• 식물병연구
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• 제18권2호
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• pp.133-138
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• 2012

2009년 11월에 서귀포에서 꽃댕강나무 흰가루병을 발견하였다. 이어 제주, 부산, 통영 등 남부지방에서도 추가적으로 발견되었다. 흰색의 균체가 잎, 어린 줄기, 꽃을 감염하여 관상가치를 떨어뜨렸으며, 발병이 지속되면 잎 앞면의 병환부는 적자색으로 변하였다. 이 흰가루병균의 형태적 특징과 분자적 분석을 통하여 이 곰팡이는 Erysiphe abeliicola U. Braun & S. Takam.로 동정되었다. 무성세대의 분류학적 특징은 이 연구를 통하여 처음으로 기재되는데, 균사의 굴곡형 부착기와 분생포자경의 짧은 기부세포가 특징적이었다. 성숙한 자낭구의 분류학적 특징은 앞선 일본의 기재와 거의 일치하였다. 우리나라 시료에서 rDNA ITS 영역의 염기서열을 처음으로 분석하여 이 종이 Erysiphe속의 Microsphaera절에 속함을 밝혔으며, 이는 형태적 특징과 상응하는 결과였다. 이로써 우리나라에서 E. abeliicola에 의한 꽃댕강나무 흰가루병을 처음으로 보고하고, 꽃댕강나무가 이 흰가루병균의 기주로 확인된 것은 세계적으로 처음이다.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.91.1-91
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• 2003

Bakanae disease, caused by Gibberella fujikuroi (anamorph Fusarium moniliforme J. Sheldon), a typical seed-borne disease of rice occurs from nursery to paddy fields. Consequently, chemical seed disinfectants is the most efficient control method. Several seed treatment methods with various fungicides were attempted to inhibit disease. Spray and 24 hrs immersion of seeds using prochloraz emulsion reduced disease infection and the control value were 99.3 and 100％, respectively. In contrast, dressing to wet seeds thiophanate-methyl＋thiram wp and benomyl＋thiram wp reduced disease infection more effectively than 24 hrs immersion of seeds. However, dressing of carpropamid+imidacloprid＋fludioxonil wp to wet seeds did not reduced disease as well as wettable liquid of fludioxonil. The results suggest that the bakanae disease might be disinfected effectively by 24 hrs immersion of seeds in prochloraz emulsion and seed dressing of fungicides.

• Tuberculosis and Respiratory Diseases
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• 제69권4호
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• pp.298-302
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• 2010

Scedosporium apiospermum, the anamorph of Pseudallescheria boydii, is a ubiquitous saprophytic fungus. S. apiospermum can cause life-threatening infections usually in immunocompromised patients or after near-drowning incidents. Here, we report the first case of disseminated infection caused by S. apiospermum after near-drowning in Korea. A 44-year-old healthy man developed aspiration pneumonia, followed by multiple brain abscesses, and endopthalmitis, after a near-drowning incident in a septic tank. S. apiospermum infection was diagnosed on the 33rd day after the incident had occurred. The patient died from the progressive renal failure 255 days after incident, although he had been treated with voriconazole.

• The Plant Pathology Journal
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• 제24권1호
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• pp.8-16
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• 2008

Aurofusarin is a polyketide pigment produced by some Fusarium species. The PKS12 and GIP1 genes, which encode a putative type I polyketide synthase (PKS) and a fungal laccase, respectively, are known to be required for aurofusarin biosynthesis in Gibberella zeae (anamorph: Fusarium graminearum). The ten additional genes, which are located within a 30 kb region of PKS12 and GIP1 and regulated by a putative transcription factor (GIP2), organize the aurofusarin biosynthetic cluster. To determine if they are essential for aurofusarin production in G. zeae, we have employed targeted gene deletion, complementation, and chemical analyses. GIP7, which encodes O-methyltransferase, is confirmed to be required for the conversion of norrubrofusarin to rubrofusarin, an intermediate of aurofusarin. GIP1-, GIP3-, and GIP8-deleted strains accumulated rubrofusarin, indicating those gene products are essential enzymes for the conversion of rubrofusarin to aurofusarin. Based on the phenotypic changes in the gene deletion strains examined, we propose a possible pathway for aurofusarin biosynthesis in G. zeae. Our results would provide important information for better understanding of naphthoquinone biosynthesis in other fdarnentous fungi as well as the aurofusarin biosynthesis in G. zeae.

