• Journal of Microbiology and Biotechnology
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• v.10 no.6
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• pp.805-810
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• 2000

An antifungal protein antagonistic to the rice blast fungus, Pyricularia oryzae was purified from Paenibacillus macerans PM-1 by ammonium sulfate fractionation, Q Sepharose Fast Flow column chromatography, Phenyl Sepharose CL-4B column chromatography and Superose 12 gen filtration. An apparent molecular mass of the purified antifungal protein was determined as 8 kDa by SDS-PAGE and 9 kDa by analytical gel filtration, respectively, suggesting that the purified protein is a monomer. The antifungal protein was stable at pH range from 7-12 and up to $100^{\circ}C$. The protein was also stable at 0.1-1% Tween 20 and Triton X-100. The N-terminal amino acid sequence of the antifungal protein was Thr-Glu-Leu-Pro-Leu-Gly-Ile-Val-Met-Asp-Lys-Tyr-Thr-Asp-Ala-Phe-Lys-Phe-Asp-Met-Phe. Comparison of the determined sequence with other peptide and DNA sequences did not reveal homology at all. Therefore, the purified antifungal protein was speculated to be a novel protein. The condidial germination in vitro of P. oryzae KJ301:93-39 by the purified protein ($5.9{\mu} g/ml$) was limited to $9{\pm}3.2%$ only, compared with $69{\pm}2.4%$ of the control. Ungerminated conidia were swollen at basa and mid cell by the purified protein. In vivo bioassay for inhibition of conidial germination of P. oryzae KJ 301, one of the most predominating racesin Korea. the purified protein ($5.9{\mu} g/ml$)strongly inhibited the conidial germination. The conidia, even though germinated, could not develop any further to produce appressoria efficiently.

• The Plant Pathology Journal
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• v.35 no.6
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• pp.564-574
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• 2019

Like many fungal pathogens, the conidium and appressorium play key roles during polycyclic dissemination and infection of Magnaporthe oryzae. Ran-binding protein microtubule-organizing center (RanBPM) is a highly conserved nucleocytoplasmic protein. In animalia, RanBPM has been implicated in apoptosis, cell morphology, and transcription. However, the functional roles of RanBPM, encoded by MGG_00753 (named MoRBP9) in M. oryzae, have not been elucidated. Here, the deletion mutant ΔMorbp9 for MoRBP9 was generated via homologous recombination to investigate the functions of this gene. The ΔMorbp9 exhibited normal conidial germination and vegetative growth but dramatically reduced conidiation compared with the wild type, suggesting that MoRBP9 is involved in conidial production. ΔMorbp9 conidia failed to produce appressoria on hydrophobic surfaces, whereas ΔMorbp9 still developed aberrantly shaped appressorium-like structures at hyphal tips on the same surface, suggesting that MoRBP9 is involved in the morphology of appressorium-like structures from hyphal tips and is critical for development of appressorium from germ tubes. Taken together, our results indicated that MoRBP9 played a pleiotropic role in polycyclic dissemination and infection-related morphogenesis of M. oryzae.

• Journal of Applied Biological Chemistry
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• v.61 no.3
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• pp.239-243
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• 2018

Essential oils of coriander (Coriandrum sativum L.) seeds were extracted by three extraction methods, steam distillation extraction (SDE), hexane extraction (HE) and supercritical extraction (SE), to compare their insecticidal activities against Sitophilus oryzae and S. zeamais. Although the essential oil extracted by HE and SE did not show insecticidal activities, the essential oil extracted by SDE showed the highest insecticidal activities against S. oryzae and S. zeamais. The chemical compositions of the essential oil extracted by SDE were analyzed by GC-MS. The most abundant compounds were linalool (59.92%), camphor (7.94%), linalool oxide (7.70%), p-cymene (7.44%), ${\alpha}-pinene$ (6.44%), limonene (3.29%) and geranyl acetate (3.19%). Camphor and linalool as major constituents showed the highest insecticidal activities against S. oryzae and S. zeamais whereas other constituents did not show insecticidal activities. As a result, the essential oil extracted by SDE, camphor and linalool showed a potential for development as insecticide against the storage pests.

