• Proceedings of the Korean Society of Crop Science Conference
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• 2007.04a
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• pp.65-73
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• 2007

The objective of this study is to understand how regulatory mechanisms respond to sugar status for more efficient carbon utilization and source-sink regulation in plants. So, we need to identify and characterize many components of sugar-response pathways for a better understanding of sugar responses. For this end, genes responding change of sugar status were screened using Arabidpsis cDNA arrays, and confirmed thirty-six genes to be regulated by sucrose supply in detached leaves by RNA blot analysis. Eleven of them encoding proteins for amino acid metabolism and carbohydrate metabolism were repressed by sugars. The remaining genes induced by sugar supply were for protein synthesis including ribosomal proteins and elongation factors. Among them, I focused on three hydrolase genes encoding putative $\beta$-galactosidase, $\beta$-xylosidase, and $\beta$-glucosidase that were transcriptionally induced in sugar starvation. Homology search indicated that these enzymes were involved in hydrolysis of cell wall polysaccharides. In addition to my results, recent transcriptome analysis suggested multiple genes for cell wall degradation were induced by sugar starvation. Thus, I hypothesized that enzyme for cell wall degradation were synthesized and secreted to hydrolyze cell wall polysaccharides producing carbon source under sugar-starved conditions. In fact, the enzymatic activities of these three enzymes increased in culture medium of Arabidopsis suspension cells under sugar starvation. The $\beta$-galactosidase encoded by At5g56870 was identified as a secretory protein in culture medium of suspension cells by mass spectrometry analysis. This protein was specifically detected under sugar-starved condition with a specific antibody. Induction of these genes was repressed in suspension cells grown with galactose, xylose and glucose as well as with sucrose. In planta, expression of the genes and protein accumulation were detected when photosynthesis was inhibited. Glycosyl hydrolase activity against galactan also increased during sugar starvation. Further, contents of cell wall polysaccharides especially pectin and hemicellulose were markedly decreased associating with sugar starvation in detached leaves. The amount of monosaccharide in pectin and hemicellulose in detached leaves decreased in response to sugar starvation. These results supported my idea that cell wall has one of function to supply carbon source in addition to determination of cell shape and physical support of plant bodies.

• Journal of Microbiology and Biotechnology
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• v.16 no.2
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• pp.247-255
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• 2006

Yeast cell wall matrix particles are composed entirely of mannoprotein and ${\beta}-glucan$. The mannoproteins of yeast cell wall can systemically enhance the immune system. We previously purified and analyzed alkali-soluble ${\beta}-glucans$ [${\beta}$-(1,3)- and ${\beta}$-(1,6)-glucans] [10]. In the present study, a wild-type strain was first mutagenized with ultraviolet light, and the cell wall mutants were then selected by treatment with 1.0 mg/ml laminarinase (endo-${\beta}$-(1,3)-D-glucanase). Mannoproteins of Saccharomyces cerevisiae were released by laminarinase, purified by concanavalin-A affinity and ion-exchange chromatography. The results indicated that the mutants yielded 3-fold more mannoprotein than the wild-type. The mannoprotein mass of mutant K48L3 was 2.25 mg/100 mg of yeast cell dry mass. Carbohydrate analysis revealed that they contained mannose, glucose, and N-acetylglucosamine. Saccharomyces cerevisiae cell wall components, mannoproteins, are known to interact with macrophages through receptors, thereby inducing release of tumor necrosis factor alpha ($TNF-{\alpha}$) and nitric oxide. Mannoprotein tractions in the present study had a higher macrophage activity of secretion of $TNF-{\alpha}$ and nitric oxide and direct phagocytosis than positive control ($1{\mu}g$ of lipopolysaccharide). In particular, F1 and F3 fractions in mannoproteins of K48L3 enhanced and upregulated the activity of nitric oxide secretion and macrophage phagocytosis by approximately two- and four-fold, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.2
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• pp.247-253
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• 1995

This paper was performed to investigate the changes of non-cellulosic neutral sugars composition in cell wall of persimmon fruit by treatment of cell wall degrading enzyme in vitro. Rhamnose, xylose and galactose in cell wall by polygalacturonase treatment, arabinose, galactose and rhamnose in cell wall by mixed enzyme treatment and arabinose and galactose in cell wall by ${\beta}-galactosidase$ treatment decreased, respectively. Noncellulosic neutral sugars of pectins extracted cell wall by enzyme treatments decreased and those by polygalacturonase treatment decreased remarkably. Rhamnose, arabinose and xylose in hemicellulose I of cell wall by polygalacturonase treatment were higher than those of untreated, and rhamnose and xylose in that by ${\beta}-galactosidase$ treatment were higher but arabinose, mnnose and galactose decreased. Xylose, mannose and glucose in that by mixed enzyme treatment were higher than those of untreatment and arabinose and galactose decreased. Contents of total non-cellulosic neutral sugars in hemicellulose of untreatment, and contents xylose, and glucose in hemicellulose II of cell wall by polygalacturonase treatmet decreased but those of other treatments were not changed.

• The Journal of the Korean Society for Microbiology
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• v.5 no.1
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• pp.9-18
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• 1970

The present study is of ultra-fine structures of Trichophyton rubrum, Trichophyton mentagrophytes, Microsporum canis and Epidermophyton floccosum by means of electron microscopy and reveals the following. 1. In contrast to the bacteria, the normal fungus contains nuclear membrane, mitochondria, endoplasmic reticulun, distinct cell wall and cell membrane and secretory granules as observed in the higher plants and animals. 2. Thickening of the cell wall, inapparent cell wall, inapparent cell membrane with the appearance of electron thin area(ETA) and increase of inclusions were observed in the L-1 treated groups. 3. Thickening of cell wall and increase of ETA were more apparent in the Epidermophyton floccosum than the other groups. 4. Increase of electron thin area was thought to be associated with autolysis.

