• 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.

• Journal of Plant Biology
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• v.34 no.1
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• pp.19-23
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• 1991

Culture of embryogenic callus and suspension were induced from rice seeds in MS2.5 medium. In hormone free N6 medium, whole plantlets were regenerated from embryogenic callus. We observed cell division and reformation of embryogenic callus on culture of protoplast isolated from embryogenic cell suspensions. In addition, we studied the influencing factors on viability of protoplast treated with electroporation. Viability was decreased according to the increase of voltage and capacitance during electroporation. An optimal level of viability was obtained after treatment with $200-300\;V/1180\;\mu\textrm{F}$ in HEM buffer at $4^{\circ}C$..

• Korean Journal of Plant Resources
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• v.28 no.3
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• pp.363-369
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• 2015

Sweet potato has low regeneration capacity, which is a serious obstacle for the fruitful production of transgenic plants. Simple and rapid regeneration method from storage root explants of purple sweet potato (Ipomoea batatas L.) was investigated. The embryogenic callus was observed from 4 cultivars and its highest rate was induced at 1 μM 2,4-D after 5 weeks of culture. Result revealed that a low concentration of 2,4-D and low light intensity was important factors for embryogenic callus formation. After subculture on medium with 5 μM ABA for 4 days, subsequently, occurred the regeneration of shoots within 4 weeks when these embryogenic callus was transferred onto the MS hormone free medium. Regenerated shoots were developed into platelets, and grown normal plants in the greenhouse. We developed a simple and quickly protocol to regenerate plantlets in storage root explants of purple sweet potato. This regeneration system will facilitate tissue culture and gene transfer research of purple sweet potato.

• 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.

• KSBB Journal
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• v.6 no.2
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• pp.201-205
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• 1991

We have investigated influencing factors on viability of Bletilla striata protoplasts electroporated in the presence of various electrical conditions. Cultures of embryogenic callus and embryogenic cell suspension were established with immature seeds of Bletilla striata. Viabilty of electroporated protoplasts was decreased according to the increaseing of electroporation voltage and capacitance. An optimal condition of electroporation for viable protoplasts was in HBM buffer at $4^{\circ}C$.

• Journal of Plant Biotechnology
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• v.30 no.4
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• pp.359-363
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• 2003

Mass propagation of tulip tree (Liriodendron tulipifera L) via somatic embryogenesis was successfully achieved with immature samaras collected from adult trees. Embryogenic tissues were induced by culturing them samaras on 1/2 LM medium (Litvay's) containing 2,4-D and BA. Somatic embryos developed from the embryogenic tissues and germinated to normal plants (emblings) upon transfer onto the same medium containing either AgNO$_3$ or activated charcoal. So far, several factors appeared to influence both the induction of embryogenic tissues and germination of the embryos into plants. These include the collection time of samaras for the induction of embryogenic tissue, sucrose level in the culture medium, the level of both AgNO$_3$ and activated charcoal, and plating density of somatic embryos on germination medium for maturation and germination of somatic embryos into plantlets.

• Korean Journal of Plant Tissue Culture
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• v.25 no.5
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• pp.335-339
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• 1998

The factors affecting the isolation and culture of the protoplast of embryogenic callus, derived from immature ovule in Citrus junos, were examined. An incubation time in enzyme solution of 16 hrs was preferable for protoplast isolation. Efficient protoplast yields were obtained from the treatment of equal concentration of 0.7 M $\textrm{BH}_{3}$ to the enzyme solution containing 1.0% cellulase, 1.0% macerozyme and 0.2% pectolyase. Protoplast cultured in MT medium with 0.1 mg/L 2,4-D showed vigorous division and some of them formed callus. Induced callus was subcultured on solid MT medium but the callus showed very slow growth. The above results show the possibility to culture from protoplast fusion in Citrus genera.

• 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 Animal Science and Technology
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• v.47 no.6
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• pp.1067-1074
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• 2005

In order to optimize tissue culture conditions of Kentucky bluegrass(Poa pratensis L.), effects of culture medium supplements, media and cultivars on embryogenic callus induction and regeneration of plants were investigated. MS medium containing 3mg/L 2,4-D and 0.1mg/L BA was optimal for embryogenic callus induction from mature seeds. The highest plant regeneration frequency(57.7%) was observed when the embryogenic calli were cultured on N6 medium supplemented with 1mg/L 2,4-D and 3mg/L BA. Among several basic media, MS and N6 medium were optimal for callus induction and plant regeneration, respectively. Genotype was an important factor in plant regenerability. ‘Newport’ showed to have higher regeneration frequency of 53.4%. Regenerated plants were grown normally when shoots transplanted to the soil. A short tissue culture period and high-frequency regeneration system would be beneficial for molecular breeding of Kentucky bluegrass through genetic transformation.

• Journal of The Korean Society of Grassland and Forage Science
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• v.24 no.1
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• pp.29-36
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• 2004

In an effort to optimize tissue culture responses of zoysiagrass(Zoysia japonica Steud.) for genetic transformation, factors affecting callus induction and plant regeneration were investigated. MS medium containing 3 mg/L 2,4-D was optimal for embryogenic callus induction from mature seed. The plant regeneration frequency of 73.3% was observed when embryogenic calli induced in this medium were transferred to N6 medium supplemented with 0.1 mg/L 2,4-D and 5 mg/L BA. Among several basic media, MS and N6 medium were optimal for callus induction and plant regeneration, respectively. Regenerated plants were grown normally when shoots transplanted to the soil. A rapid and efficient plant regeneration system established in this study will be useful for molecular breeding of turfgrass through genetic transformation.