• Journal of Korean Society of Forest Science
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• 제87권1호
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• pp.57-61
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• 1998

Somatic embryo induction, plant regeneration, and field establishment were investigated from tissue cultured winter buds of a 10-year-old tree Aralia elata. Embryogenic calli were obtained from cultures of winter buds on MS medium supplemented with 2,4-D. A number of somatic embryos were regenerated from the calli on an embryo induction medium supplemented with 2,4-D and BA. Although abnormal somatic embryos were frequently observed, most of the embryos formed were morphologically normal. All somatic embryos at the later stage of maturity germinated successfully, but only 14% of them could be developed into plantlets on MS basal medium. The plants regenerated from the somatic embryos survived well in the field (survival rates : more than 95%) and have grown normally for three years after transplanting.

• BMB Reports
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• 제44권10호
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• pp.680-685
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• 2011

The AT-hook motif is a small DNA-binding protein motif that has been found in the high mobility group of non-histone chromosomal proteins. The Arabidopsis genome contains 29 genes encoding the AT-hook motif DNA-binding protein (AHL). Recent studies of Arabidopsis genes (AtAHLs) have revealed that they might play diverse functional roles during plant growth and development. In this report, we mined 20 AHL genes (OsAHLs) from the rice genome database using AtAHL genes as queries and characterized their molecular features. A phylogenetic tree revealed that OsAHL proteins can be classified into 2 evolutionary clades. Tissue expression pattern analysis revealed that all of the OsAHL genes might be functionally expressed genes with 3 distinct expression patterns. Nuclear localization analysis using transgenic Arabidopsis showed that several OsAHL proteins are exclusively localized in the nucleus, indicating that they may act as architectural transcription factors to regulate expression of their target genes during plant growth and development.

• Korean Journal of Medicinal Crop Science
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• 제1권1호
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• pp.43-48
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• 1993

Present experiments were carried out to examine the effect of plant growthregulators for callus induction and plantlet regeneration through leaf tissue culture of Scutellaria baicalensis GEORGI. The results indicated that Callus was induced well on MS medium supplemented with 0.5mg/L NAA or 0.5mg/L NAA Plus 0.5mg/L zeatin. MS medium supplemented with 1.0mg/L BAP plus 0. 5mg /L NAA or 1. 0mg /L zeatin Plus 0.5mg /L NAA and 1.0mg /L NAA were the most effective for plant regeneration. Thin layer chromatogram of baicalin component (Rf 0.39) was observed from callus cultured on MS medium containing 0.5mg /L NAA plus 0.5mg /L zeatin.

• Korean Journal of Plant Tissue Culture
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• 제28권1호
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• pp.25-32
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• 2001

Shoot tips of grape were cultured in uitro and tried to identify optimal culture conditions for regeneration, multiple shoot formation from meristemoid tissue and those subsequent elongation of multi-shoots. Healthy growing shoots were taken in early May, rinsed with running tap water, soaked in a neutral detergent and washed with soft brushing, and washed out with tap water, then sterilized with 10g Ca(ClO)$_2$/140 mL distilled water (Wilson's solution) for 5 min. Survival percentage of the cultures which were sterilized as above procedures was highly increased, compared with the other sterilized method. Propagation of multi-shoots from meristemoid showed a good response in 3/4 strength MS medium enriched with 0.1 mg/L NAA and 3.0 mg/L BA. Shoot elongation from multi-shooting clump well occurred in 3/4 strength MS medium supplemented with 80 mg/L adenine sulfate, 0.1 mg/L NAA and 1.0~2.0 mg/L BA.

• Korean Journal of Plant Tissue Culture
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• 제22권3호
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• pp.131-135
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• 1995

Physiologically modified stem nodes derived from ex vitro and in vivo explants of hybrid aspen (Populus alba L.X P.grandidentata Michx. 'Crandon') were tested for their multiple shoot regeneration capacity using a broad spectrum dosage of cytokinins. Ex vitro derived stem nodes with excised axillary buds at the time of culture produced 11 to 13 multiple shoots on 20 to 30 $\mu$M zeatin containing Woody Plant Medium (WPM) after 6 weeks. Excision of axillary bud sprouts after 2 weeks of culture and culture of the remaining stem nodes on WPM with 1.0 to 2.0 $\mu$M BA or 10 to 30 $\mu$M zeatin produced 13 to 15 and 7 to 8 shoots per explant, respectively, Multiple tiny shoots were produced when in vivo derived stem nodes (on which all leaves were removed) were cultured on WPM with 30 to 50 $\mu$M 2iP or 20 to 50 $\mu$M zeatin. The greatest number of multiple tiny shoot proliferation (32 to 50 shoots per explant) were obtained when the explants were cultured on media containing 20 $\mu$M zeatin. Successful transplanting of these multiple shoots into the greenhouse and/or nursery was achieved.

• Korean Journal of Plant Tissue Culture
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• 제26권4호
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• pp.271-274
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• 1999

This study was undertaken to develop an efficient propagation technique for mature Betula davurica. Using aseptic materials taken from in vitro culture, the effects of media and plant growth regulators on shoot proliferation and rooting were investigated. DKW medium turned out to be the best in shoot proliferation among the media tested. Whereas axillary buds were better culture material than apical buds in proliferation of shoots, apical buds were slightly better than axillary buds on shoot elongation. Neither 1 /2 MS nor WPM medium seemed to be suitable for shoot multiplication or elongation. When the explants were cultured on 1/2 MS medium, shoot elongation was retarded by forming big callus at the base. In the case of WPM, shoots could be formed normally, but they exhibited slow growing. NAA was so effective on in vitro rooting that more than 80% rooting could be achieved on half-strength DKW medium supplemented with 1.0 mg/L NAA after 4 weeks in cultures. Ex vitro rooting using elongated shoot was also applicable to rooting and acclimatization. Rooted plantlets were successfully acclimatized in an artificial soil mixture and grew normally. The results demonstrate that efficient mass propagation of mature B. davurica can be done through tissue culture.

