• Mycobiology
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• 제47권4호
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• pp.430-440
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• 2019

Fungal contamination of built-in furniture is a frequent problem in Korea when new apartment is built. However, domestic information on the contaminating fungi is very limited. This study was conducted to isolate, identify and characterize the fungi of the problem in one of the apartment houses where the fungi were claimed in the built-in furniture before the house owner moves in. Fungi present in the furniture installed in a main room, dress room, and kitchen side were visually and microscopically confirmed and purely isolated on PDA. The isolated fungi were identified by analyzing the morphological characteristics and nucleotide sequence of the ITS, calmodulin gene, and TEF-1α gene. Aspergillus creber, A. niger, A. pseudoglacus, A. ruber, Cladosporium perangustum and Penicillium commune were identified. Four out of the six fungal species were positive for at least one enzyme in six kinds of extracellular enzyme assays. When these four species (A. creber, A. niger, C. perangustum and P. commune) were inoculated onto four kinds of wood chips of furniture materials, they were able to colonize all of the wood chips. Their settlement was better at 95% humidity condition than at 30% humidity condition. Among the four species, C. perangustum caused the darkest discoloration and secreted the most number of extracellular enzymes. The four species were re-isolated from the colonized wood chips and confirmed as the problematic fungi in the built-in furniture.

• Journal of Microbiology and Biotechnology
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• 제14권1호
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• pp.74-80
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• 2004

Aspergillus fumigatus is one of the most common fungi in the human environment, both in-doors and out-doors. It is the main causative agent of invasive aspergillosis, a life-threatening mycosis among immunocompromised patients. The genome has been sequenced by an international consortium, including the Wellcome Trust Sanger Institute (U.K.) and The Institute for Genomic Research (TIGR, U.S.A.), and a ten times whole genome shotgun sequence assembly has been made publicly available. In this study, we identified tricarboxylic acid (TCA) cycle enzymes of A. fumigatus by comparative analysis with four other fungal species. The open reading frames showed high amino acid sequence similarity with the other fungal citric acid enzymes and well-conserved functional domains. All genes present in Saccharomyces cerevisiae, Schizosaccharomyces pombe, Candida albicans, and Neurospora crassa were also found in A. fumigatus. In addition, we identified four A. fumigatus genes coding for enzymes in the glyoxylate shunt, which may be required for fungal virulence. The architecture of multi-gene encoded enzymes, such as isocitrate dehydrogenase, 2-ketoglutarate, succinyl-CoA synthetase, and succinate dehydrogenase was well conserved in A. fumigatus. Furthermore, our results show that genes of A. fumigatus can be detected reliably using GlimmerM.

• Journal of Microbiology and Biotechnology
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• 제19권1호
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• pp.11-16
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• 2009

Magnaporthe oryzae, the causal agent of rice blast, forms a specialized infection structure, called an appressorium, which is crucial for penetration and infection of the host plant. Pharmacological data suggest that calcium/calmodulindependent signaling is involved in appressorium formation in this fungus. To understand the role of the calcium/calmodulin-activated protein phosphatase on appressorium formation at the molecular level, MCNA, a gene encoding the catalytic subunit of calcineurin, was functionally characterized in M. oryzae. Transformants expressing sense/antisense RNA of MCNA exhibited significant reductions in mycelial growth, conidiation, appressorium formation, and pathogenicity. cDNA of MCNA functionally complemented a calcineurin disruptant strain (cmp1::LEU2 cmp2::HIS3) of Saccharomyces cerevisiae. These data suggest that calcineurin A plays important roles in signal transduction pathways involved in the infection-related morphogenesis and pathogenicity of M. oryzae.

• The Plant Pathology Journal
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• 제34권4호
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• pp.327-334
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• 2018

Northern corn leaf spot and southern corn leaf blight caused by Cochliobolus carbonum (anamorph, Bipolaris zeicola) and Cochliobolus heterostrophus (anamorph, Bipolaris maydis), respectively, are common maize diseases in Korea. Accurate detection of plant pathogens is necessary for effective disease management. Based on the polyketide synthase gene (PKS) of Cochliobolus carbonum and the nonribosomal peptide synthetase gene (NRPS) of Cochliobolus heterostrophus, primer pairs were designed for PCR to simultaneously detect the two fungal pathogens and were specific and sensitive enough to be used for duplex PCR analysis. This duplex PCR-based method was found to be effective for diagnosing simultaneous infections from the two Cochliobolus species that display similar morphological and mycological characteristics. With this method, it is possible to prevent infections in maize by detecting infected seeds or maize and discarding them. Besides saving time and effort, early diagnosis can help to prevent infections, establish comprehensive management systems, and secure healthy seeds.

• 식물병연구
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• 제29권2호
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• pp.130-136
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• 2023

Citrus melanoses caused by Diaporthe citri, has been one of the serious diseases in many citrus orchards of Jeju Island. To protect melanose in citrus farms, a fast and exact diagnosis method is necessary. In this study, diseased leaves and dieback twigs were collected from a total of 49 farms within March to April in 2022. A total of 465 fungal isolates were obtained from a total of 358 isolated plant samples. Among these fungal isolates, 40 representatives of D. citri isolates which were isolated from 22 twigs and 18 leaves on 23 farms were found based on cultural characteristics on potato dextrose agar and conidial morphology. Additionally, the molecular assay was carried out and compared with those by morphological diagnosis. All isolates were identified as D. citri by analyzing the sequences at the internal transcribed spacer (ITS) rDNA region using primers of ITS1/ITS4 or at β-tubulin using primer Btdcitri-F/R. Therefore, based on the present study, where the results of morphological identification of conidial type were consistent with DNA sequence analysis of certain gene, choosing a suitable method for a fast diagnosis of citrus melanose was suggested.

