• Journal of Plant Biology
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• v.17 no.4
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• pp.171-174
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• 1974

Cotyledon of Panax ginseng was cultured in the growth regulator-free Knudson C medium comprising only several kinds of mineral salts and sucrose. Shoot primordium or callus developed profusely from the cotyledonary tissue and finally plantlets were produced directly from the shoot primordium or indirectly through callus. Microscopic examination revealed that the epidermal cell as well as the mesophyll cell of the cotyledon became meristematic and divided, changing into multinucleate cell or multicellular body, eventually developing into either a shoot primordium or callus.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.6
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• pp.1041-1046
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• 1998

This study was carried out to investigate the changes and composition of the non-cellulosic neutral sugars in cell wall of soybean sprouts during growth. The composition of non-cellulosic neutral sugars in cell of soybean sprouts was rhamnose, fucose, xylose, arabinose, mannose, galactose and glucose. The galactose content of cell wall was higher than other non-cellulosic neutral sugars, and was remarkably decreased during growth. The major non-cellulosic sugars of pectic substances were rhamnose, arabinose, and galactose. The arabinose content of pectic substance was increased in cotyledon and hypocotyl during growth. The contents of non-cellulosic neutral sugars were decreased in hypocotyl during growth. The galactose content of pectic substance was higher in cotyledon than those in hypocotyl, and was increased in cotyledon. The content of rhamnose was higher in ionically associated pectic substance than that in covalently bounded pectic substance. The major non-cellulosic neutral sugars of hemicellulose were glucose, rhamnose, arabinose and galactose. The galactose of hemicellulose was decreased remarkably during growth.

• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.1
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• pp.51-55
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• 2001

This study was conducted to establish a plant cell culture system for the production of medically important secondary metabolites from Xanthium strumarium. The effects of plant growth regulators including NAA, 2,4-D, kinetin, and ABA were examined in terms of callus induction, maintenance of callus and suspension cultures. It was shown that callus was induced upon treatment with NAA while embryo was induced after treatment with 2,4-D. Callus formation was further improved by treatment with ABA and NAA. The level of callusing increased by 17-29% for the seed case, cotyledon, leaf, and hypocotyl and by 96% in the case of the root. Suspension cell lines were established using calli produced from cotyledon, hypocotyl and root and cultured at 25$\^{C}$ under light conditions. The cells grew up to 15g/L with NAA 2ppm, BA 2ppm, and ABA 1ppm treatment. Supernatants of suspension cultures of cell lines derived from coyledon and hypocotyl produced some distinctive secondary metabolites, one of which was identified as 8-epi-tomentosin, which belongs to the xanthanolides. The amounts of 8-epi-tomentosin produced by the cotyledon- and hypocotylderived cell lines were 13.4mg/L and 11.0mg/L, respectively.

• Journal of Plant Biology
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• v.33 no.4
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• pp.253-257
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• 1990

Callus-inducing ability of Alnus hirsuta was examined by culturing various tissues (leaf, hypocotyl, cotyledon and seed) on NT (Nagata & Takebe) medium, supplemented with 2.5$\mu$M 2,4-D. Leaf-originated callus was cultured on media varying in auxin (IBA and NAA) and cytokinin (BAP) concentrations to examine the effects of auxin and cytokinin on callus growth. Maximum growth was obtained at 10 $\mu$M IBA+10$\mu$M BAP and 10$\mu$M NAA without cytokinin. Cell suspensions established from cotyledon-originated callus yielded viable protoplasts after incubation for 16-18 hours in an enzyme mixture (1% (w/v) Onozuka R-10 0.5% (w/v) Macerozyme, CPW salts and 13% (w/v) mannitol, pH 5.8). Protoplasts were cultured on NT medium, supplemented with glucose, hormones and coconut milk. After 6 weeks of culture, protoplasts sustained cell divisions to form microcallus, which showed various colors from red to white.

