title: Assessment of physiological and biochemical responses, metal tolerance and accumulation in two eucalypt hybrid clones for phytoremediation of cadmium-contaminated waters.
abstract: 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.
authors.affiliation: Institute of Agro-environment and Forest Biology, National Research Council (CNR), Via Salaria Km. 29,300, 00015 Monterotondo Scalo, Roma, Italy.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Pietrini
authors.affiliation: Institute of Agro-environment and Forest Biology, National Research Council (CNR), Via Salaria Km. 29,300, 00015 Monterotondo Scalo, Roma, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Iori
authors.affiliation: Institute of Agro-environment and Forest Biology, National Research Council (CNR), Via Salaria Km. 29,300, 00015 Monterotondo Scalo, Roma, Italy.
authors.forename: Daniele
authors.initials: D
authors.lastname: Bianconi
authors.affiliation: Research Unit for Intensive Wood Production, The Agricultural Research Council (CRA), Via Valle della Quistione, 27, 00166 Roma, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Mughini
authors.affiliation: Institute of Agro-environment and Forest Biology, National Research Council (CNR), Via Salaria Km. 29,300, 00015 Monterotondo Scalo, Roma, Italy.
authors.forename: Angelo
authors.initials: A
authors.lastname: Massacci
authors.affiliation: Institute of Agro-environment and Forest Biology, National Research Council (CNR), Via Salaria Km. 29,300, 00015 Monterotondo Scalo, Roma, Italy. Electronic address: massimo.zacchini@ibaf.cnr.it.
authors.forename: Massimo
authors.initials: M
authors.lastname: Zacchini
mesh_terms: D001673:Biodegradation, Environmental; D002104:Cadmium / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*; D002734:Chlorophyll / Q000378:metabolism; D005052:Eucalyptus / Q000235:genetics / Q000378:metabolism*; D006824:Hybridization, Genetic; D008670:Metals / Q000032:analysis; D010788:Photosynthesis / Q000187:drug effects; D018515:Plant Leaves / Q000378:metabolism; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism; D018547:Plant Stems / Q000235:genetics / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*; D018508:Water Purification / Q000379:methods
chemical_list: D008670:Metals; D014874:Water Pollutants, Chemical; D002104:Cadmium; D002734:Chlorophyll
keywords: Organic acids; Photosynthesis; Polyamines; Thiols; Trees; Wastewater