검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 126

        101.
        2015.07 서비스 종료(열람 제한)
        To identify novel signaling components involved in regulation of plant responses to phosphate (Pi) starvation, we screened an Arabidopsis T-DNA activation tagging library for mutants with altered Pi-starvation responses. Here, we report the identification and characterization of novel activation-tagged mutant involved in Pi starvation signaling in Arabidopsis. The hpd (hypersensitive to Pi deficiency) mutant exhibits enhanced phosphate uptake and altered root architectural change under Pi starvation compared to wild type. Expression analysis of auxin-responsive DR5::GUS reporter gene in hpd mutant indicated that both auxin biosynthesis and auxin translocation under Pi starvation are suppressed in hpd mutant plants. Impaired auxin translocation in roots of hpd mutant was attributable to abnormal root architecture changes in Pi starvation conditions. Mis-regulation of auxin translocation in hpd mutant was further confirmed by analysis of expression patterns of auxin efflux carrier proteins, PIN-FORMED (PIN) 1, 2, and 3 fused with GFP. Not only expression levels but also expression domains of PIN proteins were altered in hpd mutant in response to Pi starvation. Molecular genetic analysis of hpd mutant revealed that the mutant phenotype is caused by the lesion in ENHANCED SILENCING PHENOTYPE4 (ESP4) gene whose function is proposed in mRNA 3’-end processing. The results propose that mRNA processing plays crucial roles in Pi homeostasis as well as developmental reprograming in response to Pi deprivation in Arabidopsis.
        102.
        2015.07 서비스 종료(열람 제한)
        UDP-glucose 4-epimerase (UGE; EC 5.1.3.2) is an enzyme that plays an essential role in the interconverts UDP-D-glucose (UDP-Glc) and UDP-Dgalactose (UDP-Gal). Five members of the Chinese cabbage (Brassica rapa) UDP-glucose 4-epimerase gene family, designated BrUGE1 to BrUGE5, have been cloned and characterized. Quantitative PCR shows that the BrUGE1and BrUGE4 mRNA are most abundant among other BrUGE genes, accounting for more than 55% of total BrUGE transcripts in most of the tissues examined. All genes showed organ specific expression pattern, two of which (BrUGE1 and 4) actively responded after Pectobacterium carotovorum subsp. carotovorum infection, while four genes (BrUGE-1, -3, -4 and -5)were shown to respond considerably against salt, drought and abscisic acid (ABA) treatments. To better understand the function of the UGE gene, we constructed a recombinant pART vector carrying the BrUGE1 gene under the control of the CaMV 35S promoter and nos terminator and transformed using Agrobacterium tumefaciens. We then investigated BrUGE1 overexpressing rice lines at the physiological and molecular levels under biotic and abiotic stress conditions. Bioassay of T3 progeny lines of the transgenic plants in Yoshida solution containing 120 mM Nacl for 2 weeks, confirmed that the BrUGE1 enhances salt tolerance to transgenic rice plants. Also T3 progeny lines of the transgenic plants, when exposed to infection caused by Xanthomonas oryzae pv oryzae, showed tolerance to bacterial blight. These results showed that BrUGE1 can be used as potential genetic resource for engineering Brassica with multiple stress resistance.
        103.
        2015.06 KCI 등재 서비스 종료(열람 제한)
        This study was performed to investigate the growth characteristics and inorganic components of Codonopsis lanceolata regarding regional differences. The plant height of Japanese Codonopsis lanceolata was 373.6 cm, so it’s revealed that it has more vigorous growth than Korean won. The flowering time of Korean Codonopsis lanceolata was 2 weeks faster than Japanese one. Total fresh weight of root was 41.0 g and 39.0 g for Korean and Japanese respectively, thus, no significance difference was found. However, regarding fresh weight, Korean one had a more fresh weight (35.4 g) of main root parts, but Japanese one had a more fresh weight (9.6 g) of the lateral root part. Each inorganic component was found more in the aboveground parts, regardless of the region and the content of K was the largest. Regarding the content of macroelements for each part of Codonopsis lanceolata, the content of Na, Mg, P, S, and Ca in Korean Codonopsis lanceolata was found the highest on the leaf, followed by stem and root. In the case of Japanese Codonopsis lanceolata, same result was found on the content of Mg and Ca, however, the highest content of Na and P was found in the stem.
        104.
