Selenium as an anti-oxidant and pro-oxidant in ryegrass
Selenium as an anti-oxidant and pro-oxidant in ryegrass
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DOI：
10.1023/a:1026512921026
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发表时间：
2000-01-01
期刊：
影响因子：
4.9
通讯作者：
Piironen, V
中科院分区：
文献类型：
--
作者：
Hartikainen, H;Xue, TL;Piironen, V
硒是人和动物体内抗氧化反应的必需元素。为了研究硒在高等植物中的生物学作用，在不含硒的土壤中或添加不同剂量的H_2SeO_4（0.1，1.0，10.0和30.0 mg Se·kg ~（-1））的土壤中种植了黑麦草。收获两次黑麦草，并分析产量的抗氧化系统和生长参数。硒具有双重作用：在低浓度下，它作为一种抗氧化剂，抑制脂质过氧化，而在较高浓度下，它是一种促氧化剂，增强脂质过氧化产物的积累。抗氧化作用与谷胱甘肽过氧化物酶（GSH-Px）活性的增加有关，但与超氧化物歧化酶（SOD）和α-生育酚无关，α-生育酚是唯一检测到的生育酚。在第二产量中，由于适当的硒添加减少脂质过氧化作用与促进植物生长相一致。当硒添加水平大于或等于10 mg kg（-1）时，氧化胁迫导致产量急剧下降。这一结果表明，硒的毒性可以归因于，除了代谢紊乱，其促氧化作用。无论是生长促进或毒性作用的硒可以解释的总叶绿素浓度的变化。
Selenium is an essential element for antioxidation reactions in human and animals. In order to study its biological role in higher plants, ryegrass ( Lolium perenne) was cultivated in a soil without Se or amended with increasing dosages of H2SeO4 (0.1, 1.0, 10.0 and 30.0 mg Se kg(-1)). Ryegrass was harvested twice and the yields were analyzed for antioxidative systems and growth parameters. Selenium exerted dual effects: At low concentrations it acted as an antioxidant, inhibiting lipid peroxidation, whereas at higher concentrations, it was a pro-oxidant, enhancing the accumulation of lipid peroxidation products. The antioxidative effect was associated with an increase in glutathione peroxidase (GSH-Px) activity, but not with superoxide dismutase (SOD) and alpha -tocopherol, which was the only tocopherol detected. In the second yield, the diminished lipid peroxidation due to a proper Se addition coincided with promoted plant growth. The oxidative stress found at the Se addition level greater than or equal to 10 mg kg(-1) resulted in drastic yield losses. This result indicates that the toxicity of Se can be attributed, in addition to metabolic disturbances, to its pro-oxidative effects. Neither the growth-promoting nor the toxic effect of Se could be explained by the changes in the total chlorophyll concentration.