Polymetallic (zinc and cadmium) hyperaccumulation in the Australian legume Crotalaria novae-hollandiae compared to Crotalaria cunninghamii

Abstract Purpose Hyperaccumulators are plants with the ability to tolerate and accumulate high concentrations of potentially phytotoxic metals. The Australian legume Crotalaria novae-hollandiae accumulates remarkably zinc (Zn), cadmium (Cd) copper (Cu) in its shoots when growing on metalliferous (Zn-Cd ‘calamine’) soils. This study aimed investigate zinc-cadmium tolerance C. compare it closely related, but non-metalliferous, cunninghamii . Methods were exposed Zn (3–1000 μM) Cd (0–60 treatments hydroponics culture. At end experiment, harvested segmented into roots, old young stems, leaves for elemental analysis Inductively coupled plasma atomic emission spectroscopy (ICP-AES). Laboratory-based micro-X-ray fluorescence (μXRF) was used elucidate distribution a shoot leaflets. Results accumulated up 1210 μg g −1 47.6 leaves, 75% reduction biomass treatment. 16,600 1250 , 70% increase Zn. species both exhibited chlorosis stunted growth treatments, while only toxicity symptoms Conclusions has limited based accumulation foliar is suspected that different uptake mechanisms compared other widely studied Zn-Cd hyperaccumulators (such as Noccaea caerulescens Arabidopsis halleri ).