1993 Fiscal Year Final Research Report Summary
Biochemical studies on dwarf-8 (D_8) seedlings of Zea mays L.
| Project/Area Number |
03454006
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
植物生理学
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| Research Institution | University of Tsukuba |
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Principal Investigator |
SAKAI Shingo University of Tsukuba, Institute of Biological Sciences, Associate Professor, 生物科学系, 助教授 (60033388)
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| Project Period (FY) |
1991 – 1993
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| Keywords | Zea mays L. / dwarf-8 / gibberellin / gibberellin-binding proteins |
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| Research Abstract |
Gibberellin-binding proteins (GBPs) were extracted from dark-grown maize seedlings of dwarf-8 (D_8) and its normal allele. The proteins were partially purified by affinity chormatography on GA_3-linked EAH-Sepharose 4B.On the basis of Scatchard plot analysis, GBPs from normal seedlings contained a high affinity component of Kd for GA_4 of o.3 uM.While the high affinity component was not detected in GBPs from D_8 seedlings but they contained a low affinity component of Kd of 13uM.The binding of H-GA_4 to GBPs from normal seedlings was inhibited by GA_1 and GA_3, but that from D_8 seedlings was weakly inhibited by GA_1 and GA_3. GA_<13>, an inactive GA, had no effect on the binding. When GBPs were separated by native-PAGE, it was clarified that the GBPs from D_8 seedlings lacked one component (GBP-3) which existed in the GBPs from normal seedlings. The GBP-3 was purified from normal seedlings. The molecular weight was estimated to be about 280,000 by gel filtration on Sephacryl S-300. It consisted of one subunit with molecular weight of 70,000. The dissociation constant for GA_4 was 0.5 uM.From these results, we considered that GBP-3 might be a candidate of a gibberellin receptor lacked in D_8 seedlings of Zea mays. To clarify the working hypothesis, we are studying cDNA clining of GBP-3 using an antibody made against GBP-3.
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