Impact of nano CeO2 on plants and bacteria, from model organisms to a soil-microbe-plant ecosystem: the design of nanos matters
Wednesday, February 26, 2014
Catherine Santaella, Ph.D.
Laboratory of Microbial Ecology of the Rhizosphere and Extreme Environments
Institute of Plant Biology and Environmental Microbiology, iCEINT, GDRi and SERENADE LABEX, France
Abstract: Currently, the knowledge on the effects of nanmaterials (NMs) on plants and soil bacteria mainly come from exposure to high levels of NMs. We have no decisive evidence on the impact of environmental concentrations of NMs on plants, their uptake and their potential entry in human food. Furthermore, plants shape microbial community structure in the rhizosphere. Nevertheless, the effects of NMs on the microbiome of plant roots are still unexplored. Two pristine and a citrate-coated nanoCeO2, with different average particle sizes and surface reactivity were used to assess relationships between nano-design and impacts on a soil-plant-microbe ecosystem. The presentation will first address the response of model organisms such as the plant Arabidopsis thaliana, and the plant root-colonizing-bacterium Pseudomonas brassicearum to nano CeO2 using metabolomics, gene expression, and imaging. Then we will focus on the impacts of nanoCeO2 at an environmental concentration (1 mg/kg) on a soil-plant-microbe ecosystem in pocket mesocosms, impacts based on soil enzymatic activities, micronutrients uptake by the plant and alteration of the microbial community structure.