• Journal of Magnetics
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• v.11 no.3
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• pp.115-118
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• 2006

Co-ferrite nanoparticles have been synthesized by the decomposition of iron(III) acetylacetonate, $Fe(acac)_3$ and Co acetylacetonate, $Co(acac)_2$ in benzyl/phenyl ether in the presence of oleic acid and oleyl amine at the refluxingtemperature of $295^{\circ}C$/$265^{\circ}C$ for 30 min. before cooling to room temperature. Particle diameter detected by PSA can be turned from 4 nm to 20 nm by seed-mediated growth and reaction conditions. Structural and magneticcharacterization of Co-ferrite were measured by use of HRTEM, SAED (selected area electron diffraction), XRD and SQUID. The as-synthesized Co-ferrite nanoparticles have a cubic spinel structure and coercivity of 20 nm $CoFe_{2}O_{4} nanoparticles reached 1 kOe at room temperature and 18 kOe at 10 K.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.196-196
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• 2017

Oilseed crop Camelina (Camelina sativa L.) is a suitable for biodiesel production that has high adaptability under low-nutrient condition like marginal land and requires low-input cost for cultivation. Enhanced abiotic stress tolerance of Camelina is very important for oil production under the wide range of different climate. CsRCI2s (Rare Cold Inducible 2) are related proteins in various abiotic stresses that predicted to localized at plasma membrane (PM) and endoplasmic reticulum (ER). These proteins are consist of eight-family that can be divided into tail (CsRCI2D/E/F/G) and no-tail (CsRCI2A/B/E/H) type of C-terminal. However, it is still less understood the function of C-terminal tail. In this study, CsRCI2D/H genes were cloned through gateway cloning system that used pCB302-3 as destination vector. And we used agrobacterium-mediated transformation system for generation of overexpression (OX) transformants. Overexpression of target gene was confirmed using RT-PCR and segregation ratio on selection media. We analyzed physiological response in media and soil under abiotic stresses using CsRCI2D and CsRCI2H overexpression plant. To compare abiotic stresses tolerance, wild type and CsRCI2D/H OX line seeds were sown on agar plate treated with various NaCl and mannitol concentration for 7 days. In the test of growth rate under abiotic stress on media, CsRCI2H OX line showed similar to NaCl and mannitol stress. In the other hand, CsRCI2D OX line showed to be improved stress tolerance that especially increased in 200mM NaCl but was similar on mannitol media. In greenhouse, WT and CsRCI2D/H OX lines for physiological analysis and productivity under abiotic stresses were treated 100, 150, 200mM NaCl. Then it was measured various parameters such as leaf width and length, plant height, total seed weight, flower number, seed number. CsRCI2H OX line in greenhouse did not show any changes in physiological parameters but CsRCI2D OX line was improved both physiological response and productivity under NaCl stress. Among physiological parameters of CsRCI2D OX line under NaCl stress, leaf length and width were observed shorter than WT but it were slightly longer than WT in 200mM NaCl stress. Furthermore, total seed weight of CsRCI2D OX line under stress displayed to decrease than WT in normal condition, but it was gradually raised with increasing NaCl stress then more than WT relatively. These results suggested CsRCI2D might be contribute to improve abiotic stress tolerance. However, function of CsRCI2H is need to more detail study. In conclusion, overexpression of CsRCI2s family can generate various environmental stress tolerance plant and may improve crop productivity for bio-energy production.

• Journal of Life Science
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• v.24 no.2
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• pp.196-208
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• 2014

During the life cycle of plants, water deficit leads to an adverse effect on its growth and development. To increase the productivity of crops, overcoming such drought stress is one of the most important issues in the field of plant study. Among plant hormones, the phytohormone, abscisic acid (ABA) plays a crucial role in eliciting resistance to drought stress as well as in multiple developmental processes, such as seed germination, stomatal closure, and seedling growth. Therefore, further understanding of the ABA-mediated signal transduction pathway in plants is an effective strategy to generate drought-tolerant plants. Posttranslational modification, such as phosphorylation and ubiquitination, is an efficient mechanism for plants to acquire quick adaptation against environmental stress conditions since this process directly affects pre-existing signaling components by modulating protein activity and stability. Here, recent reports on ABA signaling are reviewed, especially focusing on ABA transport, perception, signaling, and posttranslational modification in ABA-mediated cellular responses. Also, we present future prospects on how the control of such a mechanism can be applied to generate useful agricultural crops.

