• Mycobiology
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• 제38권3호
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• pp.215-218
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• 2010

Azoles are currently the most widely used class of antifungal drugs clinically, and are effective for treating fungal infections. Target site of azoles is ergosterol biosynthesis in fungal cell membrane, which is absent in the mammalian host. However, the development of resistance to azole treatments in the fungal pathogen has become a significant challenge. Here, we report the identification and functional characterization of a UPC2 homolog in the human pathogen Cryptococcus neoformans. UPC2 plays roles in ergosterol biosynthesis, which is also affected by the availability of iron in Saccharomyces cerevisiae and Candida albicans. C. neoformans mutants lacking UPC2 were constructed, and a number of phenotypic characteristics, including antifungal susceptibility and iron utilization, were analyzed. No differences were found between the mutant phenotypes and wild type, suggesting that the role of C. neoformans UPC2 homolog may be different from those in S. cerevisiae and C. albicans, and that the gene may have a yet unknown function.

• 한국식물병리학회지
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• 제11권1호
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• pp.39-46
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• 1995

Ditylenchus destructor isolated from diseased ginseng roots was cultured on ginseng calli, fungal mycelium (Fusarium solani), carrot discs and radish sprouts. Effects of temperature, organic material and flooding on the nematode population changes were examined. D. destructor multiplied readily on the culture media except radish sprout medium, and was cultured best on the fungal culture at 2$0^{\circ}C$. Feeding of the fungal hypha and radish root hairs, molting and mating in the fungal culture medium were observed. Addition of organic materials (perilla, sesame, soybean and ginseng leaves) in soil significantly increased Aphelenchus avenae and saprophytic nematode populations, while D. destructor populations changed little and the nematode population growths were limited by the organic amendments (except sesame leaves). The nematode populations in soil including D. destructor were decreased by flooding. The results indicate that D. destructor may survive but not multiply readily in soil without host plants and that it can be effectively controlled by flooding.

• Mycobiology
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• 제50권5호
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• pp.259-268
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• 2022

The nuclear import of proteins is a fundamental process in the eukaryotes including plant. It has become evident that such basic process is exploited by nuclear effectors that contain nuclear localization signal (NLS) and are secreted into host cells by fungal pathogens of plants. However, only a handful of nuclear effectors have been known and characterized to date. Here, we first summarize the types of NLSs and prediction tools available, and then delineate examples of fungal nuclear effectors and their roles in pathogenesis. Based on the knowledge on NLSs and what has been gleaned from the known nuclear effectors, we point out the gaps in our understanding of fungal nuclear effectors that need to be filled in the future researches.

• Mycobiology
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• 제48권4호
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• pp.263-275
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• 2020

Phlebopus spongiosus is a well-known edible ectomycorrhizal mushroom indigenous to southern Vietnam. The mushroom specimens collected from northern Thailand in this study were identified as P. spongiosus. This identification was based on morphological characteristics and the multi-gene phylogenetic analyses. Pure cultures were isolated and the relevant suitable mycelial growth conditions were investigated. The results indicated that the fungal mycelia grew well on L-modified Melin-Norkans, and Murashige and Skoog agar all of which were adjusted to a pH of 5.0 at 30 ℃. Sclerotia-like structures were observed on cultures. The ability of this mushroom to produce fruiting bodies in the absence of a host plant was determined by employing a bag cultivation method. Fungal mycelia completely covered the cultivation substrate after 90-95 days following inoculation of mushroom spawn. Under the mushroom house conditions, the highest amount of primordial formation was observed after 10-15 days at a casing with soil:vermiculite (1:1, v/v). The primordia developed into a mature stage within one week. Moreover, identification of the cultivated fruiting bodies was confirmed by both morphological and molecular methods. This is the first record of P. spongiosus found in Thailand and its ability to form fruiting bodies without a host plant.

