| Project/Area Number |
03660065
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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 |
土壌・肥料
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| Research Institution | The University of Tokyo |
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Principal Investigator |
NISHIZAWA Naoko The Univ. of Tokyo Agriculture assistant, 農学部, 助手 (70156066)
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| Co-Investigator(Kenkyū-buntansha) |
MORI Satoshi The Univ. of Tokyo, Agriculture associate professor, 農学部, 助教授 (90011915)
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| Project Period (FY) |
1991 – 1992
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| Project Status |
Completed (Fiscal Year 1992)
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| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1992: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1991: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Keywords | Mugineic Acid / Nicotianamine / Iron-deficiency stress / Barley / オオムギ根 |
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| Research Abstract |
Fe-deficiency induces the biosynthesis of mugineic acid family phytosiderophores (MAs) in graminaceous plants. Using a cell free system derived from root tips of iron deficient barley, we clarified the biosynthetic pathway of deoxymugineic acid (DMA) from methionine in vitro [ Methionine S-adenosyl methionine Nicotianamine(NA) (3"-ketoform) DMA].
In order to isolate the genes encoding the biosynthetic enzymes of MAs, we tried to purify the enzymes which synthesize nicotianamine from SAM (NA synthase) and unidentified 3"-ketoform from NA. They were partially purified by using hydrophobic chromatography, gel filtration, ion exchange, and native electrophoresis.
The characteristics of both enzymes clarified until now are as fallows.
1. Biosynthetic activity of both processes were markedly induced by iron deficiency stress.
2. Both enzymes show the same optimum PH (9).
3. Molecular weight of NA synthase is 40-50KD.
4. The enzyme synthesizing 3"-ketoform needs 2-oxoglutarate and pyridoxal phosphate (PLP) as a cofactor, and its molecular weight is about 80KD.
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