Interaction of Fe-Mn plaque and Arthrobacter echigonensis MN1405 and uptake and translocation of Cd by Phytolacca acinosa Roxb

Abstract

In this study, hydroponic experiments were conducted to investigate the role of Fe-Mn plaque and Arthrobacter echigonensis MN1405 under different solution Cd levels (0, 2 and 50 mg L^-1) on Cd uptake and translocation by Phytolacca acinosa Roxb. (P. acinosa). Results showed Cd accumulated by P.acinosa without plaque were mostly distributed in root surface, indicating that an exclusion strategy for Cd tolerance. The formation of Fe-Mn plaque could contribute to the increase in the Cd tolerance of P.acinosa, promotion of the growth, increase in the enhancement of Cd translocation. Among all the treatments, Fe-Mn plaque treatments inoculated with MN1405 accumulated the maximum DCB-Cd (46.61 ± 6.36 g kg^-1) and had the highest value of TF_aeria (2.14 ± 0.01) at 50 mg L^-1 and 2 mg L^-1 solution for Cd, respectively, demonstrating the greatest capacity to accumulate and translocate Cd. The uptake of Cd by P. acinosa in plaque treatments may result in the increase of soluble sugar and decrease of soluble protein synthesized from roots which involved in Cd detoxification and thus diminished the negative effects of Cd to some extent.

Keywords: Cd detoxification; Cd uptake and translocation; Phytoremediation; Soluble protein; Soluble sugar.