title: Role of the polycarboxylic compounds in the response of Silene vulgaris to chromium.
abstract: This work aims to investigate the nature and the specific mechanisms by which polycarboxylic compounds participate in the tolerance of Silene vulgaris to Cr with special attention given to the rhizosphere system. This knowledge is important to use this species in the implementation of phytoremediation technologies in Cr-polluted soils. According to the results, chromium is chelated and mobilized by the citric and malic acids in plant tissues, while oxalic acid might participate in the reduction and chelation of Cr in the rhizosphere. At the applied doses, the response of both exudation rate and root exudate composition (total polyphenols and quercitin) seems to involve a rearrangement in the lignification of the plant cell wall to immobilize Cr. Quercetin-3-dirhamnosyl-galactoside and apiin (apigenin-7-O-apiosyl-glucoside) have been identified as the major polyphenols in the root exudates of S. vulgaris. The increments found in the apiin concentration in root exudates seem to be related to the protection against Cr toxicity by chelation of Cr or by free radical scavenging. Though earlier response is detected in plant tissues, results from this work together with previous studies in S. vulgaris indicate that exudation might be a regulated mechanism of protection under Cr exposition in S. vulgaris that may involve mainly Cr reduction and chelation.
authors.affiliation: Dpto. de Investigación Agroambiental, IMIDRA, Alcalá de Henares, 28800, Madrid, Spain. ana.pradas@ujf-grenoble.fr.|ISTerre (Institut des Sciences de la Terre), Université Grenoble Alpes, CNRS, 38041, Grenoble Cedex 9, France. ana.pradas@ujf-grenoble.fr.
authors.forename: Ana E
authors.initials: AE
authors.lastname: Pradas Del Real
authors.affiliation: Department of Metabolism and Nutrition, Institute of Food Science, Food Technology and Nutrition (ICTAN), Spanish National Research Council (CSIC), José Antonio Novais 10, 28040, Madrid, Spain.
authors.forename: Jose Manuel
authors.initials: JM
authors.lastname: Silvan
authors.affiliation: Department of Metabolism and Nutrition, Institute of Food Science, Food Technology and Nutrition (ICTAN), Spanish National Research Council (CSIC), José Antonio Novais 10, 28040, Madrid, Spain.
authors.forename: Sonia
authors.initials: S
authors.lastname: de Pascual-Teresa
authors.affiliation: Dpto. de Investigación Agroambiental, IMIDRA, Alcalá de Henares, 28800, Madrid, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Guerrero
authors.affiliation: Dpto. de Investigación Agroambiental, IMIDRA, Alcalá de Henares, 28800, Madrid, Spain.
authors.forename: Pilar
authors.initials: P
authors.lastname: García-Gonzalo
authors.affiliation: Dpto. de Investigación Agroambiental, IMIDRA, Alcalá de Henares, 28800, Madrid, Spain.
authors.forename: M Carmen
authors.initials: MC
authors.lastname: Lobo
authors.affiliation: Dpto. de Investigación Agroambiental, IMIDRA, Alcalá de Henares, 28800, Madrid, Spain.|Department of Earth Sciences, Natural History Museum, Cromwell Road, London, SW7 5BD, UK.
authors.forename: Araceli
authors.initials: A
authors.lastname: Pérez-Sanz
mesh_terms: D001673:Biodegradation, Environmental; D002857:Chromium; D019343:Citric Acid; D008293:Malates; D019815:Oxalic Acid; D018517:Plant Roots; D029751:Silene
chemical_list: D008293:Malates; D002857:Chromium; D019343:Citric Acid; C030298:malic acid; D019815:Oxalic Acid
keywords: Chromium speciation; Exudation; Metal tolerance; Organic acids; Polyphenols; Silene vulgaris