Profiling of main metabolites in root exudates and mucilage collected from maize submitted to cadmium stress.

The aim of this study was to characterize qualitatively and quantitatively the composition of the main rhizodeposits emitted from maize (Zea mays) under Cd stress, in order to discuss their role in Cd availability and tolerance. Maize was grown for 6 weeks in sand at four Cd exposure levels (0, 10, 20, and 40 μM Cd in nutrient solution) and two types of rhizodeposits were collected at the end of cultivation period. Mucilage and other molecules adhering to rhizospheric sand were extracted with a buffer before root exudates were collected by diffusion into water.