• Biomolecules & Therapeutics
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• v.23 no.1
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• pp.77-83
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• 2015

The seed of Vigna angularis has long been cultivated as a food or a folk medicine in East Asia. Genistein (4',5,7-trihydroxyisoflavone), a dietary phytoestrogen present in this plant, has been known to possess various biological properties. In this study, we investigated the possible lifespan-extending effects of genistein using Caenorhabditis elegans model system. We found that the lifespan of nematode was significantly prolonged in the presence of genistein under normal culture condition. In addition, genistein elevated the survival rate of nematode against stressful environment including heat and oxidative conditions. Further studies demonstrated that genistein-mediated increased stress tolerance of nematode could be attributed to enhanced expressions of stress resistance proteins such as superoxide dismutase (SOD-3) and heat shock protein (HSP-16.2). Moreover, we failed to find genistein-induced significant change in aging-related factors including reproduction, food intake, and growth, indicating genistein exerts longevity activity independent of affecting these factors. Genistein treatment also led to an up-regulation of locomotory ability of aged nematode, suggesting genistein affects healthspan as well as lifespan of nematode. Our results represent that genistein has beneficial effects on the lifespan of C. elegans under both of normal and stress condition via elevating expressions of stress resistance proteins.

• The Plant Pathology Journal
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• v.34 no.1
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• pp.71-77
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• 2018

Resistance to Tomato spotted wilt virus isolated from paprika (TSWV-Pap) was overcome at high temperatures ($30{\pm}2^{\circ}C$) in both accessions of Capsicum annuum S3669 (Hana Seed Company) and C. chinense PI15225 (AVRDC Vegetable Genetic Resources). S3669 and PI15225, which carrying the Tsw gene, were mechanically inoculated with TSWV-Pap, and then maintained in growth chambers at temperatures ranging from $15{\pm}2^{\circ}C$ to $30{\pm}2^{\circ}C$ (in $5^{\circ}C$ increments). Seven days post inoculation (dpi), a hypersensitivity reaction (HR) was induced in inoculated leaves of PI152225 and S3669 plants maintained at $25{\pm}2^{\circ}C$. Meanwhile, necrotic spots were formed in upper leaves of 33% of PI15225 plants maintained at $30{\pm}2^{\circ}C$, while systemic mottle symptoms developed in 50% of S3669 plants inoculated. By 15 dpi, 25% of S3669 plants had recovered from systemic mottling induced at $30{\pm}2^{\circ}C$. These results demonstrated that resistance to TSWV-Pap can be overcome at higher temperatures in both C. chinense and C. annuum. This is the first study reporting the determination of temperatures at which TSWV resistance is overcome in a C. annuum genetic resource expressing the Tsw gene. Our results indicated that TSWV resistance shown from pepper plants possess the Tsw gene could be overcome at high temperature. Thus, breeders should conduct evaluation of TSWV resistance in pepper cultivars at higher temperature than $30^{\circ}C$ (constant temperature).

• Journal of Plant Biotechnology
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• v.44 no.3
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• pp.264-270
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• 2017

Brassinosteroid (BR), a plant steroid hormone, plays a critical role in the growth and developmental processes through its canonical signaling and crosstalk with various internal and external signaling pathways. Recent studies have revealed the essential interplay mechanisms between BR and ABA during seed germination and early seedling establishment. However, molecular mechanisms for this important signaling crosstalk are largely unknown. To understand the crosstalk between BR-mediated signaling pathways and ABA functions during early seedling development, we carried out a comparative genome-wide transcriptome analysis with an Agilent Arabidopsis $4{\times}44K$ oligo chip. We selected and compared the expression patterns of ABA response genes in ABA-insensitive bes1-D mutant with wild type seedlings on which ABA was exogenously applied. As a result, we identified 2,353 significant differentially expressed genes (DEGs) in ABA-treated bes1-D and wild type seedlings. GO enrichment analysis revealed that ABA signaling, response, and metabolism were critically down-regulated by BR-activated signaling pathways. In addition, the genome-wide transcriptome analysis data revealed that BR-regulated signaling pathways were tightly connected to diverse signal cues including abiotic/biotic stress, auxin, ROS etc. In this study, we newly identified the molecular mechanisms of BR-mediated repression of ABA signaling outputs. Also, our data suggest that interplay among diverse signaling pathways is critical for the adaptive response of the plant to various environmental factors.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.191-191
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• 2017

