Fig. 8: MtAnn1 is required for efficient mycorrhization of M. truncatula roots.
From: Annexin- and calcium-regulated priming of legume root cells for endosymbiotic infection
a pMtAnn1:GUS activity in M. truncatula A17 roots 4 wpi with R. irregularis (+AM fungi, n = 10) or mock control (n = 8) was analysed in 2 independent experiments. Representative images of root sectors inoculated with R. irregularis (+AM fungi) with or without fungal colonisation are shown. pMtAnn1:GUS (GUS) blue staining in root cortex (arrows) correlates with areas colonised by R. irregularis, visualised yellow by WGA-Alexa Fluor 488 fluorescence staining (WGA) and merged images (MERGE). b–g Phenotypic analysis of R108S or ann1-3 M. truncatula roots 6 wpi with R. irregularis. Representative images of ink-stained AM-colonised roots (b) or WGA-stained arbuscules (c) are shown. d, e Intraradical colonisation by R. irregularis was determined in R108S wild-type (n = 36) and ann1-3 (n = 38) using the gridline intersect method. Box plots show the relative surface of the root system with vesicles, arbuscules and/or intraradical hyphae (d) and the relative area corresponding specifically to arbuscules (e). f Arbuscule lengths were compared in R108S (n = 371, from 8 plants) and ann1-3 (n = 440, from 7 plants) roots at 6 wpi. g Q-RT-PCR expression analysis of MYB1 in total RNA samples from independent R108S (n = 10) or ann1-3 (n = 9) plants inoculated with R. irregularis (6 wpi). Box plots (d–g) show single values distributions (open circles or black dots) from 2 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. Asterisks indicate statistical difference between R108S and ann1-3 in (d–f) (p = 0.0004 in d, p = 0.0002 in e, two-tailed Student t-tests; p = 0.0046 in f, two-tailed Mann-Whitney test). Although there is a trend towards higher MYB expression in ann1-3 vs. R108S (g), the difference is not significant (p = 0.1228, two-tailed Student t-test). Scale bars: a = 100 µm, b = 50 µm, c = 20 µm. See also Supplementary Fig. 16. Source data are provided as a Source Data file.
