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Please use this identifier to cite or link to this item: http://hdl.handle.net/1942/17206

Title: The pH strongly influences the uranium-induced effects on the photosynthetic apparatus of Arabidopsis thaliana plants
Authors: SAENEN, Eline
HOREMANS, Nele
VANHOUDT, Nathalie
Varidenhove, Hildegarde
BIERMANS, Geert
Van Hees, May
Wannijn, Jean
VANGRONSVELD, Jaco
CUYPERS, Ann
Issue Date: 2014
Citation: PLANT PHYSIOLOGY AND BIOCHEMISTRY, 82, p. 254-261
Abstract: To study the impact of environmental uranium (U) contamination, effects should be analysed at different environmentally relevant pH levels as the speciation of U, and hence its toxicity, is strongly dependent on the pH. As photosynthesis is a major energy producing process in plants intimately connected to plant growth and known to be susceptible to metal stress, the effects of different U concentrations on photosynthesis in 18-day-old Arabidopsis thaliana (Columbia ecotype) are investigated at two contrasting pH levels, pH 4.5 and pH 7.5. At pH 4.5, U is highly taken up by the roots but is poorly translocated to the shoots, while at pH 7.5, less U is taken up but the translocation is higher. The lower U concentrations in the shoots at pH 4.5 are accompanied by a more reduced leaf growth as compared to pH 7.5. In addition, U does not influence the photosynthetic machinery at pH 7.5, while an optimization of the photosynthesis takes place after U exposure at pH 4.5. As such, more of the absorbed quanta are effectively used for photosynthesis accompanied by a decreased non-photochemical quenching and an increased electron transport rate. Since the enhanced photosynthesis at pH 4.5 is accompanied by a decreased growth, we suggest that the energy produced during photosynthesis is used for defence reactions against U-induced oxidative stress rather than for growth. As such, a high discrepancy was observed between the two pH levels, with an optimized photosynthetic apparatus at pH 4.5 and almost no effects at pH 7.5. (C) 2014 Published by Elsevier Masson SAS.
Notes: Saenen, E (reprint author), CEN SCK, Belgian Nucl Res Ctr, Biosphere Impact Studies, Boeretang 2000, B-2400 Mol, Belgium.eline.saenen@sckcen.be
URI: http://hdl.handle.net/1942/17206
DOI: 10.1016/j.plaphy.2014.06.012
ISI #: 000340698800029
ISSN: 0981-9428
Category: A1
Type: Journal Contribution
Validation: ecoom, 2015
Appears in Collections: Research publications

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