Fig. 4: Secretion-dependent suberin deposition.

a,b,f Fluorol yellow staining for suberin in roots. Fluorescence is presented as Look Up Table (LUT, Fire), scale bars, 50 μm. Representative pictures from at least 10 independent experiments with at least 6 individual roots. a WT plants treated or not with ABA. For each condition, left pictures taken at 2 mm from root tip, right pictures display the first suberizing cells (1^st cells, highlighted with arrows). b, c WT and gnl1GNL1-LM lines treated or not with ABA and/or BFA. b Pictures taken at Hyp-2 mm from hypocotyl. Arrows highlight the cortical suberin. c Quantification of maximum fluorescence intensity in cortical-epidermal walls, data presented as box plots (n = 14, 22, 10, 28, 22, 16, 14, 28 measures, from 7, 11, 5, 14, 11, 8, 7, 14 individual roots in WT (Unt, ABA, BFA, BFA+ABA) and gnl1GNL1-LM (Unt, ABA, BFA, BFA+ABA) respectively), two measures taken per root from opposite cortical cell files, different letters indicate significant differences between genotypes and growth conditions (P < 0.05). d, h TEM sections showing a cortical cell in WT and gnl1GNL1-LM lines (d) or big3 mutant (h) treated or not with ABA and/or BFA at Hyp-2mm. Arrows highlight EVBs. Lower panels correspond to a magnification from upper panels (zone defined with dashed lines). e, i Number of EVBs (in grey, left axis) and number of suberized cells (in orange, right axis) in cortical layers TEM cross-sections of full roots in WT and gnl1GNL1-LM lines (e) and in WT and big3 mutant (i) treated or not with ABA and/or BFA. Data are presented as dot plots with box plots overlaid (n = 16, 17, 16, 16, 16, 17, 16, 16, 17, 17, 16, 17, 16, 16, 17, 16 cortical cells for EVB number in WT (Unt, ABA, BFA, BFA+ABA), gnl1GNL1-LM (Unt, ABA, BFA, BFA+ABA), WT (Unt, ABA, BFA, BFA+ABA) and big3 (Unt, ABA, BFA, BFA+ABA) respectively; suberized cells per section were counted for two roots). Different letters indicate significant differences between genotypes and growth conditions for EVB counting (P < 0.05). f, g WT and big3 mutant treated or not with ABA and/or BFA. f Pictures taken at Hyp-2 mm from hypocotyl. Arrows highlight the cortical suberin. g Quantification of maximum fluorescence intensity in cortical-epidermal walls, data presented as box plots (n = 10, 16, 12, 14, 10, 16, 10, 20 measures, from 5, 8, 12, 14, 10, 16, 10, 20 individual roots in WT (Unt, ABA, BFA, BFA+ABA) and big3 (Unt, ABA, BFA, BFA+ABA) respectively), two measures taken per root from opposite cortical cell files, different letters indicate significant differences between genotypes or growth conditions (P < 0.05). c, e, g, i For boxplots, box shows the quartiles, whiskers indicate the minimum and maximum non outlier values, dots located outside the whiskers of the box plots indicate outliers falling outside 1.5 times the interquartile range above the upper quartile and bellow the lower quartile, and center line corresponds to the median.