Romero-Puertas María C, Corpas Francisco J, Rodríguez-Serrano María, Gómez Manuel, Del Río Luis A, Sandalio Luisa M
Departamento de Bioquímica, Biología Celular y Molecular de Plantas, Estación Experimental del Zaidín, CSIC, Apartado 419, E-18080 Granada, Spain.
J Plant Physiol. 2007 Oct;164(10):1346-57. doi: 10.1016/j.jplph.2006.06.018. Epub 2006 Oct 30.
The long-term effects of 50 microM CdCl(2) on the enzymatic and non-enzymatic antioxidative defences of pea (Pisum sativum L.) plants was studied in terms of activity, protein content and transcripts levels. Cadmium caused a reduction of the total glutathione content (GSH+GSSG), with the reduced form of glutathione (GSH) being most affected. The content of ascorbic acid (ASC) was also decreased by the treatment. The transcript levels of catalase (CAT) and monodehydroascorbate reductase (MDHAR) showed a Cd-dependent increase, although CAT activity and its protein content were depressed, which suggests a posttranslational modification of this protein induced by cadmium. Glutathione reductase (GR), and ascorbate peroxidase (APX) did not change significantly, either in activity or accumulation of transcript. However, cadmium treatment provoked a strong reduction in mRNA, protein level and activity of CuZn-superoxide dismutase (SOD), being the most negatively affected antioxidative enzyme, and in less extent of Mn-SOD. Transcriptome analysis of the antioxidative enzymes in leaves of pea plants grown with cadmium and treated with some modulators of the signal transduction cascade suggested that at least Ca(2+) channels, phosphorylation/dephosphorylation processes, nitric oxide, cGMP, salicylic acid (SA) and H(2)O(2) were involved in some steps between the cadmium signal and transcript expression of CuZn-SOD, CAT and MDHAR. This indicated the existence of cross-talk between these elements and reactive oxygen species (ROS) metabolism during cadmium stress.
研究了50微摩尔氯化镉（CdCl₂）对豌豆（Pisum sativum L.）植株酶促和非酶促抗氧化防御的长期影响，涉及活性、蛋白质含量和转录水平。镉导致总谷胱甘肽含量（GSH + GSSG）降低，其中还原型谷胱甘肽（GSH）受影响最大。处理还降低了抗坏血酸（ASC）的含量。过氧化氢酶（CAT）和单脱氢抗坏血酸还原酶（MDHAR）的转录水平呈现出镉依赖性增加，尽管CAT活性及其蛋白质含量降低，这表明镉诱导了该蛋白质的翻译后修饰。谷胱甘肽还原酶（GR）和抗坏血酸过氧化物酶（APX）的活性或转录积累均无显著变化。然而，镉处理导致铜锌超氧化物歧化酶（SOD）的mRNA、蛋白质水平和活性大幅降低，SOD是受影响最严重的抗氧化酶，锰超氧化物歧化酶（Mn-SOD）受影响程度较小。对镉处理的豌豆植株叶片中抗氧化酶的转录组分析表明，在镉信号与铜锌超氧化物歧化酶、过氧化氢酶和单脱氢抗坏血酸还原酶的转录表达之间的某些步骤中，至少钙（Ca²⁺）通道、磷酸化/去磷酸化过程、一氧化氮、环鸟苷酸、水杨酸（SA）和过氧化氢（H₂O₂）参与其中。这表明在镉胁迫期间，这些元素与活性氧（ROS）代谢之间存在相互作用。
