• Proceedings of the Korean Society of Plant Pathology Conference
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• 1995.06b
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• pp.27-53
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• 1995

In plant pathology there is an increasing necessity for improved cytological techniques as basis for the localization of cellular substances within the dynamic fine structure of the host-(plant)-pathogen-interaction. Low temperature (LT) preparation techniques (shock freezing, freeze substitution, LT embedding) are now successfully applied in plant pathology. They are regarded as important tools to stabilize the dynamic plant-pathogen-interaction as it exists under physiological conditions. - The main advantage of LT techniques versus conventional chemical fixation is seen in the maintenance of the hydration shell of molecules and macromolecular structures. This results in an improved fine structural preservation and in a superior retention of the antigenicity of proteins. - A well defined ultrastructure of small, fungal organisms and large biological samples such as plant material and as well as the plant-pathogen (fungus) infection sites are presented. The mesophyll tissue of Arabidopsis thaliana is characterized by homogeneously structured cytoplasm closely attached to the cell wall. From analyses of the compatible interaction between Erysiphe graminis f. sp. hordei on barley (Hordeum vulgare), various steps in the infection sequence can be identified. Infection sites of powdery mildew on primary leaves of barley are analysed with regard to the fine structural preservation of the haustoria. The presentation s focussed on the ultrastructure of the extrahaustorial matrix and the extrahaustorial membrane. - The integration of improved cellular preservation with a molecular analysis of the infected host cell is achieved by the application of secondary probing techniques, i.e. immunocytochemistry. Recent data on the characterization of freeze substituted powdery mildew and urst infected plant tissue by immunogold methodology are described with special emphasis on the localization of THRGP-like (threonine-hydrxyproline-rich glycoprotein) epitopes. Infection sites of powdery mildew on barley, stem rust as well as leaf rust (Puccinia recondita) on primary leaves of wheat were probed with a polyclonal antiserum to maize THRGP. Cross-reactivity with the anti-THRGP antiserum was observed over the extrahaustorial matrix of the both compatible and incompatible plant-pathogen interactions. The highly localized accumulation of THRGP-like epitopes at the extrahaustorial host-pathogen interface suggests the involvement of structural, interfacial proteins during the infection of monocotyledonous plants by obligate, biotrophic fungi.

• Journal of the Korean Society of Visualization
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• v.12 no.3
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• pp.9-14
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• 2014

Two-photon microscopy (TPM) has been used in plant research as a high-resolution high-depth 3D imaging modality. However, TPM is known to induce photo-damage to the plant in case of long time exposure, and optimal excitation wavelength for plant imaging has not been investigated. Longer excitation wavelength may be appropriate for in vivo two-photon imaging of Arabidopsis thaliana leaves, and effects of longer excitation wavelength were investigated in terms of imaging depth, emission spectrum. Changes of emission spectrum as a function of exposure time at longer excitation wavelength were measured for in vivo longitudinal imaging. Imaging depth was not changed much probably because photon scattering at the cell wall was a limiting factor. Chloroplast emission spectrum showed its intensity peak shift by 20 nm with transition of excitation wavelength from 849 nm or below to 850 nm or higher. Emission spectrum showed different change patterns with excitation wavelengths in longitudinal imaging. Longer excitation wavelengths appeared to interact with chloroplasts differently in comparison with 780 nm excitation wavelength, and may be good for in vivo imaging.

• Journal of Plant Biology
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• v.35 no.2
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• pp.107-116
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• 1992

The roles of RNA- and protein-synthesis and $H^{+}$ excretion in 1AA ($10\;\mu\textrm{M}$)-induced elongation were investigated using abraded hypocotyl segments of sunflower (Helianthus annuus L.). The response of elongation initiated about 13 min after IAA treatment. Removal of cuticle, acting as diffusion barrier for inhibitors, by mechanical abrasion of hypocotyl segments enhanced the effect of inhibitors markedly, but the degree of abrasion for the saturated effect of inhibition was different among inhibitors. The elongation induced by 1M was completely inhibited when cycloheximide ($10\;\mu\textrm{M}$) was applied to abraded hypocotyl segments as shortly as 4 min before the onset of the growth response (= 10 min after administration of IAA). Cordycepin ($200\;\mu\textrm{M}$) prevented completely 1AA-induced elongation when applied as shortly as 19 min before the onset of the growth response (=5 min before administration of 1AA). Vanadate (1 mM) inhibited both lAA-induced elongation and medium acidification via lAA-induced $H^{+}$ excretion to apoplast. Cycloheximide and cordycepin also prevented lAA-induced $H^{+}$ excretion strongly. However, inhibition by cycloheximide of lAA-induced elongation was not alleviated by acidifying the cell wall to pH 4.5. The results indicate that, a few minutes before the initiation of growih, protein synthesis is demanded for the initiation of 1AA-induced elongation and the $H^{+}$ excretion to cell wall, and that the H+ excretion, even though it may be necessary for elongation, does not seem to bring about acid growth simply through acidifying cell wall.l wall.

