title: Influence of the Ca/Mg ratio on Cu resistance in three Silene armeria ecotypes adapted to calcareous soil or to different, Ni- or Cu-enriched, serpentine sites.
abstract: This hydroponic study addresses the influence of low (0.3) and high (4.0) Ca/Mg molar ratios on Cu resistance of Silene armeria ecotypes from different habitats: a calcareous soil (ecotype Cadriano), a Ni-rich serpentine site (ecotype Prinzera), and an acid Cu-mine spoil soil containing serpentinite (ecotype Vigonzano). Under control conditions, without excess Cu, only Cadriano was negatively affected by the low Ca/Mg ratio. Under both low and high Ca/Mg ratios Cu resistance followed the order Vigonzano more more than Prinzera > Cadriano. More efficient Cu exclusion accounted for enhanced Cu resistance in Prinzera. The low Ca/Mg ratio increased Cu uptake in Prinzera but did not worsen toxicity effects; i.e. the plants had higher internal Cu effect concentrations. In Vigonzano Cu resistance was enhanced by the low Ca/Mg ratio. This was due only in part to better Cu exclusion. Magnesium-induced tolerance to higher Cu tissue concentrations appears to be in ecotypes from serpentine and acid mine spoils, but not in plants from calcareous soil, the exposure to low Ca/Mg ratio favours internal detoxification of Cu by means of more efficient chelation and compartmentation.
authors.affiliation: Laboratorio Fisiología Vegetal, Facultad Ciencias, Universidad Autónoma de Barcelona, E-08193 Bellaterra, Spain.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Lombini
authors.forename: Mercè
authors.initials: M
authors.lastname: Llugany
authors.forename: Charlotte
authors.initials: C
authors.lastname: Poschenrieder
authors.forename: Enrico
authors.initials: E
authors.lastname: Dinelli
authors.forename: Juan
authors.initials: J
authors.lastname: Barceló
mesh_terms: D000222:Adaptation, Physiological / Q000187:drug effects; D017632:Asbestos, Serpentine / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology*; D002614:Chelating Agents / Q000494:pharmacology; D003300:Copper / Q000378:metabolism* / Q000633:toxicity; D004351:Drug Resistance; D008274:Magnesium / Q000494:pharmacology*; D009532:Nickel / Q000494:pharmacology; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D018520:Plant Shoots / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D029751:Silene / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D012987:Soil / Q000032:analysis; D012989:Soil Pollutants / Q000378:metabolism / Q000633:toxicity
chemical_list: D017632:Asbestos, Serpentine; D002614:Chelating Agents; D012987:Soil; D012989:Soil Pollutants; D003300:Copper; D009532:Nickel; D008274:Magnesium; D002118:Calcium