The spatial scale of the cytokinin gradients.

The spatial steady state profile of cytokinin in a source-diffusion-decay model, for different degradation rates. The lower panel is zoomed in (50x) to the dotted area within the upper panel; the root sections are drawn to scale for comparison with the gradient. Dotted lines mark the characteristic length of each gradient. The blue line shows the cytokinin distribution with degradation rate and diffusion coefficient similar to auxin; the red and green lines represent gradients that could be informative at the transverse scale of the root meristematic zone.