• Journal of Plant Biology
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• v.39 no.1
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• pp.71-77
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• 1996

Embryogenic callus was selected from callus induced from hypocotyl segment cultures of Daucus carota seedlings on MS basal medium supplemented with 1.0 mg/L 2,4-D. Cell clumps prepared from the embryogenic callus were transferred to MS medium without 2,4-D for somatic embryo development. Cotyledonary abnormalities were frequently observed on somatic embryos developed after the incubation of cell clumps in MS basal medium with 1.0 mg/L 2,4-D for one week and then subculture in the same medium but without 2.4-D for two weeks. The percentage of abnormalities was as follows: 5% one cotyledon, 21% three cotyledons, 6% four cotyledons, 5% five cotyledons, 0.2% six cotyledons and 1% trumpet-like cotyledons. On the other hand, the normal somatic embryo with two cotyledons appeared at 63%. The germination rate of somatic embryos was higher in two cotyledon somatic embryos than in multicotyledonary embryos. Trumpet-like somatic embryos did not germinate normally showing limited elongation and enlargement of roots and cotyledons without shoot development. From anatomical examination circular procambium in the root of somatic embryo began to branch around the middle regions of the hypocotyl which extended into the cotyledons through the cotyledonary nodes and the number of branched procambial strands in hypocotyl was equal to the number of cotyledons. Monocotyledonous somatic embryo always had larger cotyledon than that of somatic embryos with multicotyledons and had horseshoe-like cotyledons where the procambium was of the same structure.ucture.

• Korean Journal of Medicinal Crop Science
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• v.5 no.4
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• pp.289-293
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• 1997

The effects of plant regulators on direct somatic embryogenesis in liquid culture of Rehmannia glutinosa were investigated and the proper explant for direct somatic embryo formation was studied. Direct somatic embryos were induced from leaf segments culture in the MS liquid medium containing 0.5 mg/l of both IAA and NAA, while IBA of 1.0 mg/l was required for the same effect. Many somatic embryos were directly formed at the concentration of 2.0 mg/l cytokinin such as BA, kinetin and zeatin, but somatic embryogenesis was relatively poor at above or below this level. Relatively more somatic embryos were induced in the combination of 1.0mg/l IAA and 2.0mg/l zeatin. Formation of somatic embryos begun after 6 weeks on stem segments, while 7 weeks both on petiole and leaf. However, overall production of somatic embryos after 8 weeks was higher in leaf segment than that of stem segment.

• Journal of Korean Society of Forest Science
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• v.97 no.1
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• pp.127-133
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• 2008

This study was conducted to establish the optimal condition for plant regeneration and acclimatization from somatic embryos of Panax ginseng. Cotyledon segments of Panax ginseng produced primary and secondary somatic embryos when cultured on MS and WPM media supplemented with 7% sucrose. To induce plantlet conversion, cotyledonary somatic embryos were cultured on WPM solid medium with $GA_3$ at various concentrations (1~30 mg/L) for 4 weeks. Plantlets were transferred to 1/2 WPM solid medium with $GA_3$ at various concentrations (0~5 mg/L) and 0.5% activated charcoal for shoot and root elongations. Elongated plantlets further developed into well-developed leaf and root system on 1/3 SH medium with 0.5% activated charcoal under ventilation condition for 5 months. The highest survival rate to soil was 75% when plantlets were regenerated on 1/3 SH medium without sucrose under ventilation condition.

• Korean Journal of Plant Tissue Culture
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• v.24 no.6
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• pp.345-349
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• 1997

Somatic embryos were induced through embryogenic callus derived from immature zygotic embryo culture of native Prunus yedoensis in Mt. Halla and regenerated into plantlets successfully. Embryogenic callus was induced most effectively on MS medium with 1.0 mg/L 2, 4-D and 0.1 mg/L BAP at an efficiency of approximately 60% using 45 day-old zygotic embryos after full blooming. Globular somatic embryos were induced from embryogenic callus on MS medium with 1.0 mg/L 2, 4-D and 0.1 mg/L BAP and these globular embryos developed to heart-shaped and cotyledonary embryos on hormone-free MS medium. Normal somatic embryos germinated 49% on 1/2 MS medium and the plants regenerated from the somatic embryos were morphologically normal.

• Journal of Korean Society of Forest Science
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• v.85 no.4
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• pp.667-679
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• 1996

Clonal forestry and reforestation programmes are especially interested now in development and application of controllable biotechnological systems based on the production of conifer somatic embryos in bioreactors with their following drilling and/or storage in the form of "artificial seeds". Modern achievements in conifer somatic embryogenesis has guided the development not only of biotechnological systems in forestry, but also of basic research in conifer embryology, cell and molecular biology. At the present time, the level of development of applied research on conifer somatic embryogenesis is well ahead our understanding of this complex phenomenon. The "bottleneck" situation in relation between basic and applied sciences will eventually lead to the appearance of "weak points" in biotechnological systems. In the present review, the major advances and the most pressing problems in the application of conifer somatic embryogenesis both to forest biotechnology and to basic research are in the focus of attention.

