• Journal of Plant Biotechnology
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• v.29 no.2
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• pp.135-138
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• 2002

Cotyledonary explants from immature zygotic embryos of each 85 recombinant inbred lines (RILs) were cultured on medium containing MS salts, B5 vitamins, 40 mg$^{-1}$ 2,4-dichlorophenoxyacetic acid and 30 g$^{-1}$ sucrose. Frequency of somatic embryo formation on cotyledonary explants showed in thirty-six lines(＜10%), in thirty-seven lines (11~49%), in nine lines (50~89%), and in three lines(>90%), respectively, The highest frequency (up to 90%) and number (6.36 per cotyledon) of somatic embryos were obtained from lines of KM1010, KM1032 and KM1064. Primary somatic embryos produced from three lines produced numerous secondary somatic embryos on the surfaces, which were subcultured for over one year. Upon transfer to maturation and conversion medium (Komatsuda, 1992), somatic embryos converted to plantlets at a frequency of approximately 25%.

• Journal of Plant Biotechnology
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• v.30 no.2
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• pp.167-172
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• 2003

Immature zygotic embryos of Eleutherococcus senticosus seeds matured rapidly within one month when the seeds comprising zygotic embryos were pieced to small size and cultured on 1/2 MS medium. Frequency of somatic embryos formation was declined rapidly when the zygotic embryos germinated and grew to plantlets. Embryogenic cells were induced by consecutive subculture of somatic embryos on MS medium with 1.0mg/L2,4-D. After heart-shaped somatic embryos were induced by suspension culture, these embryos were plated onto petri dish to support maturation of embryos. Germination of embryos occurred on medium with 5mg/L GA$_3$and transferred to culture bowl to stimulate the further growth. Frequency of soil survival of plantlets was influenced by soil mixture (perlite and peatmoss). The suitable combination of perlite and peatmoss was 1:5, and the soil survival rate was 78% after 4 months. The soil transferred plantlets were over-wintered in field condition after defoliation. New year sprouting of plants was achieved successfully and they grew to adult plants. These results indicate that the systematic procecure of plant production in E. senticosus for micro propagation.

• Journal of Korean Society of Forest Science
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• v.80 no.1
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• pp.1-8
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• 1991

Developmental micropropagation method and somatic embryogenesis for hybrid poplars, Populns ehrarnericana Eco28, P. nigra ${\times}$ P. moximowiczii 62-9, were established using nodule culture system. Calli of Eco28 and 62-9 clone were initiated from leaf explant on the medium with 0.5mg/l and 2.0mg/l 2, 4-D, respectively. Cell suspension culture was established from callus derived from leaf explant culture. When suspended on MS medium with optimal combination of BA and NAA fine nodules were obtained after 2 weeks of culture. For shoot regeneration, nodules were transferred into liquid and agar solidified medium. Numerous shoots were regenerated from nodules of 62-9 on liquid media. Organogenesis was effectively achieved on agar solidified regeneration media containing different concentrations of BA and adenine sulfate. Average numbers of 27 and 24 shoots per nodule were induced from 62-1 and Eco28 clones after 8 weeks of culture, respectively. In addition, somatic embryogenesis also occurred in the same regeneration medium. This procedure can be applied to vegetative propagation, utilization of somaclonal variation, production of secondary metabolite and materials of biotechnology research.

• Journal of Plant Biotechnology
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• v.29 no.3
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• pp.185-188
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• 2002

Off-white, friable embryogenic calluses were formed on the internal integument of mature seeds of yuzu (Citrus junos) cultured on Murashige and Skoog's basal medium at a frequency of 1.2%. Embryogenic calluses were proliferated when cultured on medium with 1 mg/L 2,4-D. Upon transfer to medium with 0.1 mg/L kinetin, embryogenic calluses produced numerous somatic embryos. Embryogenic suspension cultures were established by placing embryogenic calluses into liquid medium with 1 mg/L 2,4-D. When plated onto medium with 0.5 mg/L ABA, embryogenic cells developed into somatic embryos at a high frequency, and then regenerated into plantlets. Plantlets were successfully transplanted to potting soil and grown in a greenhouse.

• Journal of Plant Biotechnology
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• v.29 no.3
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• pp.189-192
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• 2002

An efficient plant regeneration system of major cultivars of sweetpotato (Ipomoea batatas (L.) Lam.) in Korea via somatic embryogenesis was established. Embryogenic calli were formed from shoot apical meristems of sweetpotato cultivars when cultured on LS medium supplemented with 1 mg/L auxin (2,4-D, picloram, dicamba). Among three kinds of auxin, 1 mg/L 2,4-D showed the highest embryogenic calli induction rate. After 4 weeks of cultures on LS medium supplemented with 1 mg/L 2,4-D, embryogenic calli induction rates of Sinhwangmi, Zami, Yulmi, and White Star were 86%, 78%, 76%, and 80%, respectively. Upon transfer onto LS basal medium, most of somatic embryos developed into plantlets. Regenerated plantlets were transplanted to potting soil and grown to mature plants in a greenhouse.

