| Project/Area Number |
11660046
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
植物保護
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| Research Institution | Tottori University |
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Principal Investigator |
MOTOICHIRO Kodama Tottori University, Faculty of Agriculture, Instructor, 農学部, 講師 (00183343)
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| Co-Investigator(Kenkyū-buntansha) |
OTANI Hiroshi Tottori University, Faculty of Agriculture, Professor, 工学部, 教授 (50032305)
KEISUKE Kohmoto Tottori University, Faculty of Agriculture, Professor, 農学部, 教授 (80032093)
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| Project Period (FY) |
1999 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥3,300,000 (Direct Cost: ¥3,300,000)
Fiscal Year 2000: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 1999: ¥1,900,000 (Direct Cost: ¥1,900,000)
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| Keywords | plant pathogen / host-specific toxin / AAL-toxin / AM-toxin / 病原シグナル因子 |
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| Research Abstract |
Alternaria alternata apple pathotype causes Alternaria blotch of susceptible apple cultivars through the production of a cyclic peptide host-specific toxin, AM-toxin. PCR, using primers designed to conserved domains of peptide synthetase genes, amplified several products from A.alternata apple pathotype which showed high similarity to other fungal peptide synthetases and were specific to the apple pathotype. Screening of a Lambda Zap genomic library with these PCR generated probes identified overlapping clones containing a complete cyclic peptide synthetase gene of 13.1-kb in length with no introns. Disruption of this gene, designated AM-toxin synthetase (AMT), by transformation of wild type A.alternata apple pathotype with disruption vectors resulted in toxin-minus mutants, which were also unable to cause disease symptoms on susceptible apple cultivars. AM-toxin synthetase is therefore a primary determinant of virulence and specificity in the A.alternata apple pathotype/apple interaction. On the other hand, A.alternata tomato pathotype causes Alternaria stem canker of tomato through the production of a polyketide host-specific toxin, AAL-toxin. PCR, using primers designed to conserved domains of polyketide synthetase genes, amplified a product from A.alternata tomato pathotype which showed high similarity to other fungal polyketide synthetases and was specific to the tomato pathotype. Disruption of this gene, designated AALPKS, by transformation of wild type A.alternata tomato pathotype with disruption vectors resulted in toxin-minus mutants, which were also unable to cause disease symptoms on susceptible tomato cultivars. The results indicate that both AM-and AAL-toxins are act as signaling facters for pathogenicity of these plant pathogens.
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