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        검색결과 16

        1.
        2017.04 구독 인증기관·개인회원 무료
        Ochratoxin A, which is frequently detected in cereals and infant diets worldwidely, is a mycotoxin to damage mainly the kidney and liver. Because ochratoxin A is highly thermostable compound. it is necessary to study ways of reducing level of ochratoxin A by controling processing steps. However, food processes, including extrusion, expansion, roasting, and steam cooking, which are used in order to mitigate the contents of ochratoxin A, are known to produce polycyclic aromatic hydrocarbons, which are generated from radicals decomposed by pyrolysis. Therefore, this study analyzed the levels of 4 polycyclic aromatic hydrocarbons, benz (a) anthracene, chrysene, benzo (b) fluoranthene and benzo (a) pyrene in rice-based products made in high pressure and heating process. Rice samples were finely ground, and homogenized samples were alkaline treatement with 1 M KOH/EtOH and extracted with liquid-liquid extraction method using n-hexane. The extracted solution was pretreated with a silica cartridge. The purified solution was dried with nitrogen gas and dissolved in 1 mL of dichloromethane and injected into GC/MSD. We had overall recoveries for 4 polycyclic aromatic hydrocarbons spiked into rice samples ranging from 92.8 to 110.2%. The limit of quantitations of benz (a) anthracene, chrysene, benzo (b) fluoranthene and benzo (a) pyrene in rice-based product were 0.19 ng/g, 0.38 ng/g, 0.51 ng/g, and 0.31 ng/g, respectively. However, these 4 polycyclic aromatic hydrocarbons in all processed rice samples were not detected.
        2.
        2012.06 구독 인증기관 무료, 개인회원 유료
        In recent times, NFC technology adaptations for smartphones have been increasing. This study proposes the adaptation of agri-food business models based on NFC technology and presents the basic technological characteristics of NFC. An NFC tag can store more information than prior tagging technology methods, such as QR codes, and provides a better user experience. Based on the unique features of NFC, this study suggests an NFC business model application for the agri-food business.
        4,000원
        3.
        2011.06 구독 인증기관 무료, 개인회원 유료
        The dissemination process of agricultural research and development (R&D) results has somewhat different characteristics from that of typical R&D results. However, these characteristics are not adequately considered on the basis of an examination of the current performance system, the resulting management plans, and strategies for the application and dissemination of the results of agricultural R&D in Korea. The performance evaluation indicator exposed the problem of the inadequate consideration of the characteristics of each of these areas, particularly the lack of unified R&D-related institutions and the inadequacy of the system to monitor outcomes. To address these shortcomings in the agricultural R&D programs in Korea, the policies pertaining to agricultural R&D performance, results management, and dissemination in the U.S. and Japan were examined. Based on these investigations, we proposed strategies to improve the agricultural R&D policies in Korea.
        6,900원
        5.
        2016.10 서비스 종료(열람 제한)
        Background : Korean mountain ginseng(Panax ginseng C.A. Meyer) are difficult to clinically apply because of its scarcity and high cost. Advances in plant biotechnology have made it possible to produce mountain ginseng extracts on a large scale using adventitious root cultures in bio-reactors. This study investigated the variations of ginsenoside compounds composition and biological activities of wild ginseng adventitious roots by fermentation process. Methods and Results : Wild ginseng adventitious roots with five days fermentation using four strain of bacteria(Leuconostoc mesenteroides(KACC 15744), Bacillus circulans(KACC 15822), Bacillus licheniformis(KACC 15823), Bacillus subtilis subsp. inaquosorum(KACC 17047)). Ginsenoside contents was analysed by using HPLC. To examine the antioxidant activity associated with biological functions, radical scavenging analyses DPPH, ABTS and SOD-like activity analyses were conducted. The total phenolic and flavonoid contents were evaluated to determine the antioxidant activity increment. The result showed increased total ginsenoside contents by fermentation process. In particular, B. licheniformis showed the highest ginsenoside contents. Regarding ginseng fermented with B. licheniformis, values of 70.6 ± 1.4%, 44.3 ± 1.7%, and 88.4 ± 1.3% were measured using DPPH, ABTS, and SOD-like antioxdiant activity analyses, respectively. The total phenolic contents in ginseng fermented with B. licheniformis was 184.5 ± 0.9 ㎍·GAE/㎖, and the total flavonoid contents was 108.5 ± 1.8 ㎍·QE/㎖ in ginseng fermented with L. mesenteroides. Conclusion : The high activity of β-glucosidase was selected bacteria. The four types of lactic acid bacteria examined, the use of B. licheniformis to ferment ginseng resulted in greatest increase in biological activities and ginsenoside contents.
        6.
