Fig. 4: Complementation of the iku2 phenotype by the mutant of testa identity ap2.

a, c Labeling of demethylesterified pectins with LM19 (a) and JIM5 (c) antibodies in testa walls of Col-0 and ap2 seeds at 6 days post-anthesis. Scale bars: 20 µm. b, d Quantification of the signal from the LM19 (b) and JIM5 (d) antibodies in the 4 outermost testa walls of Col-0 and ap2 seeds (one experiment, Col-0: n = 10 seeds, ap2-6: n = 8 seeds). The centerline shows the median; the box limits show the upper and lower quartiles; the whiskers correspond to 1.5× interquartile range. Individual points are superimposed in black. Signal intensities were compared using two-sided Student tests without adjustments for multiple comparisons, *p < 0.05, **p < 0.01, **p < 0.001, ****p < 0.0001. e Representative seeds of Col-0, iku2, ap2-6 and iku2 ap2-6 at maturity. Scale bars, 0.5 mm. f Measurements of seed area in Col-0, iku2, ap2-6 and iku2 ap2-6 (one experiment: Col-0, n = 406; iku2, n = 426; ap2-6, n = 414, ap2-6 iku2, n = 184). Superimposed on the violin plot, in the boxplot, the centerline shows the median; the box limits show the upper and lower quartiles, the whiskers correspond to 1.5× interquartile range and the single points show outliers. Seed areas were compared using two-sided Student tests without adjustments for multiple comparisons. ***p < 0.001. g Final relative seed radius as a function of three stiffening parameter values (α, ρ, η) and of the intensity of the drop of pressure (using either Col-0 pressure drop or iku2 pressure drop) in the 100 simulations best-fitting iku2 growth data using iku2 pressure drop function as an input. In the boxplot, the centerline shows the median; the box limits show the upper and lower quartiles, the whiskers correspond to 1.5× interquartile range and single points show outliers (n = 100).