• Korean Journal of Medicinal Crop Science
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• v.6 no.4
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• pp.294-298
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• 1998

The factors affecting direct somatic embryogenesis from different parts of explant in liquid culture of Scrophularia buergeriana were investigated. Direct somatic embryogenesis was dependent on the explant tissues and stem was the most efficient explant. Rapid shoot development occurred on stem after 3-week culture but roots were not developed yet. Plantlets were not formed through somatic embryogenesis after 3-week culture of petiole. Though direct somatic embryo was not observed from leaf segment culture for 3 weeks, normal plantlets were developed after 8-week culture. BA played the main role for somatic embryogenesis in liquid culture and adding of either IAA or NAA caused rather adverse effects. Culture of stem segments in MS liquid medium with BA at 0.5 mg/ l or 0.1 mg/ l was proved to be the most efficient method for producing plantlets through direct somatic embryos.

• 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.28 no.5
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• pp.273-276
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• 2001

In order to develop effective acclimatization methods for Aralia elata plantlets regenerated from somatic embryos, various acclimatizing conditions were compared regarding both survival rate and growth of the plantlets. The plantlets were transplanted into plastic boxes containing artificial soil in the presence of either several levels of MS liquid media, distilled water, 2% sucrose or 0.1% hyponex solution. They were then cultured by spraying of distilled water twice a week and maintained in the normal tissue culture room. Perlite was proved to be better than vermiculite on survival rate and growth of the plantlets. As the size of perlite (larger than 0.2 cm in diameter) increased, both the survival rate and growth of the plantlets improved. Among the various MS liquid media and different aqueous solutions tested, distilled water appeared to result in the best survival rate and growth. MS media were also effective in increasing survival rate and supporting growth when diluted to 1/4 and/or 1/8. The acclimatized plantlets could be transplanted directly onto the nursery bed and grown normally. The above results suggest that plantlets regenerated from somatic embryos of Aralia elata be effectively acclimatized using a plastic box containing perlite with distilled water treatment.

• Journal of Plant Biotechnology
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• v.42 no.4
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• pp.376-379
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• 2015

This study was conducted to evaluate the effects of different types and concentrations of organic nitrogen sources (${\small{L}}$-Glutamine and casein hydrolysate, CH) and plant growth regulators (auxins and cytokinins) on embryogenic tissue proliferation and somatic embryo production in L. kaempferi. Overall, the highest tissue fresh weight was obtained at either 2 or 4 weeks in culture when 1,000 mg/L ${\small{L}}$-Glutamine was added to the culture medium, which showed similar results with other treatments. In experiments with different types and concentrations of plant growth regulators on somatic embryo production, the highest production (426.3/90 mg tissue) was found when 0.2 mg/L IBA was added; however, no somatic embryos were induced following treatment with 0.2 mg/L BA or Kinetin. The effect of various concentrations of IBA on somatic embryo production was also tested. The best result (303/90 mg tissue) was obtained when plants were treated with 0.2 mg/L IBA; 1.0 mg/L IBA was also effective (281/90 mg tissue). The lowest result (109.3/90 mg tissue) was obtained with 5.0 mg/L IBA.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2003.04a
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• pp.61-62
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• 2003