• Mycobiology
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• 제51권5호
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• pp.273-280
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• 2023

The nucleolus is the largest, membrane-less organelle within the nucleus of eukaryotic cell that plays a critical role in rRNA transcription and assembly of ribosomes. Recently, the nucleolus has been shown to be implicated in an array of processes including the formation of signal recognition particles and response to cellular stress. Such diverse functions of nucleolus are mediated by nucleolar proteins. In this study, we characterized a gene coding a putative protein containing a nucleolar localization sequence (NoLS) in the rice blast fungus, Magnaporthe oryzae. Phylogenetic and domain analysis suggested that the protein is orthologous to Rrp8 in Saccharomyces cerevisiae. MoRRP8-GFP (translational fusion of MoRRP8 with green fluorescence protein) co-localizes with a nucleolar marker protein, MoNOP1 fused to red fluorescence protein (RFP), indicating that MoRRP8 is a nucleolar protein. Deletion of the MoRRP8 gene caused a reduction in vegetative growth and impinged largely on asexual sporulation. Although the asexual spores of DMorrp8 were morphologically indistinguishable from those of wild-type, they showed delay in germination and reduction in appressorium formation. Our pathogenicity assay revealed that the MoRRP8 is required for full virulence and growth within host plants. Taken together, these results suggest that nucleolar processes mediated by MoRRP8 is pivotal for fungal development and pathogenesis.

• 한국미생물·생명공학회지
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• 제51권1호
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• pp.99-108
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• 2023

대기 입자상물질(particulate matter, PM) 시료의 곰팡이 메타게놈 분석을 위해 DNA 추출 및 유전자 증폭 시 여러 문제가 발생한다. 본 연구에서는 PM 시료로부터 DNA를 추출하는 방법과 polymerase chain reaction (PCR)을 위한 프라이머 및 온도 조건의 최적화를 위하여 다양한 조건으로 실험하였다. 여러 조건에서 DNA 추출 여부를 비교 평가한 결과, bufffer와 proteinase K를 이용하여 20분 동안 화학적 세포 용해 처리와 bead beating 처리를 한 후 상용 DNA 추출 kit를 사용하면 DNA를 효율적으로 추출할 수 있었다. PCR 조건을 최적화하기 위해 ITS2 유전자 영역을 증폭할 수 있는 10개 조합의 프라이머를 이용하여 PCR을 수행한 결과, ITS3tagmix3/ITS4 조합의 프라이머로 annealing 온도 58℃로 하였을 때 증폭된 PCR 산물의 농도가 상대적으로 높았다. 이 조건에서도 PCR 산물의 농도가 낮은 경우에는 1차 PCR 산물을 주형 DNA로 사용하여 nested PCR을 수행하면 만족스러운 농도로 ITS2 유전자를 증폭할 수 있었다. 본 연구에서 도출한 조건으로 서울 대기 PM2.5를 포집한 필터 시료 15종을 대상으로 DNA 추출과 PCR을 수행한 결과 성공적으로 ITS2 유전자 증폭이 가능하였다. 본 연구에서 최적화한 방법은 대기 PM 시료의 곰팡이 메타게놈을 분석하고 해석하는 연구에 활용 가능하다.

• BMB Reports
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• 제32권1호
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• pp.1-5
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• 1999

In order to understand the biological role of calmodulin in plants, transgenic tobacco plants expressing a calmodulin mutant (VU-4 calmodulin, lys to ile-115) gene have been analyzed. SDS-PAGE and Western-blot analyses showed that the foreign calmodulin mutant is stably and highly expressed in the transgenic tobacco plants. The levels of $H_2O_2$were elevated approximately 2-fold in the transgenic plants. Furthermore, the transgenic tobacco plants have more than 6-fold higher levels of NADPH compared to control tobacco plants. The present findings, combined with previous data showing differences in the susceptibility of the transgenic tobacco seeds and normal tobacco seeds to fungal contamination (Oh and Yang, 1996), suggest that the expression of the calmodulin derivative gene in tobacco plants could increase resistance to infection by fungal pathogens.

• Molecules and Cells
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• 제25권4호
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• pp.553-558
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• 2008

Essential aspects of the innate immune response to microbial infection appear to be conserved between insects and mammals. In order to identify new Drosophila melanogaster genes involved in the immune response, we performed gene expression profiling of Drosophila SL2 cells stimulated with bacterial (LPS/PGN) or fungal (curdlan) components using a cDNA microarray that contained 5,405 Drosophila cDNAs. We found that some genes were similarly regulated by LPS/PGN and curdlan. However, a large number, belonging to the functional classes of cell organization, development, signal transduction, morphogenesis, cell cycle, and DNA replication, displayed significant differences in their transcription profiles between the two treatments, demonstrating that bacterial and fungal components induce different immune response even in an in vitro cell system.

• Mycobiology
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• 제34권2호
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• pp.104-107
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• 2006

Flammulina velutipes was transformed efficiently by Agrobacterium-mediated transformation system. The transformation frequency was about 16% with the gill tissues of the fungal fruiting body. Southern hybridization and genetic analysis suggest that the introduced DNA was inserted onto different locations of the fungal genome, and inherited stably to the next generation via basidiospores. Transformation or gene tagging with Agrobacterium T-DNA based vector should be useful for wide ranges of genetic or molecular biological studies of the mushroom.