Interaction of zinc with uptake and translocation of cadmium in radish

Abstract

Physiological studies carried out with animal and human subjects indicate that Cd is a toxic metal. Chelates of Zn have been helpful in combating Cd toxicity. In view of the importance of preventing or impeding the ingestion of Cd through food crops by man, solution culture studies have been carried out to determine the possibility of similar interaction in plants. In a complete nutrient solution, concentrations of 2, 20 or 100 ppb Cd were combined with 20, 100 or 400 pb Zn. Radish plants were grown in uncontained and contained air. The latter condition was created by placing trays with plants inside plastic sacs kept continuously inflated with air of 100% relative humidity. The resulting difference in transpiration regimes caused no significant change in the Zn/Cd concentration ratio of the radish roots or leaves. Under both transpiration regimes, increasing concentrations of Zn suppressed Cd uptake at the two lower Cd concentrations in the solution. At the 100-ppb level of Cd, however, increasing amounts of Zn increased Cd uptake. This holds for both roots and leaves, and may indicate damage to the roots because of the Cd concentration of the solution. This increased Cd uptake, as well as the steep yieldmore » reduction caused by the addition of enough Zn to reduce Cd uptake significantly, limits the practical possibility of the approach investigated. 18 references, 6 tables.« less