Copper toxicity in expanding leaves of Phaseolus vulgaris L.: antioxidant enzyme response and nutrient element uptake
Copper toxicity in expanding leaves of Phaseolus vulgaris L.: antioxidant enzyme response and nutrient element uptake
复制标题
DOI：
10.1016/j.ecoenv.2010.05.014
复制
发表时间：
2010-09-01
影响因子：
6.8
通讯作者：
El Ferjani, Ezzeddine
中科院分区：
文献类型：
--
作者：
Bouazizi, Houda;Jouili, Hager;El Ferjani, Ezzeddine
研究了14日龄豆苗膨大叶片中铜（CuSO4）的生物积累和毒性。在生长培养基中添加CuSO4 3 d，测定愈创木酚过氧化物酶（GPX）和过氧化氢酶（CAT）抗氧化酶活性、H2O2产量和矿质元素含量的变化。铜在暴露植株上的积累引起了严重的症状，如黄化和坏死以及干重产量的急剧下降。同时，铁、锌和钾的浓度显著降低，表明营养平衡的变化可能是观察到的症状的原因。与成熟组织相反，膨胀叶片没有表现出明显的氧化应激，因为丙二醛（MDA）含量不变，GPX和CAT活性降低或不变，内源H2O2仅在高铜浓度下增加。我们的研究结果表明，虽然过量的铜会轻微地改变豆科植物幼芽膨大叶片中抗氧化酶系统的活性，但它的毒性主要是通过引起营养平衡的紊乱来发挥的。(C) 2010爱思唯尔公司版权所有。
Bioaccumulation and toxicity of copper (CuSO4) were assessed in expanding leaves of 14-day-old bean seedlings. CuSO4 was administrated in the growth medium for three days and changes in the activities of the antioxidant enzymes guaiacol peroxidase (GPX) and catalase (CAT), and in the H2O2 production and mineral element contents were measured. Copper accumulated in exposed plants caused severe symptoms such as chlorosis and necrosis as well as a dramatic reduction in dry weight production. Simultaneously, concentrations of iron, zinc and potassium were reduced significantly suggesting that a change in nutrient homeostasis may be responsible for the observed symptoms. Contrary to mature tissues, the expanding leaves did not display significant oxidative stress, since malondialdehyde (MDA) content was unchanged, the activities of GPX and CAT were lowered or unaltered, and endogenous H2O2 only increased at high copper concentrations. Our results suggest that while excess copper slightly alters the activity of the antioxidative enzyme system in young expanding leaves of bean plants, it exerts its toxicity primarily through causing a disturbance in the nutrient balance. (C) 2010 Elsevier Inc. All rights reserved.