Extended Data Fig. 3: Characteristics of the Sln1 turgor-sensor kinase.

a, Graphical simulation of a mathematical model for appressorium function in M. oryzae. The model assumes that septins are recruited to the appressorium pore at a seeded ring structure that allows the recruitment of F-actin. Melanin is recruited to the appressorium dome in proportion to increasing turgor, and excluded from the pore. A turgor sensor (TS) is recruited to the pore to modulate melanization and turgor generation, while positively regulating septin recruitment and F-actin reorganization; this results in cuticle rupture (Supplementary Video 1). b, A mutant that lacks the turgor sensor generates excess appressorium turgor, recruits more melanin to the cell wall and prevents the recruitment of septin and F-actin to the pore; the cuticle is therefore not breached (Supplementary Video 2). c, Micrographs showing that the Δsln1 mutant is unable to invade and colonize rice tissue after 36 h.p.i. No invasive hyphae were visualized inside rice cells inoculated with Δsln1. Images are representative of n = 2 independent biological replicates. Scale bar, 10 µm. d, Localization of Sln1–GFP in conidia and appressoria of M. oryzae. Conidia were collected from a M. oryzae Guy11 transformant that expresses a Sln1–GFP gene fusion, and inoculated on glass coverslips. Images were captured at 0, 4, 6, 8 and 24 h.p.i. Micrographs are representative of the distribution of Sln1–GFP at the indicated time points in n = 3 independent biological replications of the experiment. Scale bars, 10 µm. e, Epifluorescence micrographs showing that the cellular distribution of H1–GFP in appressoria at 24 h.p.i. is unaffected by exposure of appressoria to 1.5 M glycerol at 5 h.p.i. Images are representative of n = 3 independent biological replicates; 50 appressoria were counted per replicate. Scale bar, 10 µm.