| Project/Area Number |
63540529
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
植物生理学
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| Research Institution | Toyama Medical and Pharmaceutical University |
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Principal Investigator |
NISHI Arasuke Toyama Med. & Pharmaceut. University, Fac. of Pharmaceut. Sci., Professor, 薬学部, 教授 (50019098)
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| Project Period (FY) |
1988 – 1990
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| Project Status |
Completed (Fiscal Year 1990)
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| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1990: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1989: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1988: ¥1,000,000 (Direct Cost: ¥1,000,000)
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| Keywords | Stress compound / Carrot / Elicitor / Phytoalexin / Chitinase / bateー1, 3-Glucanase / 6ーメトキシメレイン / βー1,3ーグルカナ-ゼ / 6-メトキシメレイン / β-1,3-グルカナ-ゼ / キチナーゼ / エリシター |
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| Research Abstract |
Carrot cells accumulate isocoumarin phytoalexin 6-methoxymellein when they are challenged by microorganisms. The synthesis of this compound was also elicited by oligouronides or ethylene. Cell-free extract from elicitor-treated carrot roots catalyzed NADPH-dependent synthesis of 6-hydroxyーmellein from acetyl-CoA and malonyl-CoA which was further converted to 6-methoxymellein by a specific O-methyltransferase. In the absence of NADPH, triacetic acid lactone was produced as a derailment product of the reaction. This finding suggests that the NADPH-dependent reduction takes place at the triacetate stage before the condensation of the third malonyl-CoA. Besides phytoalexin, carrot cells produced chitinasa sa a response to fungal infection. This process was elicited by various fungal components and also by ethylene. Cells accumulated many isoforms of the enzyme according to the elicitor applied to them. All the enzymes induced by various fungal components were found to be endoーchitinase while ethylene induced the production of exoーhydrolases which released chitobiose from insoluble chitin. Carrot beta-1,3-glucanse was mainly localized in cellーwall fraction. The enzymes were purified to apparent homoginity and characterized. The carrot cells contained 2 isoenzymes : both of which were glycoproteins with a similar molecular size. Unlike tobacco plants, however, teh beta-1,3-glucanase in carrot cells seem to be constitutive and was not affected by various external stresses.
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