| Project/Area Number |
08459003
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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 |
広領域
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| Research Institution | Institute of Biological Sciences, University of Tsukuba |
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Principal Investigator |
KAMADA Hiroshi Institute of Biological Sciences, University of Tsukuba, Professor, 生物学科系, 教授 (00169608)
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| Project Period (FY) |
1996 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥7,400,000 (Direct Cost: ¥7,400,000)
Fiscal Year 1998: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1997: ¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1996: ¥4,400,000 (Direct Cost: ¥4,400,000)
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| Keywords | Carrot / Arabidopsis / Somatic embryos / Zygotic embryos / Abscisic acid / Desiccation tolerance / Signal transduction / Regulation of gene expression / C-ABI3遺伝子 / 遺伝子発現制御 |
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| Research Abstract |
It is thought that seed desiccation tolerance is induced by maternally produced abscisic acid (ABA) through accumulation of Lea proteins of which the expression is controlled by ABI3/VP1 factor, a mediator of ABA signal transduction. However, the molecular mechanisms of the ABA-induced seed desiccation tolerance remains to be clarified, because it is very difficult to collect zygotic embryos at the same developmental stages. Then, I had investigated to clarify the mechanisms using carrot somatic embryos, because we can easily collect many embryos at the same developmental stages. At first, I clarified that somatic embryos acquire strong desiccation tolerance by exgenously appied ABA.Next, I had cloned a carrot gene (C-ABI3) homologous to ABI3/VP1 gene and examined the expression pattern. C-ABI3 showed embryo-specific expression in both somatic and zygotic embryos. The expression in carrot seeds was observed prior to the transient increase of endogenous ABA in the seeds. Furthermore, I had produced transgenic carrot plants and cultured cells in which C-ABI3 was expressed in the leaves or cells. Using these plants and cultured cells treated with ABA, I had examined the expression pattern of carrot ECP genes, the expression being embryo-specific and ABA-inducible and belonging to Lea gene family. The results showed that the expression of some ECP genes was observed in ABA-treated leaves and cells, but not in ABA non-treated ones and non-transformed ones irrespective of ABA treatment. Moreover, ABA-treated transgenic cultured cells showed clearly, desiccation tolerance. These results indicate that C-ABI3 is an embryo-specific transcription factor and that seed desiccation tolerance is acquired by ABA-inducibIe expression of ECP genes and accumulation of ECP proteins which are controlled by C-ABI3 factor as a mediator of ABA signal transduciton.
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