Fig. 5: Root infection is negatively impacted in ann1 mutant and RNAi transgenic roots.

Infection of M. truncatula R108 mutant (a–n) and A17 RNAi roots (o–r) for MtAnn1 with lacZ-expressing (blue) S. meliloti. At 4 dpi, quantification of the number of ITs in root hairs (a) and reaching outer cortex (b), proportion of non-infected (-) vs. infected (+) nodule primordia (NP) (c) and NPs with 1 or more ITs (d), as depicted in (e–h) (R108 n = 17, R108S n = 21, ann1-2 n = 36 and ann1-3 n = 38). At 10 dpi (i–l), quantification of nodule number/plant (R108 n = 18, R108S n = 21, ann1-2 n = 30, ann1-3 n = 21) (m) and infection level (X-gal staining intensity) (n) (R108S n = 196, ann1-2 n = 295, ann1-3 n = 310). Arrows indicate ITs (e–h) and poorly-infected nodules (i–l). Quantification of number of nodules/NP (o) and infection level (p) in pMtAnn1:GUS control (n = 51) and pMtAnn1:RNAi-MtAnn1 (n = 50) roots at 5 dpi (q, r). Control (arrowheads) and RNAi ITs (arrows) are indicated. Box plots (a, b, m–p) show the distribution of values (dots or circles) from 2 (a–d, m, n) or 3 (o, p) independent experiments. First and third quartiles (horizontal box edges), minimum and maximum (outer whiskers), median (centerline), mean (solid black circle) and outliers (crosses) are shown. Classes with the same letter (a, b, m, n) are not significantly different (p = 0.0388 in a, p = 0.0449 in b, p = 9,17e-13 in n, Kruskal-Wallis α = 5%; p = 0,076 in m, one-way ANOVA). Asterisks (c, d, o, p) indicate statistical difference relative to R108S (in c, p = 0.8408 for R108, p = 0,0027 for ann1-2, p = 0,0198 for ann1-3; in d, p = 0.7947 for R108, p = 0.0226 for ann1-2, p = 0.001 for ann1-3, two-tailed Fisher’s exact tests) or control (p = 0.0176, two-tailed Student t-test in o; p = 0.0023, two-tailed Mann-Whitney test in p). Scale bars: e–h, i–l = 100 µm, q, r = 1 mm. See Supplementary Figs. 12, 13. Source data are provided as a Source Data file.