Biodegradable chelating agent ethylenediaminedisuccinic acid reduces uptake of copper through alleviation of copper toxicity in hydroponically grown Chrysanthemum coronarium L.

Hydroponic cultures were conducted to investigate the effects of the biodegradable chelating agent S,S-ethylenediamine-disuccinic acid (EDDS) on the growth and copper uptake by garland chrysanthemum (Chrysanthemum coronarium L.), a plant species sensitive to soil chelate amendment. In the presence of 50 μmol/L Cu, the addition of EDDS increased shoot and root biomass and the vitality of cells in root tips and decreased the relative electrolyte leakage of root cells and the concentration of Cu in shoots. When the roots were pretreated with 65°C hot water for 0.5 to 2 h or with 0.001 to 0.1 mol/L HCl for 24 h before the exposure to 50 μmol/L Cu + 100 μmol/L EDDS, the concentration of Cu in shoots increased considerably compared with the plants without any pretreatment. A statistically significant correlation was found between the Cu concentrations in shoots and the relative electrolyte leakage of root cells. These results indicated that Cu-EDDS might be a less bioavailable form to plants and that some physiological damage to the roots led to enhanced accumulation of Cu in plant shoots.