impact of cadmium and zinc on root system of Lolium perenne and Trifolium repens

Lambrechts, Thomas [UCL] Lequeue, Gauthier [UCL] Lobet, Guillaume [UCL] Lutts, Stanley [UCL]

Urbanization, industrialization and agricultural practices have resulted in soil contamination with heavy metals in many world areas. Phytostabilisation is an emerging solution to limit pollutant dispersion out of the contaminated area without expensive costs. However, because of the heavy metal phytotoxicity, the implementation of a plant cover could be jeopardized. Therefore, we assessed the impact of Cd and Zn, 2 common metal pollutants, on the setting up of root system of 2 plant models, Lolium perenne and Trifolium repens. After 1 month of metal application, we measured the root mass, length and diameter according to the depth thanks to scanner and image analysis. These results were linked to root metal concentrations. We focused also on ultrastructural modifications by means of histochemical analyses and on quantification of structural polysaccharides and lignin through Van Soest global method and lignin staining. Drastic alterations of root system were highlighted, especially for Lolium perenne.