        2015.06 KCI 등재 서비스 종료(열람 제한)
        This study was conducted to compare the growth, inorganic components, and proximate components of Codonopsis lanceolata grown in 10 regions of Korea for selecting superior species and breeding by crossing. Among the all tested lines, the shortest plant height (217.12 cm) was observed from the Ulleungdo region line (No. 4) while the longest (273.9 cm) was observed from Hwasun region line (No. 9). In addition, the lines of central and northern region (No. 1~No. 7) tend to have shorter plant height than those of southern region (No. 8~No. 9) except Jejudo region line (No. 10). Flowering tends to be late towards southern region, and lines in central and northern regions were started flowering about 2 weeks earlier than those in southern regions. However, the heaviest root weight was 13.1 g, found in only Jejudo line (No. 10) whereas there was no significant difference found in the other regions which have a range of 8.3~11.0 g. The inorganic components were varied in each line, however, proportion of macroelements, such as K, Ca, and P, was the largest for every line. Especially for Heongseong region line (No. 2), had larger proportion of macroelements than the others. There was a difference of proximate compositions of Codonopsis lanceolata, except the moisture content, among all regions, however, it was generally shown that the content of crude protein (1.31~3.76%) and crude fiber (2.18~3.12%) was the highest.
        105.
        2014.12 KCI 등재 서비스 종료(열람 제한)
        The early growth response protein 1 (Egr-1) is a widely reported zinc finger protein and a well known transcription factor encoded by the Egr-1 gene, which plays key roles in many aspects of vertebrate embryogenesis and in adult vertebrates. The Egr-1 expression is important in the formation of the gill vascular system in flounders, which develops during the post-hatching phase and is essential for survival during the juvenile period. However, the complete details of Egr-1 expression during embryo development in olive flounder are not available. We assessed the expression patterns of Egr-1 during the early development of olive flounders by using reverse transcription polymerase chain reaction (RT-PCR) analysis. Microscopic observations showed that gill filament formation corresponded with the Egr-1 expression. Thus, we showed that Egr-1 plays a vital role in angiogenesis in the gill filaments during embryogenesis. Further, Egr-1 expression was found to be strong at 5 days after hatching (DAH), in the development of the gill vascular system, and this strong expression level was maintained throughout all the development stages. Our findings have important implications with respect to the biological role of Egr-1 and evolution of the first respiratory blood vessels in the gills of olive flounder. Further studies are required to elucidate the Egr-1-mediated stress response and to decipher the functional role of Egr-1 in developmental stages.
        106.
        2014.07 서비스 종료(열람 제한)
        Genome sequencing researches for considerable numbers of crops and wild plants are being developed. Cytogenetic researches according to chromosome number and size are essential to confirm and comprehend ploidy level and genome size before genome sequencing project is actually conducted. Cytogenetic researches on six food crop plants were carried out by DAPI staining and fluorescence in situ hybridization (FISH) method. Fagopyrum esculentum Moench showed 2n=2x=16, each chromosome length of 1.42㎛ to 1.77㎛, total chromosome length of 13.31㎛, and karyotypic formula of 2n=8m; Phaseolus angularis W.F. Wight, 2n=2x=22, 2.01㎛ to 3.84㎛, total 28.03㎛, 2n=9m+2sm, Perilla frutescens var. japonica Hara, 2n=2x=40, 1.73㎛ to 2.76㎛, total 44.36㎛, 2n=5m+13sm+2st. Chromosome sizes of the other three species such as, Panicum miliaceum L., 2n=2x=36, total chromosome length of 30.83㎛, Sesamum indicum L., 2n=2x=26, 27.39㎛, lpomoea batatas L., 2n=2x=30, total 33.51㎛ were too small for each chromosome type to be identified and analyzed. The result of FISH analysis using 5S and 45S rDNA probe showed species-specific chromosome locations in the genome. These preliminary analyses were carried out to decide which food crop to prioritize for genome sequencing. This work was supported by the “Cooperative Research Program for Agriculture Science & Technology Development (No.PJ009837), Rural Development Administration, Republic of Korea.
        107.
