Figure 3

Analysis of Fusarium infection on Bd coleoptile and root. a) FgUK1 symptoms on leaf sheath. Scale bar = 1 cm. b) FgUK1 symptoms on Bd21 roots (left) and mock inoculation control (right), 48 hpi. Scale bar = 0.5 cm. c-g) Light microscope images of Fg UK1 infection on Bd21 coleoptiles, 6 dpi, stained with trypan blue. c) Fg hyphae penetration attempt via infection pegs (arrows) at the junction between adjacent cells showing associated deposition of phenolic compounds. d) Unsuccessful penetration attempt via infection pegs (arrows) at the junction between adjacent cells which, at lower focal plane (e), display intense deposition of phenolic compounds beneath the attempted infection point. f) Successful penetration attempt via infection pegs (arrows) at the junction between adjacent cells which, at lower focal plane (g) appear to be prised apart. Scale bars: c = 10 μm, d = 10 μm; e = 20 μm, f & g = 10 μm. h) Light microscope image of Fg UK1 at disease front of Bd21 root infection, 48 hpi stained with trypan blue. Scale bar = 20 μm. i) CLSM image of GFP-expressing Fc at infection site of Bd21 root, 48 hpi. Arrow shows hyphal translocation between two adjacent cortical cells. Scale bar = 10 μm.