• Molecules and Cells
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• v.38 no.12
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• pp.1029-1036
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• 2015

Appropriate vessel development and its coordinated function is essential for proper embryogenesis and homeostasis in the adult. Defects in vessels cause birth defects and are an important etiology of diseases such as cardiovascular disease, tumor and diabetes retinopathy. The accumulative data indicate that ETV2, an ETS transcription factor, performs a potent and indispensable function in mediating vessel development. This review discusses the recent progress of the study of ETV2 with special focus on its regulatory mechanisms and cell fate determining role in developing mouse embryos as well as somatic cells.

• 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.

• Journal of Plant Biotechnology
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• v.32 no.2
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• pp.135-138
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• 2005

Embryogenic callus was obtained from cotyledonary explants of Codonopsis lanceloata on Murashige & Skoog's medium supplemented with 1 mg/L 2,4-D. Suspension cultures of the embryogenic calli were grown on a shaker at 100 strokes/min, and then the calli were subcultured for 2 weeks in 2,4-D-free medium to produce somatic embryo. In somatic embryos at the globular stage, cotyledon initials began to differentiate themselves in the near distal end of the procambial strand. Dicotyledons, tricotyledon, tetracotyledon and fused cotyledon were differentiated from the distal ends of two, three, four and circular procambial strands, respectively. Nearly circular procambial strand in lower hypocotyls were independently differentiated into two, three, four procambial tissues at cotyledonary node and cotyledons to form somatic embryos with dicotyledon, tricotyledon, tetracotyledon. If the distal subepidermal cells of globular embryo exclusively became cotyledon initials, the torpedo or cotyledonary embryo was characterized by somatic embryos with fused cotyledon.

• Proceedings of the Botanical Society of Korea Conference
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• 1987.07a
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• pp.213-237
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• 1987

In vitro flowering system may minimize the confounded influence of non-floral meristem parts of plants in studying the relationship of a given treatment and flowering responses. We have induced flower buds from plantlets regenerated from zygotic embryo-derived somatic embryos of ginseng, which circumvented the normal 2-year juvenile period before flowering. The result suggests that the adulthood of ginseng root explants in the experiment previously conducted by Chang and Hsing (1980; Nature 284: 341-342) is not prerequired to flowering of plantlets regenerated through somatic embryogenesis. We have also induced flower buds from elongated axillary brandches from cotyledonary nodes by culturing ginseng zygotic embryos, seedlings, and excised cotyledonary nodes. It was found that 6-benzyladenine (BA) supplemented to the medium was essential for flowering, whereas abscisic acid (ABA) was inhibitory. Gibberellic acid(GA3) was also required for flowering when ABA was present with BA in the medium. The results suggest that cytokinins, gibberellins, and inhibitors play primary, permissive, and preventive roles, respective-ly, in the induction of flowering of ginseng. Tran Thanh Van (1980; Int. Rev. Cytol., Suppl. IIA: 175-194) has developed the "thin cell layer system" in which the induction of shoots, roots, or flower buds from epidermal layer explants were controlled by culture conditions and exogenous growth regulators in the medium, Utilizing the thin cell layer system, Meeks-Wagner et al. (1989; The Plant Cell 1: 25-35) have cloned genes specifically expressed during floral evocation. However, the system is too tedious for obtaining a sufficient amount of plant materials for biochmical and molecular biological studies of flowering. We have developed a garlic callus culture system and one obvious advantaging over the thin cell layer system is that an abundant cells committed to develope into flower buds proliferate. When the above cells were compared by two-dimensional gel electrophoresis with those which have just lost the competence for developing into flower buds, a few putative proteins specific to floral evocation were detected. The garlic callus culture system can be further explored for elucidation of the molecular biological mechanism of floral evocation and morphogenesis.hogenesis.

• Journal of Animal Reproduction and Biotechnology
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• v.35 no.4
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• pp.323-328
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• 2020

Direct injection of genome editing tools such as CRISPR/Cas9 system into developing embryos has been widely used to generate genetically engineered pigs. The approach allows us to produce pigs carrying targeted modifications at high efficiency without having to apply somatic cell nuclear transfer. However, the targeted modifications during embryogenesis often result in mosaicism, which causes issues in phenotyping founder animals and establishing a group of pigs carrying intended modifications. This study was aimed to establish a genomic PCR and sequencing system of a single blastomere in the four-cell embryos to detect potential mosaicism. We performed genomic PCR in four individual blastomeres from four-cell embryos. We successfully amplified target genomic region from single blastomeres of 4-cell stage embryo by PCR. Sanger sequencing of the PCR amplicons obtained from the blastomeres suggested that PCR-based genotyping of single blastomere was a feasible method to determine mutation type generated by genome editing technology such as CRISPR/Cas9 in early stage embryos. In conclusion, we successfully genotyped single blastomeres in a single 4-cell stage embryo to detect potential mosaicism in porcine embryos. Our approach offers a simple platform that can be used to screen the prevalence of mosaicism from designed CRISPR/Cas9 systems.