Effect of Arbuscular Mycorrhizal Fungi and Earthworms on Cadmium Uptake and Antioxidant Enzyme Activities of Lantana camara in Cd-polluted Soils

A pot experiment was conducted to investigate the effects of earthworm and arbuscular mycorrhiza fungi (AMF) alone or combined inoculation on the biomass, Cd accumulation and antioxidant enzyme activities of Lantana camara L. in different Cd-spiked soils (0, 7, and 28 mg/kg soil). Results showed that Cd inhibited plant growth, decreased the concentration of P and the activities of catalase (CAT) and superoxide dismutase (SOD), and increased the activity of peroxidase (POD) and the content of malonaldehyde (MDA) in the shoots of L. camara. AMF associated with L. camara well, and AMF inoculation increased dry weights, P and Cd concentrations, Cd uptake and SOD activity, but decreased CAT activity and MDA content in the shoots. Earthworm addition increased Cd concentration and uptake and MDA content, decreased the activities of CAT, POD and SOD in the shoots. The full factorial analysis of variance indicated the main effects of AMF and earthworm on the Cd-uptake and antioxidant activities of L. camara were more important than their interactive effects. Correlation analysis showed significant correlations between the activities of all antioxidant enzymes and P and Cd concentrations in the shoots, these indicated that earthworm and AMF inoculation may influence the activities of antioxidant enzymes through the effects of P and Cd absorption in the shoots of L. camara.