1995 Fiscal Year Final Research Report Summary
A biochemical role of galactolipase in the metabolic pathway of linolenic acid in higher plants.
| Project/Area Number |
06640849
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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
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| Research Institution | HOKKAIDO TOKAI UNIVERSITY |
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Principal Investigator |
SAKAKI Takeshi HOKKAIDO TOKAI UNIVERSITY,DEPARTMENT OF BIOSCIENCE AND TECHNOLOGY,ASSOCIATE PROFESSOR, 工学部, 助教授 (70124344)
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| Co-Investigator(Kenkyū-buntansha) |
YAMADA Mitsuhiro HOKKAIDO TOKAI UNIVERSITY,DEPARTMENT OF BIOSCIENCE AND TECHNOLOGY,PROFESSOR, 工学部, 教授 (50012266)
ARIGA Hiroyoshi HOKKAIDO UNIVERSITY,FACULTY OF PHARMACEUTICAL SCIENCES,PROFESSOR, 薬学部, 教授 (20143505)
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| Project Period (FY) |
1994 – 1995
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| Keywords | Galactolipase / Galactolipids / Linolenic-acid metabolism / Environmental stresses / Jasmonic acid / Kidney bean leaves |
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| Research Abstract |
In plants, linolenic acid is partly metabolized to several important compounds, such as jasmonic acid and traumatic acid. In this project, we have tried to determine whether or not galactolipase participates in this metabolism via supplying the substrate, linolenic acid, from membrane lipids. The results obtained are as follows :
1. In addition to galactolipase associated with chloroplast membranes, we purified, in this project, a soluble type of galactolipase from kidney bean leaves. The purified protein showed a single polypeptide of 53 kDa after SDS-PAGE.Comparison of the molecular weight and several enzymic properties shows that the soluble and membrane-bound galactolipases are different, i.e., isozymes.
2. An attempt to isolate galactolipase cDNA clones using polyclonal antiserum from the libraries constructed from kidney bean leaves and from cultured cells of soybean has not succeeded yet. We are now trying to select epitope-specific antibody using immobilized proteins expressed be several clones. Preliminary experiments show that the antibody selected by a clone inhibits galactolipase, suggesting that the clone encodes galactolipase.
3. We examined a relationship of specific activities between lipoxygenase, a key enzyme of linolenic-acid metabolism, and galactolipase in nine kidney bean cultivars. We found positive correlation between them, suggesting the involvement of galactolipase in the metabolism. In addition, we could detect jasmonic acid in plant tissues using HPLC after several purification steps. Next, we will try to examine relations between the galactolipase activity and the production of jasmonic acid in plants.
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