Effects of indole-3-acetic, kinetin and spermidine assisted with EDDS on metal accumulation and tolerance mechanisms in ramie (Boehmeria nivea (L.) Gaud.)

The effects and mechanisms of indole-3-acetic (IAA), kinetin (KN) and spermidine (Spd) assisted with ethylenediamine disuccinic acid (EDDS) on Cd and Pb accumulation in ramie were investigated by a pot experiment. In the first stage, the optimum concentrations of IAA, KN, and Spd were determined. And the effects of IAA, KN, and Spd at their optimum concentration on the antioxidant enzymes, non-enzymatic antioxidants, and metal accumulation in ramie were evaluated in the secondary stage. The results show that the translocation factor (TF) of Cd and Pb were increased by approximately 47 and 112%, respectively, at the presence of KN in combination with EDDS. In comparison with IAA treatment, Cd and Pb in root symplast were increased, approximately 2.02 and 2.62 times upon the combined application of IAA and EDDS. In addition, the contents of antioxidant enzymes and non-enzymatic antioxidant were increased dramatically through the addition of IAA, KN, and Spd plus EDDS. On the whole, IAA, KN, and Spd assisted with EDDS could significantly alleviate the oxidative stress induced by Cd and Pb in ramie.