| Project/Area Number |
01480009
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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 | (The Institute of Low Temparature Science) Hokkaido University |
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Principal Investigator |
YOSHIDA Shizuo Inst.Low Temp.Sci.Prof., 低温科学研究所, 教授 (90001651)
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| Co-Investigator(Kenkyū-buntansha) |
MAESHIMA M Inst.Low Temp.Sci.Assoc.Prof., 低温科学研究所, 助教授 (80181577)
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| Project Period (FY) |
1989 – 1990
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| Project Status |
Completed (Fiscal Year 1990)
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| Budget Amount *help |
¥5,900,000 (Direct Cost: ¥5,900,000)
Fiscal Year 1990: ¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 1989: ¥3,600,000 (Direct Cost: ¥3,600,000)
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| Keywords | Cold accclimation / Cold-induced proteins / Freezing tolerance mechanism / Plasma membrane proteins / 耐凍性機構 / 耐凍性 |
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| Research Abstract |
The objective of this study was to identify plasma membrane proteins which are specifically induced by cold acclimation in wheats (Triticum aestivum L.). Two cultivars with a marked difference in the genetic capability to harden, namely spring wheat13EA\ : (cv Chinese Spring) and winter wheat (cv Norstar) were used as the experimental materials. After four weeks of growth in a cold chamber, the freezing tolerance in the shoots of winter wheat increased to -18ﾟC, whereas only to -8ﾟC in the shoots of spring wheat. In roots from both cultivars, the freezing tolerance increased very slightly after the growth under the cold environment. Cold hardening induced remarkable changes in electrophoresis patterns of plasma membrane proteins depending on c13EA\ : ultivars and tissues. Polypeptides with molecular masses ranged from 22 to 31 kDa decreased commonly in the root and shoot plasma membranes from both cultivars. of these polypeptides, 28 and 26 kDa polypeptides decreased abrupty after one week of th13EA\ : e cold hardening. On the other hand, polypeptides with molecular masses of 89, 83, 23, 18 and 17 kDa increased specifically in the shoots of winter hardy wheat. The increases of the 23, 18 and 17 kDa polypeptides were proportional to the development13EA\ : of freezing tolerance. A freeze-fracture electronmicroscopy of plasma membranes from shoot cells revealed that the intramembrane particle number on the fracture faces decreased significantly in winter wheat after cold acclimation, but less in sprin13EA\ : g wheat. These results may suggest that the plasma membrane undergoes a molecular reorganization during cold acclimation in such manner that they are stabilized against freeze-induced dehydration stress.
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