Effects of Oxygen Stress on ^1H-NMR Relaxation Time (T_1) of Vigna radiata Seedling

• 井上 眞理

  九州大学大学院生物資源環境科学研究科農業植物科学講座

• 吉村 和久

  九州大学大学院理学研究科凝縮系科学専攻集合系分子化学講座

• 大坪 繭子

  九州大学大学院生物資源環境科学研究科農業植物科学講座

• 山崎 秀雄

  琉球大学理学部

抄録

Effects of the oxygen exposure on plallts were investigated in intact hypocotyl tissues of etiolated seedlings from mung bean (Vigna radiata L.). We report here that spin-lattice NMR relaxation time (T_1) of water proton of intact tissues, which can be measured with a 180°-τ-90° pulse sequence at 20 MHz, is responsible to the oxygen exposure. When the tissues placed in the NMR tube were exposed to 95% oxygen for 5s, a rapid decrease in the T_1 values and a subsequent relaxation process were observed. The value was fully recovered to the initial one during a 40min incubation. Heat-denatured tissues did not show such recovery response, suggesting that the T_1 recovery requires heat-sensitive components contained in the tissues. To examine a possibility that scavenging activities of oxygen radicals is involved in the mechanism for the T_1 response, errects of supplemental scavengers were tested. We have found that the shortening of T_1 induced by oxygen exposure to membrane fractions was strongly suppressed by the radical scavenger superoxide dismutase (SOD), Tiron and aseorbate. These results suggest that activities of O_2 production in the tissues are involved in the mechanism for abrupt shortening of T.

収録刊行物

• Journal of the Faculty of Agriculture, Kyushu University

  Journal of the Faculty of Agriculture, Kyushu University 44 (3/4), 249-256, 2000-02

  九州大学大学院農学研究院

キーワード

• Free radical
• Mung bean (Vigna radiata)
• NMR relaxation time (T_1)
• Paramagnetic substance
• Superoxide

詳細情報

• CRID: 1390009224684026624
• NII論文ID: 110000018018
• NII書誌ID: AA00247166
• DOI: 10.5109/24325
• HANDLE: 2324/24325
• ISSN: 00236152
• 本文言語コード: en
• データソース種別:
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  • IRDB
  • Crossref
  • CiNii Articles