PME activity is required for RALF1-induced root growth repression
(A-B) Three-day-old wild-type seedlings were subjected for three days to 1 µM RALF1 and/or 2.5 µM EGCG (A). (B) Boxplots depict the root length of wild-type seedlings under different treatments shown in (A).
(C-D) Three-day-old wild-type seedlings were transferred for three days to solvent control, 1 µM RALF1 and/or 15 µM EC (C). (D) Boxplots depict root length of wild-type seedlings under different treatments shown in (C).
(E-F) Confocal microscopy images of the root epidermal cells of 6-day-old wild-type seedlings after 3 h treatment in liquid medium with 50 µM EC/EGCG or solvent control. Seedlings were stained with COS488 to visualize de-methyl esterified pectin. (F) Boxplots displaying the probe staining signal intensity shown in (E). (n=8-10 roots per treatment with a total number of 79 - 96 quantified cells).
(G-H) Confocal microscopy images of the root epidermal cells of 6-day-old wild-type and PMEI3-OE seedlings, stained with COS488 to visualize de-methyl esterified pectin. (H) Boxplots displaying the probe staining signal intensity shown in (G). (n=9 - 11 roots per treatment with 71 - 77 quantified cells, scalebars=25µM).
(I-J) Three-day-old wild-type, PMEI3-OE and PMEI5-OE seedlings were exposed for three days to 1 µM RALF1 or solvent control (I). (J) Boxplots depict the root length of wild-type compared to PMEI3-OE seedlings of the treatments shown in (I).
(K-L) Three-day-old wild-type seedlings were exposed for three days with 0.5 µM flg22 and 15 µM EGCG or solvent control (K). (L) Boxplots depict the root length of wild-type seedlings under different treatments shown in (K).
Statistical significance was determined by a one-way ANOVA with a Tukey Post Hoc multiple comparisons test (P < 0.05, letters indicate significance categories) (B, D, F, J and L) and a student’s t-test (***p = 0.0001) (H). Boxplots: Box limits are representing the 25th and 75th percentile, the horizontal line represents the median. Whiskers display min. to max. values. Representative experiments are shown. (A,C, I, K) Scale bar = 1 cm, n =11-13 roots per treatment/line.