• Proceedings of the Botanical Society of Korea Conference
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• 1993.07a
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• pp.1-36
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• 1993

It is possible to regenerate plants from calli, single cells and protoplasts of numerous species via organogenasis or embryogenesis in cell and tissue culture systems. Also such regeneration of plants can directly occur from cells of explants. However certain plant species has not been yet provided cultures suitable for plant regeneration from cells or tissues. For example, we have to confirm the regenerability of plant from cells before preparing transformed cells for application. Even more, it is very important to notice that regenerated plants in cell and tissue cultures often show structural abnormality. The mojority of those plants is functionally disordered and eventually cases degenerated. One of such examples is vitreous plants which are manifested mainly in the leaves and manifesteds to a lesser extent in the stems and roots. Regenerants in suspension cultures show more frequent vitrification than on gelled media so that relative humidity and water potential are the key factors involved in abnormal morphogenesis in vitro. The other is that somatic embryos formed in media containing BAP or high concentration of sucrose show frequently cotyledon aberrancy such as polycotyledon and born type cotyledon. The embryos with aberrant cotyledon of Codonopsis lanceolata could not germinate or regenerate into plants in many cases. In contrast, the polycotyledon embryos of Aralia cordata germinated in higher percentage than two cotyledonary embryos, but horn type cotyledonary embryos rarely germinated. The major cause of poor germination is the abnormal development of plumule apex meristem.

• Korean Journal of Plant Tissue Culture
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• v.24 no.6
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• pp.341-344
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• 1997

Calli were induced from the cotyledon and the hypocotyl of alfalfa and the callus lines were tested for the resistance to glyphosate in the liquid medium containing 0.01-3.00 mM glyphosate. Some resistant cell lines were selected from the gradual increase of glyphosate concentration and the lines resistant to 10 mM glyphosate were analyzed with EPSPS activity. Vigorous callus proliferation from the cotyledon and the hypocotyl was observed from the MS medium containing 1 mg/L 2,4-D and 0.5 mg/L kinetin. The hypocotyl was thought to be better explant source for callus induction than the cotyledon. $ID_{50}$ (Inhibition Dosage of 50%) to glyphosate was between 0.1 mM and 0.2 mM level. A49-10G and A58-10G cell lines selected as resistant to 10 mM glyphosate had 8.0 and 9.1 fold increased EPSPS activity to those of the control lines, respectively.

• Journal of Plant Biotechnology
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• v.39 no.3
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• pp.133-139
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• 2012

The influences of ethylene inhibitors ($AgNO_3$ and silver thiosulfate) and cytokinins (BAP and TDZ) on shoot regeneration from cotyledon and hypocotyl explants of B. napus cv. Youngsan were investigated. The presence of $50{\mu}M$ Silver thiosulfate (STS) in shoot regeneration medium formed shoots at 60-68% after 3-4 weeks of culture, which was enhanced by 2-fold compared to that of Silver nitrate ($AgNO_3$). Moreover, cotyledon explants were more regenerative than hypocotyls; shoots from cotyledon explants began to occur 4-5 days earlier than that of hypocotyl explants. TDZ at a concentration of $8-10{\mu}M$ was effective for shoot regeneration, compared with BAP. Consequently, the optimal shoot regeneration response was observed in medium supplemented with $50{\mu}M\;STS+8{\mu}M\;TDZ$. In transmission electron microscopy (TEM) analysis, higher density of silver nanoparticles was shown to be accumulated widely inside the cell wall and plasmodesmata of regenerating leaf cultured in medium supplemented with $AgNO_3$. By contrast, in the cell cultured in medium with STS, fine-grained deposits were partly observed in the surroundings of the cell wall.

• 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.

• Journal of Plant Biology
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• v.39 no.2
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• pp.123-126
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• 1996

The pattern of seed storage protein, vicilin, deposition and site of intracellular localization was examined in cotyledon cells of pea (Pisum sativum) seed using the immunocytochemical methods. The vicilin was confined to the cisternae fo the rough endoplasmic reticulum and dictyosome as well as protein granules newly formed in rough endoplasmic reticulum. Vacuolar protein deposites and protein bodies were also labelled by gold particles. After small protein bodies were formed in the rough endoplasmic reticulum, they were transported to large protein bodies and then fused together. Electron dense protein granule, elaborated in the dictyosome, appears to be transported from dictyosome to protein body. A few unlabelled protein granules seem to be accumulated in other type of proteins than vicilin.

• 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.