Abstract:To improve the phytoextraction capacity of Cd hyperaccumulotor Sedum plumbizicola, pot experiments were done to investigate the effects of the chelating agent ethylenediaminetetraacetic acid (EDTA) and the plant hormone abscisic acid (ABA) on the growth and Cd transport of Sedum plumbizicola and verified by field experiment. The results of pot experiments showed that the foliar spraying EDTA and ABA could promote the transport of Cd by Sedum plumbizicola, and the transport coefficient of Cd from underground part to aboveground part was EDTA > ABA. But foliar application of EDTA inhibit the growth of Sedum plumbizicola. The concentrations of Cd in different tissues of Sedum plumbizicola varied greatly, with new leaves > roots > stems > old leaves. The concentration of Cd in the new leaves was 3.6~5.4 times of that in old leaves, and the majority was enriched in the cell wall and organelle fraction, accounting for 88%~94% of the total. EDTA treatment caused a sharp increase in the proportion of Cd allocated to organelles, and ABA, on the contrary, greatly increased the proportion of Cd distributed in the cell wall of new leaves. The combination of ABA and EDTA could alleviate the inhibition of growth by EDTA, and could be conducive to the Cd transportation from root to aboveground.. Field experiment verified that the enhanced phytoextraction of Sedum plumbizicola in Cd contaminated soil based on the foliar application of ABA and EDTA was feasible. The combination of ABA and EDTA treatment significantly increased the total Cd accumulation of Sedum plumbizicola by 37.87%. The results provide theoretical guidance for strengthening the remediation of Cd contaminated soil by Sedum plumbizicola.