• Applied Microscopy
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• v.16 no.2
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• pp.49-60
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• 1986

Ultrastructures of the large and elongated cells (idioblasts) in the haustorium of a parasitic angiosperm, Cuscuta australis R. Brown growing on the host plant, Trifolium repens L. were investigated by the electron microscopy. The idioblasts were characterized by the presence of a large nucleus, small vacuoles, and dense cytoplasm including a number of various cell organelles such as ribosome, rough endoplasmic reticulum(r-ER), mitochondrion, dictyosome, proplastid, multilamellar structure(MLS), microfilament bundle(MFB), and cytosegresome. Therefore, it is suggested that the idioblasts are metabolical1y very active. Particularly, MLS, MFB, and cytosegresome observed in this study did not appear in the haustorial cells of the other parasitic angiosperms. MLS was transformed into vacuole and also incorporated with cell wall. MFB composed of microfilaments, about each 7.5 nm in diameter, was observed in nucleus and also cytoplasm. Some types of MFB were distinguished on the basis of arrangement of microfilaments. A part of cytoplasm sequestered by stacked cisternae of smooth ER(s-ER), cytosegresome, was altered into a vacuole which was formed by digestion of the sequestered cytoplasm and of cisternae of s-ER. Cell organelles such as MLS, MFB, and cytosegresome were discussed in relation to the metabolic control of the idioblasts.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1998.11a
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• pp.172-173
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• 1998

A research collection of Pseudomons solanacearum bacteria, a pathogen causing ‘bacteria wilt’ disease of more than 265 plant species, represented for northern provinces of Vietnam has recently been established and was saved for examination of antifungal activity in their culture fluids. All strains used in this work have been isolated from infected tomato, potato, and groundnut collected from production fields and they express different levels of virulence on their host plants. Cell-free culture fluids of these strains were tested for antifungal activity (to inhibit growth of mycelium and to destroy germination tube of fungal spores) on a number of fungi that either infect or associate with vegetable crops of Solanaceae family (tomato, potato, pepers...), fruit plants (banana), and even well-known by Vietnamese traditional medicine herbal plants belonging to Trifoliatus, Schefflera, Homalomena and Panax genera (Araliaceae family) of which roots are used as a resource of the herbal material. The antifungal activity was found in nearly all strains tested. Result of study on chitin, CMC, tween 80 and casein degradation abilities of the latter suggested that antifungal activity of positively-found strains may be due to their ability of extracelluar chitinase's excretion that destroy fungal cell wall.

• Journal of Microbiology and Biotechnology
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• v.15 no.5
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• pp.1073-1079
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• 2005

To investigate plant protection, pathogenesis-related (PR) proteins and plant defense enzymes related to cell wall lignification were studied in pepper plants inoculated with antagonistic Bacillus subtilis HJ927 and pathogenic strain Phytophthora capsici. Phytophthora blight disease was reduced by $53\%$ in pepper roots when preinoculated with B. subtilis HJ927 against P. capsici. The activities of PR proteins (chitinase and ${\beta}$-1,3,-glucanase) and defense-related enzymes (peroxidase, polyphenoloxidase, and phenylalanine ammonia lyase) decreased in roots of B. subtilis+P capsid-treated plants, but increased in leaves with time. The decrease and increase were much greater in P. capsici-treated plants than in B. subtilis HJ927+P capsici-treated plants, although P. capsici-treated plants had more severe damage. Therefore, changes of enzyme activities do not seem to be directly related to plant protection. We suggest that the change of these enzymes in pathogen-treated plants may be related to plant response rather than to resistance against pathogen attacks.

• Korean Journal of Microbiology
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• v.48 no.4
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• pp.246-253
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• 2012

The purpose of this study was to investigate the molecular diversity of rhizobacteria associated with ginseng of varying age levels and their plant benefiting attributes. A total of 143 different isolates belonging to 15 different bacterial genera were recovered. Although variation was found in the rhizobacterial community due to age of the plant, majority of bacteria belong to Firmicutes (58%). In which, Bacillus was found to be the predominant genus irrespective of age of the ginseng. To assess the plant benefiting attributes, 30 representative isolates were selected. The results indicated that some of the isolates could exhibit multiple plant growth promoting traits like secretion of cell wall degrading enzymes, production of indole-3-acetic acid, synthesis of siderophores, solubilization of phosphates and soil pathogens inhibition. It can be suggested that strains of B. subtilis, B. amyloliquefaciens, B. velezensis, and B. licheniformis were positive for all the above traits, which have potential to be used as plant growth promoting inoculants to improve ginseng crop in the future.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.19 no.2
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• pp.130-145
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• 2006

