Abstract:A pot experiment was conducted to investigate the plant growth,Cd content,Cd accumulation and nutrient uptake and transport in Ricinus communis (Zibima 5) when exposed to heavy metal polluted soil (100 mg·kg-1) and different EGTA treatments (0,0.5,1,and 2 mmol·kg-1).The results showed that:(1)compared with no EGTA treatment (E0),0.5-2 mmol·kg-1 EGTA inhibited the growth of castor roots,decreased the fresh and dry weight of roots by different degrees,but had no significant effect on plant total dry weight.(2) EGTA can effectively promote the translocation of Cd from roots to shoots,2 mmol·L-1 of EGTA treatment increased Cd contents in leaves by 41.34 times.The accumulation of Cd in the leaves increased significantly with elevation of EGTA doses.Compared with E0,the Cd accumulation in the leaves of EGTA treatments increased 14.0-45.6 times,and accounted for 36.89%~58.63% of the total plant amount,respectively.(3) EGTA had different effects on the mineral nutrient concentration in R.communis under Cd stress.EGTA promoted translocation of K to the shoots,while inhibited translocation of Mg to the shoots;Moreover,Ca contents in the roots,stems and leaves were increased under low dose of EGTA treatment,while high dose of EGTA decreased them.Zn contents in the leaves and Cu contents in roots and shoots were increased as EGTA concentration increased.Fe contents in leaves and roots,Mn contents in roots and shoots were significantly increased with increasing dose of EGTA treatments.Compared with no Cd control,EGTA can increase the available cadmium in soil,but reduce the absorption of K in roots.Therefore,Cd stress inhibits the growth of the plant,appropriate concentration of exogenous EGTA can significantly alleviate Cd stress in R.communis.EGTA changed the distribution of the accumulation of Cd in roots,stems and leaves of R.communis and improved the translocation of Cd from roots to shoots,especially to the leaves.It can strengthen the remediation efficiency of castor on Cd contaminated soil.K fertilizer should be applied to ensure the normal physiological metabolism of the plant.