title: The combined effect of uranium and gamma radiation on biological responses and oxidative stress induced in Arabidopsis thaliana.
abstract: Uranium never occurs as a single pollutant in the environment, but always in combination with other stressors such as ionizing radiation. As effects induced by multiple contaminants can differ markedly from the effects induced by the individual stressors, this multiple pollution context should not be neglected. In this study, effects on growth, nutrient uptake and oxidative stress induced by the single stressors uranium and gamma radiation are compared with the effects induced by the combination of both stressors. By doing this, we aim to better understand the effects induced by the combined stressors but also to get more insight in stressor-specific response mechanisms. Eighteen-day-old Arabidopsis thaliana seedlings were exposed for 3 days to 10 muM uranium and 3.5 Gy gamma radiation. Gamma radiation interfered with uranium uptake, resulting in decreased uranium concentrations in the roots, but with higher transport to the leaves. This resulted in a better root growth but increased leaf lipid peroxidation. For the other endpoints studied, effects under combined exposure were mostly determined by uranium presence and only limited influenced by gamma presence. Furthermore, an important role is suggested for CAT1/2/3 gene expression under uranium and mixed stressor conditions in the leaves.
authors.affiliation: Belgian Nuclear Research Centre, Biosphere Impact Studies, Boeretang, Belgium. nvanhoud@sckcen.be
authors.forename: Nathalie
authors.initials: N
authors.lastname: Vanhoudt
authors.forename: Hildegarde
authors.initials: H
authors.lastname: Vandenhove
authors.forename: Nele
authors.initials: N
authors.lastname: Horemans
authors.forename: Jean
authors.initials: J
authors.lastname: Wannijn
authors.forename: May
authors.initials: M
authors.lastname: Van Hees
authors.forename: Jaco
authors.initials: J
authors.lastname: Vangronsveld
authors.forename: Ann
authors.initials: A
authors.lastname: Cuypers
mesh_terms: D000975:Antioxidants / Q000378:metabolism; D017360:Arabidopsis / Q000254:growth & development / Q000502:physiology / Q000528:radiation effects*; D029681:Arabidopsis Proteins / Q000378:metabolism; D005720:Gamma Rays; D015227:Lipid Peroxidation / Q000528:radiation effects; D018384:Oxidative Stress; D018515:Plant Leaves / Q000378:metabolism / Q000528:radiation effects; D018517:Plant Roots / Q000378:metabolism / Q000528:radiation effects; D012333:RNA, Messenger / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D036226:Seedlings / Q000502:physiology / Q000528:radiation effects; D013482:Superoxide Dismutase / Q000378:metabolism; D014501:Uranium
chemical_list: D000975:Antioxidants; D029681:Arabidopsis Proteins; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; D014501:Uranium; D013482:Superoxide Dismutase