Changes of Essential Mineral Elements Contents in Response to Cu2+ Treatment in Sagittaria sagittifolia

Changes of various mineral elements (P, K, Ca, Mg, Fe, Mn, Zn and Na) contents in roots and leaves of S. sagittifolia were studied with treatment of different Cu2+ concentrations (5 μM, 10 μM, 20 μM and 40 μM) after 15 days. The results showed that: 1) Cu accumulated in roots of S. sagittifolia in large quantities, while Cu content in leaves showed no significant change; 2) It can be seen from the changes of macroelements that Cu2+ treatments had inhibited the absorption of P, K, Ca, Mg in roots of S. sagittifolia, but the contents of P, K and Mg in leaves were higher than those in the roots in all Cu2+ treatment groups; 3) It can be seen from the changes of microelements that Cu2+ treatment promoted the absorption of Fe, inhibited absorption of Mn, Zn and Na in roots of S. sagittifolia, and hindered the transport of various microelements from roots to leaves. In all the Cu2+ treatment groups, contents of Fe, Mn, Zn and Na in leaves were lower than those in the roots; 4) The critical concentration of Cu2+ to S. sagittifolia was 5 μM. It could be seen from the above results that exogenous added Cu2+ of different concentrations broke the balance of various mineral elements in S. sagittifolia, which would exert a significant impact on numerous metabolic pathways and physiological processes.