• Mycobiology
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• v.42 no.1
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• pp.1-5
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• 2014

The typical life cycle of filamentous fungi commonly involves asexual sporulation after vegetative growth in response to environmental factors. The production of asexual spores is critical in the life cycle of most filamentous fungi. Normally, conidia are produced from vegetative hyphae (termed mycelia). However, fungal species subjected to stress conditions exhibit an extremely simplified asexual life cycle, in which the conidia that germinate directly generate further conidia, without forming mycelia. This phenomenon has been termed as microcycle conidiation, and to date has been reported in more than 100 fungal species. In this review, first, we present the morphological properties of fungi during microcycle conidiation, and divide microcycle conidiation into four simple categories, even though fungal species exhibit a wide variety of morphological differences during microcycle conidiogenesis. Second, we describe the factors that influence microcycle conidiation in various fungal species, and present recent genetic studies that have identified the genes responsible for this process. Finally, we discuss the biological meaning and application of microcycle conidiation.

• Mycobiology
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• v.47 no.4
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• pp.457-465
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• 2019

MonA is a subunit of a guanine nucleotide exchange factor that is important for vacuole passing and autophagy processes in eukaryotes. In this study, we characterized the function of MonA, an orthologue of Saccharomyces cerevisiae Mon1, in the model fungus Aspergillus nidulans and a toxigenic fungus A. flavus. In A. nidulans, the absence of AnimonA led to decreased fungal growth, reduced asexual reproduction, and defective cleistothecia production. In addition, AnimonA deletion mutants exhibited decreased spore viability, had reduced trehalose contents in conidia, and were sensitive to thermal stress. In A. flavus, deletion of AflmonA caused decreased fungal growth and defective production of asexual spores and sclerotia structures. Moreover, the absence of monA affected vacuole morphology in both species. Taken together, these results indicate that MonA plays conserved roles in controlling fungal growth, development and vacuole morphology in A. nidulans and A. flavus.

• Proceedings of the Korean Environmental Health Society Conference
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• 2001.11a
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• pp.1.1-5
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• 2001

High SPM concentrations(199.8~249.4${\mu}{\textrm}{m}$/㎥) were detected in the west Korea during the Yellow Sand Periods, 2000. Majority of the total SPM were composed of about 5${\mu}{\textrm}{m}$ sized coarse particles over the periods. However, fine particles sized about 1 ${\mu}{\textrm}{m}$ and coarse particles sized about 5-6${\mu}{\textrm}{m}$ showed peaks at the graph of SPM size distribution in the Non Yellow Sand Period. Airborne fungal spores at the SPM samples were cultured and identified. Full-grown colonies during the Yellow Sand Periods, Fusarium, Aspergillus, Penicillium and Basipetospora are hyphomycetes in the division Fungi imperfecti(Deuteromycota). And morphologically more diversified mycelia of hyphomycetes were grown on the sample captured from 1.1~2.1${\mu}{\textrm}{m}$ sized SPM than on other sized samples during the Yellow Sand Period. But no mold was observed on the sample of 1.1~2.1${\mu}{\textrm}{m}$ sized SPM in the Non Yellow Sand Period. It was thought that several sorts of fine sized fungal spores were suspended in the atmospheric environment of the west Korea during the Asian dust episodes.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.476-476
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• 2012

Although plasma is an efficient means of microbial sterilization, mechanism of plasma effect on microorganisms still needs to be clarified. In addition, a limited number of studies are available on eukaryotic microorganisms such as yeast and fungi in relation to plasma application. Thus, we investigated cellular and molecular aspects of plasma effects on a filamentous fungus, Neurospora crassa by making use of argon plasma jet at atmospheric pressure. The viability and cell morphology of N. crassa spores exposed to plasma were both significantly reduced depending on the exposure time when treated in water. The intracellular genomic DNA content was dramatically reduced in fungal tissues after a plasma treatment and the transcription factor tah-3 was found to be required for fungal tolerance to a harsh plasma environment.

• Mycobiology
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• v.34 no.1
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• pp.34-37
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• 2006

Growth responses of Zea mays and Glycine max to colonization by mixture of combination of three species of arbuscular mycorrhizal (AM) fungi, two species of Glomus and a species of Scutellospora were compared. In Zea mays, plants inoculated with single species of AM fungi showed significantly higher in dry weight than non-mycorrhizal plant for all three AM fungal species. Also, growth of plants inoculated with spores of two species of AM fungi was significantly higher than nonmycorrhizal control except for plants inoculated with two Glomus species. When three species of AM fungi were inoculated, the plants showed the highest growth. In Glycine max, plants with single AM fungal species inoculation were not significantly different in plant growth from nonmycorrhizal plants. When the plants were inoculated with combination of two or more AM fungal species, their growth significantly increased compared to nonmycorrhizal plants. In both plant species, mycorrhizal root colonization by Scutellospora species was significantly lower than by Glomus species.

