Distribution And Translocation Of Rare Earth Elements In Horseradish

In this study, horseradish was used as experiment-material. The distribution and translocation of 141Ce were qualitatively and quantitatively investigated for the first time by radioisotope tracer techniques, concomitantly, the influence of rare earth elements (REEs) on the uptake of nutrition in horseradish and the effect of REEs on some physiological and biochemical index in horseradish were studied. It can provide a foundation for understanding the regulating mechanism of REEs on plant growth, environmental toxicology and food safety.The main results obtained are as follows:1. 141Ce (III) could be absorbed by horseradish and translocated with time;2. The contents of REE in horseradish different organs are increased with the increase in the REE treatment, the distribution of REE in horseradish follows the order of leaf >leafstalk > root when REEs were supplied on the foliage; the content of Ce(III) in soil is increased with the increase in the Ce(III) treatment, the content of Ce(III) in the topsoil is higher than that in the subsoil; however the content of Tb(III) in the topsoil is lower than that of the subsoil;3. The low concentration solution of Ce(III) can improve the uptake of macronutrient( K, Ca, Mg) and mineral elements(Cu, Fe, Mn) of horseradish in different growth stages, meanwhile, the low concentration of Ce(III) can inhibit the uptake of heavy metal elements(Cd, Pb, Cr), the damage of heavy metal elements to plant can be reduced; while the higher concentration of Ce(III) or Tb(III) can inhibit the uptake of macronutrient and mineral elements of horseradish in different growth stages, and the concentrations of heavy metal elements are increased in horseradish, such a behaviour and character of higher concentration Ce(III) or Tb(III) are similar to the heavy metal element;4. The growth indexes of horseradish at different growth stages can be improved by the low concentration of Ce(III), while with increasing of Ce(III) concentration the toxicity effects of Ce(III) on horseradish growth were shown, indicating that the effect of light rare earth element Ce(III) on the physiological and biochemical index of horseradish is shown the"hormesis"effect. After the treatment of the heavy rare earth element Tb(III), the effect of Tb(III) on the growth index of horseradish at different growth stages are all toxicity effect. In addition, at the period of growth bloom, the effect of rare earth element on horseradish is the most effective.