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        검색결과 129

        101.
        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.
        102.
        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.
        103.
        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.
        104.
        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’.
        105.
        2015.07 서비스 종료(열람 제한)
        To define whole genome-level of structural variation by ionization energies and radiation doses in plant, the seeds of Ilpum rice cultivar were acutely irradiated with gamma rays (100Gy, 200Gy, and 400Gy) and ion-beams (20Gy, 40Gy, and 80Gy), respectively. Six M1 rice plants were re-sequenced by Hi-Seq2500 with Ilpum cultivar as control. The average sequencing coverage of the individuals was 10.6X, and the average mapping rate to the rice reference genome (IRGSP-1.0) sequence was 96.95%. The individual plants were irradiated with gamma-400Gy and ion-50Gy had highest variation of SNP with 471,837 and 469,147, respectively. The number of insertion/deletion was 77,500 and 77,106, the synonymous and frame-shift were 7,859 and 7,763 in above two individuals. Although high genome variation shown between Ilpum cultivar and irradiated individuals, there were non-correlation between number of variation and radiation doses. However, five individuals, except ion-20Gy, showed 33 common variant blocks (CVBs) spanning 6 Mb in whole rice genome (1.6%). The CVBs were distributed on 12 rice chromosomes, Chromosome 6 had biggest CVB (5 blocks, 1.3Mb), whereas chromosome 9 had smallest CVB (0.01Mb). Total five hundred fifty one genes were in CVBs which can regard radiation sensitive genes or may be regarded as radiation hot spots in rice genome. This study will contribute to the improvement of the radiation mutation breeding research in genetic and genomic aspect.
        106.
        2015.03 서비스 종료(열람 제한)
        A case of three primary malignancies in one patient is rare. We report on a case of three primary malignancies including myxofibrosarcoma, renal cell cancer, and prostate cancer in one 18F-fluorodeoxyglucose (FDG) positron emission tomography/ computed tomography (PET/CT) evaluation of a 75-year-old man. PET/CT showed different FDG meabolism in each tumor.
        108.
        2014.07 서비스 종료(열람 제한)
        Gamma irradiation has been used as a tool for plant mutation breeding to select new cultivar with improved characteristics. Generally, the irradiation of seeds with high doses of gamma rays disturbs the synthesis of protein, hormone balance, and enzyme activity. And also, high dose of gamma rays to reduce plant height, number of tiller, and root length, although the effect of gamma-irradiated plants may depend on the species and cultivar or stress conditions. Biological effects of radiations can be divided into two types according to dose range and periods of exposure. Acute irradiation represents exposure to high-dose of irradiation over short period time, whereas the chronic irradiation is comprised of exposure to low doses of radiation over extended period of time. To compare the effects of acute and chronic exposure to ionizing radiation on two wheat cultivars (K4191 and Geumgangmil), we measured their germination rate, seedling height, and root length. In order to understand the influence of antioxidant-related genes and DNA repair-related genes, we used qRT-PCR methods to identify their expression levels. To study the behavior of a radiation-induced free radical, gamma-irradiated seeds were used for ESR spectroscopy. Plant growth pattern was showed positive correlation with ESR results. This study indicates that low level chronic radiation exposure is even more serious effects than short doses of high level radiation according to different wheat cultivar.
        109.
        2014.07 서비스 종료(열람 제한)
        Perilla frutescens (L.) is an annual herbaceous and ornamental plant in the Lamiaceae family. Perilla frutescens (L.) Britt.cv.Chookyoupjaso were irradiated using a 200 Gy gamma ray in 1995. By HPLC analysis, this new cultivar significantly induced isoegomaketone content compared with ‘Chookyoupjaso’ control. The phenotypical difference was the changed leaf color of the ‘Atom-Ketone’ from violet to green. The yield potential of this cultivar (106 kg/10a) was 1.83 folds higher than that of ‘Chookyoupjaso’ (57.65 kg/10a). The methanol extracts of ‘Atom-Ketone’ inhibit nitric oxide (NO) production in LPS-stimulated RAW 264.7 cells. This extract was further partitioned using ethyl acetate (EtOAc), butanol (BuOH), and water. The EtOAc fraction (EF-Atom-Ketone) was evaluated for antiinflammatory activities. These results indicated that the EF-Atom-Ketone reduced NO production by inhibiting inducible nitric oxide synthase (iNOS) expression. The EF-Atom-Ketone treatment also significantly diminished expression of MCP-1 and IL-6. Therefore, ‘Atom-Ketone’ reveals the potential therapeutic use of bioactive
        110.
