Cadmium and copper toxicity for tomato seedlings

We studied cadmium ( Cd) and copper ( Cu) toxicity in tomato, their accumulation in plant organs and their ability to induce phytochelatin synthesis. The seedlings were cultivated in nutrient solution supplemented with increased concentrations of CdCl2 or CuSO4 from 0 to 50 mu M. After 7 days of treatment, plants were harvested and the dry weight, the amount of thiobarbituric acid-reactive substances ( TBARS), Cd and Cu contents and SH groups rich peptides were determined. We found that Cd and Cu decrease tomato growth, notably at high Cu levels. Cd and Cu concentrations in plant organs increased with applied amounts. Cd and Cu concentrations were the highest in roots. The amount of thiobarbituric acid-reactive substances, that estimate the lipid peroxidation, was increased with heavy metal exposure and was, mainly, higher in roots with Cu treatment.