title: Distribution of chromium species in a Cr-polluted soil: presence of Cr(III) in glomalin related protein fraction.
abstract: The accumulation of Cr in soil could be highly toxic to human health; therefore Cr soil distribution was studied in rhizosphere soils from Ricinus communis and Conium maculatum and bare soil (BS) from an industrial and urban area in Argentina. Total Cr, Cr(VI) and Cr(III) concentrations were determined in 3 soil fractions: total, extractable and associated to total-glomalin-related protein (T-GRSP). BS had the highest total Cr and total Cr(VI) concentrations. Total Cr(VI) concentration from both rhizosphere soils did not differ from the allowed value for residential area in Argentina (8 μg Cr(VI) g(-1) soil), while total Cr(VI) in BS was 1.8 times higher. Total Cr concentration in all the soils was higher than the allowed value (250 μg Cr g(-1) soil). Extractable and associated to T-GRSP Cr(VI) concentrations were below the detection limit. Cr(III) bound to T-GRSP was the highest in the BS. These findings are in agreement with a long term effect of glomalin in sequestrating Cr. In both plant species, total Cr was higher in root than in shoot and both species presented arbuscular mycorrhizal fungi (AMF). As far as we know, this is the first study that reports the presence of Cr in T-GRSP fraction of soil organic matter. These findings suggest that Cr mycorrhizostabilization could be a predominant mechanism used by R. communis and C. maculatum to diminish Cr soil concentration. Nevertheless, further research is needed to clarify the contribution of native AMF isolated from R. communis and C. maculatum rhizosphere to the Cr phytoremediation process.
authors.affiliation: Laboratorio de Biodiversidad Vegetal y Microbiana, Facultad de Cs Agrarias, Universidad Nacional de Rosario, Campo Exp. Villarino, Zavalla (2123), Argentina. Electronic address: lourgilcardeza@gmail.com.
authors.forename: María L
authors.initials: ML
authors.lastname: Gil-Cardeza
authors.affiliation: Departamento Química Analítica, Facultad de Cs. Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, Rosario (2000), Argentina.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Ferri
authors.affiliation: Laboratorio de Micorrizas, Departamento de Cs. Químicas y Recursos Naturales, Universidad de La Frontera, Avda. Francisco Salazar 1145, Temuco (54-D), Chile.
authors.forename: Pablo
authors.initials: P
authors.lastname: Cornejo
authors.affiliation: Laboratorio de Biodiversidad Vegetal y Microbiana, Facultad de Cs Agrarias, Universidad Nacional de Rosario, Campo Exp. Villarino, Zavalla (2123), Argentina.
authors.forename: Elena
authors.initials: E
authors.lastname: Gomez
mesh_terms: D001118:Argentina; D002857:Chromium / Q000032:analysis*; D004784:Environmental Monitoring; D005656:Fungal Proteins / Q000032:analysis; D006023:Glycoproteins / Q000032:analysis; D012987:Soil / Q000737:chemistry*; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000032:analysis*
chemical_list: D005656:Fungal Proteins; D006023:Glycoproteins; D012987:Soil; D012989:Soil Pollutants; C573268:glomalin; D002857:Chromium
keywords: Arbuscular mycorrhizal fungi; Glomalin related soil protein; Mycorrhizostablilization; Phytoremediation; Potentially toxic elements; Trivalent and hexavalent chromium