Figure 5
Quantitative analysis of the cortical microtubule network in a plant root tip.
(A) The average cortical microtubule density (number of microtubules per micrometer) in the highlighted cells in Fig. 4, with the distance of cells from the root tip. Error bars represent the standard deviation of densities of cortical microtubules from over 10 sub-regions in each cell. (B) Schematic representation of the orientation of cortical microtubules, taken as the relative angle (θ) of each microtubule filament to the long axis of the cell. The orientation angle θ as displayed in (C) is corrected by the offset angle φ of the cell, determined by its long axis. Ψ is the angle of the microtubule filament in the coordinates of the STORM image (x–y). All angles were determined by using NIH ImageJ (http://rsbweb.nih.gov/ij/). (C) Polar plots showing the distributions of cortical microtubule orientations (θ) of the corresponding cells in Fig. 4. Adjacent cells (f1 and f2, g1 and g2) showing dramatically different cortical microtubule organizations were analyzed separately. Note that the long axis of the cell has been aligned to the 3 o’clock position in all polar plots as highlighted in purple.