        2015.09 KCI 등재 서비스 종료(열람 제한)
        Environment-friendly growth enhancers for rice are being promoted to reverse the negative impact of intensive chemical-based and conventional rice farming on yield sustainability and environmental problems. Several rhizosphere microorganisms and pyroligneous acids (PA) had demonstrated beneficial influence on growth, yield and grain quality of rice. Since most of the previous study had evaluated the effect of PGPR and PA on paddy rice singly, the effect of combined application of these on the growth and yield of paddy rice and on some soil chemical properties were determined. A four factorial pot experiment was conducted to evaluate the effect of PGPR, PA in combination with fertilizers and on different soil types. There were 54 treatment combinations including the control with three replications under complete randomized design. Plant growth parameters were evaluated using standard procedures during tillering and heading stages. Rice yield and some soil chemical properties were determined at harvest. Results showed that inoculation of Bacillus licheniformis and Fusarium fujikuroi enhanced plant growth by increasing the plant height which could be ascribe to its ability to promote IAA and GA production in plants. Inoculation of Rhizobium phaseoli enhanced chlorophyll content indicative to its ability to improve the N nutrition. However, these plant growth benefits during the vegetative stage were override by the fertilizer application effect especially during the maturity stage and grain yield. High fertilization rates on coarse-textured soil without nutrient loss resulted to high available nutrients and consequently high yield. Wood vinegar application however improved nutrient availability in soil which could be beneficial for improving soil quality. Further evaluation is necessary to fully assess the potential benefits that could be derived from inoculation of these organisms and wood vinegar application in different soil environment especially under different field conditions.
        7.
        2015.07 서비스 종료(열람 제한)
        Several E3 ubiquitin ligases have been associated with the response to abiotic and biotic stresses in higher plants. Here, we report that the hot pepper (Capsicumannuum) abscisic acid (ABA)-InsensitiveRINGprotein1gene(CaAIR1) is essential for a hypersensitive response to drought stress. CaAIR1 contains a C3HC4-type RING finger motif, which plays a role for attachment of ubiquitins to the target protein, and a putative transmembrane domain. The expression levels of CaAIR1 are upregulated in pepper leaves by ABA treatments, drought, and NaCl, suggesting its role in the response to abiotic stress. Our analysis showed that CaAIR1 displays self-ubiquitination and localized in the nucleus. We generated CaAIR1-silenced peppers via virus-induced gene silencing (VIGS) and CaAIR1-overexpressing (OX) transgenic Arabidopsis plants to evaluate their responses to ABA and drought. VIGS of CaAIR1 in pepper plants conferred an enhanced tolerance to drought stress, which was accompanied by low levels of transpirational water loss in the drought-treated leaves. CaAIR1-OX plants displayed an impaired sensitivity to ABA during seed germination, seedling, and adult stages. Moreover, these plants showed enhanced sensitivity to drought stress because of reduced stomatal closure and decreased expression of stress-responsive genes. Thus, our data indicate that CaAIR1 is a negative regulator of the ABA-mediated drought-stress tolerance mechanism.
        8.
        2015.07 서비스 종료(열람 제한)
        Drought and high salinity are the most important abiotic factors limiting plant development, growth, and crop productivity in agriculture (Munns and Tester 2008, Sengupta and Majumder 2009, Zhu 2002). As sessile organisms, plants are frequently exposed to drought and high salinity conditions, which alter water potential and cause osmotic stress, leading to serious damage to plant tissues (Bartels and Sunkar 2005, Boudsocq and Lauriere 2005). During exposure to water stress, plants display many physiological changes, such as reduction of water content, closure of stomata, and decreased cell enlargement and growth. In addition, severe and continuous water stress in plants causes the cessation of photosynthesis and disturbance of metabolism, and finally results in death (Nath et al. 2005, Shao et al. 2008). To adapt to these abiotic stress conditions, plants show a variety of responses, including the accumulation of abscisic acid (ABA) and expression of a large number of stress-related proteins (Krasensky and Jonak 2012, Lee and Luan 2012, Skriver and Mundy 1990, Stewart and Lee 1974). Although the cellular and molecular responses to environmental stress are well studied (Hasegawa et al. 2000, Thomashow 1999), the mechanisms underlying the functional modifications caused by osmotic stress are yet to be clarified, because of the complexity at the cellular level as well as at the whole plant level (Ashraf and Harris 2004, Flowers 2004, Foolad et al. 2003a, 2003b, Xiong et al. 2002).
        9.
