A novel phytoextraction strategy based on harvesting the dead leaves: Cadmium distribution and chelator regulations among leaves of tall fescue

Abstract

The treatment of large amount of hazardous plant residues from phytoextraction is costly and has been a burden for the society. This experiment was designed to evaluate the possibility of cadmium (Cd) phytoextraction by harvesting the dead leaves instead of the whole plant in tall fescue (Festuca arundinacea). Results showed that Cd was preferentially distributed in the senescent and dead leaves. EDTA, DTPA and EGTA enhanced Cd accumulations in the dead leaves which could be associated to the increase of the water-soluble inorganic Cd and Cd-organic acid complexes in shoots. The dead leaves were only 12.6-16.3% of the total shoot biomass but accumulated 73.4-87.2% of the total shoot Cd. The results indicate that a novel strategy of Cd phytoextraction based on harvesting the dead leaves is feasible to save the high treatment cost of hazardous plant residues while maintaining the acceptable phytoextraction efficiency.

Keywords: Cadmium; Chelating agent; Dead leaf; Phytoextraction; Tall fescue.