Résumé:
Copper is an essential trace element for the development of plants due to its importance role in the physiology of plants. But it is also a toxic heavy metal with high concentration. Some species grown on sites with high copper concentrations have developed protective mechanisms that will allow them to tolerate this excess metal. The aim of this work is to study the abilities of radish (Raphanus sativus) to decontaminate soils contaminated by copper. The study focuses on the exposure of radish plants (Raphanus sayivus) to copper at different doses (0, 400, 800, 1000 ppm) for two weeks just after one week of germination and five weeks of culture. Physiological analysis of exposure to copper showed inhibition of foliar and root elongation masses of fresh and dry matter of different organs of radish plants compared to controls and a decrease in foliar chlorophyll pigment content (chlorophyll a,b and total) relative to the controls. Water analysis of exposure to copper showed an increase in the relative water content (RWC) of radish plants compared to controls. While transpiration water loss (RWL) of radish plants decreases compared to controls. Biochemical analysis showed a rise in tatol protein levels of radish plants exposed to copper et different concentrations, compared to controls. Thes modified physiological, hydric and biochemical parameters suggest that copper induces stress in radish (Raphanus sayivus) during it growthcompared to controls, but radish has protective mechanisms that allow it to tolerate this exess in copper.
