1991 Fiscal Year Final Research Report Summary
Molecular demonstration of genic difference of isozymes induced by regular development and wounding.
| Project/Area Number |
01480011
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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 | Nagoya University |
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Principal Investigator |
IMASEKI Hidemasa Nagoya U., Agr. Sci., Professor, 農学部, 教授 (90023431)
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| Co-Investigator(Kenkyū-buntansha) |
YAMAZAKI Ken'ichi Nagoya U., Agr. Sci., Res. Ass., 農学部, 助手 (40182480)
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| Project Period (FY) |
1989 – 1991
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| Keywords | Ethylene biosynthesis / Wound-induced gene / Auxin-induced gene / ACC synthase / Isozymes / cDNA cloning / Stimulus-specific expression of genes |
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| Research Abstract |
The rate of ethylene production in higher plants frequently changes by various stimuli. 1-aminocyclopropane-1-carboxylate (ACC) synthase is the rate-limiting enzyme of ethylene biosynthesis, and is induced by auxin action, tissue wounding or during fruit ripening. The objective of this research is demonstrate that ACC synthase is consisted of isozymes and the isozymes are encoded by genes expressed differentially by different stimuli.
Wound-induced ACC synthase was purified to homogeneity from mechanically wounded fruits of winter squash(Cucurbita maxima), and the anitobodies : against the Purified enzyme were used to clone a CDNA(CMW33). CMW33 directed synthesis of active enzyme in E. coli and its nucleotide sequence was determined. The gene forethe wound-induced enzyme was expressed only after ; tissue wounding.
Since CMW33 sequence did, not hybridize with mRNA7induced by auxin, anxin-induced ACC synthase was purified and its partial amino acid sequences were determined. Oligonucleotides synthesized according to the amino acid sequence were used to clone a cDNA (CmA101) for the auxin-induced enzyme from winter squash. CMA101 also directed synthesis of active enzyme in E. coli. The nucleotide sequence of CMA101 was significantly different from that of CMW33 except seven regions highly conserved in their amino acid sequences. The gene corresponding to CMA101 was expressed by auxin action not by wounding. Similar isozyme genes were found in tomato. Tomato contained three different genes for ACC synthase ; these genes are expressed by auxin, wounding and during fruit ripening, respectively.
It was demonstrated by this research that ACC synthase isozymes were encoded in different genes which are expressed specifically by different stimuli.
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