1998 Fiscal Year Final Research Report Summary
Response to high temperature stress and enhancement of high temperature tolerance in plants studies with psychrophilic bacteria and algae
| Project/Area Number |
08554034
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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 | 展開研究 |
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| Research Field |
植物生理
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| Research Institution | Ehime University |
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Principal Investigator |
HAYASHI Hidenori Ehime University Faculty of Science Professor, 理学部, 教授 (60124682)
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| Co-Investigator(Kenkyū-buntansha) |
OKUYAMA Hidetoshi Hokkaido University・Graduate School for Environmental Earth Science Associate Professor, 大学院・地球環境科学研究科, 助教授 (90125295)
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| Project Period (FY) |
1996 – 1998
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| Keywords | heat tolerance / high-temperature stress / gene manipulation / heat shock protein / psychrophilic algae / cyanobacteria |
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| Research Abstract |
Plants in the natural habitat suffer from the temperature stress, daily, monthly, and yearly fluctuation of temperature. High temperature causes denaturation of proteins in the cells, causing inactivation of important physiological processes and fatal damage. To tolerate these temperature stresses, plants develop a variety of acclimating systems, such as enhancement of heat tolerance of photosynthesis. Production of heat shock proteins. Etc. To understand the responsible mechanisms to high temperature and produce heat tolerant plant by gene manipulation, we carried out the following experiments : 1) screening of proteins which denature at rather low temperature and would helpful to induce heat shock proteins under normal temperature, 2) cloning of heat shock proteins from psychrophilic bacteria which would be expressed under normal or lower temperature 3) introduction of a gene for the chloroplasts-localized small heat shock protein to cyanobacteria to enhance their high temperature tolerance.
Some enzymes in psychrophilic bacteria are inactivated at 40-50℃ like those of organisms living under normal temperature, but a ribosomal protein from Prymnesiophyte showed low homology to those of other plants and expected to be cold labile, being useful for induction of heat shock proteins when introduced into normal plants.
Cloning of heat shock proteins from psychrophilic bacteria demonstrated amino acid sequence is homologous to those from normal bacteria and it contains nucleotide sequence similar to that in promoter sequence. Indicating psychrophilic bacteria has similar function against high temperature stress, although it is much lower than that for normal bacteria.
The expression of Hsp21 resulted in acquisition of thermotolerance in cyanobacteria, especially against lethal high temperature. The results indicates the possibility of enhancement of high temperature tolerance with the gene engineering of heat shock proteins.
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