title: Accumulation of Cd, Cu and Zn in shoots of maize (Zea mays L.) exposed to 0.8 or 20 nM Cd during vegetative growth and the relation with xylem sap composition.
abstract: This work focuses on the exposure of maize plants to nanomolar concentrations of Cd, which is relevant for agricultural soils cropped with food and feed plants. Maize plants were cultivated in nutrient solution at 0.8 or 20 nM Cd during the vegetative growth stages. No significant hormesis or toxic effects of Cd were observed on maize growth, but a decrease in the allocation of Cd to shoots between the 0.8 and 20 nM Cd exposures revealed that the plants already responded to these low concentrations of Cd according to a shoot Cd excluder strategy. The Cd, Cu and Zn concentrations in shoots decreased with time as the result of an early decrease in the root/shoot ratio and of a decrease in the coefficient of allocation to aboveground for Zn and Cd at 20 nM. As a consequence, shoots of young plants were richer in micronutrients Cu and Zn but also in toxic Cd. The rate of delivery of Cd, Cu and Zn from xylem sap was successfully used to predict the time course of concentrations of Cd, Cu and Zn in the shoot. However, it overestimated the actual concentrations of Cd in the shoot, presumably because the reallocation of this trace element from shoots back to roots was not taken into account.
authors.affiliation: INRA, UMR 1391 ISPA, 33140, Villenave d'Ornon, France. christophe.nguyen@bordeaux.inra.fr.|Bordeaux Sciences Agro, UMR 1391 ISPA, 33170, Gradignan, France. christophe.nguyen@bordeaux.inra.fr.
authors.forename: C
authors.initials: C
authors.lastname: Nguyen
authors.affiliation: INRA, UMR 1391 ISPA, 33140, Villenave d'Ornon, France.|Bordeaux Sciences Agro, UMR 1391 ISPA, 33170, Gradignan, France.
authors.forename: A J
authors.initials: AJ
authors.lastname: Soulier
authors.affiliation: Unité de Services et de Recherche en Analyses Végétales et Environnementales (USRAVE), INRA, Centre de Bordeaux Aquitaine, 33140, Villenave d'Ornon, France.
authors.forename: P
authors.initials: P
authors.lastname: Masson
authors.affiliation: INRA, UMR 1391 ISPA, 33140, Villenave d'Ornon, France.|Bordeaux Sciences Agro, UMR 1391 ISPA, 33170, Gradignan, France.
authors.forename: S
authors.initials: S
authors.lastname: Bussière
authors.affiliation: INRA, UMR 1391 ISPA, 33140, Villenave d'Ornon, France.|Bordeaux Sciences Agro, UMR 1391 ISPA, 33170, Gradignan, France.
authors.forename: J Y
authors.initials: JY
authors.lastname: Cornu
mesh_terms: D002104:Cadmium / Q000032:analysis / Q000378:metabolism*; D003300:Copper / Q000032:analysis / Q000378:metabolism*; D018977:Micronutrients / Q000032:analysis / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism; D012989:Soil Pollutants / Q000032:analysis / Q000378:metabolism*; D052584:Xylem / Q000187:drug effects / Q000378:metabolism*; D003313:Zea mays / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D015032:Zinc / Q000032:analysis / Q000378:metabolism*
chemical_list: D018977:Micronutrients; D012989:Soil Pollutants; D002104:Cadmium; D003300:Copper; D015032:Zinc
keywords: Cadmium; Copper; Dilution; Growth; Partitioning; Trace elements; Xylem sap; Zinc