Hydroxy fatty acid (HFA) is an important industrial resource that known to be extracted from seeds of Castor or Lesquerella. However, mass production of HFA from those crops are difficult because of their behavior or life cycle. In this study, we applied HFA synthesis related gene FAH12, RcPDAT1, RcLPCAT, RcDGAT2, and RcPDCT on bioenergy crop Camelina sativa. Furthermore, we determined NaCl or cold stress tolerance changes of transgenic Camelina. RcFAH12, RcPDAT1, RcLPCAT, RcDGAT2, and RcPDCT genes were cloned into multigene expression vector which is engineered with seed specific promoter of FAE1 or Napin. Combination of HFA genes multi-expression vector constructs were divided into Set3 (RcFAH12, RcPDAT1-2, RcLPCAT), Set4 (RcFAH12, RcDGAT2, RCPDAT1-2, RcLPCAT), and Set5 (RcFAH12, RcDGAT2, RCPDAT1-2, RcLPCAT, RcPDCT). Transgenic HFA synthesis Camelina plants were generated using agrobacterium-mediated vacuum infiltration system. Results of fatty acid composition of T1 transgenic Camelina seeds analyzed by GC-MS showed 9.5, 9.0, and 13.6 % of HFA contents in Set3#6, Set4#8, and Set5#10, respectively. Therefore, seeds of T2 generation were harvest from Set5#10 which is shown highest HFA contents, and, 17.7, 8.1 and 10.5 % of HFA contents were determined in Set5#10-5, Set5#10-8, and Set#10-10, respectively. However, 7.7% of C18:2 and 22.3 % of C18:3 among unsaturated fatty acids were decreased in Set5#10-5 than WT. Meanwhile, we confirmed abiotic stress responses in T2 transgenic Camelina Set5#10-5 and Set5#10-10 under 0, 100, 150, and 200 mM NaCl or 25, 15, and $10^{\circ}C$ temperature for 5 weeks. Both Set5#10-5 and Set5#10-10 showed lower growth in height than WT in control and NaCl condition. Growth of leaf length and width were similar in WT and Set5#10-10 but lower in Set5#10-5 under NaCl stress. Number of opened flowers showed that both transgenic Camelina were lower than WT under normal condition. But, WT and Set5#10-10 showed similar opened flower number in 100 and 200 mM NaCl. In cold stress, 15 and $10^{\circ}C$ treatment for 5 weeks did not showed significant changes in between WT and both transgenic lines even they showed different growth rate in control condition. Taken together, growth and development are delayed by expression of exogenous HFA related genes in transgenic lines but relative abiotic stress sensitivity is similar with WT. In conclusion, reduced C18:2 or C18:3 fatty acid composition of seed by HFA synthesis is resulted from lack of resource supplement for development at seedling stage but it is not affect NaCl and cold stress tolerance.

• Journal of Plant Biotechnology
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• v.36 no.1
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• pp.87-95
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• 2009

The recombinant DNAs, pGBF, pGTF, and pZ4F, using soybean ferritin gene have constructed with the promoters derived from seed proteins, glutelin, globulin, and zein. The recombinant ferritin genes were transformed into rice plant by Agrobacterium-mediated transformation. Iron contents and agronomic traits have been evaluated in the transgenic progenies. The embryogenic calli survived from second selection medium were regenerated at the rates of 19.2% with pGBF, 15.0% with pGTF, and 18.4% with pZ4F in Donganbyeo and 6.7% with pGBF, 11.7% with pGTF, and 3.4% with pZ4F in Hwashinbyeo. The introduction of ferritin gene in putative transgenic rice plants was confirmed by PCR and Southern blot analysis and also the expression of ferritin gene was identified by Northern blot and Western blot analysis. The iron accumulation in transgenic rice grains of the transgenic rice plant, T1-2, with zein promoter and ferritin gene contained 171.4 ppm showing 6.4 times higher than 26.7 ppm of Hwashinbyeo seed as wild type rice, but the transgenic plants with globulin and glutelin showed a bit higher iron contents with a range from 2.1 to 3.0 times compare to wild type grain. The growth responses of transgenic plants showed the large variances in plant height and number of tillers. However, there were some transgenic plants having similar phenotype to wild type plants. In the T1 generation of transgenic plants, plant height, culm length, panicle length, and number of tillers were similar to those of wild type plants, but ripened grain ratio ranged from 53.3% to 82.2% with relatively high variation. The transgenic rice plants would be useful for developing rice varieties with high iron content in rice grains.

