a, TMM:BIN2-GSgreen;bin2-3 (lines 17.6 and 16.3), TMM:BIN2-GSgreen;Col-0 (lines 4.2 and 6.2), POLAR:POLAR-GFP;Col-0 (lines 14.5 and 16.3) and POLAR:POLAR-mCherry (lines 6 and 5) introduced into TMM:BIN2-GSgreen;Col-0 (line 6.2). Scale bar, 2.5 cm. b, BIN2 and POLAR gene expression in the genotypes shown in a, measured by qRT–PCR. n = 3 biologically independent experiments. c, SPCH–mCherry marking the stomatal lineage cell fate of the small dividing cells in pTMM:BIN2-GSgreen;Col-0 (line 6.2) plants. d, Localization of POLAR–GFP in plants overexpressing POLAR-GFP;Col-0 (line 14.5) presenting excessive divisions in the stomatal lineages. All experiments were repeated independently three times. Box plots show the first and third quartiles, split by the median (line) and mean (cross). Scale bars in c and d, 20 µm.