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        검색결과 128

        81.
        2015.07 서비스 종료(열람 제한)
        ‘Clara’ 품종은 국립원예특작과학원에서 2005년도에 육성한 포인세티아 품종으로 초장이 작고 컴팩트한 수형으로 포엽의 형태는 난형이며 엽맥 사이 주름의 정도는 약하다. 포엽의 길이와 폭, 잎몸의 길이와 폭, 엽병의 길이는 짧으며 단일처리 후 약 9주일이 경과하면 충분히 착색되어 출하가 가능한 품종이다. 2008년 5월과 10월 ‘Clara’ 품종의 캘러스가 형성된 삽수에 100Gy의 감마선을 24시간 동안 처리하여 유기한 돌연변이를 이용하여 2010년과 2013년에 국립원예특작과학원에서 ‘Clara Pink’와 ‘Clara White’품종을 육성하였다. 이 두 품종들은 포엽의 색이 완전히 변한 변이주를 선발하여 계통화 하였으며 2008년 5월에 감마선을 처리한 삽수들 중 포엽의 색이 분홍색인 변이지를 선발하여 2009년에 2차에 거쳐 특성검정을 실시하였다. 2010년에 ‘원예 D5-2’를 육성한 후 3차 특성검정과 품종평가회를 실시하여 최종선발하였으며, 농작물 직무육성 신품종선정위원회를 거쳐 ‘Clara Pink’로 명명하였다. 2005년 10월에 감마선을 처리한 삽수들중에서는 포엽의 색이 연황색인 변이주를 선발하여 계통화 하였으며, 2012년과 2013년에 1,2차 특성검정을 실시하였다. 2013년에 ‘원예 D5-34’를 육성하여 특성검정과 품종평가회를 실시하고 농작물 직무육성신품종선정위원회를 거쳐 ‘Clara White’로 명명하였다. ‘클라라 핑크’와 ‘클라라 화이트’ 두 품종 모두 ‘클라라’ 품종과 같은 소형으로 적심하지 않은 상태에서도 분지가 많이 발생하는 컴팩트한 수형이다. 포엽의 형태는 결각이 없는 난형이며, 엽맥 사이에 약한 주름이 있고 단일처리 후 약 9주일 경과하면 완전히 착색된다. 잎몸의 모양은 난형이며, 엽병의 길이는 짧다. 그러나 ‘클라라 핑크’와 ‘클라라 화이트’ 품종의 포엽과 엽맥의 안토시아닌 발현에 차이를 나타내었다. ‘클라라 핑크’ 의 포엽은 분홍색이며, ‘클라라 화이트’의 포엽은 연황색이다. 또한 ‘클라라 핑크’ 와 ‘클라라 화이트’ 품종은 ‘클라라’ 품종과 비교해서 잎자루 윗면의 안토시아닌 발현 정도가 약하였으며, 잎몸 윗면의 가운데 맥의 색이 ‘클라라’ 품종은 녹색과 빨강색이 함께 발현되었으나, ‘클라라 핑크’ 와 ‘클라라 화이트’ 품종은 녹색만 발현되었다.
        82.
        2015.07 서비스 종료(열람 제한)
        Regulation of fruit ripening may help extend fruit shelf life and prevent losses due to spoilage. Here, we investigated whether sound treatment could delay tomato fruit ripening. We treated harvested tomato fruits with low-frequency sound waves (1 kHz) for 6 h, and then monitored various characteristics of the fruits over 14-day period at 23±1°C. Seven days after the treatment, 85% of the treated fruits were green, versus fewer than 50% of the non-treated fruits. Most of the tomato fruits had switched to the red ripening stage by 14 days after treatment. Ethylene production and respiration rate were lower in the treated than non-treated tomatoes. Furthermore, changes in surface color and flesh firmness were delayed in the treated fruits. To investigate how sound wave treatment affects fruit ripening, we analyzed the expression of ethylene-related genes by quantitative real-time RT-PCR analysis. We found that the expression level of several ethylene biosynthetic and ethylene signaling pathway-related genes was influenced by sound wave treatment. These results demonstrate that sound wave treatment delays tomato fruit ripening by altering the expression of important genes in the ethylene biosynthesis and ethylene signaling pathways.
        83.
