Plant interaction phenotype for Lolium perenne infected with Epichloë festucae wild‐type (WT) and NADPH oxidase complex mutants. (a) Whole‐plant phenotype of E. festucae wild‐type and ∆noxA, ∆noxB, ∆noxAB and ∆noxR mutants at 8 wk post inoculation. (b, c) Epiphyllous growth (fluorescence captured with blue pseudocolour) of WT and ∆noxA E. festucae on the blade extension zone of L. perenne, showing the enhanced growth of epiphyllous hyphae in the latter. (d–g) Leaf sheath and blade cellular phenotypes of L. perenne infected with E. festucae
WT (d, e) and ΔnoxA (f, g), showing the enhanced proliferation of hyphae in the latter. Fluorescence of endophytic hyphae was captured with orange pseudocolour (from aniline blue), apart from septa captured with blue pseudocolour (from WGA‐AF488). Confocal depth series images of leaf tissue, showing hyphae stained with aniline blue/WGA‐AF488 (b–g). Images were generated by maximum intensity projection of confocal z‐stacks. Bars: (b, c) 100 μm; (d–g) 25 μm.