        2015.07 서비스 종료(열람 제한)
        A pepper bZIP transcription factor gene, CabZIP2, was isolated from pepper leaves infected with an a virulent strain of Xanthomonas campestris pv. vesicatoria (Xcv). Transient expression analysis of the CabZIP2-GFP fusion protein in Nicotiana benthamiana revealed that the CabZIP2 protein is localized in the cytoplasm as well as the nucleus. The acidic domain in the N-terminal region of CabZIP2 that is fused to the GAL4 DNA-binding domain is required to activate the transcription of reporter genes in yeast. Transcription of CabZIP2 is induced in pepper plants inoculated with virulent or avirulent strains of Xcv. The CabZIP2 gene is also induced by defense-related hormones such as salicylic acid, methyl jasmonate, and ethylene. To elucidate the in vivo function of the CabZIP2 gene in plant defense, virus-induced gene silencing (VIGS) in pepper and overexpression in Arabidopsis were used. CabZIP2-silenced pepper plants were susceptible to infection by the virulent strain of Xcv, which was accompanied by reduced expression of defense-related genes such as CaBPR1 and CaAMP1. CabZIP2 overexpression (OX) in transgenic Arabidopsis plants conferred enhanced resistance to Pseudomonas syringae pv. tomato DC3000. Together, these results suggest that CabZIP2 is involved in bacterial disease resistance.
        10.
        2015.07 서비스 종료(열람 제한)
        Plants are constantly exposed to a variety of biotic and abiotic stresses, which include pathogens and conditions of high salinity, low temperature, and drought. Abscisic acid (ABA) is a major plant hormone involved in signal transduction pathways that mediate the defense response of plants to abiotic stress. Previously, we isolated Ring finger protein gene (CaRING1) frompepper(Capsicum annuum), which is associated with resistance to bacterial pathogens, accompanied by hypersensitive cell death. Here, we report a new function of the CaRING1 gene product in the ABA-mediated defense responses of plants to drought stress. The expression of the CaRING1 gene was induced in pepper leaves treated with ABA or exposed to drought or NaCl. CaRING1-overexpressing (OX) transgenic plants showed enhanced sensitivity to ABA during the seedling growth and establishment. Furthermore, these plants were more tolerant to drought stress than the wild-type plants because of enhanced stomatal closure and increased expression of stress-responsive genes. Together, these results suggest that the CaRING1 acts as positive factor for drought tolerance in Arabidopsis by modulating ABA-mediated stomatal closing and gene expression.
        11.
        2015.07 서비스 종료(열람 제한)
        In plants, lipoxygenases (LOXs) are involved in various physiological processes, including defense responses to biotic and abiotic stresses. Our previous study has shown that pepper 9-LOX gene, CaLOX1, plays a crucial role in cell death due to pathogen infection. Here, the function of CaLOX1 in response to osmotic, drought, and high salinity was examined using CaLOX1-overexpressing (CaLOX1-OX) Arabidopsis plants. Changes in the temporal expression pattern of the CaLOX1 gene were observed when pepper leaves were treated with drought and high salinity, but not with abscisic acid (ABA), the primary hormone in response to drought stress. During seed germination and seedling development, CaLOX1-OX plants were more tolerant to ABA, mannitol, and high salinity than wild-type plants. In contrast, expression of the ABA-responsive marker genes RAB18 and RD29B was higher in CaLOX1-OX Arabidopsis plants than in wild-type plants. In response to high salinity, CaLOX1-OX plants exhibited enhanced tolerance, compared with wild-type, which is accompanied by decreased accumulation of H2O2 and high levels of RD20, RD29A, RD29B, and P5CS gene expressions. Similarly, CaLOX1-OX plants were also more tolerant than wild-type plants to severe drought stress. H2O2 production and relative increase of lipid peroxidation were lower, and the expression of COR15A, DREB2A, RD20, RD29A, and RD29B was higher in CaLOX1-OX plants, relative to those of wild-type plants. Taken together, our results indicate that CaLOX1 plays a crucial role in plant stress responses by modulating the expression of ABA- and stress-responsive marker genes, lipid peroxidation, and H2O2 production.
        12.
        2015.07 서비스 종료(열람 제한)
        Stomata are natural pores of plants and constitute the entry points for water during transpiration. However, they also facilitate the ingress of potentially harmful bacterial pathogens. The phytohormone abscisic acid (ABA) plays a pivotal role in protecting plants against biotic stress, by regulating stomatal closure. In the present study, we investigated the mechanism whereby ABA influences plant defense responses to Pseudomonas syringae pv. tomato (Pst) DC3000, which is a virulent bacterial pathogen of Arabidopsis, at the pre-invasive stage. We found that overexpression of two ABA receptors, namely, RCAR4/PYL10-OX and RCAR5/PYL11-OX (hereafter referred to as RCARs), resulted in ABA-hypersensitive phenotypes being exhibited during the seed germination and seedling growth stages. Sensitivity to ABA enhanced the resistance of RCAR4-OX and RCAR5-OX plants to Pst DC3000, through promoting stomatal closure leading to the development of resistance to this bacterial pathogen. Protein phosphatase HAB1 is an important component that is responsible for ABA signaling and which interacts with ABA receptors. We found that hab1 mutants exhibited enhanced resistance to Pst DC3000; moreover, similar to RCAR4-OX and RCAR5-OX plants, this enhanced resistance was correlated with stomatal closure. Taken together, our findings demonstrate that alteration of RCAR4- or RCAR5-HAB1 mediated ABA signaling influences resistance to bacterial pathogens via stomatal regulation.
