| Project/Area Number |
62560059
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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 |
土壌・肥料
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| Research Institution | Faculty of Horticulture, Chiba University |
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Principal Investigator |
SHIMADA Noritsugu Faculty of Horticulture, Chiba University, 園芸学部, 教授 (10009318)
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| Co-Investigator(Kenkyū-buntansha) |
WATANABE Yukio Faculty of Horticulture, Chiba University, 園芸学部, 助教授 (90114347)
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| Project Period (FY) |
1987 – 1988
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| Project Status |
Completed (Fiscal Year 1988)
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| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1988: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1987: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Keywords | Physiological role of nickel / Urease / Urea amydolyase / Nickel tolerance / Serpentine soil / ニッケル過剰障害 / ニッケル / 水生植物 / 植物中のニッケル |
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| Research Abstract |
In order to investigate the physiological functions of nickel on growth and nitrogen metabolism in higher plants, activity of urease which contains nickel as a component was determined at different conditions. Cucumber plants were cultured in nutrient solution without nickel. Concentrated stock solutions of the macronutrient elements prepared with deionized water having at least 18 Mohm resistance were purified by chelating resin(Dowex A-1).
Urease activity was not determined in the cucumber leaves grown in nickel free nutrient solution. By addition of nickel to the nutrient solution, leaf urease activity developed with increases in temperature and in light intensity. Urease activity induced by addition of nickel was strongly inhibited in the preasence of protein biosynthesis inhibitor in light, but not in the dark.
Plants collected on serpentine soil containing high concentration of nickel showed higher urease activity than that of plants on basaltic soil. In the plants collected on serpentine soil, the destribution of nickel in Ophiopogon japonicus was 91% in root and 9% in shoot. This means that in this plant the tolerance for high concentration of nickel is accomplished by inhibition of transport to shoot.
All of plants examined showed only urease activity and urea amydolyase activity was not detected by the experiments using a specific inhibitor.
From those findings, it was suggested that hydrolysis of urea in higher plants depends upon urease. If urease is a sole enzyme which hydrolyzes urea in higher plants, urease and nickel may have an important role in the reutilization system of nitrogen.
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