The Influence of Iron Application on the Growth and Cadmium Stress Tolerance of Poplar

Abstract

There is a complex cadmium (Cd) and iron (Fe) interaction in soil. To explore the influences of Fe application on the growth, Cd accumulation, and antioxidant capacity of poplar under Cd exposure, Populus tremula × P. alba ‘717’ was treated with different concentrations of Cd (0 and 100 μM) and Fe (50 and 150 μM). In addition, the root architecture, leaf chlorophyll content, Cd accumulation, and antioxidant enzyme activity were analyzed. The results showed that the high-dose Fe (150 μM) did not change poplar biomass in zero-Cd treatment but increased the chlorophyll content, total root surface area, net photosynthetic rate, and biomass accumulation of Cd-stressed poplar. In addition, under Cd stress, high-dose Fe increased the translocation factor (TF) of Cd, decreased root and leaf malondialdehyde (MDA) content, and enhanced root and leaf SOD activity. That is, high-dose Fe could alleviate the suppression of Cd on the growth of poplar and enhance the transport of Cd to aboveground tissues and the SOD activity in roots and leaves, thus alleviating the Cd-induced oxidative stress. This study will provide reference for the remediation of Cd-contaminated soils using poplar.