regions mainly in India and China. This species is commonly called turmeric, powder is used as medicinal herbs and/or flavor enhancer. It has been cultivated in southern region mainly Jindo. However, it might be possible to extend cultivation regions due to rise in average temperature. In order to select superior lines based on agronomic characteristics, we analyzed multivariate and estimated selection effects from C. longa germplasm. Methods and Results : The C. longa germplasm were cultivated in an experimental field located in Eumseong, NIHHS, RDA. The harvested roots were investigated in agronomic characteristics included in yield and then considered its relationship among the 9 germplasm by multivariate analysis method. Results from principal component analysis (PCoA) showed that it represented 70.00% and 80.44% accumulated explanation from four and five principal compounds (PC). PCoA was conducted from 9 agronomic characteristics and then correlation coefficient has been showed by analysis between each main component value and agronomic characteristics. Value of the first PC was 2.25, 24.96% explanation of total dispersion, plant height, number of rootlet and weight of rootlet were correlated with a somewhat higher level as 0.41, 0.43 and 0.52. Value of the fifth PC was 0.94, 10.43% explanation of total dispersion, the number of shoots was correlated with a higher level as 0.87. Selection effects with outstanding candidate lines including higher lines were estimated at 126.13% in yield. Conclusion : These data on multivariate based on agronomic characteristics will be give us invaluable breeding information by selection of superior lines.
        176.
        2015.07 서비스 종료(열람 제한)
        Seed color is an important factor affecting physiological and developmental process in wheat. One of the plant pigments, anthocyanins are a group of flavonoid compounds well known as pigments responsible for blue, purple, red, or yellow coloration of plant tissues. In this study, we investigated the pigmentation of purple and yellow color seed according to wheat grain developmental stages. The contents of anthocyanin and chlorophyll in the purple and yellow seeds were measured. Chlorophyll contents were changed similarly in both purple and yellow color seed, and no significant difference was observed between them. In purple color seed, the content of anthocyanin was significantly induced compared with yellow color seed. The individual anthocyanin components were investigated by ultra performance liquid chromatography (UPLC). Cyanidine-3-glucoside (C3G) and peonidine-3-glucoside (P3G) were detected as predominant anthocyanin in purple color wheat. To investigate whether structural genes in anthocyanin biosynthesis were involved in the trait differences between purple and yellow color seed, we examined the expression of anthocyanin biosynthesis-related genes (CHS, CHI, F3H, DFR, ANS, UFGT) and MYB transcription factor in developing wheat grains by using qRT-PCR. This study indicates that the expression of anthocyanin biosynthesis-related genes and MYB transcription factors correlate with anthocyanin levels of grain.
        177.
        2015.07 서비스 종료(열람 제한)
        Ionizing radiation directly and indirectly affects gene expression within the plant genome. To access the physiological response of rice to different types of ionizing radiation, rice seeds were exposed to gamma-ray and ion beam radiation. Exposure to ionizing radiation dramatically decreased the shoot length compared with non-irradiated plants. Fluorescence-activated-cell-sorting (FACs) was used to measure DNA contents. There were significant correlations of dose-dependent between irradiated plant and non-irradiated plant. The radicals induced by the ionizing radiation in the plant could be observed by electron spin resonance (ESR). It was confirmed that the number of free radicals in cell was greatly increased all irradiated plants than non-irradiated plant. A significant positive correlation was shown between ionizing radiation dose and signal intensity. In order to determine the Genetic diversity, AFLP analysis was conducted with the irradiated plant and non-irradiated plant. Based on band patterns, the cluster analysis was conducted to evaluate the genetic variation by using the UPGMA (Unweighted Pair Grouping Method of Averages). Genetic diversity of irradiated plants by low dose ion beam was the closest non-irradiated plant and irradiated by high dose gamma-ray was the furthest from non-irradiated. We describe the detailed methods of ionizing irradiation and discuss its applications in genetic research as well as plant breeding.
        178.
