| Project/Area Number |
17580038
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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 |
Plant pathology
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| Research Institution | Tokyo University of Agriculture and Technology |
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Principal Investigator |
NYUNOYA Hiroshi Tokyo University of Agriculture and Technology, Gene Research Center, Professor, 遺伝子実験施設, 教授 (60135936)
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| Co-Investigator(Kenkyū-buntansha) |
KASAHARA Masahiro Ritsumeikan University, College of Science and Engineering, Assistant Professor, 理工学部, 助教授 (70361748)
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| Project Period (FY) |
2005 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥3,400,000 (Direct Cost: ¥3,400,000)
Fiscal Year 2006: ¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 2005: ¥1,700,000 (Direct Cost: ¥1,700,000)
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| Keywords | Tobacco Mosaic Virus / Resistance Gene / N Gene / Cell Death / Hellcase Domain / TIR / NBS / LRR |
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| Research Abstract |
The resistance gene N for Tobacco mosaic virus induces hypersensitive response (HR)-mediated cell death, which leads to enclosure of virus inside infected host cells to protect the whole plant. To clarify the function of N gene, we cloned and analyzed many N-like cDNAs and showed that these cDNAs can be divided into 4 groups based on the sequence similarity. We have selected two cDNAs (HL-C26, NL-B69) as representative clones to isolate each full-length cDNAs. The whole sequences revealed that NL-C26 and NL-B69 belong to TIR-NBS-LRR class and have 78 and 73% amino acid identity to N gene product. We constructed chimeric cDNAs by replacing N gene domains with responding domains from N-like genes and introduced the chimeric cDNAs into N. tabacum cv. Samsun nn leaves with the helicase domain p50 of the virus replicase. From this approach, the chimeric constructs with TIR from NL-C26 or NL-B69 and those with NBS from NL-B69 induced clear HR. In contrast, the chimeric constructs with LRR from NL-C26 or NL-B69 did not induce HR. Consequently, the TIR domains from NL-C26 or NL-B69 and the NBS domain from NL-B69 may have functionally important amino acid sequences. In addition, the LRR domain from N gene is indispensable for HR induction. The finding of N-like gene with functional domains is unique and leads us to the establishment of HR induction system by using transient expression of N cDNA.
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