• Journal of Plant Biology
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• v.34 no.3
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• pp.201-213
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• 1991

This study has been carried out to investigate the ultrastructural changes, formation of storage materials in endosperm cells with electron microscope during the seed formation of Panax ginseng C.A. Meyer. In the early stage of seed formation with green seed coat, the endosperm was cellular type. Cell plate was largely composed of dictyosome vesicles in early stage of wall formation after mitosis. Central vacuole was gradually subdivided into several small-sized vacuoles. During the differentiation of plastids, some proplastid was replaced by amyloplast with starch grains and lamellar structure. A number of mitochondria with well developed cristae were distributed in cytoplasm. Rough endoplasmc reticulum, dictyosome, microbody, free ribosomes and polysomes were evenly distributed in cytoplasm. Spherical spherosomes were formed from dictyosome containing the lipid materials of even electron density. Protein bodies were formed by interfusing between vacuoles and vesicles derived from rough endoplasmic reticulum which contained the amorphous protein of high electron density.

• Journal of Plant Biotechnology
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• v.30 no.2
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• pp.195-199
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• 2003

Extracts of Escherichia coli as a elicit were treated to suspension cultures of Streptanthus tostus in order to observe the effect on the pholem development. By the elicit treatment, cell wall, sieve endoplasmic reticulum (SER) and p-protein were normally synthesized, but the structure of amyloplast was changed from a round form to irregular and swollen unhalthy form with a tiny starch granular. Oil drops were new synthesized and accumulated in a large oleoplast and proteins were also accumulated in a single membrane. The concentration of sucrose in the phloem, which was induced during the elicit treatment, was higher than normally developed phloem cells. These results suggest that phloem cells might be changed in the normal cycles of metabolism of lipids, carbohydrates and proteins to overcome during the eilicit stress.

• Korean Journal of Pharmacognosy
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• v.17 no.2
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• pp.134-138
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• 1986

Based on a tracer study, starch phosphorylase was implicated as an agent in the starch synthesis in sweet potato roots. The enzyme was purified from the tissue as a cluster of isozymes with an average mw of 205K (fresh roots) or 159K (roots stored for 3 mon.). On SDS polyacrylamide gel electrophoresis, one large subunit of 98K mw and several small ones of 47${\sim}57K mw were observed. From the mw data and the results of peptide mapping and immunoelectrophoretic blotting using mono- and polyclonal antibodies, it was deduced that a large part of the large subunit was cleaved at the middle part of the peptide chain to give rise to the small subunits, and on storage, the enzyme molecules were further modified by proteolysis. During the course of phosphorylase purification, a proteinaceous inhibitor of the enzyme was isolated. It had a mw of 250K and was composed of 5 identical subunits of 51K mw. In the direction of starch synthesis, the inhibitor showed a noncompetitive kinetics with a Ki of $1.3{\times}10^{-6}\;M$. By immunohistochemical methods, both the enzyme and the inhibitor were located on the cell wall and amyloplast. Crossreacting materials of the inhibitor were present in spinach leaf, potato tuber and rice grain. These findings indicate the wide occurrence of the inhibitor and also imply its possible participation in regulating starch phosphorylase activity in vivo.

• Journal of the Korean Society of Tobacco Science
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• v.17 no.1
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• pp.33-40
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• 1995

Structures of the adventitious root meristem induced from callus culture of tobaco (Nicotiana tabacum cv. NC 82) leaves were investigated by light and transmission electron microscopy. Structural differences between in vitro root and callus cells were also examined by the microscopy. The submicroscopic features of the in vitro root cells were as follows. Intercellular spaces were not developed and nuclei with two nucleoli were observed occasionally. Plasmodesmate were found in groups or sing1y on transverse and longitudinal walls. Amyloplast solely filled with starch grains, with one to five electron - dense bands, was surrounded by single membrane. in the callus cells, vacuolization of central part in the cytoplasm having mitochondria with swollen cristae and starch grains like those of in vitro root cells was a distinct feature. Vesicles which were found between cell wall and plasma membrane may be arisen by a process of protoplasmic invagination. By comparing of ultrastructures between the cells of callus and in vitro roots we found that the distinct differences lied on thickened cell walls and hypertrophed vacuoles in the former, and less thickened cell walls and several small vacuoles in the later.

• Korean Journal of Medicinal Crop Science
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• v.7 no.2
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• pp.129-137
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• 1999

The structure of amyloplasts and intercellular transport in the old and new bulbs of Frjtillaria pallidiflora were observed by means of electron microscope. The structure of internal membrane system was different between new and old amyloplasts. The active intercellular transport was observed in both new and old bulbs. The phenomena of encytosis and exocytosis always could be found in the cell membrane, and plasmodesmata established a symplasmic pathway for intercellular transport. Groups of vesicles often located at the ends of plasmodesmata, showing that they participated in the intercellular transport. These results laid a foundation for the further study on the mechanism of growth and development in Fritillaria pallidiflora.

