Relations Between Cadmium Accumulation and Organic Acids in Roots Exudation of Zea Mays L.

The influence of Cadmium(Cd) on exudation of low molecular weight organic acids (LMWOAs) were investigated based on the hydroponic culture experiment. Tartaric, citric, malic, and acetic acids were chosen as representatives of LMWOAs commonly present in roots exudation. We investigated the Cadmium accumulation in Zea Mays L.. In particular, the relationship of exudation of LMWOAs by roots with Cd accumulation in Zea Mays L. were also investigated. The results showed that under the different levels of Cd, the exudation of four organic acids by roots had the different change trend. The concentrations of four organic acids in roots exudation were in the same following sequence tartaric>citric>malic>acetic. And the content of Cd in plants increased with increasing Cd concentrations. Cd accumulation in plants had significant (P<;0.05 or P<;0.01) positive correlations with exudation of citric, tartaric and acetic acids.