Figure 3.

Reinfection/sporulation assay. Cured fungi were cocultivated with previously isolated B. rhizoxinica endosymbionts and sporulation of fungal cultures monitored by eye and light microscopy. Using wild type bacteria, after 5 days (agar plate) or 3 days (liquid media), fungal cultures start to sporulate, indicating successful reinfection and triggering of sporulation by endosymbionts. A rhizoxin biosynthesis deficient mutant shows identical behavior as the wild type. T3SS mutants (ΔsctC::Kan^r, ΔsctT::Kan^r) failed to elicit host sporulation. (a): Reinfection/sporulation assay on agar plates. (b): Sporulating R. microsporus infected by wild type bacteria. (c): Non-sporulating R. microsporus infected with T3SS mutant. (d): Reinfection/sporulation assay in liquid media (48-well plates).