• Proceedings of the Zoological Society Korea Conference
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• 1998.10b
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• pp.331.2-331
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• 1998

No Abstract, See Full Text

• Proceedings of the Zoological Society Korea Conference
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• 1995.10b
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• pp.296.1-296
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• 1995

No Abstract, See Full Text

• Journal of Microbiology and Biotechnology
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• v.13 no.3
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• pp.400-405
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• 2003

A gene (hpkA), encoding a histidine protein kinase homolog, has been identified in the upstream region of the espAB operon in Myxococcus xanthus. It encodes a 333 amino acid (35,952 Da) protein with a histidine protein kinase domain in the region from amino acid 90 to 317. Null mutations in the hpkA gene caused formation of loose irregular fruiting bodies, while wild-type strains developed tight hemispherical fruiting bodies under developmental conditions. Sporulation of the hpkA mutant was delayed by at least 12 h compared to that of the wild-type. It appeared that the hpkA mutation increased the expression of the espAB operon by more than 2-fold compared with the wild-type under developmental conditions. Expression of the hpkA gene was low under vegetative conditions, but was highly induced under developmental conditions.

• Microbiology and Biotechnology Letters
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• v.22 no.2
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• pp.115-119
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• 1994

White mutant of Ganoderma lucidum(G4142) induced the non-basediocarpous basidiospores(NBB) from the aerial mycelia on agar media by the light illumination. Light was found to be necessary for NBB formation, but it also inhibited the growth of mycelium. The best sporulation was obtained at the periodic exposure of 16 hour light and 8 hour dark. Blue and yellow light were the most effective on sporulation, however, near UV and red light did not induce any spores. Effective light intensity for NBB bearing was about 1,000 lux as white light. Even after 16 days of culture, this strain did not form the pinhead nor chlamydospore. Optimum temperature for the mycelial growth and NBB formation were 30$\circ $C. Ganoderma lucidum G4142 exhibited the formation of stroma after five days of incubation at 30$\circ $C.

• Microbiology and Biotechnology Letters
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• v.18 no.4
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• pp.429-432
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• 1990

The promoter isolated from chromosomal DNA of an alkali-tolerant Bacillus sp. YA-14 was subcloned and biochemically characterized. Also the relationships between the promoter activity and sporulation were investigated. In alkali-tolerant Bacillus sp. and Bacillus subtilis, the activity of promoter began to increase at the onset of sporulation with the same mode, and repressed in the presence of 1.0% (wtv) glucose. Among five spoO genes, three epoO genes (spoOB, spoH, spoOJ) were required for promoter expression.

• The Plant Pathology Journal
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• v.27 no.2
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• pp.110-115
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• 2011

Aggressiveness was studied in seven Plasmopara halstedii (sunflower downy mildew) pathotypes: 100, 300, 304, 314, 704, 710 and 714. Aggressiveness criteria including percentage infection, latent period, sporulation density and reduction of hypocotyl length (dwarfing) were analysed in one sunflower inbred line showing a high level of quantitative resistance. Genetic relationships were detected between the seven pathotypes using 12 EST-derived markers. Pathotypes 100, 300, 304 and 314 were characterized with shorter latent period and higher sporulation density than pathotypes 710, 704 and 714. All pathotypes showed high percentage infection values and caused a large reduction in seedling size except for pathotype 314 involved in dwarfing. Pathotypes 714, 704 and 314 had an intermediary genetic position between the pathotypes 100 and 710. No correlation was detected between aggressiveness traits and EST genotypes.

• Korean Journal of Microbiology
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• v.40 no.4
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• pp.282-285
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• 2004

In Blastocladiella emersonii, a member of zoosporic fungi, development of small sporangia containing a few nuclei can be induced. During these reduced sporogenesis, degeneration of some of the nuclei was observed within the sporangia. This observation supports the hypothesis that the nuclear degeneration is an essential part of sporulation. Morphological changes associated with the nuclear degeneration were similar to those of the autophagy of cytoplasm. This system of nuclear degeneration would become the good model system for the study of autophagy.

• Biotechnology and Bioprocess Engineering:BBE
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• v.5 no.5
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• pp.327-331
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• 2000

The application of LFH-PCR(long flanking homology region-PCR) for Bacillus subtilis gene disruption is presented. Without plasmid- or phage-vector construction, only by PCR, based on a DNA sequence retrieved from B. subtilis genome data base, kanamycin resistance gene was inserted into two genes of B. subtilis involved in sporulation, spoIIIE and spoIIIG. The effect of gene disruption on subtilisin expression was examined and the sporulation frequency of two mutants was compared to that of the host strain. For this purpose, only 2 or 3 rounds of PCR were required with 4 primers. We first demonstrated the possibility of LFH-PCR for rapid gene disruption to characterize an unknown functional gene of B. subtilis or other prokaryote in the genomic era.

• Journal of Plant Biology
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• v.6 no.1
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• pp.8-10
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• 1963

LA, Yong Joon (Coll. of Agr., Seoul National Univ.) Condial production of Cercospora beticola Sacc. on tomato juice agar. Kor. Jour. Bot. VI (1):8-10, 1963. Agar media containing various amount of tomato juice were tested to determine the degree of conidial production of Cercospora beticola. Non-sporulating culture on potato dextrose agar readily sporulated on agar media containing various amout of tomato juice 48 hours after transfer. Considerably small amount of sporulation occurred on agar media containing 10% of tomato juice. Sporulation increased considerably on media containing more than 20% of tomato juice; the higher the proportion of tomato juice in a medium, the greater the number of spores produced.

• Korean Journal of Microbiology
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• v.22 no.2
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• pp.91-96
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• 1984

The changes in the activities of Cellulase and Xylanase of A. phoencis during the life cycle were surveyed by using synchronized culture technique. Avicelase activity of the fungus was reached at peak in the initial hyphal growth stage, but decreased gradually during the conidiophore formation, vesicle-phialide formation, and sporulation stages in decreasing order. CMCase, Salicinase, and Xylanase activities were raised very high in the initial hyphal growth stage, but decreased gradually in conidiophore formation and vesicle-phialide formation stages, and then increased, more or less, in the sporulation stage.