• Microbiology and Biotechnology Letters
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• v.17 no.4
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• pp.307-312
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• 1989

Strain No.77-AG-567 showed antifungal activity against Pyricularia oryzas and Sphaerotheca fuliginea. In the process of purification of active component this strain was found to produce blasticidin S together with another antibiotic. This compound was identified as being acetoxycyc-heximide, also referred to as E-73, by UV and $^1$H NMR spectral data. Identification of this strain led us to conclude that strain No.77-AG-567 is most probably be Streptomyces atratus. It showed different characteristics from S. atbutus, so far known to produce both blasticidin S and acetoxycycloheximide. Particularly worthy of note was the difference in spore surface. In addition, acetoxycycloheximide has been known to have activity only against yeast and tumor cells but we found that it also has activity against Pyricularia oryzae and Sphasrotheca fuliginea.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.84.1-84
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• 2003

Magnaporthe grisea, the casual agent of rice blast, forms an appressorium to penetrate its host. Much has been learned about environmental cues and signal transduction pathways, especially those involving CAMP and MAP kinases, on appressorium formation during the last decade. More recently, pharmacological data suggest that calcium/calmodulin-dependent signaling system is involved in its appressorium formation. To determine the role of phosphoinositide-specific phospholipase C (PI-PLC) on appressorium formation, a gene (WPLCl) encoding PI-PLC was cloned and characterized from M. grisea strain 70-15. Sequence analysis showed that MPLCl has alt five conserved domains present in other phospholipase C genes from several filamentous fungi and mammals. Null mutants (mplcl) generated by targeted gene disruption exhibited pleiotropic effects on conidial morphology, appressorium formation, fertility and pathogenicity. mplcl mutants developed nonfunctional appressoria and are also defective in infectious growth in host tissues. Defects in appressorium formation and pathogenicity in mplcl mutants were complemented by a mouse PLCdelta-1 cDNA under the control of the MPLCl promoter. These results suggest that cellular signaling mediated by MPLCl plays crucial and diverse roles in development and pathogenicity of M. grisea, and functional conservation between fungal and mammalian Pl-PLCs.

• Journal of Microbiology and Biotechnology
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• v.16 no.7
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• pp.1158-1162
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• 2006

The glyoxylate cycle can conserve carbons and adequately supply tricarboxylic acid (TCA) cycle intermediates for biosynthesis when microorganisms grow on $C_{2}$ carbon sources. It has been reported that isocitrate lyase (ICL1), a key enzyme of the glyoxylate cycle, is highly induced when Magnaporthe grisea, the causal agent of rice blast, infects its host. Therefore, the glyoxylate cycle is considered as a new target for antifungal agents. A 1.6-kb DNA fragment encoding the ICL1 from M. grisea KJ201 was amplified by PCR, cloned into a vector providing His-tag at the N-terminus, expressed in Escherichia coli, and purified using Ni-NTA affinity chromatography. The molecular mass of the purified ICL1 was approximately 60 kDa, as determined by SDS-PAGE. The ICL1 inhibitory effects of TCA cycle intermediates and their analogs were investigated. Among them, 3-nitropropionate was found to be the strongest inhibitor with an $IC_{50}$ value of $11.0{\mu}g/ml$. 3-Nitropropionate inhibited the appressorium development in M. grisea at the ${\mu}M$ level, whereas conidia germination remained unaffected. This compound also inhibited the mycelial growth of the fungus on minimal medium containing acetate as a $C_{2}$ carbon source. These results suggest that ICL1 plays a crucial role in appressorium formation of M. grisea and is a new target for the control of phytopathogenic fungal infection.