• Korean Journal of Breeding Science
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• v.50 no.4
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• pp.463-471
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• 2018

Perilla is an oilseed crop cultivated in Korea since ancient times. Due to the high ${\alpha}-linolenic$ acid content in perilla, perilla seed oil can easily become rancid. ${\alpha}-Linolenic$ acid is synthesized by two enzymes, endoplasmic reticulum-localized ${\Delta}15$ desaturase (FAD3) and chloroplast-localized ${\Delta}15$ desaturase (FAD7) in vivo. In order to lower the ${\alpha}-linolenic$ acid content of the seed oil without disturbing plant growth, we tried to suppress the expression of only the FAD3 gene using RNA interference, whilst maintaining the expression of the FAD7 gene. Seventeen transgenic plants with herbicide ($Basta^{TM}$) resistance were obtained by Agrobacterium-mediated transformation using hypocotyls of perilla plants. The transgenic plants were firstly confirmed by treatment with 0.3% (v/v) $Basta^{TM}$ herbicide, and the expression of FAD3 was measured by Northern blot analysis. The ${\alpha}-linolenic$ acid content was 10-20%, 30-40%, and 60% in two, seven, and three of the twelve $T_1$ transgenic perilla plants which had enough seeds to be analyzed for fatty acid composition, respectively. Analysis of the fatty acid composition of $T_2$ progeny seeds from $T_1$ plants with the lowest ${\alpha}-linolenic$ acid content showed that the homozygous lines had 6-10% ${\alpha}-linolenic$ acid content and the heterozygous lines had 20-26% ${\alpha}-linolenic$ acid content. It is expected that the reduction in ${\alpha}-linolenic$ acid content in perilla seed oil will prevent rancidity and can be utilized for the production of high-value functional ingredients such as high ${\gamma}-linolenic$ acid.

• Korean Journal of Plant Tissue Culture
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• v.26 no.4
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• pp.281-287
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• 1999

Codonopsis lanceolata ("Deoduck" in Korea) is a perennial herb, and belongs to family, Campanulaceae. Its taproot is used a good source of a wild vegetable as well as an herbaceous medicine. In this study, to develop a bialaphos-resistant transgenic Codonopsis, seed germination mechanism and somatic embryogenesis of the plant were investigated, and Agrobacterium-mediated transformation with bar gene encoding phosphinothricin acetyltransferase (PAT) was performed. Attempt were made to regenerate plant from cells via somatic embryogenesis. When the cotyledons, nodes and leaf disks were cultured on MS medium containing 2,4-D and zeatin, embryogenic calli were induced. Upon transferring the somatic embryos to N6 solid medium without plant growth regulators, they developed into plantlets under continuous illumination. All plants were dead on MS basal medium containing 10 mg/L phosphinothricin (PPT) and Basta, respectively. The explants did not produce calli in the medium containing 200 mg/L kanamycin. The explants were cocultured with Agrobacterium tumefaciens for 2 days, and transformants were selected in MS basal medium containing 1.0 mg/L 2,4-D, 100 mg/L kanamycin and 500 mg/L carbenicillin. After the selection, embryogenic calli were induced and then somatic embryos were produced by subsequent subculturing. The somatic embryos were germiated on N6 basal medium containing 200 mg/L kanamycin and 500 mg/L carbenicillin. PCR analysis showed that nptII and bar genes were introduced in the Deoduck transformants. After the confirmation of bar gene expression in RNA and protein level, the transgenic Deoduck will be used to study the genetics of filial generation with the herbicide control gene, bar.gene, bar.