• 미생물과산업
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• 제20권3호
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• pp.14-21
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• 1994

Low molecular weight molecules and high molecular weight substances were found to have anti-tumor and immuno-modulating activity. Previously polysaccharides have been received much attention because of adhesives, food additives or animal foods (Whistler et al., 1976). In effort of developing new anti-tumor substances with low toxicity, numerous polysaccharides from yeast, algae, bacteria, higher plants and especially fungi have been investigated for anti-tumor and immuno-modulating activities. Thus the high molecular weight molecule was reported to have anti-tumor activity through host mediated immunity. In this brief article, attention will be paid to polysaccharides which is especially fungal origin.

• 한국균학회소식:학술대회논문집
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• 한국균학회 2018년도 춘계학술대회 및 임시총회
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• pp.19-19
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• 2018

Fungal pathogens have huge impact on health and economic wellbeing of human by causing life-threatening mycoses in immune-compromised patients or by destroying crop plants. A key determinant of fungal pathogenesis is their ability to undergo developmental change in response to host or environmental factors. Genetic pathways that regulate such morphological transitions and adaptation are therefore extensively studied during the last few decades. Given that epigenetic as well as genetic components play pivotal roles in development of plants and mammals, contribution of microbial epigenetic counterparts to this morphogenetic process is intriguing yet nearly unappreciated question to date. To bridge this gap in our knowledge, we set out to investigate histone modifications among epigenetic mechanisms that possibly regulate fungal adaptation and processes involved in pathogenesis of a model plant pathogenic fungus, Magnaporthe oryzae. For functional and comparative analysis of histone modifications, a web-based database (dbHiMo) was constructed first to archive and analyze histone modifying enzymes from eukaryotic species whose genome sequences are available. Based on the database entries, we carried out functional analysis of genes encoding histone modifying enzymes. Here I provide examples of such analyses that show how histone acetylation and methylation is implicated in regulating important aspects of fungal pathogenesis. Current analysis of histone modifying enzymes is followed by ChIP-seq and RNA-seq experiments to pinpoint the genes that are controlled by particular histone modifications. We anticipate that our work will provide not only the significant advances in our understanding of epigenetic mechanisms operating in microbial eukaryotes but also basis to expand our perspective on regulation of development in fungal pathogens.

• Mycobiology
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• 제36권4호
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• pp.236-241
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• 2008

The colonization of an arbuscular mycorrhizal fungus Glomus intraradices BEG110 in the soil caused a decrease in disease severity in cucumber plants after fungal inoculation with Colletotrichum orbiculare. In order to illustrate the resistance mechanism mediated by G. intraradices BEG110, infection patterns caused by C. orbiculare in the leaves of cucumber plants and the host cellular responses were characterized. These properties were characterized using transmission electron microscopy on the leaves of cucumber plants grown in soil colonized with G. intraradices BEG110. In the untreated plants, inter- and intra-cellular fungal hyphae were observed throughout the leaf tissues during both the biotrophic and necrotrophic phases of infection. The cytoplasm of fungal hyphae appeared intact during the biotrophic phase, suggesting no defense response against the fungus. However, several typical resistance responses were observed in the plants when treated with G. intraradices BEG110 including the formation of sheaths around the intracellular hyphae or a thickening of host cell walls. These observations suggest that the resistance mediated by G. intraradices BEG110 most often occurs in the symplast of the host cells rather than in the apoplast. In addition, this resistance is similar to those mediated by biotic inducers such as plant growth promoting rhizobacteria.

