Extended Data Fig. 7: Auxin response and biosynthesis is required for CSC maintenance and iCSC induction by WOX5.
a–b: DR5:GFP expression in the Col-0 wild type (a) and pWOX5»bdl (b). The images shown are representative of n = 10 independent roots measured and producing similar results. c-d: QC184 expression in the Col-0 wild type (c) and pWOX5»bdl (d). The images shown are representative of n = 15 independent roots measured and producing similar results. The QC (white) and the CSCs (yellow) are indicated. Scale bars: 50 μm. e-f: Lugol-stained roots of the indicated genotypes in 5-day-old seedlings. Termination of CSCs is indicated by the accumulation of starch granules in wei8-1 tar1-1 mutants (f) compared to the Col-0 wild type (e). Insets show the magnification of CSC niche as indicated by white rectangular. The QC is outlined by dashed lines. White arrowheads indicate the CSC position. g: Frequency of roots with indicated numbers of CSC layers in the indicated genotypes. For Col-0, n = 51, wei8-1, n = 51, tar1-1, n = 60, wei8-1 tar1-1, n = 56 roots were analyzed. n.s., not significant; ***, p < 0.001, comparing presence vs. absence of starch-free CSC layers by a two-sided Fisher’s exact test with Bonferroni correction for multiple testing. pCol-0 vs wei8-1 tar1-1 = 0.001. h-i: iCSC induction by WOX5 is largely suppressed in wei8-1 tar1-1 (i), compared with 35S:WOX5-GR in the Col-0 wild-type (h) background. 5-day-old seedlings were induced by 10 μM DEX for 16 h. Dotted white lines indicate QC position. Asterisk with waved brackets indicate iCSC layers. In e-i, Scale bars: 20 μm. j: Quantification of the suppression of extra CSC layers as shown in (h-i). Error bars denote SD of 15 measurements. ****, p < 0.0001 by a two-sided Fisher’s exact test.
