Cadmium and copper genotoxicity in plants
Heavy metal contamination in soils is easily transmitted to human through plants via the food chain. A major concern is to understand the plant response to heavy metal soil contamination to develop phytoremediation. Two plant models have been investigated in our study, the tomato, which is of agronomical importance, Arabidopsis, which is used as a model for molecular genetics. Heavy metal toxicity is described to induce oxidative stress linked to oxidation of proteins and membrane lipids but also to alterations of DNA damage response. We have investigated the metabolic response of cadmium and copper in parallel in both plant models and analyzed the transcriptional response of Arabidopsis RNR genes coding for isoforms of ribonucleotide reductase, an essential enzyme involved in DNA synthesis. Both Cd and Cu had a dose-dependent effect on plant growth. We also observed a rapid increase of catalase activity upon Cd or Cu treatments in tomato and Arabidopsis. At the transcriptional level, treatment with Cd resulted in a biphasic induction of two RNR genes in Arabidopsis; the first induction peak could be paralleled to the increase of the catalase activity.
KeywordsHeavy Metal Ribonucleotide Reductase TBARS Content Heavy Metal Treatment Phytochelatin Synthesis
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