• The Plant Pathology Journal
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• 제26권4호
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• pp.313-320
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• 2010

Genetic instability of the rice blast fungus Magnaporthe oryzae has been suggested as a major factor underlying the rapid breakdown of host resistance in the field. However, little information is available on the mechanism of genetic instability. In this study, we assessed the stability of repetitive DNA elements and several key phenotypic traits important for pathogenesis after serially transferring two isolates though rice plants and an artificial medium. Using isolate 70-15, we obtained a total of 176 single-spore isolates from 10 successive rounds of culturing on artificial medium. Another 20 isolates were obtained from germ tubes formed at the basal and apical cells of 10 three-celled conidia. Additionally, 60 isolates were obtained from isolate KJ201 after serial transfers through rice plants and an artificial medium. No apparent differences in phenotypes, including mycelial growth, conidial morphologies, conidiation, conidial germination, appressorium formation, and virulence, or in DNA fingerprints using MGR586, MAGGY, Pot2, LINE, MG-SINE and PWL2 as probes were observed among isolates from the same parent isolate. Southern hybridization and sequence analysis of two avirulence genes, AVR-Pita1 and AVR-Pikm, showed that both genes were also maintained stably during 10 successive generations on medium and plants. However, one reversible loss of restriction fragments was found in the telomere-linked helicase gene (TLH1) family, suggesting some telomere regions may be more unstable than the rest of the genome. Taken together, our results suggest that phenotype and genotype of M. oryzae isolates do not noticeably change, at least up to 10 successive generations on a cultural medium and in host plants.

• Current Research on Agriculture and Life Sciences
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• 제3권
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• pp.112-119
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• 1985

관상식물(觀賞植物)에 병해조사(病害調査) 일환(一環)으로 대구(大邱)와 근교(近郊)의 온실(溫室) 등(等)에 재식(栽植)되어 있는 19과(科) 34속(屬) 34종(種)의 식물(植物)에 대(對)하여 진균(眞菌)에 이병(罹病)된 식물(植物)을 조사(調査)한 결과(結果), Glomerella 속균(屬菌) 등(等) 16속(屬) 병원진균(病原眞菌)에 의(依)하여 32속(屬) 32종(種)의 식물(植物)에서 37종(種)의 병(病)이 발생(發生)하고 있었다. 이들 중 우리나라에서 이제까지 보고(報告)되지 않은 미기록병해(未記錄病害)는 Glomerella속균(屬菌), Colletotrichum속균(屬菌), Ceratocystis속균(屬菌), Pestalotia속균(屬菌), Gloeosporium속균(屬菌), Macrophoma속균(屬菌), Sphaceloma속균(屬菌), Botrytis속균(屬菌), Alternaria속균(屬菌), Phyllosticta속균(屬菌), 및 Phomopsis속균(屬菌) 등(等)에 의(依)하여 19속(屬) 19종(種)의 관상식물(觀賞植物)에 22종(種)의 병(病)이 발생(發生)하고 있음을 확인(確認)하였다.

• Current Research on Agriculture and Life Sciences
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• 제3권
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• pp.120-128
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• 1985

대구(大邱)를 중심(中心)으로 한 5개(個) 지역(地域)에 재식(裁植)되어 있는 23과(科) 28속(屬) 32종(種)의 관상식물(觀賞植物)에 대(對)하여 진균(眞菌)에 이병(罹病)된 식물(植物)을 조사(調査)한 결과(結果) Uncinula 속균(屬菌) 등(等) 21속(屬)의 병원진균(病原眞菌)에 의(依)하여 26속(屬) 30(種)의 식물(植物)에서 45종(種)의 병(病)이 발생(發生)하고 있었다. 이들 중(中) 우리나라에서 이제까지 보고(報告)되지 않은 미기록병해(未記錄病害)는 Uncinula속균(屬菌), Phyllosticta속균(屬菌), Discosia속균(屬菌), Macrophoma속균(屬菌), Colletotrichum속균(屬菌), Pestalotia속균(屬菌), Phomopsis속균(屬菌), Gloeosporium속균(屬菌), Alternaria속균(屬菌), Fusicoccum속균(屬菌) 및 Sphaceloma속균(屬菌) 등(等)에 의(依)하여 15속(屬) 16종(種)의 식물(植物)에 22종(種)의 병(病)이 발생(發生)하고 있었다.