• 한국식물병리학회지
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• 제10권2호
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• pp.83-91
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• 1994

Stem tissues of tomato plants (cv. Kwanyang) inoculated with Phytophthora capsici were examined by light and electron microscopy to compare early cytological differences between comaptible and incompatible interactions of tomatoes with the fungus. Twenty four hours after inoculation, the compatible isolate S 197 colonized severely the epidermis, cortex, and xylem vessels of stem tissue, whereas only few fungal cells colonized the stem tissues inoculated with the incompatible isolate CBS 178.26. Fragmented plasma membrane, distorted chloroplast, degraded cell wall, remnants of host cytoplasm were early ultrastructural features of the damaged host cell observed both in the compatible and incompatible interaction, a number of vesicles were distributed in the space between fungal cell walls and plasma membrane. The degradation of host cell walls by P. capsici was more pronounced in the compatible than the incompatible interactions. The incompatible interactions of tomato cells with P. capsici were characterized by formation of host cell wall apposition in the cortical parenchyma cells, indicating that the apposition of electron-dense material from the host cell walls may function as a plant defense reaction to the fungus. The fungal cells encased by wall appositions had abnormal cytoplasm and separated plasma membranes. The haustorium which formed from the fungal hyphae did not further penetrate through the host wall apposition and cytoplasmic aggregation, especially in the incompatible reactions. In contrast, the haustorium of the compatible isolate S 197 was not encased by wall appositions.

• Plant Resources
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• 제3권3호
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• pp.163-172
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• 2000

We compared microstructural features of the ordered cell and disordered leaves in Citrus junos Sieb. by electron microscopy. In the cell of the ordered leaves, many chloroplasts and large vacuoles were particularly observed. Also a lot of vessel, companion cell and big nucleus were presented in vascular bundle regions. The mitochondria and the other organelles were interspersed among the chloroplasts in a thin, peripheral layer of cytoplasm. The chloroplast possessed typical grana and intergranal lamellae, numerous starch grains and a few small osmophilic globules. Besides, microbodies were closely associated with the mitochondria and the chloroplast. The process of the formation of the secondary cell wall from primary cell wall was observed the vessel elements, the tonoplast wall and the secondary cell wall. It was observed that the oil sac with the unique perfume distributed the adjacent cell wall. In the cell of disordered leaves, the all of the organelles were thrust toward the cell wall due to the fusion of vacuoles in the cells. It was observed that a lot of the very small particles spreaded in the cytoplasm. The loss of unique perfume of the leaves was resulted in the destruction of the oil sac. Also, there was not observed grana, lamellae, starch and osmophillic globules in the chloroplast. The small distributed organelles was not observed but the elongation of the cell wall was proceed no longer. Therefore, the plasma membrane diverged from the cell wall. All of organelles in the cell had poor function and deformation. A massive vacuole was fulfilled in single cell and the vacuole contains a lot of large and small particles. The organelles were presented on the side of the cell wall according to the enlargement of vacuole and they were observed to be breakdown.

• The Plant Pathology Journal
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• 제27권1호
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• pp.8-13
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• 2011

The induced resistance of cucumber leaves treated with oligochitosan to the infection of the cucumber powdery mildew, Sphaerotheca fuliginea, was investigated using transmission electron microscopy. The results showed that when the plants were treated with oligochitosan and challenged with inoculum, a significant decrease of the disease occurred. The mycelial development in the treated leaves was markedly inhibited. The cytoplasm of the powdery mildew mycelium was aggregated, with its organelles disintegrated and the cytoplasm collapsed. The protoplasm in haustoria became electron-dense. Haustoria became malformed, their organelles disintegrated, the hausterial wall thickened and eventually the whole complex necrotized. The host cells produced defence structures and materials associated with infection and a hypersensitive response. The host cell wall was thickened and deeply stained; several layers of papilla structure were produced under the cell wall; dark materials were deposited between the cell wall and plasmalemma; extrahaustorial plasmalemma was deeply stained and extrahaustorial matrix appositions had large deposits of electron-dense material; the cytoplasm was disordered, host organelles disintegrated and eventually the whole host cell disintegrated and necrotized.

• Asian-Australasian Journal of Animal Sciences
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• 제14권6호
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• pp.862-879
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• 2001

The walls of all higher plants are organized as a cellulosic, fibrillar phase embedded in a matrix phase composed of non-cellulosic polysaccharides, some proteins and, in most secondary walls, lignin. At the effective utilization of plant biomass, qualitative and quantitative analyses of plant cell walls are essential. Structural features of individual components are being clarified using newly developed equipments and techniques. However, "empirical" procedures to elucidate plant cell walls, which are not due to scientific definition of components, are still applied in some fields. These procedures may give misunderstanding for the effective utilization of plant biomass. In addition, interesting the investigation of wall organization is moving towards not only qualitatively characterisation, but also quantitation of the associations between wall components. These involve polysaccharide-polysaccharide and polysaccharide-lignin cross-links. Investigation of the associations is being done in order to understand the chemical structure, organization and biosynthesis of the cell wall and physiology of the plants. Procedures for qualitative and quantitative analyses based on the definition of cell wall components are reviewed focussing in nutritional elucidation of forage grasses by ruminant microorganisms.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2007년도 춘계학술발표회
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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.

