• Korean journal of applied entomology
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• v.11 no.2
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• pp.101-107
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• 1972

This experiment was conducted in order to determine the fungi associated with ear blight of rice and their chemical control. 1, Pyricularia oryzes, Helminthosporium oryzne, Epicoccum purpurascens, Curvularia lunata, Cladosporium cladosporoides and Alternaria tenuis et al. were mainly detected in large quantities from the discolored seeds of recommended varieties but Trichoconis padwickii, Fusarium dimerum, and Nigrospora oryzae were mainly detected from Tongil. 2. Pyricularia oryzae, Nigrospora oryzae, and Curvularia lunate et at. were from the necks; Helminthosporium oryzae, Trichoconis padwickii, Stemphylium sp. , Cladosporium cladosporoides, and Alternaria tenuis et at. were from the branches of ear; and Phoma spp. was mainly detected from the kernels. 3. In the laboratory Difolatan WP $0.13\%$ gave good control of Helminthosporium oryzae, Cladosporium cladosporoides, and Alternaria tenuis, et al.; and Dithane M-45 WP $0.2\% gave especially good control of Pyricularia oryzae, Trichoconis padwickii, and Curvularia lunate. 4. In field experiments, the appropriate date of chemical spray was milk ripening stage or panicle emergence stage. Under these conditions Hinosan Ec and Kasugamin Ec were more effective than Difolatan WP and Dithane M-45 WP. However, the assessment of ear blight was complicated by a severe outbreak of neck blast.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.119.2-120
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• 2003

Seed-borne fungal pathogens on rice seeds were investigated in order to evaluate their effect on rice grain quality. Rice seeds of two cultivars, Ilmibyeo and Daesanbyeo were collected from 27 areas of Korea and the fungal parasites on seeds were isolated by using a blotter method. Isolation frequency and number of species were varied from collection areas of seed samples. A total 13 species of fungi were identified from the seeds. Among them, Altemana alternata was the most frequent over the country. Bipoiaris oryzae most commonly from Gyeongbuk and Jeonbuk, Alternaria padwickii from Jeonbuk, and Nigrospora oryzae from Choongnam. However Bipolaris. oryzae, Alternaria padwickii, and Nigrospora oryzae were the most frequently isolated fungi from Gyeongbuk and Jeonbuk, and Chungnam, respectively. B. oryzae, A. alternata, A. padwickii, and N. oryzae were dominants on Ilmibyeo showing 10.3％, 10.2％, 5.2％, and 5.2％ infection rate, respectively. While, N. oryzae, A alternata, and Cladosporium sp. were most frequently isolated fungi from Deasanbyeo revealing 15.1％, 9.6％, and 7.5％ infection rate, respectively. These fungi inhabiting on hulls or endosperms of rice seed might be considered as potential factors decreasing rice grain quality. Further investigation of the fungi on grain rice quality are undergoing.

• Korean Journal of Microbiology
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• v.27 no.3
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• pp.216-220
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• 1989

As the bsic study about protoplast fusion of amylolytic fungus Aspergillus oryze and nonamyloytic sugar fermenter, Saccaromyces cerevsisae, the intraspecific protoplast fusion of A. oryzae was carried out and the properties of the obtained fusants were investigated. For protoplast fomation from mycellia of auxotrophs, Novozyme 234 as lytic enzyme was the most effective and optimal pH was determined to be pH 5.5-6.0. When the two types of protoplasts were treated with a fusogen including 30% PEG4000, they fused effectively and most of fusants were heterokaryons. Protoplasts aggregated with 30% PEG4000 after fusion treatment were observed by the microscope. Protoplast regeneration frequency was 1.46 to 13.8% and complementation frequency of fusion was 0.12 to 0.16. Fusant strains had a 1.5-fold DNA content compared to that of parent strain. And amylase activity was intermediate between those of parent strains.

• Microbiology and Biotechnology Letters
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• v.27 no.5
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• pp.404-409
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• 1999

The most favorable nitrogen source for the production of protease by Aspergillus oryzae PF was 2% soybean flour among sodium nitrate, ammonium sulfate, defatted soybean, skim milk, casein, peptone, and yeast extract. The production of protease from A. oryzae PF was higher at the concentration of 2% lactose than at variable concentration of glucose, sucrose, soluble starch, corn starch, potato starch, wheat starch, rice starch, cellulose, and gum arabic. Protease production was affected by the concentration of KH2PO4, Triton X-100, CaCo3, and MgSO4, and it was the highest at the highest at the concentration of 3% KH2PO4, 0.01% Triton X-100, 0.3% CaCO3, and 0.06% MGSO4.

• Mycobiology
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• v.40 no.3
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• pp.214-216
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• 2012

Soft rot on banana fruit caused by Rhizopus oryzae was identified for the first time in Korea. Colonies were white to light brown and formed numerous sporangiospores. Optimum temperature for mycelial growth was $30^{\circ}C$. Sporangia were globose and $30{\sim}200{\mu}m$. Sporangiophores were usually straight, $8{\sim}20{\mu}m$, and rhizoids usually in groups of 3~5. Columella were globose to sub-globose and $90{\sim}110{\mu}m$. Sporangiospores were sub-globose or oval and $4{\sim}10{\mu}m$. Based on its mycological characteristics, molecular analysis, and pathogenicity to host plants, this fungus was identified as Rhizopus oryzae Went & Prisen Geerligs. This is the first report of soft rot on banana caused by Rhizopus oryzae in Korea.

