• The Korean Journal of Pesticide Science
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• v.2 no.1
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• pp.40-45
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• 1998

An antagonistic fungus inhibiting growth of various phytopathogenic fungi was isolated from greenhouse soils and identified. Mophological features of fruiting structures on potato dextrose agar and colorless globose to ovate heavy walled hyaline cells from the vegetative mycelium grown on MY20 agar indicate that this antagonist is Aspergillus terreus. The antagonistic activity is due to the production of antifungal compounds. An antifungal compound was purified from its culture filtrate using chloroform extraction, column chromatography, and thin layer chromatography. The purified antibiotic was effective to various phytopathogenic fungi and identified as butyrolactone I. $ED_{50}$ values measured by petri-plate assay through effective dosage(ED)-probit analysis were 9.7, 13.7, 23.3, 42.6 and 102.7 ppm on Botrytis cinerea, Rhizoctonia solani, Pythium ultimum, Phytophthora capsici, and Fusarium oxysporum, respectively.

• The Plant Pathology Journal
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• v.32 no.4
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• pp.347-356
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• 2016

Plants protect themselves from pathogen attacks via several mechanisms, including hypersensitive cell death. Recognition of pathogen attack by the plant resistance gene triggers expression of carboxylesterase genes associated with hypersensitive response. We identified six transcripts of carboxylesterase genes, Vitis flexuosa carboxylesterase 5585 (VfCXE5585), Vf-CXE12827, VfCXE13132, VfCXE17159, VfCXE18231, and VfCXE47674, which showed different expression patterns upon transcriptome analysis of V. flexuosa inoculated with Elsinoe ampelina. The lengths of genes ranged from 1,098 to 1,629 bp, and their encoded proteins consisted of 309 to 335 amino acids. The predicted amino acid sequences showed hydrolase like domains in all six transcripts and contained two conserved motifs, GXSXG of serine hydrolase characteristics and HGGGF related to the carboxylesterase family. The deduced amino acid sequence also contained a potential catalytic triad consisted of serine, aspartic acid and histidine. Of the six transcripts, Vf-CXE12827 showed upregulated expression against E. ampelina at all time points. Three genes (VfCXE5585, VfCXE12827, and VfCXE13132) showed upregulation, while others (VfCXE17159, VfCXE18231, and VfCXE47674) were down regulated in grapevines infected with Botrytis cinerea. All transcripts showed upregulated expression against Rhizobium vitis at early and later time points except VfCXE12827, and were downregulated for up to 48 hours post inoculation (hpi) after upregulation at 1 hpi in response to R. vitis infection. All tested genes showed high and differential expression in response to pathogens, indicating that they all may play a role in defense pathways during pathogen infection in grapevines.

• Applied Biological Chemistry
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• v.35 no.1
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• pp.14-22
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• 1992

A series of new N-[1-(benzotriazol-1-yl)aryl]arylamine derivatives were synthesized and their antifungal activities $(pI_{50})$ in vitro against Pyricularia oryzae, Fusarium oxysporum f. sp. sesami, Valsa ceratosperma and Botrytis cinerea were dertermined by the agar medium dilution method. From the results of the quantitative structure-activity relationships $(QSAR_S)$ analysis, $hydrophobicity({\pi})$, $electronic({\Sigma\sigma})$ and molar $refractivity({\Sigma}M_R)$ parameter of X & Y-substituents on the phenyl group were also shown to be important factor in determining the variation in the antifungal activity. 4-Bromo group substituents (1d & 2b) were the most effective compounds and the $half-life(T_{1/2})$ on the hydrolysis of X(1) at netural pH was about 1.5 day. Molecular orbital(MO) functions of substrate compound, linear free energy relationships$(LFER_S)$ on the antifungal reactivity arid the results of molecular design were also discussed.

• Korean Journal of Environmental Agriculture
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• v.20 no.1
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• pp.57-62
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• 2001

Twelve antagonistic strains against Fusarium wilt of watermelon-rootstock gourd were selected from 54 bacterial isolates which were isolated from the rhizosphere of crop plants growing in various locations. They showed strong inhibitory effects on growth of Fusarium osysporum f. sp. niveum, the causal agent of watermelon-rootstock gourd Fusarium wilt. Among these antagonists, the isolate YJ-3 was the most pronounced in growth-promoting ability for watermelon-rootstock gourd. The growth of watermelon-rootstock gourd in bed soil inoculated with YJ-3 was better by 46 and 13% than those in commercial bed soil alone and in bed soil inoculated with commercial microbial inoculant, respectively. The antagonistic plant growth-promoting rhizobacterium, strain No. YJ-3, was identified as Bacillus sp. on MIDI system. Furthermore, Bacillus sp. YJ-3 showed antifungal activity on growth against Alternaria cucumerina, Botrytis cinerea, Colletotrichum orbiculare, Didymella bryoniae, Rhizoctonia solani and Fusarium oxysporum.

• Food Science and Preservation
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• v.9 no.2
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• pp.131-136
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• 2002

Quality changes of satsuma mandarin (Citrus unshiu Marc. var. miyagawa) during storage by storage warehouse were investigated. Citrus were treated with 2000-folds diluted iminoctadime-triacetate solution and 1.5% chitosan with 0.5% CaCl$_2$ solution, and were at 30$\^{C}$ for 24 hr before storage. The citrus of about 12kg/26L plastic container were stored at room temperature, and at 4$\^{C}$ with 87% relative humidity. Decay ratio of citrus with precise temperature and humidity control were lower than the others during storage. Penicillium italicum Monilia candida Alternara citri, Mucor hiemalis, Phomopsis citri Botrytis cinerea, Phoma citricarpa Clomererella cingulata, Penicillium digitatum were identified as putrefactive microorganisms in citrus storage. Weight loss, moisture content of peel and flesh were decreased slowly during storage. 24% of original acid content were decreased at room temperature on 120 days storage, compared to 15∼18% loss on cold storage. Total sugar of citrus was decreased rapidly after 90 days, and vitamin C content were also decreased rapidly after 60 days during storage.