        2013.12 KCI 등재 서비스 종료(열람 제한)
        The innate immune system is the only defense weapon that invertebrates have, and it is the fundamental defense mechanism for fish. The innate immune response is important in newly hatched flounders because it is closely involved in the initial feeding phase, which is why it is essential for survival during the juvenile period. The expression analysis of genes involved in the innate immune response in the olive flounder (Paralichthys olivaceus) in the days after hatching is incomplete. Therefore, we have begun to examine the expression patterns of genes specifically induced during the development of the innate immune system in newly hatched flounders. Microscopic observation showed that pronephron formation corresponded with the expression of perforin-encoding gene. These results suggest that perforin plays a vital role in the innate immunity of the kidney during developmental stages. Perforin expression was strong at the start of the development of the innate immune response, and continued throughout all the development stages. Our findings have important implications with respect to perforin’s biological role and the evolution of the first defense mechanisms in olive flounder. Further studies are required to elucidate the perforin-mediated innate immunity response and to decipher the functional role of perforin in developmental stages.
        108.
        2013.08 서비스 종료(열람 제한)
        MFG-E8 (Milk fat globule-epidermal growth factor VIII), also called lactadherin or BA46, SED1 is a glycoprotein found in milk and mammary epithelial cells, it is a major protein component associated with milk fat globule membrane. Previously, our study showed that expression of MFG-E8 is gradually increased with hepatic differentiation of human embryonic stem cells (hESCs). Therefore, we hypothesized that MFG-E8 would be an early cancer stem cell marker, which may predict cancer progression. Our results showed that MFG-E8 was expressed in various human cancer cell lines such as HepG2, Hep3B, and Huh7. Production and secretion of the MFG-E8 were also confirmed in the conditioned media of those three cell lines using enzyme-linked immunosorbent assay. Next, we analyzed the MFG-E8 expression in 11 clinical cases of cholangiocellular carcinoma (CC) and 33 cases of hepatocellular carcinoma (HCC) by immunohistochemistry and examined the potential correlation with β-catenin and AFP, which are known cancer markers. According to hitological criteria, the progression of HCC and CC was evaluated and classified into high, low, metastatic, and well-, moderate-, poor-differentiated, respectively. Statistical analysis indicated that incidence of both HCC and CC is significantly associated with male compared to female (P<0.05). Tumor size also has positive correlation with age (r2=08948). Our immunohistochemistry data showed that MFG-E8 was expressed both HCC and CC tissue. Interestingly, the MFG-E8 expression was significantly increased with cancer progression (P<0.05) in both cases. Additionally, b-cateninexpression was increased and its localization was changed from membrane to cytoplasm and nucleus with the degree of HCC. Likely b-catenin, AFP was also increased with the degree of HCC but it was not correlated with severalty of CC. Importantly, both AFP and b-catenin were highly co-localized with MFG-E8 in HCC. These results suggest that MFG-E8 may have important physiological roles and its expression in HCC and CC would be considered as an important prognostic factor.
        109.
        2012.09 KCI 등재 서비스 종료(열람 제한)
        Citrus is one of the major fruits produced in Korea. There are about 20 species mainly grown in Jeju Island, Korea. Four representative species, which are quite different in the shape of leaf and the taste of fruit, were selected and were used to profile the transcriptomes. These species are ‘Miyagawa Wase’ (C. unshiu Marcov.) satsuma mandarin, ‘Kiyomi’ (C. unshiu Marcov. × C. sinensis) mandarin hybrid, ‘Dangyuja’ (C. grandis) and ‘Natsudaidai’ (C. natsudaidai). Classification of the up-regulated and down-regulated genes using the Cluster of Orthologous Groups of proteins (COG) database reveals that the number of genes included in each group differed significantly among the four species. Several genes that showed significant differences in expression on the microarray were selected and their expression patterns were examined by reverse transcription- ploymerase chain reaction. Metabolic genes such as tyrosine decarboxylase and β-glucosidase ligase were found to be highly expressed in Miyagawa Wase, relative to other species. On the other hand, the expression level of mannose phosphate isomerase was lower in Miyagawa Wase. An efflux pump gene was found to be up-regulated in Kiyomi, whereas cinnamyl-alcohol dehydrogenase was down-regulated. β-carotene 15,15’-dioxygenase, which is involved in the vitamin metabolism, was up-regulated in Natsudaidai. Interspecific differentiations of gene expression are analyzed in terms of the metabolic pathways and their possible roles in citrus species.
        110.