• Journal of Plant Biotechnology
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• v.38 no.4
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• pp.258-262
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• 2011

Embryogenic callus was induced from the cultures of immature embryos of Camellia japonica L. on Murashige & Skoog's (MS) solid medium supplemented with 1 mg/L 2,4-dichlorophenoxy acetic acid (2,4-D), and then the embryogenic callus was proliferated on same medium for 4 weeks over. The embryogenic callus was sub-cultured on MS basal medium without 2,4-D to produce coyledonary stage of somatic embryo. The frequency (%) of somatic embryogenesis was 25.1%, and the majority of somatic embryos formed had a abnormal morphology with cupshaped cotyledon (48.3%), one cotyledon (12.6%), three cotyledons (9.4%), four cotyledons (1.9%), whereas was only normal morphology with two cotyledon (27.5%). When the somatic embryos with normal or abnormal cotyledons transfer to MS basal medium or $\frac{1}{2}$ MS medium with/or without plant growth regulators ($GA_3$, IBA) for regeneration, the frequency (%) of two-cotyledon embryos regenerated into plantlets was higher 11.1% than one cotyledon (0.0~8.3 %), three cotyledons (0.0~5.8%), four cotyledons (0.0%), cup-shaped (0.3~4.2%). These results demonstrated that the anomalous cotyledons of somatic embryos could caused to decrease the rate of plant regeneration.

• Korean Journal of Plant Tissue Culture
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• v.21 no.1
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• pp.7-14
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• 1994

Immature zygotic embryos of five Korean soybean cultivars cultured on Murashige and Skoog's (MS) medium supplemented with various concentrations of 2,4-Dichlorophenoxyacetic acid (2,4-D) produced somatic embryos without forming an intervening callus. The highest frequency (up to 90%) of somatic embryo formation was obtained when zygotic embryos were cultlued on medium containing 1 to 2 mga 2, 0-D in four cultivars. However the frequency was highly variable to the cultivars. Transversely sliced primary somatic embryo halves were also capable of forming secondary embryos at frequencies of up to 70% when cultured on medium containing 0.1 to 1 mg/L 2,4-D. Somatic embryos formed on zygotic embryos cultured on medium containing 0.1 to 0.2 mg/L 2,4-D had two cotyledons more frequently than one horn-type cotyledon and those on medium containing 0.5 to 4mg/L 2,4-LD had a horm-type cotyledon at a prominently higher freequency. However somatic embryos on medium containing 10mg/L or higher concentrations of 2,4-D were usually shunted at the globular stage even after transfer to medium containing lower concentrations of 2,4-D or other growth regulators. non somatic embryos with one or two cotyledons or a hem-type cotyledon were transferred to medium containing $GA_3$, those with two cotyledons converted to plantlets at a higher frequency (25%) than the others.

• Development and Reproduction
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• v.13 no.4
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• pp.291-296
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• 2009

In most larvae of ascidian, two sensory pigment cells, otolith and ocellus, lie in their brain vesicle. They also have a third type of sensory cells: hydrostatic pressure receptor (Hpr) cells. The Hpr cells were presumed to be hydrostatic pressure-detection cells, but their precise functions is still disputed. In this study, we investigated whether an FGF signaling is involved in formation of Hpr cells. When fertilized eggs were injected with Hr-FGF9/16/20 antisense MO, the resulting larvae showed severe abnormalities with no expression of the Hpr cell-specific Hpr-1 antigen. Similar results were obtained using an FGF receptor inhibitor, SU5402, and an MEK inhibitor, U0126. Embryos treated with SU5402 or U0126 during the 32-cell and hatching stages did not express the Hpr-1 antigen. To elucidate the temporal requirement for the FGF signaling in formation of Hpr cells, embryos were treated with SU5402 for 2 h, or U0126 for 20 min during various embryonic stages. Larvae treated with SU5402 from the 16-cell stage to the 64-cell stage did not express the Hpr-1 antigen, whereas those treated at the early gastrula stage expressed the Hpr-1 antigen. When U0126 treatment was carried out at various stages between the 8-cell and late gastrula stages, larvae scarcely formed the Hpr cells. They showed expression of the Hpr-1 antigen when embryos were placed in U0126 just before the neural plate stage. These results suggest that FGF9/16/20 signaling is involved in formation of Hpr cells from the primary neural induction stage to the late gastrula stage.

• Journal of Veterinary Clinics
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• v.26 no.6
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• pp.524-527
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• 2009

Spontaneously infected and non-infected dairy cows were assessed in a cross-sectional study aimed at determining whether bovine leukocyte markers may diagnose intra-mammary infections (bovine mastitis). Animals located in herds where bovine mastitis was highly prevalent were investigated (n = 31 animals). The expression of three cell-surface markers (CD11b, CD4 and CD8) was assessed, and the somatic cell count (SCC) and bacteriological analyses (both cultures and PCR tests) were also conducted. Cows identified as infected revealed statistically significant higher milk leukocyte CD11b, CD4 percentage and milk CD4/CD8 ratios than non-infected cows. Immunological markers may diagnose spontaneous bovine mastitis.

• Journal of Korean Society of Forest Science
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• v.99 no.4
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• pp.633-637
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• 2010

This study was conducted to evaluate various effects of kinds of culture medium, concentrations of abscisic acid (ABA) or /kinds of osmotica on maturation of somatic embryos (SEs) with four (LL-L, LL-K, LL-P and LL-N) embryogenic tissue lines (ETLs) in Japanese larch (Larix leptolepis). In comparison of two culture medium, the LL-P produced the highest number of the cotyledon-staged SE (134.9/90 mg tissue) in 1/2LM medium. In contrast, no SEs were obtained except the LL-P (32.9) in medium of BLG. Effects of two concentrations of ABA in the medium with four ETL for SEs maturation were also compared. In the test of 60 or 100 ${\mu}M$ ABA, the highest result was obtained in 60 ${\mu}M$ ABA (142.9). However, the influence of ABA had little on SEs production except the LL-N regardless of concentrations of ABA. In comparison of different kinds/concentrations of osmotica, the best response was obtained from the treatment of 0.2 M maltose, the LL-K (540.5). In conclusion, the effects of production of SEs were greatly rely on the ETLs, rather than kinds of medium, concentrations of ABA or osmotica which were used in maturation of SEs.