Inhibitory effects of reactive X-3B red dye (RRD) on iron uptake by three crops.

Previous field investigations and a pot-culture experiment treated with 0, 5, 10, and 20 mg kg^-1 of reactive X-3B red dye (RRD), combined with chemical and statistical analyses, indicated that the amount of iron accumulated in seeds of soybean (Glycine max) and rice (Oryza sativa) and edible parts of watermelon (Citrullus Vulgaris Schrad) decreased with the increase in the amount of RRD added to various soils including burozem, aquorizem and krasnozem. There were significant negative relationships between the uptake of iron by the crops and the concentration of RRD added to the soils. Thus, chemical pollution of some organic dyes in agricultural soils may result in the deficiency of iron in crops. According to the extraction with 1.0 M NH₄OAc solution and the determination of enzyme activity, the adverse effect inhibiting the uptake of iron in crops was chemical chelation and immobilization of iron with RRD. The activity of iron reductase was also greatly affected. [ABSTRACT FROM AUTHOR]