        2015.07 서비스 종료(열람 제한)
        Ionizing radiation affects gene expression from plant genomes. To monitor the genome-wide transcriptional changes induced by three types of ionizing radiation, we used the rice RNA sequencing to identify genes that are up- or down-regulated by gamma rays (GAs), proton (PRs) and ion beams (IBs). The Oryza sativa jacalin-like lectin domain containing proteins (OsJAC1) gene was highly induced by GAs, PRs and IBs. OsJAC1 was selected based on the expression patterns of a genome-wide dataset of RNA sequencing. Many jacalin-related lectin genes have been shown to be associated with disease resistance, biotic and abiotic stress signaling. Therefore, we studied its expression pattern in response to different abiotic stress and phytohormone treatments. The expression patterns of OsJAC1 under two different abiotic stress conditions (salt and heat stress) and phytohormones (salicylic acid and methyl jasmonate) were examined. The transcripts of OsJAC1 were significantly induced in response to abiotic stress conditions, including salt and heat treatments. In addition, it was induced in response to the salicylic acid and methyl jasmonate treatments, respectively. To investigate the sub-cellular localization of OsJAC1, the gene was expressed as a fusion protein tagged with GFP, in tobacco leaf epidermis and examined under confocal microscope. The OsJAC1 was clearly localized at the nucleus. These results provide critical insights into the molecular functions of the rice jacalin-like lectin domain containing proteins as receptors of external signals.
        179.
        2015.07 서비스 종료(열람 제한)
        To understand molecular mechanisms underlying adaptation of plant cells to saline stress and stress memory, we developed Arabidopsis callus suspension-cultured cells adapted to high salt. Adapted cells to high salt exhibited enhanced tolerance compared to control cells. Moreover, the salt tolerance of adapted cells was stably maintained even after the stress is relieved, indicating that the salt tolerance of adapted cells was memorized. Salt-adapted and stress memorized cells were densely aggregated and formed multi-layered cell lump. Cell morphology analysis using transmission electron microscopy indicated that cell wall thickness of salt-adapted cells was significantly induced compared to control cells. In order to characterize metabolic responses of plant cells during adaptation to high salt stress as well as stress memory, we compared metabolic profiles of salt-adapted and stress-memorized cells with control cells by using NMR spectroscopy. A principle component analysis showed clear metabolic discrimination among control, salt-adapted and stress-memorized cells. Compared with control cells, metabolites related to shikimate metabolism such as tyrosine, and flavonol glycosides, which are related to protective mechanism of plant against stresses were largely up-regulated in adapted cell lines. Moreover, coniferin, a precursor of lignin, was more abundant in salt-adapted cells than control cells. The results provide new insight into metabolic level mechanisms of plant adaptation to saline stress as well as stress memory.
        180.
        2015.07 서비스 종료(열람 제한)
        ‘Tocomi-1’, a new japonica rice cultivar derived from a 200 Gy gamma ray irradiation with high tocopherol content and red pericarp. The local adaptability test of MRXII-1001-1 was carried out from 2012 to 2014 and it was named as ‘Tocomi-1’ in 2014. This variety is medium matured with heading date of August 12 in honam plain area of Korea. This variety is about 80 cm tall culm length and 106 spikelets per panicle. Its 1,000 grain-weight of rice seeds is 25.4 g. The yield potential of this variety is about 5.15 MT/ha in local adaptability test for three years. This variety exhibited greater seed longevity than the Donganbyeo, indicating a crucial role for tocopherols in maintaining viability during quiescence, and displayed faster seedling growth during the early growth stage. Tocopherol contents was 50% higher than the Donganbyeo. To study the molecular mechanism underlying vitamin E biosynthesis, we examined the expression patterns of seven rice genes encoding vitamin E biosynthetic enzymes. Accumulation levels of the OsVTE2 transcript and OsVTE2 protein in the ‘Tocomi-1’ were significantly higher than in the Donganbyeo. Sequence analysis revealed that the ‘Tocomi-1’ harbored a point mutation in the OsVTE2 promoter region, which resulted in the generation of MYB transcription factor—binding cis-element. These results help identify the promoter regions that regulate OsVTE2 transcription, and offer insights into the regulation of tocopherol content in ‘Tocomi-1’.