• Mycobiology
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• 제37권3호
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• pp.171-182
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• 2009

Many aspergilli that belongs to ascomycetes have sexuality. In a homothallic or self-fertile fungus, a number of fruiting bodies or cleistothecia are formed in a thallus grown from a single haploid conidia or ascospores. Genome-sequencing project revealed that two mating genes (MAT) encoding the regulatory proteins that are necessary for controlling partner recognition in heterothallic fungi were conserved in most aspergilli. The MAT gene products in some self-fertile species were not required for recognition of mating partner at pheromone-signaling stage but required at later stages of sexual development. Various environmental factors such as nutritional status, culture conditions and several stresses, influence the decision or progression of sexual reproduction. A large number of genes are expected to be involved in sexual development of Emericella nidulans (anamorph: Aspergillus nidulans), a genetic and biological model organism in aspergilli. The sexual development process can be grouped into several development stages, including the decision of sexual reproductive cycle, mating process, growth of fruiting body, karyogamy followed by meiosis, and sporulation process. Complicated regulatory networks, such as signal transduction pathways and gene expression controls, may work in each stage and stage-to-stage linkages. In this review, the components joining in the regulatory pathways of sexual development, although they constitute only a small part of the whole regulatory networks, are briefly mentioned. Some of them control sexual development positively and some do negatively. Regarding the difficulties for studying sexual differentiation compare to asexual one, recent progresses in molecular genetics of E. nidulans enlarge the boundaries of understanding sexual development in the non-fertile species as well as in fertile fungi.

• 한국식물학회:학술대회논문집
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• 한국식물학회 1999년도 제13회 식물생명공학심포지움 New Approaches to Understand Gene Function in Plants and Application to Plant Biotechnology
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• pp.41-44
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• 1999

Magnaporthe grisea (Hebert) Barr (anamorph: Pyricularia grisea) is a typical heterothallic Ascomycete and the causal agent of rice blast, one of the most destructive diseases on rice (Oryza sativa L.) worldwide. The interactions between cells of the pathogen and those of the host involve a complex of biological influences which can lead to blast disease. The early stages of infection process in particular may be viewed as a sequence of discrete and critical events. These include conidial attachment, gemination, and the formation of an appressorium, a dome-shaped and melanized infection structure. Disruption of this process at any point will result in failure of the pathogen to colonize host tissues. This may offer a new avenue for developing innovative crop protection strategies. To recognize and capture such opportunities, understanding the very bases of the pathogenesis at the cellular and molecular level is prerequisite. Much has been learned about environmental cues and endogenous signaling systems for the early infection-related morphogenesis in M. grisea during last several years. The study of signal transduction system in phytopathogenic filamentous fungi offers distinct advantages over traditional mammalian systems. Mammalian systems often contain multiple copies of important genes active in the same tissue under the same physiological processes. Functional redundancy, alternate gene splicing, and specilized isoforms make defining the role of any single gene difficult. Fungi and animals are closely related kingdoms [3], so inferences between these organisms are often justified. For many genes, fungi frequently possess only a single copy, thus phenotype can be attributed directly to the mutation or deletion of any particular gene of interest.

