Stress Induced by Heavy Metals Cd and Pb in Bean (Phaseolus Vulgaris L.) Grown in Nutrient Solution

Abstract

The increasing number of cases of soil contamination by heavy metals has affected crop yields, and represents an imminent risk to food. Some of these contaminants, such as cadmium (Cd) and lead (Pb), are very similar to micronutrients, and thus can be absorbed by plants. This study evaluated the translocation of increasing amounts of cadmium and lead and the effects of these metals in the production of beans. Bean plants were grown in nutrient solution Clark and subjected to increasing levels of Cd (from 0 to 0.5 mg L⁻¹) and Pb (from 0 to 10 mg L⁻¹). Cadmium concentration of 0.1 mg L⁻¹ translocated 39.8% to the shoot, and dry matter production was reduced by 45% in shoots and 80% in roots, compared to the control treatment. Lead showed impaired movement in the plant, however the concentration of 1.0 mg L⁻¹ was observed in 5.7% of metal translocation to the leaves. The concentration of 10 mg L⁻¹ Pb reduced dry matter production of roots and shoots in 83% and 76%, respectively, compared to the control treatment.

Keywords:

• cadmium
• lead
• nutritive solution
• Phaseolus vulgaris L