Clonal propagation of high-value forest trees through somatic embryogenesis (SE) has the potential to rapidly capture the benefits of breeding or genetic engineering programs and to improve raw material uniformity and quality. A major barrier to the commercialization of this technology is the low quality of the resulting embryos. Several factors limit commercialization of SE for Corsican pine, including low initiation rates, low culture survival, culture decline causing low or no embryo production, and inability of somatic embryos to fully mature, resulting in low germination and reduced vigour of somatic seedlings. The objective was to develop a Corsican pine maturation medium that would produce cotyledonary embryos capable of germination. Treatments were arranged in a completely randomized design. Data were analyzed by analysis of variance, and significant differences between treatments determined by multiple range test at P=0.05. Corsican pine (Pinus nigra var. maritima) cultures were initiated on modified !P6 medium. Modifications of the same media were used for culture multiplication and maintenance. Embryogenic cultures were maintained on the same medium semi solidified with 2.5 g/l Gelrite. A maturation medium, capable of promoting the development of Corsican pine somatic embryos that can germinate, is a combination of iP6 modified salts, 2% maltose, 13% polyethylene glycol (PEG), 5 mg!l abscisic acid (ABA), and 2.5 g/l Gelrite. After initiation and once enough tissue developed they were grown in liquid medium. Embryogenic cell suspensions were established by adding 0.951.05 g of 10- to 14-day-old semisolid-grown embryogenic tissue to 9 ml of liquid maintenance media in a 250ml Erlenmeyer flask. Cultures were then incubated in the dark at 2022$^{\circ}$C and rotated at 120 rpm. After 2.53 months on maturation medium, somatic embryos were selected that exhibited normal embryo shape. Ten embryos were placed horizontally on 20 ml of either germination medium ($\frac{2}{1}$strength Murashige and Skoog (1962) salts with 2.5 g/l activated charcoal) or same medium with copper sulphate adjusted to 0.25 mg/1 to compensate for copper adsorption by activated carbon. 2% and 4% maltose was substituted by 7.5% and 13% PEG respectively to improve the yield of the embryos. Substitution of' maltose with PEG was clearly beneficial to embryo development. When 2% of the maltose was replaced with 7.5% PEG, many embryos developed to large bullet-shaped embryos. At latter stages of development most embryos callused and stopped development. A few short, barrel-shaped cotyledonary embryos formed that were covered by callus on the sides and base. When 4% of the maltose was removed and substituted with 13% PEG, the embryos developed further, emerging from the callus and increasing yield slightly. Microscopic examination of the cultures showed differing morphologies, varying from mostly single cells or clumps to well-formed somatic embryos that resembled early zygotic embryos only liquid cultures with organized early-stag. A procedure for converting and acclimating germinants to growth in soil and greenhouse conditions is also tested. Seedling conversion and growth were highly related to the quality of the germinant at the time of planting. Germinants with larger shoots, longer, straighter hypocotyls and longer roots performed best. When mature zygotic embryos germinate the root emerges, before or coincident with the shoot. In contrast, somatic embryos germinate in reverse sequence, with the cotyledons greening first, then shoot emergence and then, much later, if at all, the appearance of the root. Somatic seedlings, produced from the maturation medium, showed 100% survival when planted in a field setting. Somatic seedlings showed normal yearly growth relative to standard seedlings from natural seed.

• Journal of Plant Biotechnology
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• v.2 no.3
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• pp.123-128
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• 2000

To enhance in vitro plantlet regeneration efficiency of soybean through embryogenesis, the culture conditions such as material part and size of immature seed, 2,4-D, pH and solidifying agents for somatic embryogenesis were investigated. Somatic embryogenesis was induced from the immature embryo, immature cotyledon and embryonic axis explants of the immature seed on MS medium supplemented with 2.0 mg/L 2,4-D. The highest rate (up to 22.9%) of somatic embryogenesis was obtained from the immature cotyledon, following embryonic axis and the immature embryo. The rate varied with the developmental stages of seed. The maximum rate (25.4%) of embryogenesis was obtained from 3-4 mm length of the seed (after 25 days of flowering). The optimum concentration of 2,4-D for embryogenesis was 10 mg/L. The optimum pH was at 5.8 and solidifying agent for medium was better with 0.4% gelrite than with agar. For rapid multiplication of shoot tips from the germinating somatic embryos, they were cultured on MS medium containing 2 mg/L indole-3-butyyic acid (IBA) and 1 mg/L 6-benzyladenine (BA). After then somatic embryos with one and three cotyledons were transferred to the growth regulator free medium. The medium exhibited the higher rate (ca. 50%) of development than the multiplication medium.

