• The Plant Pathology Journal
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• 제15권3호
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• pp.168-171
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• 1999

Crude extracts of pathogenic Streptomyces turgidiscabies isolates produced necrotic reaction on potato slices. Necrosis was first visible 24 hr after application and increased in severity over several days. However, necrosis was not observed when crude extracts of nonpathogenic strains were applied onto tuber slices. Presence of thaxtomin A from crude extracts of pathogenic S. turgidiscabies was identified by thin layer chromatography and high performance liquid chromatography. Nonpathgenic strains did not produce thaxtomin A in oatmeal broth. Inoculation of potato tuber slices with thaxtomin A partially purified from crude extract of a pathogenic S. turgidiscabies ST5 reproduce necrotic reaction suggesting that thaxtomin A is a pathogenicity determinant in S. turgidiscabies.

• The Plant Pathology Journal
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• 제19권1호
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• pp.13-18
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• 2003

From 1996 to 1999, potato-growing areas in Korea were surveyed for identification and distribution of potato scab pathogens. Potato scab was widely distributed in the mass cultivation areas, especially in Jriu island, southern areas of Chonnam and Gyounggi provinces, and the alpine area of Gangwon province. Jeju island was the most affected area by this disease. A total of 55 Streptomyces strains were isolated from potato scab lesions, among which 40 strains were pathogenic on progeny tubers. Among the pathogenic strain, 21 strains were identified as previously described S. scabies, 7 Strains as S. turgidiscabies, and 5 Strains as S. acidiscabies, while 7 strains were observed as having distinct phenotypic properties. These strains were classified into six distinct clusters based on phenotypic characteristics and selected representative strains for each cluster. S. scabies (S33) had grey spores in a spiral chain. Mean-while, S. turgidiscabies (S27) had grey spores, S. acidiscabies (S71) had white spores, S. luridiscabiei (S63) had yellow-white spores, S. puniciscabiei (S77) had purple-red spores, and S. niveiscabiei (S78) had thin and compact white spores, all in a rectiflexuous chain. Pathogenicity was determined by the production of thaxtomin A and homologs of necl and ORFtnp genes. In TLC, representative strains S27, S71, S63, S77, and S78 produced a yellow band that co-migrated with the authentic thaxtomin A. However, thaxtomin A was not detected in chloroform extracts from oatmeal broth culture and Slice tuber tissue of S. luridiscabiei (S63) and S. puniciscabiei (S77) by HPLC analysis. In addition, no homologs of necl and ORFtnp genes in S. acidiscabies (S71), S. luridiscabiei (S63), S. puniciscabiei (S77), and S. niveiscabiei (S78) were detected by PCR and Southern hybridization analysis.

• KSBB Journal
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• 제25권2호
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• pp.167-172
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• 2010

농작물에 심각한 피해를 주는 phytotoxin을 생산하는 S. scabiei ATCC 49173의 분자 유전학적인 연구를 위해 대장균으로부터 S. scabiei로 plasmid DNA를 도입하는 접합 전달법을 이용한 형질전환법을 확립하였다. 본 연구를 통해 확인된 S. scabiei의 접합전달용 최적배지는 50 mM의 $MgCl_2$를 첨가한 MS배지이며 접합전달에 사용되는 DNA 수용체인 포자는 $45^{\circ}C$의 열처리와 $5{\times}10^7$이상의 plasmid DNA 공여체가 필요하다는 것을 확인하였다. 또 얻어진 접합전달체에 대하여 Southern blot hybridization과 벡터가 삽입된 염색체부분의 염기서열분석을 통해 attB site의 특성을 분석한 결과 S. scabiei 염색체의 pirin 상동체를 코드하는 ORF내에 단일위치로 존재하고 있으며 이미 밝혀진 다른 방선균유래 attB site의 염기서열에 대해 86.3%~96.1%의 상동성을 보였다.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.134.2-135
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• 2003

The plant-pathogenic species S. scabies, S. acidiscabies, and S. turgidiscabies cause the scab disease of potato and produce the phytotoxins, thaxtomins. necl, a gene conferring a necrogenic phenotype, is involved in pathogenicity and physically linked to the thaxtomin A biosynthetic genes. Identification of the pathogenic strains of Streptomyces from soil was performed through the polymerase chain reaction by using specific pathogenicity primer sets derived from the necl gene sequences of Streptomyces smbies. The DNA was extracted from soil using a bead-beating machine and modifications of the FastPrep system. The DNA was suitable for direct use in the PCR. The PCR products showed the bands of approximately 460 bp. This methods can be very usuful in identifying species responsible for scab diseases and studying on the ecology of plant-pathogenic Streptomyces spp.

• The Plant Pathology Journal
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• 제18권6호
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• pp.338-341
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• 2002

The potato scab is caused by several species of Streptomyces. Among these species, only pathogenic strains were found to produce thaxtomin A characterized by necrotic bioassay and HPLC. In this study, identification of the pathogenic strains of Streptomyces was performed through the polymerase chain reaction (PCR) by using specific pathogenicity primer sets derived from the nec1 gene sequences of Streptomyces scabies. The expected PCR products were obtained approximately 580 bp and confirmed by sequencing. This PCR technique can be used effectively to identify the pathogenic Streptomyces species, that cause scab on potato tubers.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2005년도 International Meeting of the Microbiological Society of Korea
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• pp.162-165
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• 2005

Potato scab, an important disease that affects developing tubers, causes a major problem in potato cultivation. The major potato cultivation areas in Korea are located in two Northern provinces, Gangwon and Gyeonggi, and two Southern provinces, Jeju island, and South Jeolla. In these areas, potato scab is widely distributed and has caused severe problem in potato cultivation. Therefore, potato-growing areas were surveyed for identification and distribution of potato scab pathogens from 1996 to 1999. Pathogenic Streptomyces strains were isolated from potato scab lesions and six representative Streptomyces species were characterized based on their phenotypic and molecular characteristics including, pathogenicity, physiological and morphological properties, analyses of 16SrRNA genes and 16S-23S ITS region, DNA relatedness, production of thaxtomin A, and the presence of nec1 and ORFtnp gene homologs. Three species were identified as previously described Streptomyces scabies, S. turgidiscabies, and S. acidiscabies, while other three species having distinct phenotypics properties were identified as novel S. luridiscabiei, S. puniciscabiei, and S. niveiscabiei.