Copper bioconcentration and bioaccumulation in different eucalyptus species and their impact on plant physiology

Abstract

Some plant species can bioaccumulate copper in their tissues and can be used for phytoremediation in contaminated soils. This work aimed to determine the bioconcentration and bioaccumulation of copper in eucalyptus species and how they affect the physiology of plants. The experimental design was completely randomized in a factorial arrangement (4 × 6), with four species of eucalyptus (Eucalyptus grandis W. Hill ex. Maiden, Corymbia citriodora (Hook.) K.D. Hill and L.A.S. Johnson, Eucalyptus saligna Smith and Eucalyptus dunnii Maiden), six doses of copper (zero, 80, 160, 240, 320, 400 mg kg−1), with twelve repetitions, carried out for 120 days in a greenhouse condition. The exotic species showed a high potential for growing in soils with high copper concentrations and also a potential for copper bioremediation. The highest copper concentration accumulation was shown mainly in the root system of the seedlings of Eucalyptus grandis, Eucalyptus saligna, Eucalyptus dunnii and Corymbia citriodora. E. saligna the copper toxicity was less pronounced, and the plants showed better physiologic effects. Cu levels increased with the doses, with greater intensity for species E. grandis and E. saligna with values of 21.1 and 15.5 mg kg−1, respectively. Also, the species showed a high capacity for copper bioaccumulation in the root system and showed high characteristics for phytoaccumulation and phytoextraction. So, these plants have great characteristics to grow in copper-contaminated sites being useful to reduce free copper in the environment.