Objectives : The aim of this work is the approaching of properties-flavours theory and the making of morphological standard in Artemisiae herba. Methods : The properties-flavours theory were attempted with bibliographic method and various climate-information. The external-internal morphological standards were determined by using stereoscope and butanol series. Conclusions : The following is a list the conclusion of the approaching of properties-flavours theory and how to make the standard of morphological standard in artemisiae herba. 1. The significant analysis for the artemisiae herba as the properties-flavours theory, is a follow-up survey of the effect written in the official oriental medicine book 2. The other analytic methods according to the gathering time, processing or storing system or especially nature or growth environment(altitude, temperature,. the mean moisture, and the agronomical survey) by way of the explanation of properties-flavours theory appears so many insufficiency at the many cases. 3. In the case of artemisiae herba., there are 2 cases(Artemisia capillaris $T_{HUNB}$ and A. iwayomogi $K_{ITAMURA}$) in current and recently A. aruwa L. is substituted for artemisiae herba in circulation. 4. The external and internal characteristics according to the shape of original plant or herbal states, entirely correspond to all the official oriental medicine boo 5. According to the place of productiot the difference appeals. (1) A. capillatis $T_{HUNB}$. has leaves like a fine thread, and A. iwayomogi $K_{ITAMURA}$ has big and wide leaves, and shows some reddish color, and A. aruwa L. has narrow leaves, its section lines long vertically. (2) In the internal shapes, as the A. capillatis $T_{HUNB}$. leaves', upper epidermal cell wall shows relatively straight form, its all upper- lower epidemical cell wall has a stoma, and calcium rosette crystal is relatively few. As iwayomogi $K_{ITAMURA}$, all upper- lower epidermal cell wall is wavelike concave, and hypodermics has many stoma and many calcium rosette crystal. (3) In the internal shapes of A. aruwa L. the shape of leaves' epidermal cell is irregular and has so many non-glandular hair nad glandular hair on its surface.

• The Plant Pathology Journal
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• v.33 no.1
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• pp.95-100
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• 2017

Fungicide-resistant Alternaria alternata impede the practical control of the Alternaria diseases in crop fields. This study aimed to investigate cytological fungicide resistance mechanisms of A. alternata against dicarboximide fungicide iprodione. A. alternata isolated from cactus brown spot was cultured on potato-dextrose agar (PDA) with or without iprodione, and the fungal cultures with different growth characteristics from no, initial and full growth were observed by light and electron microscopy. Mycelia began to grow from one day after incubation (DAI) and continued to be in full growth (control-growth, Con-G) on PDA without fungicide, while on PDA with iprodione, no fungal growth (iprodione-no growth, Ipr-N) occurred for the first 3 DAI, but once the initial growth (iprodione-initial growth, Ipr-I) began at 4-5 DAI, the colonies grew and expanded continuously to be in full growth (iprodione-growth, Ipr-G), suggesting Ipr-I may be a turning moment of the morphogenetic changes resisting fungicidal toxicity. Con-G formed multicellular conidia with cell walls and septa and intact dense cytoplasm. In Ipr-N, fungal sporulation was inhibited by forming mostly undeveloped unicellular conidia with degraded and necrotic cytoplasm. However, in Ipr-I, conspicuous cellular changes occurred during sporulation by forming multicellular conidia with double layered (thickened) cell walls and accumulation of proliferated lipid bodies in the conidial cytoplasm, which may inhibit the penetration of the fungicide into conidial cells, reducing fungicide-associated toxicity, and may be utilized as energy and nutritional sources, respectively, for the further fungal growth to form mature colonies as in Ipr-G that formed multicellular conidia with cell walls and intact cytoplasm with lipid bodies as in Con-G.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.4
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• pp.481-486
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• 1995

The salt stress at seedling stage of winter barley was examined in different concentrations of NaCl containing 1/2 Hoagland solution. Fresh weight of seedling at 30 days after seeding was highest at 25mM of NaCl concentration containing 1/2 Hoagland solution but if the NaCl concentration was more than 50mM it began to decrease seriously. Water content in plant was decreased according to increase of NaCl concentration in 1/2 Hoagland solution, so physiological mechanism of NaCl in barley was different from saline plant. Stoma number per cm$^2$ of first leaf was higher than that of control in case of stressed by NaCl but in that case the leaf length was decreased so the number of stoma per first leaf was slightly decreased. Chloroplast shape was not changed by 75mM of high NaCl contained 1/2 Hoagland solution but cell division at root growing point was inhibited by 75mM of NaCl. As the result of salt stress mitochondria was ruined in structure and irregular solid was found to be transfered from the cytoplasm to the cell wall in root growing point.