• 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.

• Journal of Plant Biology
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• v.32 no.4
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• pp.227-233
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• 1989

Single cells obtained from suspension culture of mature embryo-derived callus in wheat(Triticum aestivum L. cv Jang Kwang) were cultured to regenrated into the plantlet. Cell clusters and embryogenic calluses were efficiently developed from when the single cells clutured on the MS medium supplemented with 10${\mu}{\textrm}{m}$ 2,4-D. Upon transfer to hormone-free MS medium containing 10 mg/I AgNO3, embryogenic calluses gave rise to shoots, probably through somatic embryogenesis.

• Korean Journal of Plant Tissue Culture
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• v.22 no.5
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• pp.283-290
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• 1995

This experiment was canted out to obtain embryogenic callus and to understand developmental mechanism of somatic embryogenesis in Oenanthe javanica ($B_{L.}$) DC. experiments included the examination of explant source and media for embryogenic callus production and the observation of developmental pattern of embryogenic cells and non-embryogenic cells. Embryogenic calli were formed on zygotic pro-embryos together with their endosperms when they were cultured on Ms media containing 1.0mg/L 2,4-D. Embryogenic calli were also formed on the intact surface in vitro grown stem or petiole segmentsafrer 6-8 weeks of culture, whereas non-embryogenic calli were formed on cut surfaces of the stem and petiole after 2 weeks of culture. Non-embryogenic calli were rhizogenic in suspension and solid media culture.

• Korean Journal of Medicinal Crop Science
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• v.14 no.4
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• pp.255-260
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• 2006

Culture conditions for high frequency plant regeneration via somatic embryogenesis from embryogenic cell suspension cultures of Hovenia dulcis are described. Germinated somatic embryos were selected for induction of secondary embryogenesis. Friable embryogenic cells were induced directly from somatic embryos when transfer to 1/3 MS solid or liquid medium lacking plant growth regulators. The temperature strongly effected on induction of secondary embryognesis than other conditions in culture. All somatic embryos produced friable embryogenic cell clumps within 10 days when germinated somatic embryos cultured in 1/3 MS medium at $30^{\circ}C$ in suspension culture. No somatic embryos formed from embryogenic cell suspension cultures at $18^{\circ}C$. Numerous somatic embryos were induced and subsequently developed uniformly into germination stage from suspended cell clumps after 4 weeks of culture on $18^{\circ}C$. Plantlets conversion were observed on $18^{\circ}C$ when germinated somatic embryos were transferred to 1/3 MS solid medium without plant growth regulators or supplemented with 0.1-0.5 mg/l benzyladenine.

• Korean Journal of Medicinal Crop Science
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• v.15 no.5
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• pp.346-351
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• 2007

An efficient somatic embryogenesis and plant regeneration protocol was developed for Schisandra chinensis Baill, using embryogenic cell suspensions and optimized media conditions. Friable embryogenic callus was induced from cotyledonary leaf and hypocotyl explants of 7 days old seedlings on MS agar medium supplemented with 1.0 to $4.0\;mg\;l^{-1}$ of 2,4-dichlorophenoxyacetic acid (2,4-D). Fast growing and well dispersed embryogenic cell suspensions were developed within two months when embryogenic calli were transferred to MS liquid medium containing $1.0\;mg\;l^{-1}\;2,4-D$. One third strength of MS medium was the best for both overall growth and development of somatic embryos in liquid culture. Over 3400 viable somatic embryos were produced from each 150 ml flask with an initial cell density of 30 mg in 30 ml medium. Germinated somatic embryos developed in liquid medium converted into plantlets after transferred to half-strength MS semi-solid medium. Approximately 90% of the converted plantlets were successfully transplanted to soil and grew into fertile plants.

• KSBB Journal
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• v.8 no.5
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• pp.504-507
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• 1993

A declining tendency in embryogenic capability was seen during 6 months culture period during which embryo production decreased from 1000 embryos/ml to 500 embryos/ml. The presence of extracellular factors extracted from newly established embryo cultures restored the embryogenic capability and even enhanced the embryo production up to 5 times (2500 embryos/ml) for old carrot suspension cultures compared with that of control cultures. The stimulating effect on the embryo production indicates that the enhancing effect comes from extracellular compounds that are probably protein molecules.

• Journal of Plant Biology
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• v.32 no.4
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• pp.247-253
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• 1989

Protoplasts were enzymatically isolated from suspension culture of sweet potato. High yields of single protoplasts were produced from nonembryogenic cell aggregates. However, most protoplasts obtained from embryogenic cell clumps were spontaneously fused during enzyme treatment; a small portion of them remained single. Upon transfer to Murashige and Skoog's(MS) liquid medium supplemented with 0.1 mg/1 6-benzyladenine(BA) and 1 mg/12,4-dichlorophenoxyacetic acid(2,4-D), protoplasts from nonembryogenic cell aggregates sustained cell divisions to form cellus. Upon subculture onto MS media with 0.2 mg/12,4-D or without growth regulators, the callus did not give rise to any organs. On the other hand, first cell division of single protoplasts from embryogenic cell clumps was sporadically observed.

• Korean Journal of Plant Tissue Culture
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• v.27 no.4
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• pp.245-258
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• 2000

Somatic embryogenesis has become a major tool in the study of plant embryology, as it is possible in culture to manipulate cells of many plant species to produce somatic embryos in a process that is remarkably similar to zygotic embryogenesis. Traditionally, the process has been studied by an examination of the ex vitro factors which influence embryo formation. Later structural, physiological and biochemical approaches have been applied. Host recently, molecular tools are being used. Together, these various approaches are giving valuable information on the process. This article gives an overview of somatic embryogenesis by reviewing information on the morphogenesis, physiology, biochemistry and molecular biology of the process. Topics covered include a brief description of the factors involved in the production of embryogenic cells. Carrot cell suspension is most commonly used, and the development of a high frequency and synchronous system is outlined. At the physiological and biochemical lev-els various topics, including the reactivation of the cell cycle, changes in endogenous growth regulators, amino acid, polyamine, DNA, RNA and protein metabolism, and embryogenic factors in conditioned medium are all discussed. Lastly, recent information on genes and molecular markers of the embryogenic process are outlined. Somatic embryogenesis, the best example of totipotency in plant cells, is not only an important tool in studies in basic biology, but is potentially of equal significance in the micropropagation of economically important plants.

• 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.

• Korean Journal of Plant Tissue Culture
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• v.27 no.3
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• pp.233-238
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• 2000

To obtain a basic information of the development of Genus Viola, morphological and histological observation of in vitro calli and cells in Viola culture cells were investigated. There were two callus types obtained by long term subculture of wild viola (Viola partrinii DC. ) petiole callus. One was friable callus - soft and pale green in color and small cells in size, and the other was compact callus - compact and deep bluish green in color, large cells in size. In scanning electron microscopic observation, friable callus was composed of voculated cell around small. cell clump, while compact callus was composed of cells filled with protoplasm Somatic embryogenesis was observed from suspension culture of the compact callus.