水保所知识产出(1956---)知识库

(S,S)-ethylenediaminedisuccinic acid (EDDS) has a strong capacity to mobilize potentially toxic elements
(PTEs) in phytoextraction. It can release NH 4
þ -N via biodegradation, which can enhance N supply to soil
thereafter promote plant growth and plant resistance to PTEs. However, the advanced feature of released
N in the EDDS-enhanced phytoextraction remains unclear. In the current study, the effects of N supply
released from EDDS on ryegrass phytoextraction and plant resistance to PTEs were investigated in detail
by a comparison with urea. Our results supported that the addition of both EDDS and urea increased N
concentration in soil solution, yet EDDS needed more time to release available N for plant uptake and
transported more N from root to shoot. Additionally, EDDS significantly increased the concentration of all
targeted PTEs, i.e. Cu, Zn, Cd, and Pb, in the soil solution, which results in higher levels of their occurrence
in plant biomass compared with urea. By contrast, the supply of N slightly enhanced the ryegrass uptake
of micro-nutrients, i.e. Cu and Zn, yet it caused negligible effects on nonessential elements, i.e. Cd and Pb.
The mobilized PTEs by EDDS lead to elevated oxidative stress because higher levels of malondialdehyde
and O 2
??
were observed. The supply of N attenuated oxidative stress caused by O 2
??
and H 2 O 2 , which was
associated with enhanced activities of superoxide dismutase and peroxidase. Our results advanced the
understanding of the exogenous N supply and metal resistance mechanisms in the EDDS-enhanced
phytoextraction. This study also highlighted that EDDS can serve as a N source to ease N-deficient
problems in PTEs-contaminated soils.