• Korean Journal of Plant Tissue Culture
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• v.22 no.6
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• pp.323-327
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• 1995

This experiment was carried out to observe the origin and developmental pattern of somatic embryos of Oenanthe javanica ($B^{L}.$) DC. The experiment included observation of embryogenic cells and their development stages by light microscope, transmission electron microscope and scanning electron microscope. The embryogenic cells, which were smaller than non-embryogenic cells in size with expanded nucleus and dense cytoplasm. When stained with hematoxylin, the embryogenic cells were readily distinguished from the non-embryogenic cells of which cell walls were stained with safranin. It was observed at somatic embryos developed from single cells on the epidermis of developing embryos or in the surface or inside of embryogenic clumps by segmentation pattern. Observation with a transmission electron microscope revealed that the embryogenic cells had dense cytoplasm expanded nucleus, small vacuoles, large amyloplasts containing starch grains, and abundant organelles including lipid bodies. Under a scanning electron microscope, embryogenic callus was shown to consist of very smaller cells than non-embryogenic cells in an orderly arrangement and covered with a net-like structure, while the non-embryogenic callus consisted of large cells, irregular in size and arrangement, and covered with a gelatin-like material.

• Journal of Plant Biotechnology
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• v.30 no.1
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• pp.35-40
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• 2003

In this study we investigated the effect of gametocides on the number of larger-sized pollen in anther, and also induced callus from the anther culture of Zoysia japonica Steud. Before culturing, we have observed pollens in anther through fluorescence and electron microscopes to know pollen dimorphism. There were two types of pollens observed. One type (30-36 ${\mu}{\textrm}{m}$ in diameter) consisted of vacuolated, larger-sized pollens and the other (15-20 ${\mu}{\textrm}{m}$ in diameter) smaller-sized ones with dense cytoplasm and plenty of amyloplasts. Within few hours, all the smaller-sized pollens were dead, while larger-sized ones were viable for one or two days. To induct larger-sized pollens, various gametocides were leaf-sprayed on three booting stages cultured under 4$0^{\circ}C$ /15$^{\circ}C$ (day/night) before anther culturing. Number of these larger pollens were few (less than 1%) in anther without spraying gametocides. GA$_3$increased the number of larger-sized pollens when applied at mid-booting stage. GA$_3$ with 50 mg/L treatment caused the highest percentage (25.4%) of the larger-sized pollen. Anthers with GA$_3$ treatment were only produced calli on AA medium (modified B$_{5}$+8.0 mg/L 2,4-D ＋0.2 mg/L kinetin), but callus formation was quite low (less than 1%).).

• Applied Microscopy
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• v.41 no.1
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• pp.55-60
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• 2011

Reduced plants of Spirodela polyrhiza consisting only of fronds, stalks and roots form turions during dormancy. In development, mature fronds produce offspring fronds by vegetative reproduction, and turions arise laterally from the mother frond before dormancy. The turion primordium is derived from the frond, while the frond primordium forms within the turion tissue. In the present study, cellular features, especially those of the plastids, of the above four tissue types have been examined and compared using electron microscopy. Proplastids, found to be numerous in the frond and turion primordia, differentiated into chloroplasts rapidly upon growth. The proplastids were small and the thylakoidal membrane system was rudimentary, howerver the chloroplasts exhibited variation by cell type. Chloroplasts were found within cells of the frond, stalk and root tissue. The thylakoidal membrane system, which formed grana stacks, was moderately developed within frond chloroplasts, while only a few were present in those of the stalk and root cortical cells. One to two starch grains were accumulated within frond chloroplasts, but little to none were found in stalk and root cortical chloroplasts. Contrary to other types of root chloroplasts, those found in the root cap cells developed chloroplasts similar to the frond type. Unlike proplastids of the turion primordia, numerous large amyloplasts occupied most of the turion cell volume. Moreover, the turion cell produced quite large starch grain (s) within the amyloplasts. Accumulation of the starch grains continued until they occupied the most of the stroma and in some cases, individual starch grains reached up to $9.0{\mu}m$ in length. None to little, if any, thylakoidal or internal membranous systems were seldom detected in these amyloplasts. Although the degree of cellular and tissue differentiation was rather minimal within their reduced body, the functional differentiation of Spirodela polyrhiza was very efficient, as is the case in other advanced species.

• Korean Journal of Plant Resources
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• v.8 no.3
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• pp.237-246
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• 1995

In this study, the callus was induced and regenerated from the immature embryo and ultrastructural characteristics of developmental stages in Citrus junos SIEB, were investigated. The yellowish callus was induced by 5 to 6 week of culture of citrus. In proliferation callus after 6 weeks of culture, large vacuole was formed by fusion between adjacent small ones. In the non-embryogenic callus cultured for 12weeks, re-differentiated cells of callus showed the large nucleus with globular nucleus and amyloplast with large size of starches. In the embryogenic callus cltured for 14-16 weeks, the active exocytosis occurred in cells, secretory vesicles appeared on cell membrane and small particles from cytoplasm were released to intercelluar space. In the embryogenic callus cultured for 24 weeks, a sperical type of chloroplast bounded on cytoplasm by double membrane and typical grana was dispersed equally among matrix. In the normal plantlet after 26 weeks of culture, a lot of vessels and companion cells apperaed in the leaf cell of plantlet. In the normal plantlet after 30 weeks of culture, the immature leaf showed many small companion cells, sieve tubes and central vacuole. Also, the secondary vacuole protruded into the central vacuole and elongated chloroplasts near plasma membrane. In the matured plant habituated on the soil, palisada tissue composed of orderly arranged cells contained the nucleus in the center of the cell and large vacuoles on either side of the nucleus.