Effects of chelators on the uptake and accumulation of cadmium,lead,zinc and copper in soil by Celosia argentea L.

【Objective】 The experimental objective was to investigate the effects of chelatorsethylene diamine disuccinate(EDDS),nitrilotriacetic acid(NTA)and glycol-bis-(2-aminoethylether)-N,N,N',N'-tetraacetic acid(EGTA)on the uptake and accumulation of cadmium(Cd),lead(Pb),zinc(Zn)and copper(Cu)with Celosia argentea L.,and to provide data support for the application of chelators and C. argentea L. in environmental repairation.【Method】 The application effects of EDDS(1.0,2.0 and 3.0 mmol/kg),NTA(1.0,2.0 and 3.0 mmol/kg)and EGTA(1.0,2.0 and 3.0 mmol/kg)were evaluated on the uptake and transportation of heavy metals(Cd,Pb,Zn and Cu)from soil with C. argentea L. by pot experiment in greenhouse,and without the addition of chelating agent as contrast(CK).【Result】 The results indicated that 1.0-2.0 mmol/kg EDDS,1.0-3.0 mmol/kg NTA,1.0-2.0 mmol/kg EGTA promoted significantly the growth of C. argentea L.(P<0.05,the same below)compared with CK,and among them,1.0 mmol/kg EGTA had the best effect,the dry weight increased by 37.5% than that of CK. 1.0-2.0 mmol/kg EDDS,2.0-3.0 mmol/kg NTA,1.0-2.0 mmol/kg EGTA significantly promoted the absorption and accumulation of Cd in C. argentea L.,and the highest bioconcentration factors and translocation factor were respectively 1.55 and 1.61 times as those of CK with applying 2.0 mmol/kg EGTA. 2.0-3.0 mmol/kg EDDS,1.0-3.0 mmol/kg NTA and 1.0-3.0 mmol/kg EGTA could significantly promote the absorption and accumulation of Pb in C. argentea L.,and the bioconcentration factors and translocation factor of Pb in C. argentea L. were improved compared with CK,and the highest bioconcentration factors and translocation factor were respectively 1.63 and 1.47 times as those of CK with applying 3.0 mmol/kg EGTA. 1.0 and 2.0 mmol/kg EDDS and 2.0 mmol/kg EGTA could significantly promote the absorption and accumulation of Zn in C. argentea L.,and the highest bioconcentration factor was as 1.18 times as that of CK when applying 1.0 mmol/kg EDDS. With applying 2.0 mmol/kg NTA,and the highest translocation factor was as 1.22 times as that of CK. With applying 1.0-3.0 mmol/kg EDDS,1.0-3.0 mmol/kg NTA and 1.0-3.0 mmol/kg EGTA could significantly promote the absorption and accumulation of Cu in C. argentea L.,and the highest bioconcentration factor was as 2.07 times as that of CK with applying 2.0 mmol/kg EDDS,and the highest translocation factor was as 2.52 times as that of CK with applying 3.0 mmol/kg EGTA.【Conclusion】 In this study,three chelators EDDS,NTAE and EGTA in a suitable dose can promote the absorption and accumulation of Cd,Pb,Zn and Cu in C. argentea L.(except 3.0 mmol/kg EGTA reduces the absorption and accumulation of Cd,and except 3.0 mmol/kg EDDS,3.0 mmol/kg NTA,1.0 mmol/kg EGTA and 3.0 mmol/kg EGTA reduces the absorption and accumulation of Zn). Therefore,the suitable dose of the three chelators as inductive activators can enhance absorption and accumulation of heavy metals Cd,Pb,Zn and Cu in C. argentea L.