• 한국식품영양과학회지
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• 제34권10호
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• pp.1633-1637
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• 2005

Driselase, Cellulase, Macerozyme R-200, Macerozyme R-10및 Sumyzyme MC 등 5종의 시판 식물세포벽분해효소가 당근의 세포벽물질(CWM)로부터 제조한 알콜불용성 잔사(AIR)와 cellulose fraction의 f-hydroxybenzoic acid 추출에 미치는 영향을 조사하였다. 당근AIR의 주된 페놀화합물은 P-hydroxybenzoic acid로 1,977 $\mu$g/g AIR였으며, vanillin, ferulic acid, p-hydroxybenzaldehyde가 각각 55.9, 13.6, 10.6 $\mu$g/g AIR인 것으로 나타났다. 효소에 함유되어있는 ferulic acid의 함량은 Driselase, Cellulase, Macerozyme R-200, Macerozyme R-10, Sumyzyme MC에서 각각 2,319, 2,060, 391, 95.2, 34.1 $\mu$g/g인 것으로 나타났다. 이들 효소와 세포벽물질과의 반응을 조사한 결과, Driselase와 AIR의 반응 후 유리된 p-hydroxybenzoic acid의 함량은 56 $\mu$g/g AIR로 알칼리 (4 M NaOH) 추출한 총량의 2.8$\%$에 해당한다. 따라서 p-hydroxybenzoic acid는 AIR과 셀룰로오스 분획으로부터 이들 효소에 의해 분리되기 어려운 것으로 나타났다.

• Asian-Australasian Journal of Animal Sciences
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• 제14권7호
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• pp.935-940
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• 2001

To determine the effect of different growth stages and cultivars on the chemical composition of sorghum plant and its morphological fractions, samples of whole plant, leaf and stem of J.S-263, J.S-88 and Hegari cultivars, harvested at various growth stages were drawn for analysis. All the samples were analysed for their dry matter contents and various cell wall components such as NDF, ADF. hemicellulose, cellulose, lignin, cutin and silica. Significant increase in DM contents of whole sorghum plant, leaf and stem was observed with advancing stage of growth. The highest DM content was recorded in leaf fraction of the plant. All the cell wall constituents increased significantly in whole sorghum plant, leaf and stem as the plant matured. The maximum NDF, ADF, cellulose and lignin contents were observed in stem fraction, followed by whole plant. However, the hemicellulose, cutin and silica contents were higher in leaf fraction of the plant. The cultivars were found to have some effect on the chemical composition of whole plant, leaf and stem fractions. The results indicated that plant maturity had a much greater effect on the chemical composition of sorghum plant, whereas it was little affected by cultivars.

• Molecules and Cells
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• 제20권1호
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• pp.119-126
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• 2005

${\alpha}$-Expansins are bound to the cell wall of plants and can be solubilized with an extraction buffer containing 1 M NaCl. Localization of ${\alpha}$-expansins in the cell wall was confirmed by immunogold labeling and electron microscopy. The subcellular localization of vegetative ${\beta}$-expansins has not yet been studied. Using antibodies specific for OsEXPB3, a vegetative ${\beta}$-expansin of rice (Oryza sativa L.), we found that OsEXPB3 is tightly bound to the cell wall and, unlike ${\alpha}$-expansins, cannot be solubilized with extraction buffer containing 1 M NaCl. OsEXPB3 protein could only be extracted with buffer containing SDS. The subcellular localization of the OsEXPB3 protein was confirmed by immunogold labeling and electron microscopy. Gold particles were mainly distributed over the primary cell walls. Immunohistochemistry showed that OsEXPB3 is present in all regions of the coleoptile and root tissues tested.

• Asian-Australasian Journal of Animal Sciences
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• 제12권3호
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• pp.366-370
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• 1999

Samples of whole plant, leaf and stem of Akbar, Neelum, UM-81 and lZ-31 cultivars of maize fodder harvested up to 14 weeks at different growth stages were drawn and analysed for dry matter contents and various cell wall constituents such as NDF, ADF, hemicellulose, cellulose, lignin, cutin and silica. The dry matter contents of whole maize plant, leaf and stem increased significantly (p<0.01) with advancing plant age. Maximum dry matter was found in the leaf fraction of the plant. The cell wall components continued to increase significantly (p<0.001) in whole maize plant and its morphological fractions as the age advanced. Maximum values for NDF, ADF, cellulose and lignin were observed in stem followed by whole plant and leaf, whereas hemicellulose, cutin and silica contents were higher in leaf fraction of the plant. The cultivars were observed to have some effects on chemical composition of all plant fraction. The results indicated that maturity had a much greater effect on the concentration of all the structural components than did the cultivars. It was concluded that maize fodder should be cut preferably between 8th to 9th week of age (flowering stage) to obtain more nutritious and digestible feed for livestock. Among the maize cultivars, Neelum proved to be the best, due to its higher dry matter contents and lower lignin concentration.

• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2005년도 추계학술대회 및 한일 식물생명공학 심포지엄
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• pp.371-374
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• 2005

In our previous work in transcriptional regulation of sugar, expression of genes encoding putative glycosyl hydrolases in Arabidopsis was induced by sugar starvation. They were annotated as b-galactosidase (At5g56870), ${\beta}-xylosidase$ (At5g49360) and ${\beta}-glucosidase$ (At3g60140), which belong to glycosyl hydrolase family that has a catalytic domain of polysaccharides. From the primary structure of deduced amino acid sequence, they were predicted to localize to cell wall. Further investigation of these cell wall hydrolases implicated that cell wall polysaccharides provide metabolizable sugars to nutrient allocation under sugar starvation.