Silicon induced cadmium tolerance of rice seedlings

Cadmium (Cd2+) toxicity and effects of silicon (Si) applications on the cellular and intracellular accumulations and distributions of Cd were investigated by conventional electron microscopy and EDX analysis. The Si-deprived rice (Oryza sativa L.) plants (-Si) differ greatly from Si-replete ones in cell walls and vacuoles distributions of Ca in their leaves and roots. Energy dispersive x-ray microanalysis revealed that considerable amounts of Cd could be detected in the cytoplasm, vacuole or cellular organelles in -Si rice plants, while very little to be found in +Si ones. From the nanochemical and nanobiological points of views, cell wall templates mediated the formation of colloidal silica with the high specific adsorption property to prevent the uptake of Cd into the cell.