Impact of U(VI) on the metabolism of plant cells as a function of the U(VI) concentration: An isothermal microcalorimetric and spectroscopic study


Impact of U(VI) on the metabolism of plant cells as a function of the U(VI) concentration: An isothermal microcalorimetric and spectroscopic study

Sachs, S.; Fahmy, K.; Oertel, J.; Geipel, G.; Bok, F.

Knowledge of the radionuclide transfer in the environment up to the food chain is the basis for a reliable safety assessment of potential nuclear waste disposal sites as well as for the evaluation of suitable remediation measures for radioactively contaminated areas, e.g., NORM sites. The uptake of radionuclides by plants is often described by transfer factors. To improve the knowledge of the underlying processes, the interactions of plants with radionuclides, e.g., uranium, are investigated on a molecular level (e.g., Günther et al., 2003, Laurette et al., 2012, Geipel and Viehweger, 2015). We studied the interaction of U(VI) with canola cells (Brassica napus) and focused on the concentration-dependent influence of U(VI) on the cell metabolism. Isothermal microcalorimetry was used as an extremely sensitive tool to monitor the metabolic heat flow of the cells in the absence and presence of U(VI). The cell viability was studied using the MTT test (Mosmann, 1983). The speciation of U(VI) in the nutrient medium was determined by time-resolved laser-induced fluorescence spectroscopy (TRLFS) and thermodynamic modeling to correlate the impact of U(VI) on the cell metabolism with its speciation.
Isothermal microcalorimetry is a highly sensitive monitor of the concentration and probably speciation-dependent U(VI) toxicity in plant cells. The metabolic response of the cells correlates very well with their mitochondrial activities. This opens possibilities to distinguish between chemo- and radiotoxic effects of U(VI) in calorimetric experiments.

Keywords: Plants; metabolism; uranium; isothermal microcalorimetry; TRLFS; thermodynamic modeling

  • Contribution to proceedings
    4th International Conference on Radioecology and Environmental Radioactivity, 03.-08.09.2017, Berlin, Germany, 978-2-9545237-7-4
  • Poster
    4th International Conference on Radioecology and Environmental Radioactivity, 03.-08.09.2017, Berlin, Germany

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Publ.-Id: 25192