        2012.07 서비스 종료(열람 제한)
        Phosphorus is one of the macronutrients essential for plant growth and development, as well as crop productivity. Many soils around the world are deficient in phosphate (Pi) that plants can utilize. To cope with the stress of Pi starvation, plants have evolved many adaptive strategies, such as changes of root architecture and enhanced Pi acquisition form soil. To understand molecular mechanism underlying Pi starvation stress signaling, we characterized the activation-tagged mutant showing altered responses to Pi deficiency compared to wild type Arabidopsis and named hsp3 (hypersensitive to Pi starvation3). hsp3 mutant exhibits enhanced phosphate transporter activity, resulting in higher Pi content than wild type. However, in root architectural change under Pi starvation, hsp3 shows hyposensitive responses than wild type, such as longer primary root elongation, lower lateral root density. Histochemical analysis using hsp3 mutant expressing auxin-responsive DR5::GUS reporter gene, indicated that auxin allocation from primary to lateral roots under Pi starvation is aborted in hsp3 mutant. Molecular genetic analysis of hsp3 mutant revealed that the mutant phenotype is caused by the lesion in ENHANCED SILENCING PHENOTYPE4 (ESP4) gene whose function is proposed in mRNA 3’ end processing. Here, we propose that mRNA processing plays a crucial role in Pi homeostasis in Arabidopsis.
        111.
        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.
        112.
        2012.07 서비스 종료(열람 제한)
        Development of transgenic plant with desirable traits to cultivated plant is one of the important procedures in plant molecular breeding. However, applicable assessment of transgenic plant in laboratorial scale is not much except cultivating transgenic plant for a whole life in field condition. Here, we analyzed chlorophyll fluorescence in three transgenic soybean lines with AtMYB44 transcription factor for assessment of photosynthetic activity under abiotic stresses such as drought. Soybean varieties used in this study were ‘Bert’ and ‘Bert’ derived three transgenic soybeans, ‘AtMYB44 CM35101’, ‘AtMYB44 CM2471’, and ‘AtMYB44 CM4481’. Analyzed five different chlorophyll fluorescence variables are maximum PSII quantum yield (QY_max), steady state PSII quantum yield (QY_Lss), steady state non-photochemical quenching (NPQ_Lss), coefficient of photochemical quenching in steady-state (Qp_Lss), and fluorescence declineratio in steady-state (Rfd_Lss). To determine main chlorophyll fluorescence variable affected by abiotic stress, principal component analysis (PCA) was conducted with five chlorophyll fluorescence variables measured from four varieties. QY_Lss and NPQ_Lss were main chlorophyll fluorescence variables to evaluate abiotic stress, particularly in drought stress. In comparison with transgenic soybean lines based on chlorophyll fluorescence variables, ‘AtMYB44 CM2471’ and ‘AtMYB44 CM4481’ are more tolerant to drought than the others. Interestingly, three transgenic soybean lines which have a same AtMYB44 gene with different regions of chromosome revealed the quite different responses of chlorophyll fluorescence to drought treatment.
        115.
        2010.09 서비스 종료(열람 제한)
        Previously we have succeeded to isolate stem cells (HEAC) from human eyelid adipose tissue, and functionally differentiate them into insulin-secreting cells. In the present study, we examined whether insulin family members might affect the insulinogenic differentiation of HEAC. Insulin treatment during culture affected little on the insulin and c-peptide secretions from HEAC after culture. However, insulin-like growth factor (IGF) 1 treatment decreased both secretions, whereas IGF2 greatly increased the secretions in a glucose-dependent manner. HEAC treated with IGF2 showed stronger expression of Pdx1, Isl1, Pax6 and PC1/3 genes compared to the control. They also showed distinct staining with insulin and c-peptide antibodies, and dithizone. While insulin or IGF2 treatment increased total cell number by 1.3- or 1.5-fold, respectively, each treatment increased the amount of insulin secretion by 27.1- or 78.1-fold, respectively. IGF2-enhanced insulinogenic differentiation was completely blocked by an antibody against insulin receptor (IR), but not by an antibody against IGF1 receptor (IGF1R). Differentiated HEAC showed expression of both IR and IGF1R genes while they expressed neither IGF2 nor IGF2R genes. Based upon these results, it is suggested that whereas IGF1 might inhibit the insulinogenic differentiation of HEAC, insulin and IGF2 could enhance the differentiation, and that the enhancing effect could be mediated via IR.
        120.
        2006.08 KCI 등재 서비스 종료(열람 제한)
        Research Institute (HARI), NTCS, RDA, in 2004. This cultivar has a short grain shape and about 123 days growth duration from trans-planting to harvesting under the reclaimed saline area of the south-western and the mid-western coastal plain and Honam plai
        6 7