Cadmium-induced transcriptional and enzymatic alterations related to oxidative stress

• Published in: Environmental and experimental botany Vol. 63; no. 1; pp. 1 - 8
• Main Authors: Smeets, Karen, Ruytinx, Joske, Semane, Brahim, Van Belleghem, Frank, Remans, Tony, Van Sanden, Suzy, Vangronsveld, Jaco, Cuypers, Ann
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.05.2008; Oxford; New York, NY: Elsevier Science; Elsevier Science
• Subjects: antioxidant activity; Antioxidative defence; application rate; Arabidopsis thaliana; Biological and medical sciences; cadmium; Cadmium toxicity; Environmentally realistic metal concentrations; enzyme activity; Fundamental and applied biological sciences. Psychology; Gene expression; genes; hydrogen peroxide; leaves; lipoxygenase; messenger RNA; Oxidative stress; Physiological diseases. Varia; Phytopathology. Animal pests. Plant and forest protection; phytotoxicity; redox imbalance; redox potential; roots; superoxide anion; transcription (genetics); Arabidopsis thaliana; Oxidative stress; Gene expression; Antioxidative defence; Environmentally realistic metal concentrations; Cadmium toxicity; Cruciferae; Toxicity; Dicotyledones; Angiospermae; Spermatophyta
• ISSN: 0098-8472; 1873-7307
• DOI: 10.1016/j.envexpbot.2007.10.028

The early antioxidative defence mechanisms were studied in Arabidopsis thaliana by applying a range of realistic Cd concentrations. Our data suggest that a 24 h exposure to 20 μM CdSO 4 is already too toxic to study moderate toxicity, whereas a highly coordinated oxidative stress-related defence response could be observed after Cd application of 5 and 10 μM. Significant differences in transcript abundance of several genes involved in antioxidative defence were observed. The generation of superoxide seems the main cause of oxidative stress in the roots, whereas in the leaves hydrogen peroxide appears to be an important player. Furthermore, an increased transcript level of lipoxygenase, a potential inducer of oxidative stress, suggests a central role of this gene in causing the Cd-related redox imbalance. Our results show that Cd as a non-redox-active metal induces oxidative stress and indicate that the antioxidative defence system is moderated by the activation of different genes in different organs and cellular compartments.