Unraveling uranium induced oxidative stress related responses in Arabidopsis thaliana seedlings. Part I: responses in the roots

Nathalie Vanhoudt, Hildegarde Vandenhove, Nele Horemans, Tony Remans, Kelly Opdenakker, Karen Smeets, Daniel Martinez Bello, Jean Wannijn, May Van Hees, Jaco Vangronsveld, Ann Cuypers

    Research outputpeer-review


    This study aimed to investigate oxidative stress related responses in Arabidopsis thaliana exposed to uranium concentrations ranging from 0.1 to 100 µM for 1, 3 and 7 days. Results are reported separately for roots and leaves in two papers. Results of Part I indicate that oxidative stress related responses in the roots were only triggered following exposure to the highest uranium concentration of 100 µM. A fast oxidative burst was suggested based on the observed enhancement of lipoxygenase (LOX1) and respiratory burst oxydase homolog (RBOHD) transcript levels already after 1 day. The first line of defense was attributed to superoxide dismutase (SOD), also triggered from the first day. The enhanced SOD-capacity observed at protein level corresponded with an enhanced expression of iron SOD (FSD1) located in the plastids. For the detoxification of H2O2, an early increase in catalase (CAT1) transcript levels was observed while peroxidase capacities were enhanced at the later stage of 3 days. Although the ascorbate peroxidase capacity and gene expression (APX1) increased, the ascorbate/dehydroascorbate redox balance was completely disrupted and shifted towards the oxidized form. This disrupted balance could not be inverted by the glutathione part of the cycle although the glutathione redox balance could be maintained.
    Original languageEnglish
    Pages (from-to)630-637
    JournalJournal of environmental radioactivity
    Issue number6
    StatePublished - Mar 2011

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