• Korean Journal of Food Science and Technology
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• v.28 no.6
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• pp.1142-1145
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• 1996

Long term-storage of citrus oranges after harvest has been hindered mainly by molds The goal of this research was to collect and identify those molds, which would help find a way to extend shelf-life after harvest. During the period of 1994 to 1995, fourteen different strains were isolated and purified from putrefied fruit (Citrus unshiu var.) that was stored at room temperature under open air. The storage disease was caused by the following molds: Penicillium italicum, 25.8%, Monilia candida, 19.8%; Alternaria citri, 18.1%; Mucor hiemalis, 11.0%; Phomopsis citri, 6.6%; Botrytis cinerea. 5.5%; Phoma citricarpa, 3.8%; Glomerella cingulata, 3.8%; P. digitatum, 1.1%; other molds, 4.5%; Most of the strains showed pectinolytic activity and putrefaction. These citrus fruit-putrefying molds will be used as target strains for the control of microorganisms during post-harvest storage.

• Food Science and Preservation
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• v.10 no.2
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• pp.224-229
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• 2003

This study was carried out to isolate of antagonistic bacterium to Allium cepa L. pathogens. A total of 250 strains were isolated from A. cepa L. roots. The isolates were screened for antagonism to A. cepa L. pathogens and the isolated strain No. YJ-4 was selected among these bacteria. It was identified as Bacillus ehimensis based on morphological and physiological characteristics according to the Bergey's mannual of systematic bacteriology, Sherlock system of Microbial ID Int and 165 rDNA sequences methods. Bacillus ehimensis YJ-4 showed broad spectrum of antibacterial and antifungal activities against plant pathogens as Alternaria porri, Botrytis cinerea, Erwinia carotovora subsp. carotovora Fusarium of oxysporium, penicillium sp., Pseudomonas sp., Rhizoctonia solani, Sclerotium cepivotum, Septoria sp., Stemphylium botryosum. Speially B. ehimensis YJ-4 showed high antifungal activity on growth against F. oxysporium, the causal agent of onion Fusarium wilt.

• The Korean Journal of Mycology
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• v.46 no.4
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• pp.511-518
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• 2018

Initiation of spore germination in filamentous fungi such as Aspergillus nidulans and Botrytis cinerea requires the presence of nutrients. In this study, involvement of sugar sensing machinery was suggested in the germination of A. nidulans spores. Germination did not occur when the spores of A. nidulans were incubated in distilled water, whereas they were successfully germinated in the presence of 5% glucose with a germination rate of over 98% after 6hr incubation. Similar results were obtained when the spores were incubated in the presence of various sugars such as fructose, sucrose, and starch. Interestingly, spore germination was not observed in the presence of D-arabinose, whereas L-arabinose could induce germination as determined by the formation of germ tubes, indicating the presence of sugar sensing machinery that distinguish between the enantiomers of sugars. This inference was further supported by a decrease in germination rate (less than 25%) upon treatment of spores with trypsin. Subsequent MALDI-TOF mass spectrometry analysis of the surface proteins of spores identified ten proteins among which eight were involved in sugar metabolism. Taken together, our results suggest that spore germination in A. nidulans is initiated by the interaction of sugars with sugar binding proteins on the surface of spores.

• Korean Journal of Organic Agriculture
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• v.26 no.4
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• pp.649-660
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• 2018

To control the pepper anthracnose caused by Colletotrichum acutatum, antifungal bacterium strains which was selected among bacterium from natural soil, was tested the antimicrobial activity against various pathogens and its control efficacy on anthracnose disease in the fields. We confirmed that antagonistic activity of CAB13001 strain to pathogens such as Sclerotinia cepivorum, Sclerotinia sclerotium and Botrytis cinerea including Colletotrichum acutatum was remarkable superior with the dual culture method in the artificial medium. In vitro bioassay using the green pepper fruit, CAB13001 strain suppressed the lesion development of Anthracnose disease, and its control value compared to the untreated one was 82.4% on pepper fruit in field test. These results suggested that CAB13001 strain could be a very useful biological control agents to anthracnose disease caused by air born plant pathogens of pepper. By the way, analysis of nucleotide sequence of the gene 16S rDNA, antagonistic bacterium CAB13001 strain used in this study was identified as Burkholderia lata.

• The Plant Pathology Journal
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• v.35 no.3
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• pp.208-218
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• 2019

Here, we reported a novel secreted protein elicitor PeBL2 from Brevibacillus laterosporus A60, which can induce hypersensitive response in tobacco (Nicotiana benthamiana). The ion-exchange chromatography, high-performance liquid chromatography (HPLC) and mass spectrometry were performed for identification of protein elicitor. The 471 bp PeBL2 gene produces a 17.22 kDa protein with 156 amino acids containing an 84-residue signal peptide. Consistent with endogenous protein, the recombinant protein expressed in Escherichia coli induced the typical hypersensitive response (HR) and necrosis in tobacco leaves. Additionally, PeBL2 also triggered early defensive response of generation of reactive oxygen species ($H_2O_2$ and $O_2{^-}$) and systemic resistance against of B. cinerea. Our findings shed new light on a novel strategy for biocontrol using B. laterosporus A60.