• Molecules and Cells
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• 제41권10호
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• pp.923-932
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• 2018

Ethylene regulates numerous aspects of plant growth and development. Multiple external and internal factors coordinate ethylene production in plant tissues. Transcriptional and post-translational regulations of ACC synthases (ACSs), which are key enzymes mediating a rate-limiting step in ethylene biosynthesis have been well characterized. However, the regulation and physiological roles of ACC oxidases (ACOs) that catalyze the final step of ethylene biosynthesis are largely unknown in Arabidopsis. Here, we show that Arabidopsis ACO1 exhibits a tissue-specific expression pattern that is regulated by multiple signals, and plays roles in the lateral root development in Arabidopsis. Histochemical analysis of the ACO1 promoter indicated that ACO1 expression was largely modulated by light and plant hormones in a tissue-specific manner. We demonstrated that point mutations in two E-box motifs on the ACO1 promoter reduce the light-regulated expression patterns of ACO1. The aco1-1 mutant showed reduced ethylene production in root tips compared to wild-type. In addition, aco1-1 displayed altered lateral root formation. Our results suggest that Arabidopsis ACO1 integrates various signals into the ethylene biosynthesis that is required for ACO1's intrinsic roles in root physiology.

• The Plant Pathology Journal
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• 제32권4호
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• pp.311-320
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• 2016

Xanthomonas axonopodis pv. glycines (Xag) is a necrotrophic bacterial pathogen of the soybean that causes bacterial pustules and is a nonhost pathogen of the chili pepper. In the current study, chili pepper fruit wound inoculated in planta with Xag 8ra formed necrotic lesions on the fruit surface and induced several structural and chemical barriers systemically in the fruit tissue. The initial defense response included programmed cell death of necrotizing and necrotized cells, which was characterized by nuclear DNA cleavage, as detected by TUNEL-confocal laser scanning microscopy (CLSM), and phosphatidylserine exposure on cell walls distal to the infection site, as detected by Annexin V FLUOS-CLSM. These two responses may facilitate cell killing and enhance transportation of cell wall materials used for cell wall thickening, respectively. The cells beneath the necrotic tissue were enlarged and divided to form periclinal cell walls, resulting in extensive formation of several parallel boundary layers at the later stages of infection, accompanying the deposition of wall fortification materials for strengthening structural defenses. These results suggest that nonhost resistance of chili pepper fruit against the nonhost necrotrophic pathogen Xag 8ra is activated systematically from the initial infection until termination of the infection cycle, resulting in complete inhibition of bacterial pathogenesis by utilizing organspecific in situ physiological events governed by the expression of genes in the plant fruit organ.

• Korean Journal of Plant Tissue Culture
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• 제24권6호
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• pp.369-374
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• 1997

Immature flower buds of 'Desio' carnation were cultured on MS agar medium supplemented with 1 ㎎/L 2,L-D. Embryogenic calli were formed from 5-10% of the buds less than 20 ㎜ in length, but only non-embryogenic calli were produced from explants of shoot apex leaf, internode, and flowere buds larger than 20 ㎜. The same method was applied to 16 cultivars of cut Sower carnation and embryogenic calli were obtained in 7 cultivars. Several embryogenic callus lines were selected and maintained through subcultures over 120 weeks without loss of embryogenic competence. The embryogenic cultures were also proliferated rapidly in liquid agitation cultures using MS medium supplemented with 1mg/L 2,4-D. Numerous embryos were formed on the periphery of the cell aggregates upon transfer to auxin-free MS agar medium. Plantlets were transplanted in potting soil and grown to bloom in six months.

• Korean Journal of Veterinary Research
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• 제58권1호
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• pp.9-16
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• 2018

A preliminary study into the protective mechanisms of adaptive immunity against porcine reproductive and respiratory syndrome virus (PRRSV) in piglets (n = 9) born to a gilt challenged intranasally with a type-2 PRRSV. Immune parameters (neutralizing antibodies, $CD3^+CD4^+$, $CD3^+CD8^+$, $CD3^+CD4^+CD8^+$ T-lymphocytes, and PRRSV-specific interferon $(IFN)-{\gamma}$ secreting T-lymphocytes) were compared with infection parameters (macro- and microscopic lung lesion, and PRRSV-infected porcine alveolar macrophages ($CD172{\alpha}^+PRRSV-N^+\;PAM$) as well as with plasma and lymphoid tissue viral loads. Percentages of three T-lymphocyte phenotypes in 14-days post-birth (dpb) peripheral blood mononuclear cell (PBMC) had significant negative correlations with percentages of $CD172{\alpha}^+PRRSV-N^+\;PAM$ (p < 0.05) as well as with macroscopic lung lesion (p < 0.01). Plasma and tissue viral loads had significant (p < 0.05) negative correlations with $CD3^+CD4^+CD8^+$ T-lymphocyte percentage in PBMC. Frequencies of $CD3^+CD8^+$ and $CD3^+CD4^+$ T-lymphocytes in 14-dpb PBMC had significant negative correlations with of lymph node (p = 0.04) and lung (p = 0.002) viral loads. $IFN-{\gamma}$-secreting T-lymphocytes frequency had a significant negative correlation with gross lung lesion severity (p = 0.002). However, neutralizing antibody titers had no significant negative correlation (p > 0.1) with infection parameters. The results indicate that T-lymphocytes contribute to controlling PRRSV replication in young piglets born after in-utero infection.