Assessment of physiological and biochemical responses, metal tolerance and accumulation in two eucalypt hybrid clones for phytoremediation of cadmium-contaminated waters

• Published in: Journal of environmental management Vol. 162; pp. 221 - 231
• Main Authors: Pietrini, Fabrizio, Iori, Valentina, Bianconi, Daniele, Mughini, Giovanni, Massacci, Angelo, Zacchini, Massimo
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.10.2015; Academic Press Ltd
• Subjects: Biochemistry; Biodegradation, Environmental; Cadmium; Cadmium - analysis; Cadmium - chemistry; Cadmium - metabolism; Chlorophyll - metabolism; Chlorophylls; Cloning; Environmental restoration; Eucalyptus; Eucalyptus - genetics; Eucalyptus - metabolism; Eucalyptus camaldulensis; Eucalyptus globulus; Exposure; Flowers & plants; Genotype & phenotype; Heavy metals; Hybridization, Genetic; Metals - analysis; Organic acids; Photosynthesis; Photosynthesis - drug effects; Physiology; Plant Leaves - metabolism; Plant Roots - genetics; Plant Roots - metabolism; Plant Stems - genetics; Plant Stems - metabolism; Plants (organisms); Polyamines; Restoration; Thiols; Tolerances; Trees; Wastewater; Water Pollutants, Chemical - analysis; Water Pollutants, Chemical - chemistry; Water Pollutants, Chemical - metabolism; Water Purification - methods; Trees; Thiols; Photosynthesis; Polyamines; Wastewater; Organic acids
• ISSN: 0301-4797; 1095-8630
• DOI: 10.1016/j.jenvman.2015.07.053

Eucalyptus is a promising species for ecological restoration but plant performances under environmental constraints need to be better investigated. In particular, the toxic effects of metals on this plant species are poorly described in the literature. In this work, morpho-physiological and biochemical responses to cadmium were analysed in two eucalypt genotypes (hybrid clones of Eucalyptus camaldulensis × Eucalyptus globulus ssp. bicostata J.B. Kirkp named Velino ex 7 and Viglio ex 358) exposed for 3 weeks to 50 μM CdSO4 under hydroponics. The two eucalypt clones showed a different sensitivity to the metal. The growth reduction caused by cadmium was less than 30% in clone Velino and about 50% in clone Viglio. Cadmium mostly accumulated in plant roots and, to a lesser extent, in stem, as highlighted by the low translocation factor (Tf) measured in both clones. Net photosynthesis measurement, chlorophyll fluorescence images, transpiration values and chlorophyll content revealed a cadmium-induced impairment of physiological processes at the leaf level, which was more evident in clone Viglio. Metal binding and antioxidative compound content was differentially affected by cadmium exposure in the two eucalypt clones. Particularly, the content of thiols like cysteine and glutathione, organic acids like oxalate and citrate, and polyamines were markedly modulated in plant organs by metal treatment and highlighted different defence responses between the clones. Cadmium tolerance and accumulation ability of the eucalypt clones were evaluated and the potential of E. camaldulensis for the reclamation of metal polluted-waters is discussed. •A study on physio-biochemical responses to Cd in Eucalyptus sp. was performed.•Cd induced in leaves a different impairment of physiological processes between clones.•Metal ligand and antioxidant content was differently affected by Cd between clones.•A notable Cd bio-concentration potential was highlighted in this species.•Results are promising for the utilization of this species for wastewater remediation.