A, BiFC (split-YFP) analysis of HOs and phytochrome. Strains (SChS29-33) were grown over night at 28°C minimal medium with 2% threonine and 0.2% glucose. MitoTracker Red CMOXRos was used for mitochondrial staining. The mitotracker signal was observed in the RFP and the split-YFP signal in the YFP channel of the fluorescent microscope. Pictures in both channels were overlaid (merge). The left pictures show the same hyphae in differential interference contrast (DIC). The scale bar represents 10 µm. 