Fig. 3: XopR clusters Arabidopsis formin in vivo and in vitro.

a Representative images of the AtFH6-GFP clusters and moving trajectories in Arabidopsis. Seven-day-old seedlings were dip-inoculated with Xcc/XccΔhrcC/XccΔxopR for 24 h before imaging using VA-TIRFM. b–e Distributions of signal intensity (from left to right, n = 454, n = 406, n = 650, and n = 636 punctates), mean square displacement (MSD) and diffusion coefficient (n = 0 movies from six seedlings for each infection assay), and percentage distribution of the bleaching step (n = 165 punctates for mock, n = 167 for Xcc, n = 165 for XccΔhrcC, and n = 164 for XccΔxopR) were analyzed for AtFH6-GFP foci. The relative ratios of total bleaching steps are indicated in brackets, which were normalized by mock without Xcc. Error bands and error bars in Fig. 3c, d are ± SD. Whiskers represent min to max. f Representative dual-color TIRF images of 2.5 nM AtFH1-FH1C (10% Alexa647-AtFH1-FH1C) with 2.5 nM XopR (10% XopR-mRuby2) on an immobilized supported lipid bilayer (SLB). g Signal intensity quantification of AtFH1-FH1C (50% Alexa647 labeled) on SLB for Supplementary Fig. 5g (n = 250 particles, Error bar, SD). h Representative dual-color confocal images of AtFH1-FH1C (5 μM, 10% Alexa647-AtFH1-FH1C) with XopR (5 μM, 10% Alexa488-XopR) that were incubated on dynamic SLB with 50 mM NaCl for 15 min before imaging. i Actin polymerization rate in the pyrene–actin assay, which was normalized by spontaneous actin polymerization, in the presence of 100 nM AtFH1-FH1C and XopR (left to right, 0, 25, 50, 100, 200, 400, and 1600 nM) at the indicated stoichiometries in the presence of 5 μM profilin AtPRF1 (n = 4 for 0, 25, 50, 100, 200 nM, n = 6 for 400 nM, and n = 7 for 1600 nM; Error bar, SD). Scale bar: 2 μm for a, 10 μm for b–f, 2 μm for magnified images in f, 10 μm for h. Two-tailed Student’s t-test was performed assuming equal variance. Ns no significant difference, *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001.