Figure 5.

Bio-imaging of NO level in the roots of cucumber seedlings treated with Cd in the presence or absence of aminoguanidyne (AG) (A) and the mean related fluorescence density ± SD (B). After 3 days of treatment with Cd, plants were transferred to the control conditions for another 3 days (Cd) or to the control nutrient solutions with aminoguanidyne (Cd + AG). At the same time, control plants were also treated with aminoguanidyne (control + AG). NO production was monitored by labeling with the NO-specific fluorescent dye DAF-2D and imaged using fluorescent microscopy. The images are representative for at least three roots for each treatment from three independent replications of the experiment. Asterisks on the figure indicate significant differences (* p < 0.05). The intensity of green fluorescence in the images was analyzed and expressed as the average number of pixels in green channel on a scale ranging from 0 to 255. MZ—meristematic zone, EZ—elongation zone, DZ—differentiation zone.