Uptake of selenium and its antioxidant activity in ryegrass when applied as selenate and selenite forms
Uptake of selenium and its antioxidant activity in ryegrass when applied as selenate and selenite forms
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DOI：
10.1007/s11104-005-5691-9
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发表时间：
2005-10-01
期刊：
影响因子：
4.9
通讯作者：
Mora, ML
中科院分区：
文献类型：
--
作者：
Cartes, P;Gianfreda, L;Mora, ML
硒（Se）是动物和人类营养中必需的微量元素，但它对植物是否必需仍有争议。然而，越来越多的实验证据表明，硒通过硒依赖性谷胱甘肽过氧化物酶（GSH-Px）活性对高等植物抗氧化胁迫具有保护作用。研究了硒化学形态、亚硒酸盐和硒酸盐及其施用量对黑麦草地上部硒浓度的影响及其对黑麦草抗氧化系统的影响。白羊座)，通过测量GSH-Px活性和脂质过氧化作用，在智利南部的Andisol中进行了评估。此外，还确定了土壤-植物硒的关系，并提出了一种从酸性土壤中提取有效硒的简便方法。在55 d的试验中，黑麦草种子在盆栽中播种，土壤分别用亚硒酸钠或硒酸钠（0 ~ 10 mg Se kg(-1)）处理。结果表明，施用亚硒酸盐和硒酸盐均能提高硒的含量。然而，硒处理植株的地上部硒含量最高。在两种硒源下，茎部硒浓度与GSH-Px活性均呈极显著正相关；该酶活性的硒依赖性主要与施硒的化学形式有关，而与植物组织中的硒浓度无关。此外，硫代巴比妥酸活性物质（TBARS）测定的脂质过氧化在低硒水平下下降，在植株中达到最低水平，约为20 mg Se kg(-1)，然后在此水平以上稳步上升。此外，用酸萃取法评价土壤有效硒的结果表明，无论施用何种化学形式的硒，土壤硒与地上部硒浓度均呈良好的正相关关系。
Selenium (Se) is an essential micronutrient for animal and human nutrition, but whether it is essential to plants remains controversial. However, there are increasing experimental evidences that indicate a protective role of Se against the oxidative stress in higher plants through Se-dependent glutathione peroxidase (GSH-Px) activity. The effects of the Se chemical forms, selenite and selenate, the rate of their application on shoot Se concentration and their influence on the antioxidative system of ryegrass (Lolium perenne cv. Aries), through the measurement of GSH-Px activity and lipid peroxidation, were evaluated in an Andisol of Southern Chile. Moreover, a soil-plant relationship for Se was determined and a simple method to extract available Se from acid soils is proposed. In a 55-day experiment ryegrass seeds were sown in pots and soil was treated with sodium selenite or sodium selenate (0-10 mg Se kg(-1)). The results showed that the Se concentration in shoots increased with the application of both selenite and selenate. However, the highest shoot Se concentrations were obtained in selenate-treated plants. For both sources of Se, there was a significant positive correlation between the shoot Se concentration and the GSH-Px activity; and the Se-dependence of this enzymatic activity was related especially with the chemical form of applied Se rather than the Se concentration in plant tissues. Furthermore, the lipid peroxidation, as measured by Thiobarbituric Acid Reactive Substances (TBARS), decreased at low levels of shoot Se concentration, reaching the lowest level at approximately 20 mg Se kg(-1) in plants and then increased steadily above this level. In addition, the acid extraction method used to evaluate available Se in soil showed a positive good correlation between soil Se and shoot Se concentrations irrespective of chemical form of Se applied.