Diversity of Ni growth response and accumulation in Central-Eastern Mediterranean Odontarrhena (Brassicaceae) populations on and off serpentine sites

Nickel response and accumulation were analyzed in 12 populations from seven Central-Eastern Mediterranean Odontarrhena taxa on off serpentine sites to test the presence of metal-induced growth stimulation its relationship with tolerance plant Ni concentration. Seedlings cultivated hydroponics increasing NiSO4 concentrations obtain dose-response curves evaluate levels roots shoots. In all accessions, a metal stimulatory effect was present low-dose zone significantly fitted Brain-Cousens hormetic model. Accessions showed broad variation tolerance, most tolerant plants requiring highest culture medium for optimal growth. Significant differences also detected positive found between accumulation. The non-serpentine O. chalcidica similarly capable hyperaccumulation, suggesting this ability be species-wide trait. case muralis, species that preferentially avoids soils, two same Ni-enhanced accessions other investigated here, but only at lowest concentration, reached shoot amounts approaching hyperaccumulation threshold. Therefore, capacity tolerate accumulate could considered specieswide trait taxa, both endemic facultative. Regarding concentration by nature, neither field-collected nor those their natural soils origin related tolerance. On hand, appeared as main driving factor native habitats.