| Project/Area Number |
08456170
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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 |
Applied molecular and cellular biology
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| Research Institution | Nagoya University |
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Principal Investigator |
SASAKI Yukiko Nagoya University, Graduate School of Bioagricultural Sciences, Professor, 農学部, 教授 (00026519)
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| Project Period (FY) |
1996 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥7,000,000 (Direct Cost: ¥7,000,000)
Fiscal Year 1997: ¥3,100,000 (Direct Cost: ¥3,100,000)
Fiscal Year 1996: ¥3,900,000 (Direct Cost: ¥3,900,000)
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| Keywords | acetyl-CoA carboxylase / pea / fatty acid synthesis / light activation |
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| Research Abstract |
Most plants have two forms of acetyl-CoA carboxylase, the prokaryotic and the eukaryotic forms. Major site of fatty acid synthesis in plants is plastids, where the prokaryotic forms of acetyl-CoA carboxylase and fatty acid synthetase are located. Cytosol has the eukaryotic form of acetyl-CoA carboxylase, but it is not known that fatty acid synthetase is located in cytosol. The objective of this research is to show the gene of eukaryotic form of fatty acid synthetase in plants. I planned to clone the gene using PCR.The primers were selected using the database of the gene from yeasts and animals. Just a little sequence homology was found. Using the sequence PCR was tried. But I can not get any DNA fragments from pea. Probably, plants lost the eukaryotic form of fatty acid synthetase. So, it seems likely that plants do not have the eukaryotic forms of fatty-acid synthesis apparatus.
Plants synthesize seed oil during seed development. I surveyed which acetyl-CoA carboxylase is abundant during the development. Results indicated that the prokaryotic, plastidic acetyl-CoA carboxylase is abundant. Probably plants synthesize fatty acids using plastidic enzyme.
During these experiments I found a link between light and fatty acid synthesis in chloroplasts. This is an answer to 15-years-old question. In chloroplasts fatty acid synthesis is stimulated by light. The reason has not known. I found that plastidic acetyl-CoA carboxylase is activated by reduction. The reducing power comes from light and is transmitted by a signal transduction pathway that Buchanan had characterized. Light is accepted by photosystem I and decompose water, and electron is produced. The electron reduces ferredoxin. The reduced ferredoxin reduces thioredoxin. The reduced thioredoxin reduces acetyl-CoA carboxylase, and activates the enzyme. The results show the reason why fatty acid synthesis in plants coordinates with photosynthesis.
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