        2014.09 서비스 종료(열람 제한)
        Chemoresistance is one of the main problems to treat different kinds of cancers or cancer cells. Therefore, it is necessary to find out the strategies to make the cancer cells sensitive to chemotherapy along with optimal dosage of drugs. We examined sensitivity of MCF7 cells through pretreating with an epigenetic modulator, azacytidine (AzaC) to doxorubicin (Dox). The cells were treated with 5 and 10 mM of AzaC for a week, subsequently with 50, 100 and 500 nM of doxorubicin for 24 and 48h. It was found that pretreatment of AzaC significantly enhance the sensitivity of MCF7 cells to Dox, inducing cell death. After 24h 15% cells underwent apoptosis in 500 nM dox treatment group while 23.4% cells death occurred in AzaC pre treatment group. After 48h MCF7 cells treated with Dox showed 19.0% cell death while AzaC sensitized cells showed 50.0% cells death when exposed to 500 nM of Dox for 48h. Western blot analysis showed the upregulations in the expression of bax, caspase-3, caspase-9 and p53 in AzaC-sensitized MCF7 cells treated with Dox as compared to those treated with only Dox. There was no clear indication for pro-apoptosis genes in the cells treated with individual drugs. These results showed that pretreatment with the epigenetic modulator significantly increased the sensitivity of MCF7 cells to Dox. Therefore it is concluded that demethylation event might enhance the activity of DNA intercalating agents to induce DNA damage in breast cancer cells.
        84.
        2014.07 서비스 종료(열람 제한)
        Watermelon (Citrullus lanatus) is one of the most economically important cucurbitaceous crop over the world. Anthracnose disease caused by Colletotrichum orbiculare, result to severe damage to cucurbits worldwide. Anthracnose is a typical plant disease which significantly affecting the yield of cucurbit crop. Pathogeneis-related (PR) proteins are well-known plant defense proteins against pathogens. Therefore, we observed PR genes expression patterns when watermelon got anthracnose disease. We did RT-PCR experiment to evaluate differences of PR genes expression pattern among Au-Producer(R), one of the representative of resistance watermelon varieties against anthracnose, and 920533(S), one of the representative of susceptible watermelon varieties against anthracnose. As a result, there were differences of the expression of several PR genes between the R and S watermelon. Analysis of the function of these genes is expected to perform in the future.
        85.
        2014.07 서비스 종료(열람 제한)
        Watermelon (Citrullus lanatus) is one of the most economically important cucurbitaceous crop over the world. Screening of proper reference genes was needed to reverse transcription quantitative real-time PCR (qRT-PCR), and it is bausic step of many researches including gene expression analysis. However, the reference genes on watermelon has not yet been reported systematically. Therefore, eight candidates of reference genes were selected with reference to Arabidopsis or cucumber papers. They are β-Actin, elongation factor 1-α, glyceraldehy-3-phosphate-dehydrogenase, NADP-isocitrate dehydrogenase, leunig, polypyrimidine tract-binding protein1, ubiquitin-conjugating eznyme E2, and 18S ribosomal RNA. The expression levels of genes were evaluated by qRT-PCR under biotic stress (Colletotrichum orbiculare treatment), plant hormone treatment (100 μM ABA), and abiotic stresses such as drought, cold (4℃), salt (250 mM NaCl) stresses. We founded appropriate reference genes which did not induce or reduce gene expression levels under broad spectrum of stresses by qRT-PCR analysis. These results may provide proper information for the use of appropriate reference genes for gene expression studies in watermelon qRT-PCR analysis.
        86.
        2014.07 서비스 종료(열람 제한)
        Heat shock transcription factors(HSFs) are the major heat shock factors regulating the heat stress response. They participate in regulating the expression of heat shock proteins (HSPs), which are critical in the protection against stress damage and many other important biological processes. In this study, a genome-wide analysis was carried out to identify all HSFs soybean genes. Twenty six nonredundant HSF genes(GmHsf) were identified in the latest soybean genome sequence. Chromosomal location, protein domain and motif organization of GmHsfs were analyzed in soybean genome. The phylogenetic relationships, gene duplications and expression profiles of GmHsf genes were also presented in this study. According to their structural features, the predicted members were divided into the previously defined classes A–C, as described in Arabidopsis. Using RT-PCR, the expression patterns of 26 GmHsf genes were investigated under heat stress. The data revealed that these genes presented different expression levels in response to heat stress conditions. Real-time (q)RT-PCR was performed to investigate transcript levels of five GmHsfs in response to multiple abiotic stresses. Differential expression of five GmHsfs implies their role during abiotic stresses. Subcellular localization using GFP-fusion protein demonstrated that GmHsf12 and GmHsf34 were restricted to the nucleus and GmHsf28 was localized in the nucleus and cytoplasm in plant. The results provide a fundamental clue for understanding of the complexity of the soybean HSF gene family and cloning specific function genes in further studies and applications.
