Cadmium Toxicity Symptoms in Transgenic and Non Transgenic Plants.

Transformed soybean (35S-BIP2 e 35S-BIP4) plants were compared to a control prepared with non-transgenic plants (wild type). The seedlings were prepared in trays with substrate and 20 days after germination were transplanted to plastic recipients containing 4 L of nutrient solution at ¼ ionic strength. After one week the seedlings were transferred to a Clark original solution where they were grown by 8 days, after addition of Cd at the concentrations 0.0; 0.5; 1.0; 1.5; 2.0 mg/L as CdCl_2.H₂O. The pH was maintained at 6,0 ± 0,2 and the solutions continuously aerated. The trial was set as a 3×5 factorial (2 transgenic lines and 1 “wild” line, exposed to 5 Cd concentrations) with 4 replications, in a randomized block design with 60 experimental units. The soybean leaves of plants grown in treatments with higher Cd concentrations showed redness in the veins that was spread over the entire leaf in some treatments. It was observed differences among treatments which suggest that the transgenic soybean may deal better than the wild soybean as related to the tolerance to Cd.