Effects of pH on uranium uptake and oxidative stress responses induced in Arabidopsis thaliana

Eline Saenen, Nele Horemans, Nathalie Vanhoudt, Hildegarde Vandenhove, Geert Biermans, May Van Hees, Jean Wannijn, Jaco Vangronsveld, Ann Cuypers, Hans Vanmarcke

    Research outputpeer-review


    Since it is unknown how different U species determine U uptake and translocation within plants and how they might affect the oxidative defence mechanisms of these plants, this study aimed to analyse U uptake and oxidative stress related responses of different U species in Arabidopsis thaliana plants (Columbia ecotype). Eighteen-day-old seedlings were exposed for three days to 25 µM U in a Hoagland nutrient solution of which the pH was adjusted to 4.5, 5.5, 6.5 or 7.5. Results indicate that there is a different rate in U uptake and translocation at the different pHs, with high uptake and low translocation at low pH and lower uptake but higher translocation at high pH. After U exposure, an increased glutathione reductase activity and total glutathione concentration were observed in U-exposed roots, pointing towards an important role for glutathione in the root defence system against U either by chelation (phytochelatin production) or antioxidative defence mechanisms (cellular redox state). In the leaves, the antioxidative defence mechanisms were activated upon U exposure, indicated by an increased superoxide dismutase and catalase activity.
    Original languageEnglish
    Pages (from-to)2125-2133
    JournalEnvironmental Toxicology and Chemistry
    Issue number9
    StatePublished - Jun 2013

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