• 한국식물학회:학술대회논문집
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• 한국식물학회 1985년도 워크샵 및 심포지엄 북한산국립공원의 식생
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• pp.19-22
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• 1985

Magnaporthe grisea (Hebert) Barr (anamorph: Pyricularia grisea) is a typical heterothallic Ascomycete and the causal agent of rice blast, one of the most destructive diseases on rice (Oryza sativa L.) worldwide. The interactions between cells of the pathogen and those of the host involve a complex of biological influences which can lead to blast disease. The early stages of infection process in particular may be viewed as a sequence of discrete and critical events. These include conidial attachment, gemination, and the formation of an appressorium, a dome-shaped and melanized infection structure. Disruption of this process at any point will result in failure of the pathogen to colonize host tissues. This may offer a new avenue for developing innovative crop protection strategies. To recognize and capture such opportunities, understanding the very bases of the pathogenesis at the cellular and molecular level is prerequisite. Much has been learned about environmental cues and endogenous signaling systems for the early infection-related morphogenesis in M. grisea during last several years. The study of signal transduction system in phytopathogenic filamentous fungi offers distinct advantages over traditional mammalian systems. Mammalian systems often contain multiple copies of important genes active in the same tissue under the same physiological processes. Functional redundancy, alternate gene splicing, and specilized isoforms make defining the role of any single gene difficult. Fungi and animals are closely related kingdoms [3], so inferences between these organisms are often justified. For many genes, fungi frequently possess only a single copy, thus phenotype can be attributed directly to the mutation or deletion of any particular gene of interest.

• Journal of Microbiology and Biotechnology
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• 제9권6호
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• pp.870-872
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• 1999

The ubiquinone and G+C contents of the bioflocculant-producing fungus, a new Aspergillus strain, were detennined using high-perfonnance liquid chromatography. The internal transcribed spacers 1 and 2 (ITS1 and ITS2), and the 5.8S ribosomal DNA (rDNA) of the strain were amplified and sequenced. The strain contained ubiquinone-l0($H_2$)as a major quinone and the G+C content was 49 mol%. A phylogenetic analysis of the ITS regions indicated that the strain belonged to the genus Aspergillus according to its previously classified morphological characteristics. Based on a sequence homology search, the strain was most closely related to Petromyces muricatus (anamorph, A. muricatus; accession number, AJ005674). The sequence of a new Aspergillus strain in ITS1 and ITS2, and 5.8S rDNA showed 97% homology to P. muricatus. Therefore, the strain is believed to be a new bioflocculant-producing Aspergillus strain.

• The Plant Pathology Journal
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• 제27권1호
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• pp.20-25
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• 2011

Gibberella zeae (anamorph: Fusarium graminearum), a homothallic (self-ferile) ascomycete with ubiquitous geographic distribution, causes serious diseases in several cereal crops. Ascospores (sexual spores) produced by this fungal pathogen have been suggested as the main source of primary inoculum in disease development. Here, we report the function of a gene designated GzRUM1, which is essential for ascospore formation in G. zeae. The deduced product of GzRUM1 showed significant similarities to the human retinoblastoma (tumor suppressor) binding protein 2 and a transcriptional repressor, Rum1 in the corn smut fungus (Ustilago maydis). The transcript of GzRUM1 was detected during the both vegetative and sexual stages, but was more highly accumulated during the latter stage. In addition, no GzRUM1 transcript was detected in a G. zeae strain lacking a mating-type gene (MAT1-2), a master regulator for sexual development in G. zeae. Targeted deletion of GzRUM1 caused no dramatic changes in several traits except ascospore formation. The ${\Delta}$GzRUM1 strain produced perithecia (sexual fruit bodies) but not asci nor ascospores within them. This specific defect leading to an arrest in ascospore development suggests that GzRUM1, as Rum1 in U. maydis, functions as a transcriptional regulator during sexual reproduction in G. zeae.

• 식물병연구
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• 제28권4호
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• pp.248-251
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• 2022

2022년 10월 충청남도 예산군(36°40'12.7"N, 126°51'36.4"E)에서 좀돌팥 흰가루병을 조사하였다. 병징은 주로 잎의 앞면에 발생하였으며 뒷면에는 흰가루병이 약하게 발병하였다. 흰가루병의 자낭구는 잎의 뒷면에서 확인하였다. 흰가루병균 무성세대 및 유성세대의 형태적 특징과 더불어 internal transcribed spacer rDNA, 28S large subunit 염기서열을 계통분석한 결과, 흰가루병균은 Podosphaera xanthii로 동정되었다. 이는 한국에서 Podosphaera xanthii에 의한 좀돌팥 흰가루병을 처음으로 보고한다.