title: Naturally-assisted metal phytoextraction by Brassica carinata: role of root exudates.
abstract: Due to relatively high chelant dosages and potential environmental risks it is necessary to explore different approaches in the remediation of metal-contaminated soils. The present study focussed on the removal of metals (As, Cd, Cu, Pb and Zn) from a multiple metal-contaminated soil by growing Brassica carinata plants in succession to spontaneous metallicolous populations of Pinus pinaster, Plantago lanceolata and Silene paradoxa. The results showed that the growth of the metallicolous populations increased the extractable metal levels in the soil, which resulted in a higher accumulation of metals in the above-ground parts of B. carinata. Root exudates of the three metallicolous species were analysed to elucidate their possible role in the enhanced metal availability. The presence of metals stimulated the exudation of organic and phenolic acids as well as flavonoids. It was suggested that root exudates played an important role in solubilising metals in soil and in favouring their uptake by roots.
authors.affiliation: Dipartimento di Chimica e Biotecnologie Agrarie, Università di Pisa, Via del Borghetto 80, 56124 Pisa, Italy. mfquart@agr.unipi.it
authors.forename: Mike F
authors.initials: MF
authors.lastname: Quartacci
authors.forename: Barbara
authors.initials: B
authors.lastname: Irtelli
authors.forename: Cristina
authors.initials: C
authors.lastname: Gonnelli
authors.forename: Roberto
authors.initials: R
authors.lastname: Gabbrielli
authors.forename: Flavia
authors.initials: F
authors.lastname: Navari-Izzo
mesh_terms: D001673:Biodegradation, Environmental; D001937:Brassica / Q000737:chemistry / Q000378:metabolism*; D052918:Environmental Restoration and Remediation / Q000295:instrumentation / Q000379:methods*; D019216:Metals, Heavy / Q000032:analysis / Q000378:metabolism*; D053147:Plant Exudates / Q000737:chemistry / Q000378:metabolism*; D012989:Soil Pollutants / Q000032:analysis / Q000378:metabolism*
chemical_list: D019216:Metals, Heavy; D053147:Plant Exudates; D012989:Soil Pollutants