• Journal of Plant Biotechnology
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• v.4 no.2
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• pp.53-58
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• 2002

Adverse environmental conditions such as drought, high salt and cold/freezing are major factors that reduces crop productivity worldwide. According to a survey, 50-80% of the maximum potential yield is lost by these "environmental or abiotic stresses", which is approximately ten times higher than the loss by biotic stresses. Thus, improving stress-tolerance of crop plants is an important way to improve agricultural productivity, In order to develop such stress-tolerant crop plants, we set out to identify key stress signaling components that can be used to develop commercially viable crop varieties with enhanced stress tolerance. Our primary focus so far has been on the identification of transcription factors that regulate stress responsive gene expression, especially those involved in ABA-mediated stress response. Be sessile, plants have the unique capability to adapt themselves to the abiotic stresses. This adaptive capability is largely dependent on the plant hormone abscisic acid (ABA), whose level increases under various stress conditions, triggering adaptive response. Central to the response is ABA-regulated gene expression, which ultimately leads to physiological changes at the whole plant level. Thus, once identified, it would be possible to enhance stress tolerance of crop plants by manipulating the expression of the factors that mediate ABA-dependent stress response. Here, we present our work on the isolation and functional characterization of the transcription factors.n factors.

• Korean Journal of Plant Resources
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• v.21 no.3
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• pp.204-209
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• 2008

We have cloned an LTP gene (PoLTP1) from poplar (Populus alba ${\times}$ P. tremula var. glandulosa) suspension cells and examined changes in its expression levels in response to various stresses and ABA treatment. The full-length PoLTP1 cDNA clone encodes a polypeptide of 116 amino acids with typical characteristics of LTPs, notably a conserved arrangement of cysteine residues. Southern blot analysis indicate that two or three copies of the PoLTP1 are present in the genome of the investigated hybrid poplar. In addition, northern analysis of samples from soil-grown plants indicate that PoLTP1 is tissue-specifically expressed in the leaves and flowers. The gene is significantly up-regulated by treatment with mannitol, NaCl and ABA, but not by either cold or wounding. These results indicate that PoLTP1 is involved in osmotic stress responses in poplar plants and suspension cells.

• Plant Biotechnology Reports
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• v.3 no.3
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• pp.183-190
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• 2009

Rho-related GTPase of plants (ROP) plays an important role in plant growth and development as a signaling protein. Plant RopGEFs are recently identified ROP activator proteins in Arabidopsis. In this study, we cloned 14 RopGEFs in Arabidopsis and characterized their expression patterns in response to abiotic stresses. Fourteen RopGEF genes were categorized into three groups based on their amino acid homologies and molecular sizes. Most RopGEFs were expressed predominantly in flower but some RopGEFs displayed a tissue-specific expression pattern. RopGEF1, 4, 5, and 11 were expressed in all tissues including root and leaves whereas RopGEF7, 8, 9, and 13 were expressed only in flowers. The transcript levels of 14 RopGEFs were changed significantly depending upon abiotic stresses such as cold, heat, drought and salts. RopGEF5 transcription was up-regulated by salt and drought treatment but down-regulated by heat. RopGEF14 transcript level was also increased by salt but decreased by heat stress. The transcript levels of RopGEF1, 7, 9, and 12 were enhanced in response to heat stress but showed no changes in response to cold stresses. Drought stress activated Group 3 RopGEFs such as RopGEF5 and 7. Taken together, 14 RopGEFs are responding to the abiotic stresses individually or as a group.

