Extended Data Fig. 3: Measure of G2 phase duration in various cell types.

a, EdU pulse-chase strategy for direct measurement of the G2 phase duration. Seedlings were labeled with a short (15 min) pulse of the thymidine analogue EdU and then chased for different periods of time, in the absence of EdU and in the presence of an excess of thymidine to reduce further EdU incorporation, before Click-It detection of EdU labeled nuclei, as indicated in the upper part of the figure. The lower part of the figure contains a simplified scheme to illustrate cell cycle progression during the chase period. Cells in S-phase are all labeled with EdU during the pulse. Then, with time, cells progress across G2 and eventually enter mitosis. Quantification of mitotic cells labeled with EdU in the different chase times measures the G2 length. The average G2 phase duration corresponds to the chase time where 50% of mitotic cells appear labeled, assuming a normal distribution of the EdU labeled cells. b, Average duration of G2 in various cell types. The fraction of EdU-labeled mitosis was quantified at different chase times after a pulse with EdU (15 min) by counting labeled (red) and unlabeled (blue) mitotic figures in individual roots (n = 10 per time point). The percentage of labeled mitoses was calculated for each root, and the mean ± SD is shown. The average G2 duration was estimated as the time point at which 50% of the maximum number of EdU-labeled mitotic figures was reached in the pulse-chase curve (indicated by the thin lines in each case). Panel a created with BioRender.com.