• Mycobiology
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• 제42권1호
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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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• 제47권4호
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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.

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2001년도 Proceedings of the 3rd Annual Meeting of Yellow Sea Environment
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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.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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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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• 제34권1호
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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.

• 한국임상수의학회지
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• 제36권3호
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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.

• 한국균학회지
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• 제22권2호
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• pp.172-183
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• 1994

접합내생균근 균(AMF)이 있는 토양을 이용하여 여러 종류의 비료를 주면서 식물을 재배하여, AMF포자 증식에 대하여 관찰하였다. 식물뿌리에서 AM화된 뿌리는 여러가지 형태가 현미경 관찰을 통하여 확인되었으며, 정상적인 Vesicles, Arbuscles 및 sporulation 과정도 관찰되었으며, 꽃송이와 같은 특수한 형태도 관찰되었다. 포자증식에 있어서의 80일간의 관찰과 뿌리염색을 통한 뿌리감염도의 관찰결과, 40일 주기로 포자의 생산에 증감이 주기적으로 일어나는 것을 관찰하였다. 비료를 첨가한 토양에서 수수, 파, 고추 및 차풀의 순으로 포자 증식에 좋은식물로 나타났으며, 그 포자 증식이 조건에 따라 다양하게 나타났다. 비료의 첨가에서는 인산이 없는 비료에서 포자증식이 크게 일어났으며, 21-17-17 비료에서는 포자증식 적었다. 식물별로 본다면, 수수, 고추, 파등의 순으로 포자증식이 많이 되었다.

• 한국균학회지
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• 제21권1호
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• pp.38-50
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• 1993

내생균근 균이 포함된 토양을 이용하여 4종류의 식물인 수수, 돌콩, 차풀 및 참깨를 재배하여, arbucular mycorrhizae의 감염도 및 포자 증식을 조사 하였다. 감염율의 변화는 계속하여 50일까지 증가하고 있는 반면에 포자생성은 30일 이후에 증가율이 감소하는 것이 관찰되었다. 이로써, AM 감염도는 포자생성과 상관관계를 갖지 않은 것으로 나타났다. 또한, 다양한 지역의 토양을 포트배양하여 포자의 증식을 조사하였으며, 다음과 같은 결과를 얻었다. 다양한 토양을 이용하여 포트배양한 결과 많은 양의 새로운 포자를 얻을 수 있었으며, 82개 토양 중 43개 토양에서 포자의 증식이 관찰되었으며 4속 15종의 포자가 동정되었다. 포트배양한 토양의 pH를 조사한 결과 pH에 따라 포자의 생성이 일정한 경향을 보였으며, 대체로 낮은 pH에서 많은 포자 증식을 관찰하였다.

• Journal of Microbiology and Biotechnology
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• 제14권4호
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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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• 제29권1호
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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.