• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.1
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• pp.38-42
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• 2006

When whole cells are subjected to pyrolysis gas chromatography/mass spectrometry (Py-GC/MS) analysis, it provides biochemical profiles containing overlapping signals of the majority of compounds. To determine marker compounds that discriminate embryogenic calluses from nonembryogenic calluses, samples of embryogenic and nonembryogenic calluses of five higher plant species were subjected to Py-GC/MS. Genetic programming of Py-GC/MS data was able to discriminate embryogenic calluses from nonembryogenic calluses. The content ratio of 5-meyhyl-2-furancarboxaldehyde and 5-(hydroxymethyl)-2-furancarboxaldehyde was greater in nonembryogenic calluses than in embryogenic calluses. However, the content ratio of phenol, p-cresol, and $^1H-indole$ in embryogenic calluses was 1.2 to 2.4 times greater than the ratio in nonembryogenic calluses. These pyrolysates seem to be derived from the components of the cell walls, which suggests that differences in cell wall components or changes in the architecture of the cell wall playa crucial role in determining the embryogenic competence of calluses.

• Journal of Plant Biology
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• v.32 no.4
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• pp.247-253
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• 1989

Protoplasts were enzymatically isolated from suspension culture of sweet potato. High yields of single protoplasts were produced from nonembryogenic cell aggregates. However, most protoplasts obtained from embryogenic cell clumps were spontaneously fused during enzyme treatment; a small portion of them remained single. Upon transfer to Murashige and Skoog's(MS) liquid medium supplemented with 0.1 mg/1 6-benzyladenine(BA) and 1 mg/12,4-dichlorophenoxyacetic acid(2,4-D), protoplasts from nonembryogenic cell aggregates sustained cell divisions to form cellus. Upon subculture onto MS media with 0.2 mg/12,4-D or without growth regulators, the callus did not give rise to any organs. On the other hand, first cell division of single protoplasts from embryogenic cell clumps was sporadically observed.

• Journal of Plant Biology
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• v.38 no.1
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• pp.55-62
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• 1995

Embryogenic cell (EC) suspension cultures derived from mature seed-embryo of rice (Oryza sativa L cv. Kye Hwa) were used for the expression patterns of isozyme and enzyme activity. EC suspension cultures were composed of cells that were densely cytoplasmic, potentially embryogenic. However, nonembryogenic cell (NEC) cultures were composed of large, elongated and vacuolated cells. These cells were analyzed for the isozyme pattern and enzyme activity of EC and NEC. Isozyme patterns of peroxidase, esterase, acid phosphatase and malate dehydrogenase exhibited striking difference in the total number of bands, specificity and intensity of band. Also, these isozymes showed very high activity in the EC. Specific band, band activity and higher enzyme activity of isozyme in EC was absent or low in NEC, which may indicate an association of these specific isozymes with morphological characterization and totipotency of embryogenic cells. These results indicate that specific pattern and activity of enzyme in EC could probably be used as a biochemical marker of EC in rice.n rice.

• Korean Journal of Plant Tissue Culture
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• v.24 no.3
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• pp.167-173
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• 1997

The embryogenic callus (EC), from which somatic embryos could be induced, was compared with nonembryogenic callus(NE) to study the origin and features of totipotent cell in water dropwort (Oenanthe stolonifera DC). To induce and maintain of EC and the NE, meristematic stem and immature floret were inoculated in MS media supplemented with 1 mg/L 2,4-D, and with 2.5 mg/L NAA and 5mg/L BA, respectively, The EC was not induced from the NE even after subculturing in MS medium supplemented with 1 mg/L 2,4-D. Plantlets were not regenerated from the NE in hormone-free medium. In histochemical comparison of the EC with the NE by light microscopy, the EC had smaller cells in size, dense cytoplasm, and more starch granules of cells compared to the NE cells. The cell from the EC, as observed by transmission electron microscopy, had smaller vaculoes, well developed ribosomes, mitochondria, and endoplasmic reticulum, whereas the cells from the NE had larger vacuoles and underdeveloped organelles. In protein pattern from NE, EC and Somatic embryo (SE), as analyzed by SDS polyacrylamide gel electrophoresis, different proteins specific for tissue were observed: 17 and 28 KD for NE, 50, 52, 57, 66, 68 KD for EC and 20 KD for SE. DNA polymorphism was also observed between EC and NE as analyzed by RAPD (randomly amplified polymorphic DNA) method. The origin of totipotent stem cell and the relationship between irreversible genomic change arose in differentiation and the loss of totipotency in plant were discussed.