Fig. 4.

Auxin controls the actin-dependent cellular occupancy of the vacuole. (A and B) Surface renderings of vacuoles of Col-0 seedlings treated with DMSO (control) (A) or auxin (NAA; 250 nM, 20 h) (B). Seedlings were stained with BCECF-AM (green), and PI (red). (C and D) Quantification of relative vacuole volume (*P < 0.05) (C) and surface-to-volume ratio (***P < 0.001) (D) for control and auxin treatment. (E–H) Surface renderings of vacuoles after treatment with DMSO (control) (E), auxin (NAA; 500 nM, 6 h) (F), or LatB (500 nM, 6 h) (G) or cotreatment with LatB and auxin (H). (I–L) Surface renderings of DMSO-treated act2act8 (I) and xi-k/1/2 (K) mutants and auxin-treated act2act8 (J) and xi-k/1/2 (L) mutants. (M) Surface-to-volume ratios. ***P < 0.001. (N–Q) MorphoGraphX-based cellular and vacuolar segmentation to quantify volume in cells treated with DMSO (control) (N), auxin (NAA) (O), JASP (2.5 µM, 6 h) (P), or cotreated with JASP and NAA (Q). (R–U) Cellular and vacuolar segmentation of act2act8 (R and S) and xi-k/1/2 (T and U) mutants treated with DMSO (R and T) or with auxin (NAA) (S and U). (V) MorphoGraphX software was used to measure vacuolar volume in respect to cellular volume. *P < 0.05, ***P < 0.001. Data represent means ± SEM (n = 10 z-stacks from five individual seedlings for every condition for C, D, and M and n > 11 cells for V). (Scale bars: 5 µm.)