| Project/Area Number |
09660121
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Bioproduction chemistry/Bioorganic chemistry
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| Research Institution | The Institute of Physical and Chemical Research (RIKEN) |
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Principal Investigator |
ASAMI Tadao RIKEN,Plant Functions Labratory, Senior Scientist, 植物機能研究室, 先任研究員 (90231901)
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| Co-Investigator(Kenkyū-buntansha) |
NAKANO Takeshi RIKEN,Plant Functions Labratory, Scientist, 植物機能研究室, 研究員 (30281653)
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| Project Period (FY) |
1997 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥2,900,000 (Direct Cost: ¥2,900,000)
Fiscal Year 1998: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1997: ¥2,200,000 (Direct Cost: ¥2,200,000)
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| Keywords | abscisic acid / gibberellin / receptor / aleurone cell / amylase / protoplast / 液胞 / 細胞膜 / 植物ホルモン / アリューロン細胞 / 蛍光標識 / シグナル伝達 / cGMP |
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| Research Abstract |
Identification of the site where plant hormones are perceived at the cellular level is an essential step towards the isolation and identification of the receptors themselves. For such a purpose aleurone cells of barley seeds provide an ideal biological system because they respond to both gibberellin (GA) or abscisic acid (ABA) in a direct and easily detectable way. In order to study the perception of these two hormones by aleurone protoplasts in a real time mode, we prepared and used fluorescence-labeled bioactive GA (FGA) or ABA (FABA). The most important point in introducing fluorescence functional group into GA or ABA molecules is to keep the intrinsic activity of the plant hormones. Finally FABA and FGA could be prepared and subjected to the next experiments. The binding of FABA or FGA_4 to aleurone protoplasts was analyzed with a flowcytometer. The result showed that FABA or FGA_4 bind to protoplasts and while the binding of FABA was quenched to some extent by the addition of ABA, the binding of FGA_4 to protoplasts was not quenched by the addition of GA_3. Fluorescein itself, which was the fluorescence-bearing functional group of both FABA and FGA_4, did not bind to cells, i.e., the ABA part in FABA molecule and the GA part in FGA4 molecule play a determinant role for the binding. Analysis with a cell scan type microscope suggested that the FABA was on the plasma membranes even 60 minutes after the treatment, whereas FGA_4 was readily incorporated into cytosol. This result is consistent with that obtained by flowcytometry. The method described above for analyzing the binding of FABA or FGA_4 to receptors will make it possible to detect a desensitization or an appearance and disappearance of receptors depending on the conditions where aleurone protoplasts exist.
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