• Plant Biotechnology Reports
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• v.2 no.1
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• pp.33-39
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• 2008

In this paper, we would like to show unexpected morphogenic potential of cell suspensions derived from seedling explants of Gentiana kurroo (Royle). Suspension cultures were established with the use of embryogenic callus derived from seedling explants (root, hypocotyl and cotyledons). Proembryogenic mass proliferated in liquid MS medium supplemented with $0.5mg\;l^{-1}$ 2,4-D and $1.0mg\;l^{-1}$ Kin. The highest growth coefficient was achieved for root derived cell suspensions. The microscopic analysis showed differences in aggregate structure depending on their size. To assess the embryogenic capability of the particular culture, 100 mg of cell aggregates was implanted on MS agar medium supplemented with Kin ($0.0-2.0mg\;l^{-1}$), $GA_3$ ($0.0-2.0mg\;l^{-1}$) and AS ($80.0mg\;l^{-1}$). The highest number of somatic embryos was obtained for cotyledon-derived cell suspension on $GA_3$-free medium, but the best morphological quality of embryos was observed in the presence of $0.5-1.0mg\;l^{-1}$ Kin, $0.5mg\;l^{-1}$ $GA_3$ and $80.0mg\;l^{-1}$ AS. The morphogenic competence of cultures also depended on the size of the aggregate fraction and was lower when size of aggregates decreased. Flow cytometry analysis reveled luck of uniformity of regenerants derived from hypocotyl suspension and 100% of uniformity for cotyledon suspension.

• Korean Journal of Plant Resources
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• v.8 no.3
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• pp.237-246
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• 1995

In this study, the callus was induced and regenerated from the immature embryo and ultrastructural characteristics of developmental stages in Citrus junos SIEB, were investigated. The yellowish callus was induced by 5 to 6 week of culture of citrus. In proliferation callus after 6 weeks of culture, large vacuole was formed by fusion between adjacent small ones. In the non-embryogenic callus cultured for 12weeks, re-differentiated cells of callus showed the large nucleus with globular nucleus and amyloplast with large size of starches. In the embryogenic callus cltured for 14-16 weeks, the active exocytosis occurred in cells, secretory vesicles appeared on cell membrane and small particles from cytoplasm were released to intercelluar space. In the embryogenic callus cultured for 24 weeks, a sperical type of chloroplast bounded on cytoplasm by double membrane and typical grana was dispersed equally among matrix. In the normal plantlet after 26 weeks of culture, a lot of vessels and companion cells apperaed in the leaf cell of plantlet. In the normal plantlet after 30 weeks of culture, the immature leaf showed many small companion cells, sieve tubes and central vacuole. Also, the secondary vacuole protruded into the central vacuole and elongated chloroplasts near plasma membrane. In the matured plant habituated on the soil, palisada tissue composed of orderly arranged cells contained the nucleus in the center of the cell and large vacuoles on either side of the nucleus.

• Journal of Plant Biotechnology
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• v.42 no.4
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• pp.388-395
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• 2015

Somatic embryogenesis is as an excellent technology for potential use in plant mass production, germplasm conservation, or genetic engineering. We examined the effect of cold storage using 3 embryogenic callus lines with different levels of embryogenesis competence derived from immature zygotic embryo cultures of Kalopanax setemlobus. Somatic embryo induction, germination and plant conversion were evaluated after 1, 3 and 6 months storage at $4^{\circ}C$ in the dark. Most cold-stored embryogenic calli formed somatic embryos normally even after 6 months; however, the induction rate was gradually decreased by increasing the storage period. The most competent line tended to show a slight decline in somatic embryo induction rate, as compared with other lines after cold storage. In general, cold storage resulted in reduced somatic embryo germination and plant regeneration, although 93% somatic embryo germination and 91% plant conversion were achieved regardless of the storage period. Cold storage led to cell browning and degradation. Additionally, the cell structures were confirmed by the aceto-carmine and evans blue dye evaluation. Collectively, our results showed that embryogenic callus of K. septemlobus could be preserved at $4^{\circ}C$ without subculture for 6 months, and suggested the need for storage of relatively more competent embryogenic calli lines to support somatic embryo induction.

• Korean Journal of Medicinal Crop Science
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• v.7 no.4
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• pp.275-281
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• 1999

Embryogenic calli of Codonopsis lanceolata were cultured on MS agar medium containing various concentrations of sucrose as a carbon source. Upon transfer to MS basal medium, somatic embryos of cotyledonary stage converted to plantlets. When sucrose was added with greater than 4%, the number of shoots and roots regenerated from somatic embryo increased. However, the growth of shoots and roots was retarded in agar medium with more than 2% sucrose, but promoted in medium with lower concentration of sucrose. Saponin contents of shoots regenerated from somatic embryos, embryogenic calli, non-embryogenic calli, and native roots were determined by HPLC. Saponin contents of native root was variable, depending on regenerant, embryogenic calli, and cotyledonary embryos. The saponin contents of regenerated roots in medium with high sucrose was similar to native roots. Saponins content based on cell differentiation to shoot and root was dramatically decreased. This results could be effectively controlled for the production of useful secondary metabolites.

