Romero-Puertas M C, McCarthy I, Sandalio L M, Palma J M, Corpas F J, Gómez M, del Río L A
Departamento de Bioquímica, Biología Celular y Molecular de Plantas, Estación Experimental del Zaidín, CSIC, Granada, Spain.
Free Radic Res. 1999 Dec;31 Suppl:S25-31. doi: 10.1080/10715769900301281.
The effect of growing pea plants with 50 microM CdCl2 on the activated oxygen metabolism was studied at subcellular level in peroxisomes isolated from pea leaves. Cadmium treatment produced proliferation of peroxisomes as well as an increase in the content of H2O2 in peroxisomes from pea leaves, but in peroxisomal membranes no significant effect on the NADH-dependent O2*- production was observed. The rate of lipid peroxidation of membranes was slightly decreased in peroxisomes from Cd-treated plants. This could be due to the Cd-induced increase in the activity of some antioxidative enzymes involved in H2O2 removal, mainly ascorbate peroxidase and glutathione reductase, as well as the NADP-dependent dehydrogenases present in these organelles. The activity of xanthine oxidase did not experiment changes by Cd treatment and this suggests that O2*- production in the peroxisomal matrix is not involved in Cd toxicity. This was supported by the absence of changes in plants treated with Cd in the Mn-SOD activity, responsible for O2*- removal in the peroxisomal matrix. Results obtained indicate that toxic Cd levels induce imbalances in the activated oxygen metabolism of pea leaf peroxisomes, but its main effect is an enhancement of the H2O2 concentration of these organelles. Peroxisomes respond to Cd toxicity by increasing the activity of antioxidative enzymes involved in the ascorbate-glutathione cycle and the NADP-dependent dehydrogenases located in these organelles.
在从豌豆叶片分离的过氧化物酶体的亚细胞水平上，研究了用50微摩尔氯化镉培养豌豆植株对活性氧代谢的影响。镉处理导致豌豆叶片过氧化物酶体增殖以及过氧化物酶体中过氧化氢含量增加，但在过氧化物酶体膜上，未观察到对依赖NADH的超氧阴离子产生有显著影响。镉处理植株的过氧化物酶体中膜脂过氧化速率略有降低。这可能是由于镉诱导参与过氧化氢清除的一些抗氧化酶活性增加，主要是抗坏血酸过氧化物酶和谷胱甘肽还原酶，以及这些细胞器中存在的依赖NADP的脱氢酶。镉处理未使黄嘌呤氧化酶活性发生变化，这表明过氧化物酶体基质中的超氧阴离子产生与镉毒性无关。这一点得到了镉处理植株中负责过氧化物酶体基质中超氧阴离子清除的锰超氧化物歧化酶活性未发生变化的支持。所得结果表明，有毒镉水平会导致豌豆叶片过氧化物酶体活性氧代谢失衡，但其主要影响是提高这些细胞器中的过氧化氢浓度。过氧化物酶体通过增加参与抗坏血酸-谷胱甘肽循环的抗氧化酶以及这些细胞器中依赖NADP的脱氢酶的活性来应对镉毒性。
