• 한국균학회소식:학술대회논문집
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• 2015.11a
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• pp.18-18
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• 2015

Wilt disease in Oak trees occurs during summer season in Korea. Mass attack of trees by an ambrosia beetle (Platypus koryoensis) was the characteristic feature before appearance of the wilting symptoms. Raffaelea sp. caused the discoloration of xylem area called as wound heartwood. Raffaelea sp. was observed both on the body surfaces and inside the mycangia of the beetle Platypus sp. The scanning electron microscope (SEM) analysis showed that fungal spores were present within the wall of gallery and vessels that formed tyloses. The results revealed that the water movement in vessels was blocked as the fungus started to grow which caused the formation of tyloses thereby resulting wilt symptoms. We found that both female and male beetle Platypus sp. had fungi on their bodies and their large and small mycangia. This study confirmed that the fungus was transferred to oak trees by Platypus sp.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.2
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• pp.167-172
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• 2009

The maxilla rarely undergoes necrosis due to its rich vascularity. Maxillary necrosis can occur due to bacterial infections such as osteomyelitis. viral infections such as herpes zoster and fungal infections such as mucormycosis, aspergillosis etc. Herpes zoster is a common viral infection, the oral soft tissue manifestations of which are widely known and recognized. Extremely rare complications such as osteonecrosis, and secondary osteomyelitis in maxilla were observed. But, reports of spontaneous tooth exfoliation and jaw osteonecrosis following herpes zoster infection in the distribution of the trigeminal nerve are extremely rare in the literature. We report a case of maxillary necrosis by herpes zoster in an uncontrolled diabetic patient. There was extensive necrosis of the buccal and palatal mucoperiosteum and exposure of the alveolar bone. This patient was successfully treated using a removal of necrotic bone and nasolabial flap. We briefly discuss different diseases which can lead to maxillary necrosis and a review. Analysis of the pathogenesis of herpes zoster and bone necrosis are discussed.

• The Plant Pathology Journal
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• v.35 no.2
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• pp.91-99
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• 2019

Mitogen-activated protein kinase (MAPK) cascades in fungi are ubiquitously conserved signaling pathways that regulate stress responses, vegetative growth, pathogenicity, and many other developmental processes. Previously, we reported that the AbSte7 gene, which encodes a mitogen-activated protein kinase kinase (MAPKK) in Alternaria brassicicola, plays a central role in pathogenicity against host cabbage plants. In this research, we further characterized the role of AbSte7 in the pathogenicity of this fungus using ${\Delta}AbSte7$ mutants. Disruption of the AbSte7 gene of A. brassicicola reduced accumulation of metabolites toxic to the host plant in liquid culture media. The ${\Delta}AbSte7$ mutants could not efficiently detoxify cruciferous phytoalexin brassinin, possibly due to reduced expression of the brassinin hydrolase gene involved in detoxifying brassinin. Disruption of the AbSte7 gene also severely impaired fungal detoxification of reactive oxygen species. AbSte7 gene disruption reduced the enzymatic activity of cell walldegrading enzymes, including cellulase, ${\beta}$-glucosidase, pectin methylesterase, polymethyl-galacturonase, and polygalacturonic acid transeliminase, during host plant infection. Altogether, the data strongly suggest the MAPKK gene AbSte7 plays a pivotal role in A. brassicicola during host infection by regulating multiple steps, and thus increasing pathogenicity and inhibiting host defenses.

• Microbiology and Biotechnology Letters
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• v.51 no.2
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• pp.167-173
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• 2023

Proteolytic enzymes secreted by Aspergillus, as pathogenicity factors, affect blood coagulation and fibrinolysis, and therefore the target proteins of their action in the bloodstream are of significant interest. In the present study, the action of the isolated protease of A. terreus 2 on different human plasma proteins was shown. The protease of A. terreus 2 exhibited the highest proteolytic activity against hemoglobin, which was 2.5 times higher than the albuminolytic activity shown in both of the protein substrates used. In addition, the protease has significant ability to hydrolyze both fibrin and fibrinogen. However, the inability of the A. terreus 2 protease to coagulate rabbit blood plasma and coagulate human and bovine fibrinogen indicates the severity of the enzyme's action on human blood coagulation factors. It should be considered as a potential indicator of this isolated protease's participation in fungal pathogenesis. The protease shows no hemolytic activity. Furthermore, its activity is insignificantly inhibited by thrombin inhibitors, and is not inhibited by plasmin inhibitors.

• Research in Plant Disease
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• v.13 no.1
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• pp.34-39
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• 2007

Lichen thalli of Dirinaria applanata heavily colonized on the twigs of dead or dying Rhododendron trees in Solok island, Jeonnam province in Korea. Pathogenesis of the lichen on the trees was investigated to find out the possibility of lichen as a causal agent. Histological examination of the lichen colonized twigs was attempted with differential staining technique. Lichen-forming fungus colonized only on the surface of bark and there was no direct penetration of fungal hyphae into the plant tissues. Symbiotic algae of the lichen was also examined. The isolated algal cells were inoculated on artificially induced wounds of the healthy trees. Histological examination of the inoculated tissues showed that some algal cells were successfully colonized inside the tissues without any pathogenic symptoms, even 2 months later, The extract of the lichen thalli was also examined using 10% of DMSO solution. Treated tissues showed no pathogenic symptoms, even 4 weeks later. The results suggested that the lichen was not directly involved in the death of the trees.