        2014.07 서비스 종료(열람 제한)
        Perilla frutescens (L.) is an edible plant, not only used as s food ingredient, but also in skin cream, soaps, and medicinal preparetions. ‘Atom-Ros’, a perilla (Perilla frutescenc (L.) Britt. cv. Chookyoupjaso was developed in 1995 by 200 Gy gamma irradiation-mutagenesis. This new cultivar has high rosmarinic acid content more than two fold compare with ‘Chookyoupjaso’ control. The observed phenotypical difference was changed leaf color of the ‘Atom-Ketone’ from violet to green. The yield potential of this cultivar (123.5 kg/10a) was 2.14 fold higher than that of ‘Chookyoupjaso’ (57.65 kg/10a). The methanol extracts of ‘Atom-Ros’ were tested for inhibition of nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophase cells. Atom-Ros showed significant inhibition of NO production. This rosmarinic acid extracted from ‘Atom-Ros’ has a good potential to be developed as an antioxidant agent.
        111.
        2014.02 서비스 종료(열람 제한)
        낙동강 본류에 위치한 8개보의 수문 및 하구둑 배수문의 홍수시 운영방안을 내부경계로 포함하는 부정류 계산모형을 개발하였다. 보의 운영방안으로는 보 수위가 어떤 기준수위보다 낮으면 수문을 폐쇄하고 기준수위 이상이면 수문을 개방하되, 수문개도는 보 수위와 기준수위의 차에 비례하도록 하는 방안이 적용되었다. 하구둑의 경우 외조위가 하구둑 내수위보다 높으면 수문을 폐쇄하되, 창녕함안보 통과유량을 기준으로 기존 및 증설 배수문을 개방하는 현재의 운영방안과 8개 보의 경우와 동일한 방법으로 개도를 결정하는 새로운 운영방안 등 2개의 운영방안을 적용할 수 있도록 하였다. 개발된 계산모형을 적용하여 2003년 9월 홍수에 대한 모의계산을 수행하였다. 새로운 하구둑 운영방안의 매개변수에 대한 민감도를 분석하였으며, 기존의 운영방안을 적용할 경우의 계산결과와의 비교 분석을 수행하였다.
        117.
        2013.03 KCI 등재 서비스 종료(열람 제한)
        본 연구에서는 감태 효소 추출물과 그것의 폴리페놀 추출물의 화장품 원료로서의 효능을 알아보기 위하여 항산화, 항당화, 미백, 항염 효과와 관련된 실험을 실시하였다. 감태 효소 추출물과 폴리페놀 추출물은 강력한 라디컬 소거능을 가지고 있으며 BSA/Glucose 시스템에서 최종당화생성물의 형성을 저해하는 항당화 활성과 타이로시네이즈 저해를 통한 우수한 미백력을 가지고 있음을 확인하였다. 또한 두 추출물 모두 세포 내에서 PGE2와 NO 생성 저해를 통한 항염 효과를 나타내었다. 이러한 결과를 종합해 볼 때, 감태 효소 추출물과 그 폴리페놀추출물은 화장품 원료로서의 응용 가능성이 있을 것으로 사료된다.
        118.
        2012.07 서비스 종료(열람 제한)
        In order to adapt to various environmental stresses, plants have employed diverse regulatory mechanisms of gene expression. Epigenetic changes, such as DNA methylation and histone modifications play an important role in gene expression regulation under stress condition. It has been known that some of epigenetic modifications are stably inherited after mitotic and meiotic cell divisions, which is known as stress memory. To understand molecular mechanisms underlying stress memory mediated by epigenetic modifications, we developed Arabidopsis suspension-cultured cell lines adapted to high salt by stepwise increases in the NaCl concentration up to 120 mM. Adapted cell line to 120 mM NaCl, named A120, exhibited enhanced salt tolerance compared to unadapted control cells (A0). Moreover, the salt tolerance of A120 cell line was stably maintained even in the absence of added NaCl, indicating that the salt tolerance of A120 cell line was memorized even after the stress is relieved. By using salt adapted and stress memorized cell lines, we intend to analyze the changes of DNA methylation, histone modification, transcriptome, and proteome to understand molecular mechanisms underlying stress adaptation as well as stress memory in plants.
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