• 한국전자현미경학회:학술대회논문집
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• 2007.05a
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• pp.75-78
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• 2007

The localization of cellulase were investigated in the capitate glandular trichomes of Pelargonium ${\times}$ fragransby a transmission electron microscopy. The secretory cells of capitate trichomes involved in biosynthesis and its secretion. Secretory material is transported to the space between the plasma membrane and cell wall, and subsequently accumulated in the secretory cavity. The splitting of secretory cell wall during the formation of secretory cavity is suggested that wall-forming enzymes, such as cellulase, may contribute to the wall separation process. Cellulase reaction product was localized in the secretory cell, the secretory cavity and in the subcuticular wall of glandular trichomes. Reaction products were present over fibrillar matrix in the secretory cavity associated with both the inner wall and the subcuticular wall.

• Microbiology and Biotechnology Letters
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• v.1 no.1
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• pp.19-23
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• 1973

This experiment was done to investigate the growth and the fine structural changes of Bacillus subtilis which were influenced by the penicillin with electromicroscope. The results were as follows; 1) The higher the concentration of penicillin the more prominent inhibition of the growth was observed. 2) The septa was not formed, derangements of synthesis of cell wall and cell membrane. 3) Cytoplasm was increased with swelling of cell body because of weakness of cell membrane induced by deranged synthesis of cell membrane. Some of the cells showed disruption of their membrane with loss of cytoplasm, remaining empty space, which suggest loss of cell function. 4) It can be suggested that penicillin had affected on the cell wall of Bacillus subtilis, and inhibited growth of the cell by deranging the formation of the cell wall.

• YAKHAK HOEJI
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• v.45 no.5
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• pp.491-493
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• 2001

Coagulase-negative Staphylococcus sp #39, isolated from raw-milk showed reduced susceptibility to vancomycin. The minimun inhibitory concentration for strain #39 was at 8$\mu\textrm{g}$ of vancomycin per ml. Transmitting electron microscopy displayed that this strain had a 2.5-3.5 times thicker cell wall than a vancomucin sensitive strain of Staphylococcus sp. The strain #39 also had an increased cell volume. These data indicate that the reduced susceptibility may be due to the thickness of the cell wall of the test strain.

• Journal of Conservation Science
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• v.2 no.2 s.2
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• pp.15-24
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• 1993

To understand the morphological change of ancient woods, samples classified by cell type, burial environment and species were collected and observed using microscopy. Decay of wood by cell type could classified into two types. First, degraded secondary wall was formed granular residues in $S_2$ layer and was remained $S_3$ layer and compound middle lamella. Second, the cell wall was slightly degraded and cracked in secondary wall. A gradual thinning of cell wall was occured. The compound middle lamella was separated from secondary wall. The resistance of degradation is increased at vessels, parenchyma, and tracheid and wood fiber in the order named. The type of degradation by species could be classified into four types. Overall degradation type; the degradation of cell wall is usually heavy and the extent of degradation Varies by part of the same sample. Partial degradation type ; this type shows severely different decay type by part of the sample. Nondegraded cells were mixed with degraded cells on the same sample. Erose degradation type ; thinning of the cell wall was occoured and the degradation type was different by part. Slight degradation types ; secondary wall was slightly degraded, cracked and separated from compound middle lamella. Considering different type of burial environment, dry wood was similiar to sound wood and slightly decayed. Waterlogged and peat burial wood was heavilydecayed. Between species of under the same environment, decay type and extent were diferentiated from each other.

• The Plant Pathology Journal
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• v.18 no.3
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• pp.115-120
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• 2002

Xanthomonas axonopodis pv. glycines, the causal agent of bacterial pustule of soybean, induces hypersensitive response (HR) in a non-host plant, hot pepper (Capsicum annuum). A wild-type strain (8ra) and its non-patho-genic mutant (8-13) of X. axonopodis pv. glycines were inoculated into the pepper leaf tissues and their subcellular responses to the bacterial infections were examined by electron microscopy. Intrastructural changes related to HR were found in the leaf tissues infected with 8ra from 8 h after inoculation, characterized by separation of plasmalemma from the cell wall, formation of small vacuoles and vesicles, formation of cell wall apposition, and cellular necrosis. No such responses were observed in the tissues infected with the mutant. In 8ra, the bacterial cells were attached to the cell walls, with the cell wall material dissolved into and appearing to encapsulate the bacterial cells. The bacterial cells later became entirely embedded in the cell wall material. On the other hand, in 8-13, the bacterial cells were usually not attached tightly to the plant cell wall, and no or poor encapsulation of the bacteria by the wall material occurred, although these were encircled by rather loose wall materials at the later stages.

• The Korean Journal of Mycology
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• v.38 no.1
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• pp.29-33
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• 2010

KGD1 gene was cloned by functional complementation of defects in $\beta$-1,3-glucan synthase activity of the previously isolated Saccharomyces cerevisiae mutant LP0353, which displays a number of cell wall defects at restrictive temperature. We performed the gene disruption experiment to characterize the function of KGD1 gene, which encodes $\beta$-ketoglutarate dehydrogenase, in cell wall biosynthesis. The disruption of KGD1 showed the decreased growth rate, the increase of chitin synthases activity, alterations in cell wall composition, and increase of susceptibility to cell wall inhibitors such as Calcofluor white and Nikkomycin Z. These results suggested that KGD1 might be involved in cell wall biogenesis, especially the biosynthesis of $\beta$-1,6-glucan and chitin in S. cerevisaie.