• Asian Journal of Turfgrass Science
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• v.23 no.2
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• pp.345-352
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• 2009

Zoysiagrass (Zoysia japonica Steud) is a warm season turfgrass species widely used for sports field and golf courses. Many cultivars are propagated through vegetative methods. This study was conducted to develop an optimum culture medium and culture conditions for embryogenic callus induction and plant regeneration, and to establish a cell suspension culture system for use in zoysiagrass breeding and propagation. The results indicated that adding $Cu^{++}$ at 2.5 mg $L^{-1}$ to the induction medium was optimum for callus induction. Increasing the numbers of sub-culture cycles improved the quality of calli. The optimum dosage for cell suspension culture ranged from 2.5 to 10 mL. The embryogenic callus suspension used in this study had a plant regeneration rate of 58%.

• Korean Journal of Plant Tissue Culture
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• v.26 no.2
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• pp.121-126
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• 1999

Calli were induced from the petiole explants of Pimpinella brachycarpa on MS medium supplemented with 0.5 mg/L 2,4-D and 0.1 mg/L BA after four weeks of culture. Compact clusters of small and dense cells among these calli were selected and suspension-cultured as the source of embryogenic calli. When transferred to MS medium with 0.1 mg/L NAA, the suspension-cultured cells grew to embryogenic callus. Somatic embryos derived from these embryogenic calli developed into plantlets. The cDNA library was constructed in the embryogenic callus and in order to screen the cDNA library, these cDNAs were plated at a density 1.5 $\times$ 10^5 plaques per 15 cm petridish. Among 19 clones showing preferential hybridization with petiole HD-Zip gene, five clones were obtained after second screening. Four clones among them, were highly homologous to P. brachycarpa shoot-tip Phz4 gene, but one clone, Phc5 was about 1.5 kb which has an extra 163 bp to 5' upstream of Phz4. The Phc5 was 1,531 bp containing poly A tails of 18 bases. ATG start codon for Phc5, was located at position 284 with an open reading frame of 906 by which encodes a polypeptide of 302 amino acids. The Phc5 protein revealed that the polypeptides between 135 and 195 contain a homeodomain as the `leucine zipper' motif.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2002.04b
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• pp.159-159
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• 2002

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2002.04b
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• pp.160-160
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• 2002

• KSBB Journal
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• v.10 no.1
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• pp.23-29
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• 1995

Calli were induced from leaf base region of germinated rice(Oryza sativa L. cv. Nakdong) with high frequency of up to 65% on LS medium supplemented with $2.5mg/{\ell}2$, 4-D in the dark at $27^{\circ}C$. Embryogenic calli of pale yellow, globular type were selected and used for the initiation of cell suspension cultures in AA2 liquid medium with $2mg/\ell$ 2,4-D, 0.2mg/$\ell$ kinetin arid $0.1mg/\ell$ GA3. Protoplasts were isolated from the embryogenic cell suspensions after 4 months of culture and then were electroporated with 400V/cm for 1 msec. Electroporated protoplasts divided with plating efficiency of 1.1% on PCM liquid medium supplemented with $2.5mg/\ell$ 2, 4-D, $0.1mg/\ell$ kinetin and 10mM proline. The protoplasts-derived microcalli were cultured on $0.2{\mu}m$ membrane fitter placed onto LS2.5 solid medium containing fine suspension cells as a feeder cells, for 2 weeks in the dark at $27^{\circ}C$. After an additional 2 weeks of culture under fluorescent light of $30{\pm}/3{\mu}E$.m^{-2}S^{-1}, yellow calli of 2mm diameter were transferred to regeneration medium. Shoots were produced from the green spot of protoplasts-derived calli and plants were regenerated form protoplast-derived green calli with frequencies of 11∼33%.

• Korean Journal of Plant Tissue Culture
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• v.21 no.5
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• pp.287-291
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• 1994

In order to elucidate the effect of abscisic acid (ABA) on the abnormality of somatic embryos, somatic embryos were induced from embryogenic cell clumps derived from cotyledon segment of Aralia cordata. When embryogenic cell clumps were pretreated medium containing 0.2 mg/L ABA for 3 weeks before transferring to MS basal medium, the frequency of embryos with normal cotyledons enhanced 68% as compared with control. However when clumps pretreated in medium containing 0.2 mg/L ABA were transferred to medium containing 0.1 mg/L ABA, the Sequency decreased to about 29%. In the case of globular embryos cultures in medium containing various concentrations of ABA (0.01 to 1.0mg/L), the frequency of dicotyledonary embryo formation decreased propotionally to ABA concentration. Also, when somatic embryos at various stages were cultured in medium containing ABA, those with polycotyledons appeared at higher frequency.