| Project/Area Number |
15370015
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
植物生理・分子
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| Research Institution | HOKKAIDO UNIVERSITY |
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Principal Investigator |
TANAKA Ayumi HOKKAIDO Univ., Institute of Low Temperature Science, Prof., 低温科学研究所, 教授 (10197402)
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| Co-Investigator(Kenkyū-buntansha) |
TANAKA Ryouichi HOKKAIDO Univ., Institute of Low Temperature Science, Assistant Prof., 低温科学研究所, 助手 (20311516)
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| Project Period (FY) |
2003 – 2005
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| Project Status |
Completed (Fiscal Year 2005)
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| Budget Amount *help |
¥15,100,000 (Direct Cost: ¥15,100,000)
Fiscal Year 2005: ¥5,200,000 (Direct Cost: ¥5,200,000)
Fiscal Year 2004: ¥4,800,000 (Direct Cost: ¥4,800,000)
Fiscal Year 2003: ¥5,100,000 (Direct Cost: ¥5,100,000)
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| Keywords | Chlorophyll / Photosynthesis / Metabolism / Chloroplast / 光エネルギー / 発育 |
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| Research Abstract |
Recently, significant progress has also been made toward elucidating the linkages between chlorophyll metabolism and other cellular processes including leaf senescence, programmed cell death, and plastid signaling. The purpose of the present research is to complete chlorophyll metabolic pathway and to identify all the genes involved in the pathway. Chlorophyll metabolism has been extensively studied with various organisms and almost all of the chlorophyll biosynthetic genes have been identified in higher plants. However, only the gene for 3, 8-divinyl protochlorophyllide a 8-vinyl reductase (DVR), which is indispensable for the photosynthetic organisms to produce monovinylchlorophyll or dinvinyl chlorophyll, has not been identified yet. In this study, we isolated an Arabidopsis mutant that accumulated divinyl chlorophyll instead of monovinyl chlorophyll by ethyl-methane sulfonate mutagenesis. Map-based cloning ofthis mutant resulted in the identification of a gene (At5g18660) that shows sequence similarity with isoflavon reductase genes. The mutant phenotype was complemented by the transformation with the wild-type gene. A recombinant protein encoded by At5g18660 was expressed in E.coli and found to catalyze the conversion of divinyl chlorophyllide to monovinyl chlorophyllide ; thereby indicating that the gene encodes a functional DVR. DVR is encoded by a single-copy gene in the Arabidopsis genome. With the identification of DVR, finally all genes required for chlorophyll biosynthesis have been identified in higher plants. Analysis of the complete genome of Arabidopsis showed that it has 15 enzymes encoded by 27 genes for chlorophyll biosynthesis from 3 glutamyl-tRNAglu to chlorophyll b.
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