Interaction of nickel and manganese in uptake, translocation and accumulation by the nickel-hyperaccumulator plant, Alyssum bracteatum (Brassicaceae)

Abstract

Serpentine soils are often characterised by high concentrations of heavy metals, high plant diversity and endemism, and, in some cases, the presence of plants that hyperaccumulate nickel (Ni). Nickel uptake by hyperaccumulator plants could potentially be affected by other heavy metals in serpentine soils, such as manganese (Mn), which competes for uptake at roots. The present study investigated interactions between Ni and Mn in metal uptake, translocation and storage in a serpentine-endemic Ni-hyperaccumulator plant, Alyssum bracteatum (Brassicaceae), native to western Iran. The results based on a factorial treatment of seedlings using Ni and Mn and elemental analyses showed that whole shoot and root Ni concentrations were inversely correlated with Mn in the growing medium. Likewise, whole shoot and root Mn concentrations were inversely correlated with Ni in the medium, suggesting competition between Ni and Mn for uptake at roots. No evidence was found for competition between Ni and Mn for translocation between the roots and shoot.