1991 Fiscal Year Final Research Report Summary
Spore Attachment Mechanism of Reproductive Cells in Seaweeds, Especially on the Autoinhibitory Substance Against Spore Attachment of Red Algae
| Project/Area Number |
02640532
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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 |
植物形態・分類学
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| Research Institution | Hokkaido University |
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Principal Investigator |
TATEWAKI Masakazu Hokkaido University, Faculty of Science, Professor, 理学部, 教授 (50000881)
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| Co-Investigator(Kenkyū-buntansha) |
SUZUKI Minoru Hokkaido University, Faculty of Science, Associate Professor, 理学部, 助教授 (30000855)
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| Project Period (FY) |
1990 – 1991
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| Keywords | Red algae / Allelopathy / Allelochemical / Autoinhibitory substance / Unsaturated fatty acid / Icosapentaenoic acid / Octadecatetraenoic acid |
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| Research Abstract |
1)It was confirmed that many red algae produce some autoinhibitory substances against their own spore attachment to the substratum nearby when the mother plant is releasing the spore.
2) Production of such extracellular active substances were prepared as solutions from secretion or decoction of mother plants of each species. These solutions inhibited the spore attachment and germination not only in its own species but also in other species. Depending upon various concentrations, these solutions killed the spares and on the contrary, stimulated the further development of germlings.
This phenomenon is the so-called " allelopathy".
3)The allelochemicals were indicated to function as an inhibitory or stimulatory substance for the growth of seaweeds. They were species specific and also have something in common among various species.
4)An active compound was isolated from methanol extracts of red alga Neodilsea yendoana by high performance liquid chromatography(HPLC)combined with mass spectrometry. This compound was identified as 5, 8, 11, 14, 17-icosapentaenoic acid and the same was isolated from other four species of red algae. Further another compound from five species of brown algae was isolated successively and identified as 6, 9, 12, 15-octadecatetraenoic acid. These unsaturated fatty acids also inhibited the spore attachment and gerstances secreted from red and brown algae examined.
This suggests that there is an allelopathic environment and various allelopathic interactions take place in the sea. The allelochemicals play a very important role as inhibitors or stimulators for the growth of seaweeds growing on the rocky shore.
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