Effect of cadmium on lateral root growth measured 18 days after start of the treatment. A. Lateral root density (n = 10). B. Length of the apical unbranched zone (n = 10). C. Lateral root growth, illustrated by the relationship between the insertion position (distance from the parent root apex) and the length of the lateral roots. D. Length of the lateral root apical meristem (nmock = 102, nCd = 100). Significant differences (t-test, p-value < 0.05) are indicated by stars. E. Pictures of root apical meristem of control (left) and cadmium treated plants (right). Black lines represent 100 μm. Arrowheads indicate the limits of the root apical meristem.