Fig. 4: Experimental measurements of the cell wall porosity in Col0 wild type and sfr8 arabidopsis leaves.
From: Understanding pectin cross-linking in plant cell walls
a Change in the fluorescence of the FM4-64-stained plasma membrane (see text) for Col0 and sfr8 cell wall samples. A time series of three representative fluorescence images reported for each point in time for each genotype are shown. The optical microscopy images were taken before quenching (F0), immediately after addition of trypan blue (F) and at 3-min intervals thereafter. The scale bar (yellow) is 5 μm. b Change in the relative fluorescence (F/F0) as a function of time. The mean values of F/F0 are measured every 3 min within a 0–15 min time interval, for both Col0 and sfr8. The value at the Y-axis intersection represents the unquenched sample (F/F0) and is equivalent to 1.0. Three separate Regions of Interest (ROI) were assessed per epidermal peel (39 and 42 ROI for Col0 and sfr8, respectively). The data were combined from three separate experiments. For statistical comparisons, a two-way ANOVA with Bonferroni’s multiple comparisons test82 was employed. The p values at time points 0, 3, and 6 min are 0.0141, 0.003, and 0.0221, respectively. Other time points showed no significant difference. The “*” and “**” symbols indicate moderate (p value ≪ 0.05) and strong (p value ≪ 0.01) evidence, respectively, for a significant statistical difference between the two time series. c SEM images of Col0 and sfr8 cell walls. Three representative images, taken from 3 different leaves, are shown for both genotypes. The scale bar (yellow) is 0.25 μm. d Pore size (area, nm2) frequency distributions for Col0 and sfr8. The pore size distributions from the ROI (9 and 11 ROI for Col0 and sfr8, respectively) of three individual plants per genotype was assessed. A frequency distribution with a bin width and range of 15 and 5–305 nm2, respectively, was employed.