• Journal of Veterinary Clinics
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• v.36 no.3
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• pp.172-175
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• 2019

A young slaty-backed gull was found dead nearby Seongsan harbor, Seogwipo-si, Jeju. Grossly, focal ulceration and a protuberant nodule were observed in intermediated zone between proventriculus and gizzard. Numerous discrete or confluent white-yellowish nodules were scattered on the surface of liver. Caudal portion of left kidney was replaced by a white-yellowish nodule. Three raised masses were observed in the spleen. Histologically, there were severe ulceration with hemorrhage in the gizzard and multifocal granulomatous inflammations in liver, kidney, spleen, and lungs. Pink to dark-red, round to oval fungal spores and pseudohyphae in granulomatous lesions were confirmed by periodic acid-Schiff stain. Candida albicans were isolated from the lesions of liver, kidney, spleen and gizzard using fungal culture and confirmed by VITEK 2 system. Based on the gross, histopathological findings, and fungal examination, this case was diagnosed as systemic candidiasis of a wild slaty-backed gull. In our best knowledge, this is the first report for systemic candidiasis characterized by multifocal granulomatous lesions in internal organs of a wild gull in Korea.

• The Korean Journal of Mycology
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• v.22 no.2
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• pp.172-183
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• 1994

The productions of arbuscular mycorrhizal fungal(AMF) spores were observed by adding three different commercial fertilizers on AMF inhabiting soils. Various morphological features, vesicles, arbuscles, sporulations of spore, and flower-like-structures, were also found in the mycorrhizal roots during 80 days after transplanting. Spore prodcutions of the employed AMF were observed to be periodically increased with the intervals of 40 days. Sorghum, green onion, hot pepper, and wild legume plants were appeared to be a good plant for productions of AMF and as the host of AMF. The productions of AMF spores was inversely related to phosphate fertilizer, and also observed to be low in the plant pots added with whole balanced fertilizers.

• The Korean Journal of Mycology
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• v.21 no.1
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• pp.38-50
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• 1993

Four plant (Sorghum bicolor, Cassia mimosoides var. nomame, Sesamum indicum and Glycine soja) were cultivated at the pots including the soils containing arbuscular mycorrhizal fungi and were also investigated with the colonizations and productions of arbuscular mycorrhizal fungi. Whereas the colonizations of arbuscular mycorrhizal fungi continuosly increased on the roots until 50 days, the productions of arbuscular mycorrhizal fungal spores were fluctuated with the terms of 30 days after inoculated. This indicated that the colonizations on the roots were not correlated with productions of arbuscular mycorrhizal fungal spores. Also, the various soils collected were applied to this technique by using pot cultures. Out of 82 various soils collected, the spore productions of arbuscular mycorrhiaze were observed only from 42 soils. The spores cultured under artificial conditions were identified to 15 species with four genera. The spore productions of arbuscular mycorrhizal fungi using this technique would be considered to be related to the soil pH: The spore productions were found in the low pH for the species of Acaulospora and Glomus, the those near pH 7.6 for the species of some Glomus, Scutellospora and Gigaspora.

• Journal of Microbiology and Biotechnology
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• v.14 no.4
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• pp.885-890
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• 2004

A survey for vesicular-arbuscular mycorrhizae (VAM) occurrence was undertaken in three endangered vegetation sites in the area of Kudankulam atomic power station. Fifteen VAM fungal species were isolated from the root-zone soils of fourteen different plant species. There was a significant correlation observed between the number of spores and of percentage root colonization as exemplified by Phyllanthus niruri and Paspalum vaginatum (450, 95%; 60, 25%). Although VAM species are not known to be strictly site specific, the fact that Acaulospora elegans was observed only in site 1, Glomus pulvinatum in site 2 only, and Gl. intraradices in site 3 only, showed site-specificity in this study. To confirm the infection efficiency, two host plant species in the sites, P. niruri and Eclipta alba, were selected and inoculated in field with three selected VAM fungal spores. Gl. fasciculatum was found to be the most efficient VAM species in percentage root colonization, number of VAM spores, and dry matter content. When the nutrients in roots of P. niruri and E. alba were analyzed, there was higher uptake of K (4.2 and 3.4 times, respectively) and Ca (5.3 and 4.9 times, respectively), the analogues for $^{137}Cs$ and $^{90}Sr$, respectively. From the results, it might be concluded that VAM association helps the plants survive in a disturbed ecosystem and enhances uptake and cycling of radionuclides from the ecosystem.

• The Plant Pathology Journal
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• v.29 no.1
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• pp.52-58
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• 2013

Fusarium head blight (FHB) caused by the filamentous fungus Fusarium graminearum is one of the most severe diseases threatening the production of small grains. Infected grains are often contaminated with mycotoxins such as zearalenone and trichothecences. During survey of contamination by FHB in rice grains, we found a bacterial isolate, designated as BN1, antagonistic to F. graminearum. The strain BN1 had branching vegetative hyphae and spores, and its aerial hyphae often had long, straight filaments bearing spores. The 16S rRNA gene of BN1 had 100% sequence identity with those found in several Streptomyces species. Phylogenetic analysis of ITS regions showed that BN1 grouped with S. sampsonii with 77% bootstrap value, suggesting that BN1 was not a known Streptomyces species. In addition, the efficacy of the BN1 strain against F. graminearum strains was tested both in vitro and in vivo. Wheat seedling length was significantly decreased by F. graminearum infection. However, this effect was mitigated when wheat seeds were treated with BN1 spore suspension prior to F. graminearum infection. BN1 also significantly decreased FHB severity when it was sprayed onto wheat heads, whereas BN1 was not effective when wheat heads were point inoculated. These results suggest that spraying of BN1 spores onto wheat heads during the wheat flowering season can be efficient for plant protection. Mechanistic studies on the antagonistic effect of BN1 against F. graminearum remain to be analyzed.