• The Korean Journal of Mycology
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• v.23 no.3 s.74
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• pp.257-265
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• 1995

Morphological characteristics and pathogenicity of Rhizoctonia species causing blight diseases of turfgrasses were studied. The species were identified as Rhizoctonia cerealis Van der Hoeven, R. oryzae Ryker et Gooch, and R. solani $K{\ddot{u}hn}$ based on their morphological and cultural characteristics. Isolates of R. solani were assigned to anastomosis groups (AG) with cultural type 1 (1A), 2-2 (IIIB), and 2-2 (IV). R. cerealis, R. oryzae and R. solani induced sheath rot and foliar blight symptoms on creeping bentgrass (Agrostis palustris) and zoysiagrass (Zoysia japonica). Inoculation tests showed that disease severity with isolates of R. cerealis and R. oryzae were more serious to creeping bentgrass than zoysiagrass. AG 1(1A) isolates of R. solani were strongly pathogenic on creeping bentgrass, but moderate to zoysiagrass. AG 2-2 (III) isolates were moderately pathogenic to zoysiagrass, but weakly to creeping bentgrass. AG 2-2 (IV) isolates from zoysiagrass were moderately pathogenic to zoysiagrass, but weakly to creeping bentgrass.

• The Plant Pathology Journal
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• v.27 no.1
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• pp.89-92
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• 2011

Cyclic AMP receptor-like protein (Clp), is known to be a global transcriptional regulator for the expression of virulence factors in Xanthomonas campestris pv. campestris (Xcc). Sequence analysis showed that Xanthomonas oryzae pv. oryzae (Xoo) contains a gene that is strongly homologous to the Xcc clp. In order to determine the role of the Clp homolog in Xoo, a marker exchange mutant of $clp_{xoo4158}$ was generated. Virulence and virulence factors, such as the production of cellulase, xylanase, and extracellular polysaccharides (EPS) and swarming motility were significantly decreased in the $clp_{xoo4158}$ mutant. Moreover, the mutation caused the strain to be more sensitive to hydrogen peroxide and to over-produce siderophores. Complementation of the mutant restored the mutation-related phenotypes. Expression of $clp_{xoo4158}$, assessed by reverse-transcription realtime PCR and clp promoter activity, was significantly reduced in the rpfB, rpfF, rpfC, and rpfG mutants. These results suggest that the clp homolog, $clp_{xoo4158}$, is involved in the control of virulence and resistance against oxidative stress, and that expression of the gene is controlled by RpfC and RpfG through a diffusible signal factor (DSF) signal in Xanthomonas oryzae pv. oryzae KACC10859.

• Journal of Applied Biological Chemistry
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• v.59 no.2
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• pp.149-154
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• 2016

An endophytic bacterial strain was isolated from kimchi, a Korean traditional fermented Brassica campestris and identified as Bacillus subtilis MJMP2 based on the 16S rRNA sequence. This strain showed strong antagonistic activity against Xanthomonas oryzae pv. oryzae (Xoo) KACC10331, the pathogen of bacterial rice blight disease, as well as activity against some other rice phytopathogenic fungi. The active compound was purified through size-exclusion chromatography and preparative High-performance liquid chromatography. The molecular weight was determined as m/z 1043 by mass spectroscopy, which is identical to that of iturin A. Furthermore, a crude extract from the culture supernatant of Bacillus subtilis MJMP2 showed inhibitory activity against rice blight disease in both a rice leaf explant assay and a pot assay. The crude extract also enhanced the length of roots of Arabidopsis thaliana. These results suggest that the strain Bacillus subtilis MJMP2 could be used as a biological agent to control rice blight disease.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.7
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• pp.1002-1008
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• 2012

For the production of Korea traditional cereal wine makgeolli, a rice fermentation starter nuruk was Rhizopus oryaze CCS01 commercial nuruk. The carbohydrate content of rice nuruk was higher, the levels of moisture, ash, crude protein, and crude fat were lower. In particular, the saccharifying activity of rice nuruk was 2.2 times higher than commercial nuruk. pH, alcohol, and viable yeast cells of makgeolli made rice nuruk were higher than those of makgeolli made commercial nuruk. In contrast, the levels of acidity, $^{\circ}Brix$, viable lactic acid bacteria (LAB) cells, and browning of makgeolli made rice nuruk were lower than those of makgeolli made commercial nuruk, the alcohol content of glutinous rice (GUR) makgeolli made rice nuruk higher other samples. These results suggest that rice nuruk R. oryzae CCS01 make new type cereal makgeolli.

• The Plant Pathology Journal
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• v.28 no.4
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• pp.364-372
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• 2012

Xanthomonas oryzae pv. oryzae causing bacterial leaf blight disease in rice produces and secretes Hpa1 protein that belongs to harpin protein family. Previously it was reported that Hpa1 induced defense responses when it was produced in tobacco. In this study, we expressed hpa1 gene in rice and Arabidopsis to examine the effects of Hpa1 expression on disease resistance to both fungal and bacterial pathogens. Expression of hpa1 gene in rice enhanced disease resistance to both X. oryzae pv. oryzae and Magnaporthe grisea. Interestingly, individual transgenic rice plants could be divided into four groups, depending on responses to both pathogens. hpa1 expression in Arabidopsis also enhanced disease resistance to both Botrytis cineria and Xanthomonas campestris pv. campestris. To examine genes that are up-regulated in the transgenic rice plants after inoculation with X. oryzae pv. oryzae, known defense-related genes were assessed, and also microarray analysis with the Rice 5 K DNA chip was performed. Interestingly, expression of OsACS1 gene, which was found as the gene that showed the highest induction, was induced earlier and stronger than that in the wild type plant. These results indicate that hpa1 expression in the diverse plant species, including monocot and dicot, can enhance disease resistance to both fungal and bacterial plant pathogens.