• The Korean Journal of Food And Nutrition
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• v.6 no.2
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• pp.89-95
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• 1993

A Nuluk, a Korean traditional Koji for brewing, was made with wheat flour and Aspergillus oryzae L2 which had a good aroma and strong abilities In producing saccharogenic and dextrogenic enzymes. The cultural conditions for the production of saccharogenic and proteolytic enzymes were tested. The productivity of dextrogenic enzyme was improved when Nuluk was made with unsteamed wheat flour as compared with steamed one, but that of proteolytic enzyme was reduced. The addition of water containing 0.5% hydrochloric acid was unfavorable for the production of those two enzymes. The optimum ratio of water added to wheat flour for the production of those two enzymes was 28$^{\circ}C$ on the basis of wheat flour, The productivity of saccharogenic enzyme was enhanced when the Nuluk was molded after 20 hours of precultivation, but that of proteolytic enzyme was reduced as compared with no molding. The optimum temperatures for the production of saccharogenic enzyme and proteolytic enzyme were 36$^{\circ}C$ and 28$^{\circ}C$, respectively.

• Microbiology and Biotechnology Letters
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• v.19 no.2
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• pp.109-115
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• 1991

Twenty-five fungal strains producing an extracellular soybean milk clotting enzyme were isolated from 146 soil samples, and identified as 11 species belonging to six genera of Aspergillus oryzae (5 strains), Aspergillus flavus (2 strains), Aspergillus parasiticus (1 strain), Aspergillus tamarii (2 strains), Aspergillus niger (4 strains), Aspergillus fumigatus (2 strains), Mucor hiemalis (2 strains), Wallemia sebi (4 strains), Scopulariopsis condida (1 strain), Fusarium redolens(1 strain) and Verticillum lecanii (1 strain). Among them, Aspergillus oryzae 020 and Aspergillus tamarii 287 showed relatively high soybean milk clotting activity. The coagulabilities of the enzyme from representative strains of those species decreased as the pH of soybean milk increased from 6.0 to 7.0 The optimum temperature for soybean milk clotting enzymes of those strains were 65$^{\circ}C$.

• Journal of Microbiology and Biotechnology
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• v.7 no.2
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• pp.157-159
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• 1997

A 340-bp chitin synthase gene(CHS) fragment was cloned from the genomic DNA of Pyricularia oryzae using a PCR process with two primer DNAs corresponding to highly conserved sequences within fungal CHS genes. The entire DNA nucleotide sequences of the cloned DNA fragment were determined and analyzed. The amino acid sequences deduced from the nucleotide sequence of the amplified DNA fragment showed 86% homology to that of the Aspergillus fumigatus CHSE gene (9). Using this PCR-amplified DNA, about 2.3 kb of including the PCR fragment of CHSE gene was cloned from genomic library.

• Journal of Microbiology and Biotechnology
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• v.14 no.4
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• pp.863-867
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• 2004

$\alpha$-Galactosidase from A. oryzae DR-5 was induced in the presence of melibiose, raffinose, galactose, and locust bean galactomannan. The enzyme was purified to homogeneity by precipitation with acetone followed by ion-exchange chromatography using DEAE-Sephacel. The purified enzyme showed a single band in both nondenaturing-PAGE and SDS-PAGE. The enzyme was a glycoprotein in nature by activity staining. The molecular weight of the purified enzyme was 93-95 kDa by SDS-PAGE. The enzyme exhibited the optimum pH and temperature at 4.7 and $60^\circ{C}$, respectively. $\alpha$-Galactosidase activity was strongly inhibited by $Ag^{2+}, Hg^{2+}, Cu^{2+}$, and galactose. EDTA, 1,10-phenanthraline, and PMSF did not inhibit the enzyme activity, whereas N-bromosuccinimide completely inhibited enzyme activity. Investigation by TLC showed complete hydrolysis of stachyose and raffinose in soymilk in 3 h at pH 5.0 and $50^\circ{C}$.