        87.
        2014.07 서비스 종료(열람 제한)
        The plant-specific NAC (NAM, ATAF, and CUC)-domain proteins play important roles in plant development and stress responses. Comparative time-course expression analyses were carried out to analyze the expression levels of 62 soybean NAC genes during drought stress in order to search for the stress-inducible NAC genes. Ten GmSNAC (Glycine max stress-inducible NAC) genes having the significant differential expression in response to the drought stress and abscisic acid (ABA) hormone application were further investigated for their expression profiles with various stresses such as drought, high salinity, cold and with ABA treatments by the quantitative real-time PCR analyses. In this research, the full-length cDNAs of eight GmSNAC were isolated for the further studies. Eight GmSNAC proteins were tested for their transcription activation in the yeast assay system. Two GmSNAC proteins showed the very high transcriptional activities and the other two GmSNAC proteins displayed moderate levels of transactivation while the remaining four GmSNAC proteins lacked transactivation in yeast. Subcellular localization of eight GmSNAC proteins was analyzed via the green fluorescent protein-GmSNAC fusion protein in tobacco plant cell. Three GmSNAC proteins with the C-terminal transmembrane domain were localized to the nucleus and cytoplasmic fractions. The other five GmSNAC proteins were targeted to the nucleus. The function of GmSNAC49 gene was further investigated using the overexpression transgenic Arabidopsis. Germination rate in transgenic plants over-expressing GmSNAC49 was delayed in the media supplemented with mannitol or ABA compared with that of wild-type (WT) plants. The 35S:GmSNAC49 transgenic Arabidopsis displayed improved tolerance to drought stress compared to the WT. The results of this systematic analysis of the GmSNAC family responsive to abiotic stress will provide novel tools and resources for the development of improved drought tolerant transgenic soybean cultivars
        88.
        2014.07 서비스 종료(열람 제한)
        Comparative time-course expression analyses were carried out to analyze the expression levels of 60 soybean WRKY genes during abiotic stress in order to search for the stress-inducible WRKY genes. Five GmWRKY(Glycine max WKRY) genes having the significant differential expression in response to the drought stress and abscisic acid(ABA) hormone application were further investigated for their expression profiles with various stresses such as drought, high salinity, cold and with ABA treatments by the quantitative real-time PCR analyses. In this research, the full-length cDNAs of five GmWRKY were isolated for the further studies. Five GmWRKY proteins were tested for their transcription activation in the yeast assay system. GmWRKY3 proteins showed the very high transcriptional activities and the other two GmWRKY proteins displayed moderate levels of transactivation while the remaining two GmWRKY proteins lacked transactivation in yeast. Subcellular localization of five GmWRKY proteins was analyzed via the green fluorescent protein-GmWRKY fusion protein in tobacco plant cell and all of GmWRKY proteins were targeted to the nucleus. In order to analyze the function of GmWRKY genes in plant, 35S:GmWRKY overexpression(OE) transgenic Arabidopsis were generated. Root growth and germination rates in transgenic OE plants were investigated in the media supplemented with mannitol, NaCl or ABA compared with that of wild-type(WT) plants. The 35S:GmWRKY42 transgenic Arabidopsis displayed reduced tolerance to drought stress compared to the WT. The results of this systematic analysis of the GmWRKY family responsive to abiotic stress will provide novel tools and resources for the development of improved drought tolerant transgenic soybean cultivars
        89.
        2014.07 서비스 종료(열람 제한)
        The tight regulators of fruit set initiation, gibberellin (GA) and auxin, have been applied for decades to induce parthenocarpy, fruit set without fertilization. The integration of GA and auxin signaling mediated by either GA or auxin application during parthenocarpy has been actively reported in tomato, and recently we reported that GA application at pre-bloom also activating auxin signaling and down-regulated negative regulators of fruit set initiation in grapevines. However, the activation of auxin signaling upon GA application without up-regulation of auxin biosynthesis is still unclear. In this study, expression patterns of three auxin efflux transporter genes, VvPIN1a, VvPIN2 and VvPIN4, were monitored during inflorescence development in ‘Tamnara’ grapevines with or without GA application. Without GA application, transcription levels of VvPIN1a and VvPIN4 gradually increased from 14 days before full bloom (DBF) to 2 and 5 days after full bloom (DAF), respectively, except down-regulation of VvPIN1a during 5 DBF to full bloom. However, VvPIN2 expression declined steadily after peaking at 10 DBF. With GA application, VvPIN1a did not show significantly different expression patterns when compared to no GA application, with the exception of 4-fold up-regulation at full bloom, but transcription of VvPIN4 was reduced between 5 and 2 DBF. In addition, VvPIN2 was down-regulated between 12 and 10 DBF by more than 50% compared to levels in the absence of GA application. These reductions of both VvPIN2 and VvPIN4 with GA application prior to pollination suggest that GA application might regulate auxin distribution, instead of auxin biosynthesis, to activating auxin signaling during parthenocarpic fruit initiation.