        13.
        2012.07 서비스 종료(열람 제한)
        The plant hormone abscisic acid (ABA) serves as an integrator of environmental stress such as drought, to trigger stomatal closure by regulating specific ion channels in guard cells. We previously reported that SLAC1, an outward anion channel required for stomtal closure, was regulated via reversible protein phosphorylation events involving ABA signaling components including protein phosphatase 2C members and a SnRK2-type kinase (OST1). In this study, we reconstituted the ABA signaling pathway as a protein-protein interaction relay from the PYL/RCAR type receptors, to the PP2C-SnRK2 phosphatase-kinase pairs, to the ion channel SLAC1. The ABA receptors interact with and inhibit PP2C phosphatase activity against the SnRK2-type kinase, releasing active SnRK2 kinase to phosphorylate and activate the SLAC1 channel, leading to reduced guard cell turgor and stomatal closure. Both yeast-two hybrid and bi-molecular fluorescence complementation assays were used to verify the interactions among the components in the pathway. The biochemical assays demonstrated the activity modifications of phosphatases and kinases by their interaction partners. The SLAC1 channel activity was used as a readout for the strength of the signaling pathway depending on the presence of different combinations of signaling components.
        15.
        2004.08 KCI 등재 서비스 종료(열람 제한)
        연구는 자기조절 초점에 따른 목표추구 행동의 차이를 알아보고자 하는 것이다. 자기조절 초점은 Higgins(1998)가 제시한 증진초점(promotion focus)과 예방초점(prevention focus)을 사용하였으며, 목표추구행동은 Bagozzi, Baumgartner, Pieters(1998)의 목표지향적 정서(goal-directed emotion) 모델을 설정하였다. 이러한 연구목적을 달성하기 위해 고등학교 운동선수를 모집단으로 하여 총 15개의 운동 종목 총 455명을 표집하였다. 본 연구의 조사도구는 자기조절 초점 척도와 목표지향적 정서 척도를 사용하였으며, Higgins(1998)와 Bagozzi 등(1998)이 사용했던 것을 본 연구의 목적에 맞게 수정 및 보완하여 사용하였다. 연구 절차는 먼저 측정 도구를 개발하였고, 그 후 시합이 있기 2~3주전에 자기조절 초점 척도와 목표 확립, 기대 정서, 의지 과정의 목표지향적 정서를 측정하였으며, 시합이 끝난 1주 이내에 도구 행동, 목표 획득, 목표-결과 정서의 목표지향적 정서를 측정하였다. 자료분석은 상관관계분석과 독립 표본 t검증을 실시하였다. 자기조절 초점을 두 집단으로 구분하고, 이에 따른 목표지향적 정서의 평균 차이를 검증한 결과, 쾌의 기대 정서와 의지 과정에서 통계적으로 유의한 차이가 나타났다. 또한 불쾌의 기대 정서와 목표 달성을 제외한 모든 차원에서 증진 초점이 예방 초점보다 높은 평균값을 나타냈다. 이 결과는 Higgins(1998)의 예언과 일치하는 것이다. 그리고 자기조절 초점에 따른 목표-결과 정서간의 평균 차이 검증에서는 예방 초점이 목표 달성을 실패했을 때 나타나는 초조 정서에서만 통계적으로 유의한 차이가 나타났다. 그러나 평균값에서는 예방 초점이 증진 초점보다 모든 차원에서 높은 수치를 나타냈다. 이 결과에 대해 한국의 운동 선수들이 예방 초점과 증진 초점간에 상대적으로 강하거나 약한 측면에서 논의하였다.
        16.
        2001.06 KCI 등재 서비스 종료(열람 제한)
        One-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis (1D SDS-PAGE) was used to determine whether it would provide improved resolving power of hordein proteins concomitant with improved identification of Korean barley cultivars and germplams. This system gave rapid and reproducible separations of hordein polypeptides. Total fourteen of clear and easily scorable subunits were identified in Korean barley cultivars and germplasms and their polymorphic constitutions could provide biochemical genetic information in progeny analysis and endosperm quality improvement in barley breeding programs. Each hordein polypeptides residing in B, C, and D hordein pattern designations were scored to prepare a cultivar catalogue of protein patterns. On the basis of this character, 7 hordein polypeptide patterns were constructed from 108 barley cultivars and experimental lines. The molecular weight of hordein subunits in Korean barley cultivars and experimental lines varied in the range of 98 to 48 kDa. In contrast, less polymorphic hordein polypeptides were found in the low protein barley lines including malting barleys than those found in Korean barley cultivars and experimental lines