| Project/Area Number |
10660059
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Plant nutrition/Soil science
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| Research Institution | Shizuoka Univ. |
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Principal Investigator |
KUBOI Toru Shizuoka Univ., Agr. Fac., Prof., 農学部, 教授 (20132847)
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| Co-Investigator(Kenkyū-buntansha) |
HARA M Shizuoka Univ., Agr. Fac., Assist., 農学部, 助手 (10293614)
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| Project Period (FY) |
1998 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 2001: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2000: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1999: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1998: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Keywords | higher plant / active oxygen / heavy metal / carrot / Cd / 解毒システム / クロストレランス / カドミウム / SOD / 相互耐性 |
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| Research Abstract |
The purpose of this study is to characterize the Cd tolerance mechanisms on carrot (Daucus carota L.) cells using a two carrot cell lines, non-tolerant (CW) and Cd tolerant (CCd1) cells. Both cells were pretreated with 20-80 μM Cd for 1 day and transferred to a Cd-free medium. The CCd1 cells in all the pretreatments continuously excluded Cd over a 4-day period, unlike the CW cells. Therefore, a larger depletion of Cd was found in the CCd1 cells, which may be partially attributed to Cd tolerance. However a high capacity for Cd exclusion cannot fully account for the Cd tolerance of the CCd1 cells. Hence, other mechanism of Cd detoxification should exist in the CCd1 cells. Under Cd stress, the contents of phytochelatins (PCs) of the CW cells were higher than those of the CCd1 cells. The ascorbate/glutathione cycle in the CW and CCd1 cells showed different responses against Cd. The activity of ascorbate peroxidase in the CW and CCd1 cells decreased by 80-160 and 160 μM Cd, respectively. After Cd treatment, the activity of glutathione reductase in the CW cells decreased drastically ; whereas, the activity in the CCd1 cells increased. The content of ascorbate in both cells decreased by Cd treatment, but that in the CCd1 cells was more than CW cells and recovered with increasing time. Cd tolerance in the CCd1 cells may be related to active ascorbate/glutathione cycle. From these results, new mechanism of Cd tolerance was clarified. The CCd1 cells strengthened the natural Cd tolerance-mechanism of the CW cells. Cd tolerance of carrot cells is related to exclusion of Cd and antioxidative defense system, particularly, ascorbate/glutathione cycle.
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