| Project/Area Number |
11460075
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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 |
林産学
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| Research Institution | Hokkaido University |
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Principal Investigator |
FUJIKAWA Seizo Hokkaido Univ., Grad. School of Agr., Prof., 大学院・農学研究科, 教授 (50091492)
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| Co-Investigator(Kenkyū-buntansha) |
FUNADA Ryo Hokkaido Univ, Grad. School of Agr., Asso. Prof., 大学院・農学研究科, 助教授 (20192734)
TAKEZAWA Daisuke Hokkaido Univ. Inst. of Low Temp. Sci., Lec., 低温科学研究所, 助手 (20281834)
ARAKAWA Keita Hokkaido Univ. Inst. of Low Temp. Sci., Lec., 低温科学研究所, 助手 (00241381)
SANO Yuzou Hokkaido Univ. Grad. School of Agr., Asso. Prof., 大学院・農学研究科, 助手 (90226043)
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| Project Period (FY) |
1999 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥11,800,000 (Direct Cost: ¥11,800,000)
Fiscal Year 2001: ¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 2000: ¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 1999: ¥7,100,000 (Direct Cost: ¥7,100,000)
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| Keywords | Cold adaptation / Freezing behavior / Cell wall / Deep supercooling / Extracellular freezing / Cold-induced proteins / Untifreeze proteins / Gene cloning / 木部放射柔細胞 / 凍結 / 細胞壁結合蛋白質 / シラカンバ / 電子顕微鏡 / 低温環境 |
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| Research Abstract |
This study concerned to cold temperature adaptation of woody plant cells with the relation to the cell wall properties. This study provided a new evidence by cryo-scanning electron microscopy that xylem parenchyma cells of all hardwood species with thick and rigid cell walls, including boreal hardwood species, responded to subfreezing temperatures by deep supercooling. The mechanism of deep supercooling in xylem parenchyma cells has been studied in previous works and hypothesized to be due to the smaller size of micro-capillaries in the cell walls. However, this study confirmed that there was no distinct change in capillary size of the cell walls between cells exhibiting extracellular freezing arid deep supercooling. This study provided a new evidence that degree of supercooling is distinctly reduced by extraction of soluble substances in xylem cell protoplasts, suggesting the accumulation of antifreeze substances, which might drastically promote deep supercooling. We are currently analyzing candidates of antifreeze proteins and cloning their genes. In addition to these studies, this study also concerned to freezing adaptation mechanisms of cortical parenchyma cells of woody plants, which had comparatively thin soft cell walls and adapted to subfreezing temperature by extracellular freezing. All these results revealed specific physiological response of woody plant cells to environmental stresses as well as suggested the possibility of industrial application of stress-induced proteins from woody plant cells.
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