• Microbiology and Biotechnology Letters
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• v.19 no.4
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• pp.337-342
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• 1991

A bacterium producing the antifungal compound KRF-001 isolated from soil was selected and identified as Bacillus subtilis. The antibiotic KRF-001 was active against various fungi. Effecacy of KRF-001 at various concentration for controlling leaf blast of rice in the paddy field was evaluated and compared with recommended rates of kasugamycin, blasticidin- s and tricyclazole. KRF-001 caused no irritation on the skin of rabbits and LD50 for mice was deduced more than 5000 mg/kg which indicates the possibility of low toxicity or no toxicity.

• The Korean Journal of Pesticide Science
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• v.9 no.2
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• pp.132-139
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• 2005

New ${\beta}$-methoxyacrylate derivatives 1-4 having thio-enol side chain were prepared and subjected to in vivo screening for fungicidal activity against phytopathogenic fungi and many of them showed good fungicidal activities against especially rice blast and wheat leaf rust at 100 ppm.

• The Korean Journal of Mycology
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• v.33 no.2
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• pp.86-88
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• 2005

Antifungal activity of the extracts of plants and marine microalgae against Magnaporthe grisea was investigated. Acetone extracts of promegranate rind, leek seed, and maize husk demonstrated high antifungal activity against M. grisea. MIC (minimum inhibitory concentration) of acetone extracts of promegranate rind, leek seed, and maize husk was 100 ng/ml, $50\;{\mu}g/ml,\;and\;100\;{\mu}g/ml$ respectively. Ethanol extract of Amphiprora gigantea showed antifungal activity against M. grisea with MIC of $100\;{\mu}g/ml$.

• Research in Plant Disease
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• v.10 no.1
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• pp.1-7
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• 2004

The year of 2003 was characterized as a cool humid year. Low temperature and frequent rains were continued during March to July, resulting in 1.6 times higher rainfalls and 32％ less sunshine period compared to the average yean Due to 2003's climatic condition, rice blast, and bacterial leaf blight occurred severely. Higher rainfalls caused severe epidemic of phytophthora disease and, in case of red-pepper, 55％ of cultivation acreage was devastated by the disease over the country. Besides, crop diseases which become severe under cool-humid conditions, such as gray mold, sclerotinia rot, downy mildew, increased significantly compared to the previous year. In fruit trees, brown spot of apple, and pear scab occurred severely causing much yield loss.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.19
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• pp.1-6
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• 1975

From the cross Tongil$^2//IR833/IR1317$ glutinouse rice lines wx 126 were bred. Some of these lines were earlier than standard variety and later than glutinous check variety. Some of them yielded as much as standard variety and showed better resostances to blast, stripe deseases and smaller brown plant hopper than standard variety. It was sosscussed that, theough the vreedong procedure, following points were proved, 1)back-cross program in roce breeding was effocoent, 2)semi-dwarf plant type of "Tongil" has high yielding poteneoality and 3) the variety "Tongil" was a good for recurrent parent for back-cross program. back-cross program.

• Research in Plant Disease
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• v.24 no.2
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• pp.87-98
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• 2018

The fungal species contain diverse transposable elements and repetitive sequences up to ~10% of their genome. It has been reported that distribution of transposable elements tends to correlate with the host range of the pathogen. Moreover, transposable elements cause the loss of an avirulence gene in the pathogen, which resulted in disease on a resistance cultivar. Thus, the transposable elements in the fungal pathogens may be one of the key factors driving the plant-fungus interactive evolution. In this article, we reviewed classification and biological functions of transposable elements in Magnaporthe species.

• Applied Biological Chemistry
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• v.40 no.2
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• pp.139-143
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• 1997

This research aims at developing a new pesticide by means of synthesizing new 2-iminothiazoline derivatives and testing their bilolgical activity. In an effort to prepare 2-iminothiazolines, primary amines were treated to have reaction with isothiocyanate, followed by a treatment of ${\alpha}-halo$ ketone derivatives. Their antifungal activaty was tested against six different plant diseases. A compound that has a phenylimino group at C-2, methyl at C-3, phenylcarbamoylmethyl at C-4, and hydrogen at C-5 on the thiazoline skeleton was found to be most active.