• Korean Journal of Plant Resources
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• v.27 no.4
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• pp.392-399
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• 2014

Plant senescence is one of the survival strategies to use limited nutrients efficiently during growth, development and adaptation. In this study, we isolated a gene (PagSEN1) homologous to SENESCENCE 1 from Populus alba ${\times}$ P. glandulosa. The PagSEN1 gene encodes a putative protein consisting of 243 amino acids containing a rhodanese domain. Southern blot analysis suggested that two copies of the PagSEN1 gene are present in the poplar genome. We characterized its transcriptional expression under various conditions mimicking senescence and environmental stresses. The PagSEN1 was expressed most strongly in mature leaves but most weakly in roots. The gene was significantly up-regulated by treatments with mannitol, NaCl, ABA and JA, but not by cold, SA and GA3. These results indicate that PagSEN1 is involved in senescence response induced by environmental stresses.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.78.1-78
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• 2003

An osmotin-like protein (CAOSMl) gene was isolated from pepper leaves infected with the avirulent strain Bv5-4a of Xmthomonas campestris pv. vesicatoria. The cDNA encodes a polypeptide of 250 amino acids with a molecular mass of 27, 361 Da. Its amino acid sequence is highly homologous to various osmotin-like proteins from other plant species. The CAOSMl gene expression was organ- and tissue-specifically regulated In pepper plants. The CAOSMl mRNA was intensely localized in the endodermis area of root tissue and in the phloem cells of vascular bundles of red fruit tissue, but not in leaf, stem, and green fruit tissues of healthy pepper plants. Infection by X. c. pv vesintoria, Colletotrichum coccodes, or Phytopkhora capsici iinduced CAOSMl transcription in the leaf or stem tissues. Expression of the CAOSMl gene was somewhat higher in the incompatible than the compatible interactions of pathogens with pepper. The CAOSMl mRNA was prevalently localized in the phloem cells of the vascular bundle of leaf tissues infected by C. coccodes. The CAOSMl gene was activated in leaf tissues by treatment with ethylene, methyl jasmonate, high salinity, cold acclimation and mechanical wounding, but not by abscisic acid (ABA) and drought. These results indicate that the pepper CAOSMl protein functions in response to Pathogens and some abiotic stresses in pepper plants

• BMB Reports
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• v.37 no.5
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• pp.538-545
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• 2004

A new CRT binding factor (CBF) gene designated Cbcbf25 was cloned from Capsella bursa-pastoris, a wild grass, by the rapid amplification of cDNA ends (RACE). The full-length cDNA of Cbcbf25 was 898 bp with a 669 bp open reading frame (ORF) encoding a putative DRE/CRT (LTRE)-binding protein of 223 amino acids. The predicted CbCBF25 protein contained a potential nuclear localization signal (NLS) in its N-terminal region followed by an AP2 DNA-binding motif and a possible acidic activation domain in the C-terminal region. Bioinformatic analysis revealed that Cbcbf25 has a high level of similarity with other CBF genes like cbf1, cbf2, and cbf3 from Arabidopsis thaliana, and Bncbf5, Bncbf7, Bncbf16, and Bncbf17 from Brassica napus. A cold acclimation assay showed that Cbcbf25 was expressed immediately after cold triggering, but this expression was transient, suggesting that it concerns cold acclimation. Our study implies that Cbcbf25 is an analogue of other CBF genes and may participate in cold-response, by for example, controlling the expression of cold-regulated genes or increasing the freezing tolerance of plants.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2002.04a
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• pp.41-47
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• 2002

Adverse environmental conditions such as drought, high salt and cold/freezing are major factors that reduces crop productivity worldwide. According to a survey, $50-80\%$ of the maximum potential yield is lost by these 'environmental or abiotic stresses', which is approximately ten times higher than the loss by biotic stresses. Thus, Improving stress-tolerance of crop plants is an important way to improve agricultural productivity. In order to develop such stress-tolerant crop plants, we set out to identify key stress signaling components that can be used to develop commercially viable crop varieties with enhanced stress tolerance. Our primary focus so far has been on the identification of transcription factors that regulate stress responsive gene expression, especially those involved in ABA-mediated stress response. Be sessile, plants have the unique capability to adapt themselves to the abiotic stresses. This adaptive capability is largely dependent on the plant hormone abscisic acid (ABA), whose level increases under various stress conditions, triggering adaptive response. Central to the response is ABA-regulated gene expression, which ultimately leads to physiological changes at the whole plant level. Thus, once identified, it would be possible to enhance stress tolerance of crop plants by manipulating the expression of the factors that mediate ABA-dependent stress response. Here, we present our work on the isolation and functional characterization of the transcription factors.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2002.04b
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• pp.41-47
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• 2002

