| Project/Area Number |
05640739
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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 |
植物生理
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| Research Institution | Okazaki National Research Institute |
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Principal Investigator |
HAYASHI Hidenori Okazaki National Research Institute, National Institute for Basic Biology, Associate Professor, 基礎生物学研究所, 助教授 (60124682)
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| Project Period (FY) |
1993 – 1994
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| Project Status |
Completed (Fiscal Year 1994)
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| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1994: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1993: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Keywords | heat shock protein / chaperonine / stress response / cyanobacteria / thermo tolerance / gene manipulation |
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| Research Abstract |
Heat shock proteins (HSPs) are stress proteins which are induced by various environmental stresses. Some of them are known to act as molecular chaperones which assist in the correct folding of other polypeptides and their assembly. Plants have to acclimate to the environmental change to survive and maintain themselves alive since they can not escape from the unfovarite environments. So HSPs might play important roles on the stress response in plants. Very little is known about the role of HSPs in plants on the response to the environmental stresses although a huge number of data indicate the induction of HSPs by various stresses in plants. To examine the role of heat shock proteins in adaptation to high-temperature stress in cyanobacteria, we isolated the genes for the heat shock protein from one of the transformable cyanobacteria, Synechococcus PCC7002. Analyzes of nucleotide sequences demonstrated the existence of two groEL-homologous genes in a single species of cyanobacteria. Heat shock treatment increased the levels of both groEL-homologous gene mRNAs. However, two genes were not equivalent. For example one groEL-homologous gene was accompanied by the groES gene as in E.coli groEL,while the other was not. To understand the roles of GroEL homologs in adaptation to high-temperature stress in cyanobacteria, an insertional mutant of Synechococcus PCC7002 in which one of two groEL genes was interrupted by an antibiotic resistant gene cartridge was constructed and its thermal tolerance was analyzed. Analyzes of the viability of the groEL-disrupted mutant demonstrated that both groEL gene contributed to the heat-shock response. In addition, analyzes of the thermal tolerance of photosynthetic oxygen evolution suggested that the heat shock proteins, at least one of the groEL gene did not contribute to the acquisition of the thermal tolerance of photosynthesis.
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