Physiological and genetic response of Arabidopsis thaliana to multiple stressors (R-1988)

Nuclear energy production encompasses a variety of industrial activities, from mining and milling through to power generation and waste management. These nuclear facilities release radioactive substances together with non-radioactive substances (e.g. heavy metals). Uranium and thorium and their decay chain daughter radionuclides are the radionuclides of primary interest released from uranium mines and mills and tailings management facilities. Although ecosystems are exposed to multiple stressors, effects induced in biota are generally studied under single stressor conditions. The effect of a single pollutant/stressor may, however, be affected by the presence of other contaminants/stressors. There is, therefore, a pressing need for testing multiple stressor effects in order to provide a confident basis for prediction of multiple stressor effects. The aim of this study is to assess the biological effects induced in the test plant Arabidopsis thaliana by bioaccumulation of uranium (238U) and thorium (232Th) alone or in combination. The influence of environmental conditions (eg. pH) on 238U and 232Th uptake and distribution in the plant and the resulting effects will be studied. A multi-biomarker approach will be used containing robust parameters such as growth and photosynthesis together with more subtle ones such as the presence of DNA damage, oxidative stress, metabolites and gene expression. The effects observed for both radionuclides will be compared with the effects induced by a more conventional pollutant (cadmium) or in a multiple stressor context. This information is important for assessing biological and environmental effects and related remediation actions for multipolluted sites.

Keywords:ARABIDOPSIS THALIANA, CADMIUM, ENVIRONMENTAL CONDITIONS, HEAVY METALS, MULTIPLE STRESSOR, OXIDATIVE STRESS, URANIUM

Disciplines:Biological sciences