Adverse environmental conditions such as drought, high salt and cold/freezing are major factors that reduces crop productivity worldwide. According to a survey, 50-80% of the maximum potential yield is lost by these 'environmental or abiotic stresses', which is approximately ten times higher than the loss by biotic stresses. Thus, improving stress-tolerance of crop plants is an important way to improve agricultural productivity. In order to develop such stress-tolerant crop plants, we set out to identify key stress signaling components that can be used to develop commercially viable crop varieties with enhanced stress tolerance. Our primary focus so far has been on the identification of transcription factors that regulate stress responsive gene expression, especially those involved in ABA-mediated stress response. Be sessile, plants have the unique capability to adapt themselves to the abiotic stresses. This adaptive capability is largely dependent on the plant hormone abscisic acid (ABA), whose level increases under various stress conditions, triggering adaptive response. Central to the response is ABA-regulated gene expression, which ultimately leads to physiological changes at the whole plant level. Thus, once identified, it would be possible to enhance stress tolerance of crop plants by manipulating the expression of the factors that mediate ABA-dependent stress response. Here, we present our work on the isolation and functional characterization of the transcription factors.

• Journal of Society of Preventive Korean Medicine
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• v.18 no.2
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• pp.101-113
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• 2014

Objective : Ephedra Herba has been widely used for patients with common cold, asthma in eastern countries, especially china japan and korea. Recently it has been also used for obesity in clinic with high frequency. This study was designed to investigate the effects of Ephedra Herba ethyl-acetate fraction (EEAF) on hyperlipidemic mice. Method : Effects on total cholesterol, HDL-cholesterol, triglyceride, AST, ALT, fasting blood glucose in serum were measured in this experiment, and in addition, histopathological and gene expression changes in liver tissue was also observed. Results : In our study, EEAF did not affect weight gain in hyperlipidemic mice. Oral administration of EEAF lowered levels of total cholesterol which were elevated by induction of hyperlipidemia. And administration of EEAF lowered fasting blood glucose significantly. By carrying out ontological analysis, large numbers of genes were identified in up or down regulated genes. The expression of the genes that were altered in response to high-fat diet was restored to normal levels in EEAF treated mice, with a recovery rate of 49%. And it was considered that fatty acid metabolism was one of important key pathway of the recovery. Conclusion : Results in our study suggest that EEAF can prevent obese and through regulation of dyslipidemia and hyperglycaemia.

• Molecules and Cells
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• v.40 no.10
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• pp.697-705
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• 2017

The maintenance of inorganic phosphate (Pi) homeostasis is essential for plant growth and yield. Plants have evolved strategies to cope with Pi starvation at the transcriptional, post-transcriptional, and post-translational levels, which maximizes its availability. Many transcription factors, miRNAs, and transporters participate in the Pi starvation signaling pathway where their activities are modulated by sugar and phytohormone signaling. Environmental stresses significantly affect the uptake and utilization of nutrients by plants, but their effects on the Pi starvation response remain unclear. Recently, we reported that Pi starvation signaling is affected by abiotic stresses such as salt, abscisic acid, and drought. In this review, we identified transcription factors, such as MYB, WRKY, and zinc finger transcription factors with functions in Pi starvation and other environmental stress signaling. In silico analysis of the promoter regions of Pi starvation-responsive genes, including phosphate transporters, microRNAs, and phosphate starvation-induced genes, suggest that their expression may be regulated by other environmental stresses, such as hormones, drought, cold, heat, and pathogens as well as by Pi starvation. Thus, we suggest the possibility of cross-talk between Pi starvation signaling and other environmental stress signaling pathways.