• Korean Journal of Plant Resources
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• v.8 no.2
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• pp.153-157
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• 1995

Embryogenic callus induces from shoot tip and leaf segment of Zanthoxylum piperitum for producing somatic embryogenesis and plant regeneration were cultured in vitro on Murashige and Tucker's(MT) medium treated with casein hydrolysate $NH_4NO_3$, $KNO_3$ and plant growth regulator. The most effective somatic embryogensis was observed in the medium added by two fold $NH_4NO_3$(3300mg/l)+2. 4-D 0.1mg/l and $KNO_3$(3800mg/l)+2.4-D 0.1mg/l. Also, MT medium supplemented with casein hydrolysate 700mg/l added by 2, 4-D 0.1mg/l were effective in obtainingn somatic embryos from embryogenic callus The effect ofm MT medium supplemented with casein hydrolysate without 2, 4-D was lower than that with (3300mg/l) 2, 4-D for the formation of somatic embryos.

• Journal of Crop Science and Biotechnology
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• v.11 no.1
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• pp.23-30
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• 2008

The relationship between three phenological parameters and somatic embryogenesis was investigated during a two-year period. Staminodes and petals from six hybrids and two clones as controls were sowed on three distinct primary callus growth media. Flowering level, fructification level, and leaf thrusts rhythm as phenological parameters were measured simultaneously during the weekly harvest of flower buds. Mean and coefficient of variation of the measured parameters highlighted stable phenological phases. The relationship between phenological parameters and somatic embryogenesis was investigated first by comparing the variation of somatic embryogenesis and that of the phenological parameters, and second by using Pearson's linear correlation. Except for the fructification level in both control clones the first year, the other parameters recorded stable phenological phases, regardless of the genotype and year. Favorable and unfavorable phases for the somatic embryogenesis were identified. In hybrids, favorable phases included February, August, September, and October. In both control clones, time interval propitious to embryogenesis stretched from February to December. The significance of the coefficient of correlation seemed to establish a relationship between somatic embryogenesis and phenology. However, a causal link could not be established. Leaf thrusts rhythm was revealed to be the phenological parameter most linked to somatic embryogenesis. Attempts to optimize embryogenesis during unfavorable phases, showed that a correction of 2.4 D/TDZ concentration is not the solution.

• IMMUNE NETWORK
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• v.7 no.3
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• pp.117-123
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• 2007

Background: This study was designed to investigate the role of the hepatocyte growth factor (HGF) with regards to differentiation of somatic stem cells originating from the human umbilical cord blood (UCB) into hepatic lineage cells in vitro culture system. Methods: Mononuclear cells from UCB were cultured with and without HGF based on the fibroblast growth factor (FGF)-1, FGF-2, and stem cell factor. The cultured cells were confirmed by immunofluorescent staining analysis with albumin (ALB), cytokeratin-19 (CK-19), and proliferating cell nuclear antigen (PCNA) MoAb. ALB and CK-18 mRNA were also evaluated by reverse transcription-polymerase chain reaction. In order to observe changes in proliferating capacity with respect to the cultured period, CFSE with affinity to proliferating cells were tagged and later underwent flow cytometry. Results: In the HGF-treated group, cultured cells had a large oval shaped appearance with adherent, but easily detachable characteristics. In the HGF-non treated group, these cells were spindle-shaped with strong adherent characteristics. Expressions of ALB and CK-19 were evident in HGF-treated group compared to non-expression of those in to HGF-non treated group. Dual immunostaining analysis of the ALB producing cells showed presence of PCNA in their nuclei, and ALB and CK-18 mRNA were detected on the 21st day of cultured cells in the HGF-treated group. Conclusion: Our findings suggest that HGF has a pivotal role in differentiating somatic stem cells of human UCB into hepatic lineage cells in vitro.

• Journal of Life Science
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• v.8 no.6
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• pp.623-626
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• 1998

Conditions for somatic embryogenesis and plant regeneration from stem tissues of Euphorbia pulcherrima were esta-blished. Explants from leaf, petiole, stem were examined for their embryogenesis on MS solid medium supplemented with plant growth hormones in combination at various concentrations. From leaf or petiole explants, callus was indu-ced well but never proceeded to the embryonic stage in our expermental conditions. From stem explants, however, multiple shoots following callus induction emerged in about 6 to 8 weeks on MS agar medium supplemented with 1.5 mg/L of benzyladenine. Upon transfer, roots were developed on hormone-free MS solid medium.