Differential expression and regulation of antioxidative enzymes by cadmium in pea plants

• Published in: Journal of plant physiology 2007-10, Vol.164 (10), p.1346-1357
• Main Authors: Romero-Puertas, María C., Corpas, Francisco J., Rodríguez-Serrano, María, Gómez, Manuel, del Río, Luis A., Sandalio, Luisa M.
• Format: Article
• Language: English
• Subjects: antioxidant activity; Antioxidants; Antioxidants - metabolism; ascorbate peroxidase; ascorbic acid; Biological and medical sciences; Cadmium; Cadmium - pharmacology; catalase; Cell physiology; enzyme activity; Fundamental and applied biological sciences. Psychology; gene expression regulation; Gene Expression Regulation, Plant - drug effects; glutathione; glutathione reductase (NADPH); heavy metals; messenger RNA; Molecular and cellular biology; monodehydroascorbate reductase; Oxidative stress; peas; physiological response; phytotoxicity; Pisum sativum; Pisum sativum - drug effects; Pisum sativum - enzymology; Pisum sativum - genetics; plant biochemistry; Plant Proteins - metabolism; plant response; plant stress; protein content; ROS; Signal Transduction; soil pollution; superoxide dismutase; transcription (genetics)
• ISSN: 0176-1617; 1618-1328
• DOI: 10.1016/j.jplph.2006.06.018

The long-term effects of 50 μM 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 2O 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.