Fig. 2

Localization of Cd²⁺ in barley roots exposed to Cd treatments. Representative micrographs show the binding of Cd²⁺ to Leadmium™ Green AM dye at longitudinal and cross sections of root tips from two barley genotypes Zhenong8 (left panel) and W6nk2 (right panel) after 15 days of Cd treatment a the first two lines are images from the green fluorescence indicate the fluorescent dye in Cd²⁺, the third and fourth are images of bright-field plus green flurescence. Roots were exposed to 0 and 50 μM Cd for 5, 10 and 15 days before staining. Scale bars = 250 μm. b Relative Cd²⁺ fluorescence density from longitudinal section of root tips. Black, white, shaded and grey bars represent 0, 5, 50, 500 μM Cd, respectively. Data are means ± SD (n = 5). * and ** denote significant difference at P < 0.05 and P < 0.01, respectively, between Zhenong8 and W6nk2 at each of the four Cd levels over 15 days. Arrows denote specific differences between two genotypes