Concentration-dependent Cd accumulation in roots of durum wheat seedlings. Concentration-dependent Cd accumulation in roots (A) of high and low Cd-accumulating isolines of durum wheat. Intact roots of 6-d old seedlings were exposed for 30 min to 15 mL of complete nutrient solution containing 5–1800 nM Cd labelled with 109Cd. Desorbable Cd (B) was removed following treatment by a 30 min (2°C) wash in non-radiolabelled nutrient solution containing 50 μM DTPA. Inset shows desorbable Cd expressed as a percentage of total Cd accumulation in the roots. Means and standard errors of 5 replicates (3 plants per replicate) are plotted.