        90.
        2013.12 서비스 종료(열람 제한)
        Neutropenic enterocolitis (NE), the most serious gastrointestinal complication, has been reported as a clinical syndrome that occurs in the setting of disease- or chemotherapy-induced neutropenia. Complications of NE include bowel necrosis with perforation, fistula, stenosis, massive bleeding, abscess formation, and pneumatosis intestinalis (PI). Most physicians recommend initial conservative management with bowel rest, intravenous fluids, total parenteral nutrition, broad-spectrum antibiotics, and normalization of neutrophil counts. Surgical intervention is recommended in the event of obstruction, perforation, persistent gastrointestinal bleeding despite correction of thrombocytopenia and coagulopathy, or clinical deterioration. We experienced a patient whose abdominal computed tomography scan showed pneumoretroperitoneum, intramural gas in the colon, and inferior vena caval gas. Her condition improved after treatment with granulocyte colony-stimulating factor and broad-spectrum antibiotics. We report on this case along with a review of the literature.
        91.
        2013.08 서비스 종료(열람 제한)
        Use of nature-derived matrices of a part of body tissues has been used to repair damaged tissues in practical terms. Recently, the same idea has also been applied to regenerate whole organs including the heart, liver, lung, and pancreas etc. Thus, so-called bio-artificial organ technology becomes a promising way of overcoming the lack of donor organs and immune rejections in organ transplantation if we can obtain recipient stem cells. Although the regenerated heart in vitro so far may demonstrate some typical organ's responses in vitro and vivo, it is still far from a fully functional organ for transplantation. We initiated a study to look at changes occurring during the generation of bio-artificial organ using the mouse model. Adult hearts were dissected out and perfused for acellularization with SDS-containing buffer and washed several times. Enzymatic treatment also evaluated the acellular purity by isolating genomic DNA and total RNA before and after DNase and RNase treatments. For recellularization, differentiating H9C2 cell or cells derived from P19 EC cells along with mesenchymal stem cells were seeded on the finally obtained heart matrix several times before submerging culture for generating the heart. Histological analyses revealed that complete removal of cellular components. The intensive staining of alcian blue (pH 1.5 and 2.5) suggests that acid mucopolysaccharides, glycocomponents and sulfate-containing saccharides are widely spread within the heart matrix. There was little DNA and RNA in the heart matrix after the enzymatic treatments as judging by the DAPI or PI staining. Cell seeding and subsequent submerging culture showed substantial heart tissue development as evidenced by immunocytochemistry and RT-PCR in the recellularized and grown heart. From these results, we suggest that each procedure for bio-artificial organ has to be carefully examined to improve the entire process.
        92.
        2013.07 서비스 종료(열람 제한)
        Gibberellic acid (GA) is a well-characterized plant hormone, which plays a critical role in various plant growth and development. including stem elongation, floral indcution and seed development. GA is known to cause enlargement of ripening fruits and, especially in grapevines, GA shows a unique function: the induction of seedlessness in seeded grape varieties. However, despite extensive previous studies about GA, there has been no clear verification of the mechanism that induces seedlessness in grapes. To understand how GA treatment results in artificial parthenocarpy of seeded grapes at molecular levels, we analyzed transcriptional changes in seeded grapes with and without GA application in various inflorescence developmental stages using RNA-seq. At 14 days before flowering (DBF), seeded grapes were treated with 100 ppm GA and clusters were collected at three developmental stages: 7 DBF, full bloom, and 5 days after flowering (DAF). Of a total of 28,974 genes that were mapped to grape genome reference sequences, 7,013 and 9,064 genes were up- and down-regulated, respectively, in the GA-treated grape as compared to the non-GA-treated control at 7 DBF, full bloom, and 5 DAF. Clustering analysis revealed that these genes could be grouped into 9 clusters with different expression patterns. We also carried out functional annotation based on gene ontology categories. There were significant differences in the expression of the GA and auxin-related gene families. These findings expand our understanding of the complex molecular and cellular mechanisms of GA-induced parthenocarpy of grapes and provide a foundation for future studies on seed development in grapevines.
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