• Research in Plant Disease
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• v.17 no.2
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• pp.136-141
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• 2011

In other previous in vitro tests, the hyphal growth of Raffaelea quercivorus was inhibited by the treatments of various concentration of nano-silver. In this field tests, treatment of different concentrations of nano-silver to oak trees in Cheolwon and Hongcheon sites showed the inhibition effects against wilt disease caused by Raffaelea quercivorus. However, nano-silver-treated oak tree in Chuncheon site showed mild wilt symptoms with no phytotoxicity. Scanning electron microscope (SEM) observation confirmed that the spore and hypha of Raffaelea sp. inside the vessels were damaged by nano-silver. This result indicates the application of nanosilver is effective for control of Raffaelea quercivorus in the field.

• Journal of Plant Biotechnology
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• v.33 no.2
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• pp.93-97
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• 2006

The calmodulin as a Ca$^{2+}$-binding protein mediates cellular Ca$^{2+}$ signals in response to a wide array of stimuli in higher eukaryotes. Plants produce numerous calmodulin isoforms that exhibit differential gene expression patterns and sense different Ca$^{2+}$ signals. SCaM-5 is a soybean calmodulin that is involved in plant defense signaling. Here, we constructed a SCaM-5 CDNA under control of CaMV 35S promoter and transformed it into tomato (Lycopersicon esculentum). The constitutive over-expression of SCaM-5 in tomato plants exhibited a high levels of pathogenesis-related (PR) gene expression, and conferred an enhanced resistance to two fungal pathogen (Phytophthora capsici, Fusarium oxysporum), and a bacterial pathogen, Pseudomonas syringae pv. tomato DC3000. Thus, this results collectively suggest that SCaM-5 plays an important role in plant defense of tomato.

• The Plant Pathology Journal
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• v.33 no.2
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• pp.193-205
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• 2017

Histone methylation plays important roles in regulating chromatin dynamics and transcription in eukaryotes. Implication of histone modifications in fungal pathogenesis is, however, beginning to emerge. Here, we report identification and functional analysis of a putative JmjC-domain-containing histone demethylase in Magnaporthe oryzae. Through bioinformatics analysis, we identified seven genes, which encode putative histone demethylases containing JmjC domain. Deletion of one gene, MoJMJ1, belonging to JARID group, resulted in defects in vegetative growth, asexual reproduction, appressorium formation as well as invasive growth in the fungus. Western blot analysis showed that global H3K4me3 level increased in the deletion mutant, compared to wild-type strain, indicating histone demethylase activity of MoJMJ1. Introduction of MoJMJ1 gene into ${\Delta}Mojmj1$ restored defects in pre-penetration developments including appressorium formation, indicating the importance of histone demethylation through MoJMJ1 during infection-specific morphogenesis. However, defects in penetration and invasive growth were not complemented. We discuss such incomplete complementation in detail here. Our work on MoJMJ1 provides insights into H3K4me3-mediated regulation of infection-specific development in the plant pathogenic fungus.

• Journal of Microbiology and Biotechnology
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• v.23 no.11
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• pp.1493-1499
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• 2013

A novel radiation-resistant Filobasidium sp. yeast strain was isolated from seawater. Along with this strain, a total of 656 yeast isolates were purified from seawater samples collected from three locations in the West Sea of Korea and assessed for their radiation tolerance. Among these isolates, five were found to survive a 5 kGy radiation dose. The most radiation-resistant strain was classified as Filobasidium sp. based on 18S rDNA sequence analysis and hence was named Filobasidium RRY1 (Radiation-Resistant Yeast 1). RRY1 differed from F. elegans, which is closely related to RRY1, in terms of the optimal growth temperature and radiation resistance, and was resistant to high doses of ${\gamma}$-ionizing radiation ($D_{10}$: 6-7 kGy). When exposed to a high dose of 3 kGy irradiation, the RRY1 cells remained intact and undistorted, with negligible cell death. When these irradiated cells were allowed to recover, the cells fully repaired their genomic DNA within 3 h of growth recovery. This is the first report in which a radiation-resistant response has been investigated at the physiological, morphological, and molecular levels in a strain of Filobasidium sp.

• Tuberculosis and Respiratory Diseases
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• v.78 no.3
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• pp.258-261
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• 2015

Eosinophilic lung diseases are heterogeneous disorders characterized by varying degrees of pulmonary parenchyma or blood eosinophilia. Causes of eosinophilic lung diseases range from drug ingestion to parasitic or fungal infection as well as idiopathic. The exact pathogenesis of eosinophilic lung disease remains unknown. Urushiol chicken can frequently cause allergic reactions. Contact dermatitis (both local and systemic) represents the most-common side effect of urushiol chicken ingestion. However, there has been no previous report of lung involvement following urushiol chicken ingestion until now. A 66-year-old male was admitted to our hospital with exertional dyspnea. Serial chest X-ray revealed multiple migrating infiltrations in both lung fields, with eosinophilic infiltration revealed by lung biopsy. The patient had ingested urushiol chicken on two occasions within the 2 weeks immediately prior to disease onset. His symptoms and migrating lung lesions were resolved following administration of oral corticosteroids.