Fig. 3: Oxygen entry through the wound suppresses hypoxia signalling and promotes periderm regeneration.
From: Plants monitor the integrity of their barrier by sensing gas diffusion
a,b, Cross-sections of 14-day-old intact proPCO1:erVenus roots (a) and 21-day-old proPCO1:erVenus roots right after injury (b, top) or at 2 dai (b, middle); and quantification of proPCO1:erVenus signals in the vascular region at 0 and 2 dai (b, bottom). Two-tailed Welch’s t-test was used (**P < 0.01). c, The quasi-steady-state oxygen concentration was measured and quantified before and after the periderm peeling. Paired Wilcoxon rank-sum test was used (*P < 0.05). d, Cross-sections of 25-day-old proPER15:erVenus roots at 1 dai grown on MS (mock) or 10 µM ACC-supplemented MS (ACC) plates in ambient air, or on MS (hypoxia) or 10 µM ACC-supplemented MS (ACC + hypoxia) plates under 5% oxygen concentration for 1 dai. e, The proportion of cells at the wound site showing Venus signal intensities above the threshold was quantified at 1 dai in mock ACC-treated, hypoxia-treated and ACC + hypoxia-treated proPER15:erVenus roots. Kruskal–Wallis test followed by Dwass–Steel–Critchlow–Fligner pairwise comparisons was used (different letters indicate statistically significant differences between two groups; P < 0.01). f, Cross-sections of 21-day-old ate1-2;ate2-1 roots at 4 dai grown on MS (mock) or 10 µM ACC-supplemented MS (ACC) plates for 4 dai. g, The proportion of suberized cell formation at the wound site in mock and ACC-treated 21-day-old wild-type and ate1-2;ate2-1 roots at 4 dai. Two-sided Fisher’s exact test was used to test for significant differences between mock- and ACC-treated ate1-2;ate2-1 (**P < 0.01). h, Schematic of periderm integrity surveillance mechanisms mediated by ethylene and oxygen diffusion. n indicates the number of examined cross-sections in b,e,g and the number of repeats in c. Venus signal intensities in a,b,d and intensity of suberin staining with Fluorol yellow in f are shown according to the colour scales on the right. The top (brighter) area of the scale represents a higher intensity of signals. White, SR2200 (cell wall). Scale bars, 50 µm.
