Fig. 2: HAN acts downstream of WOX5 during the induction of CSC-like cells.
a,b, Representative confocal images of 6-day-old roots showing accumulation of starch-positive amyloplasts in the indicated genotypes Col-0, han-30 (a) and 35S:WOX5-GR, 35S:WOX5-GR, han-30 (b) after 24 h of DEX treatment, followed by mPS-PI staining. White arrowheads indicate the CSC layer, red arrowheads the starch grains in the differentiated cell layers and yellow arrowheads the QC position. c, Percentage of roots with starch grains in different layers of the indicated genotypes. *PC5 = 0.0474, ****PQC–C4 < 0.0001 using a two-sided Fisher’s exact test comparing 35S:WOX5-GR and 35S:WOX5-GR han-30 genotypes. d, Induction of HAN expression after DEX treatment as indicated. Left images, confocal images of PI-stained 35S:HAN-GR-expressing roots carrying the CC reporter QC0680:erGFP. Right images, DIC images of roots expressing 35S:Gal4-VP16-GR UAS:HAN (35»HAN). Lugol staining shows starch grains in the CCs (brown), and blue signal shows expression of the QC-specific reporter QC184:GUS. e–g, Expression of the columella stem cell marker J2341 (green) increases after induction of 35S:HAN-GR (e), similarly to after 35S:WOX5-GR induction (f and g). Representative images of n > 20 roots from each of 3 independent lines (d–g). Scale bars, 20 μm.
