Fig. 2

BP1 forms nuclear puncta in vivo. A Top, diagram of F. graminearum BP1 (top) with two intrinsically disordered regions (IDR1 and IDR2). Bottom, IDR analysis using the Predictor of Natural Disordered Regions (PONDR) database (http://pondr.com/). Regions with an average strength (PONDR score) ≥ 0.8 were considered to be disordered. B BP1 localization in hyphae of ΔBP1-C grown in YEPD medium at 25 °C for 24 h. The nuclei were stained with DAPI (4′,6-diamidino-2-phenylindole; blue fluorescence, 405-nm laser). The localization of BP1 to nuclear puncta is indicated by yellow arrows, scale bar, 2 μm. C Fluorescence intensity along the white line shown in B of the images of the ΔBP1-C strain expressing BP1-GFP and stained with DAPI. D BP1-GFP fluorescence in ΔBP1-C hyphae under control conditions (CK) or treated with 1% (w/v) 1,6-hexanediol before examination for GFP puncta. Scale bar, 5 μm. E 1,6-Hexanediol sensitivity of ΔBP1. The wild-type PH-1, ΔBP1, and ΔBP1-C strains were incubated on potato dextrose agar (PDA) containing 1% (w/v) 1,6-hexanediol for 3 days. Quantification of mycelial growth inhibition by 1,6-hexanediol for each strain is shown in the bar graph to the right. Different lowercase letters denote significant differences at P = 0.05. F ΔBP1-C complement strain grown in YEPD medium at 25 °C for 24 h. Fusion of nuclear puncta formed by BP1-GFP was examined by epifluorescence microscopy. Scale bar, 5 µm. G BP1-GFP nuclear puncta in the ΔBP1 mutant were subjected to fluorescence recovery after photobleaching (FRAP) experiments using a Zeiss LSM 980 confocal laser-scanning microscope. The bleaching laser intensity was set to 50%, and the excitation wavelength was 488 nm. H Quantification of BP1-GFP fluorescence intensity before and after bleaching, with six droplets included in the analysis