• 한국균학회소식:학술대회논문집
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• 2015.11a
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• pp.23-23
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• 2015

Rice blast disease caused by M. oryzae is the most devastating fungal disease in rice. During the infection process, M. oryzae secretes a large number of glycosyl hydrolase (GH) proteins into the apoplast to digest host cell wall and assist fungal ingress into host tissues. In this study, we identified a novel M. oryze arabinofuranosidase B (MoAbfB) which is secreted during fungal infection. Live-cell imaging exhibited that fluorescent labeled MoAbfB was highly accumulated in fungal invasive structures such as appressorium, tips of penetration peg, biotrophic interfacial complex (BIC), as well as invasive hyphal tip. Deletion of MoAbfB mutants extended biotrophic phase followed by enhanced disease severity, whereas, over-expression of OsMoAbfB mutant induced rapid defense responses and enhanced rice resistance to M. oryzae infection. Furthermore, exogenous treatment of MoAbfB protein showed inhibition of fungal infection via priming of defense gene expression. We later found that the extract of MoAbfB degraded rice cell wall fragments could also induce host defense activation, suggesting that not MoAbfB itself but oligosaccharides (OGs) derived from MoAbfB dissolved rice cell wall elicited rice innate immunity.

• The Plant Pathology Journal
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• v.24 no.2
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• pp.131-142
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• 2008

Magnaporthe oryzae, the causal agent of the rice blast disease, poses a worldwide threat to stable rice production. The large-scale functional characterization of genes controlling the pathogenicity of M. oryzae is currently under way, but little is known about heat shock protein 40 (Hsp40) function in the rice blast fungus or any other filamentous plant pathogen. We identified 25 genes encoding putative Hsp40s in the genome of M. oryzae using a bioinformatic approach, which we designated M. oryzae heat shock protein forty (MHF 1-25). To elucidate the roles of these genes, we characterized the functions of MHF16 and MHF21, which encode type ill and type n Hsp40 proteins, respectively. MHF16 and MHF21 expression was not significantly induced by heat shock, but it was down-regulated by cold shock. Knockout mutants of these genes $({\Delta}$mhf16 and ${\Delta}$mhf21) were viable, but conidiation was severely reduced. Moreover, sectoring was observed in the ${\Delta}mhf16$ mutant when it was grown on oatmeal agar medium. Conidial germination, appressorium formation, and pathogenicity in rice were not significantly affected in the mutants. The defects in conidiation and colony morphology were fully complemented by reintroduction of wild type MHF16 and MHF21 alleles, respectively. These data indicate that MHF16 and MHF21 play important roles in conidiation in the rice blast fungus.

• International Journal of Industrial Entomology and Biomaterials
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• v.47 no.1
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• pp.12-24
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• 2023

Sitophilus oryzae L. (Rice Weevil) is a stored pest of rice that causes extensive loss throughout the world. We tested the leaf powders of 12 plant species viz., Chrysanthemum sp., Cinnamomum zeylanicum, Citrus grandis, Citrus limon, Gliricidia sepium, Gymnema sylvestre, Hemigraphis colorata, Michelia champaca, Moringa oleifera, Murraya koenigii, Polyalthia longifolia, and Sauropus androgynus at dosages of 1.00, 1.50, 2.00 and 3.00g against the adult rice weevil and mortality was recorded at 1, 2, 3, 5, 7, 12 and 2l days after treatment (DAT) by direct contact toxicity for their adulticidal effect. We observed 100 percent adult mortality in C. zevlanicum and M. koenigii among the tested leaf powders. In addition, the first-time tested H. colorata and S. androgynus also caused high mortality compared to other plants. All the plant powders caused moderate to high adult mortality. Hence, these plants could be effective botanical insecticides against S. oryzae as they comprise a potential source of bioactive chemicals and are generally free from toxicants. Applications of these natural derivatives in S. oryzae control could reduce the cost of control methods and storage of rice contamination. Therefore, the present study indicates that some plant extracts can be used as an alternative to toxic synthetic chemicals in the management of rice weevils.