Lycopersicon esculentum submitted to Cd-stressful conditions in nutrition solution: Nutrient contents and translocation

The increasing number of cases on soil contamination by heavy metals has affected crop yields, besides representing an imminent risk to food. Some of these contaminants, such as cadmium, are very similar to micronutrients and thus more easily absorbed by the plants. This study assessed the effect of increasing amounts of cadmium on the content and translocation of micro and macronutrients in tomato. Tomatoes were grown in Clark's nutrient solution and subjected to increasing levels of Cd: 0, 0.025, 0.1, 0.5 and 1.0 mg L−1. The plants contaminated by cadmium had a maximum reduction in the aerial part compared to the control of: 2.25 g kg−1, 2.80 g kg−1, 18.93 mg kg−1 and 14.15 mg kg−1 for K, Ca, Mn and Zn, respectively. In other parts of the tomato were reduced from 2.3 g kg−1 K in fruits and 280.5 mg kg−1 of Mn in the roots. In addition to changes in the levels of some nutrients, the restricted Cd translocation in 1.15percent P and 2.8percent Cu to shoots compared to control, but did not affect the translocation of K, Ca, Mg and Zn.

► The toxic effect of Cd is related to their deposition on the roots, due to the formation of stable chelates.
► The presence of Cd reduces the contents of K, Ca, Mn and Zn in the aerial part.
► The presence of Cd reduces the contents of K in fruit and Mn in roots.