Self-fertility of G. zeae strains grown on carrot agar. Dissecting microscopic pictures were taken 10 days after sexual induction. Each strain was inoculated on carrot agar without (upper) and with (lower) 0.5% POL. WT, G. zeae wild-type strain GZ3639; Δacs1, ACS1 deletion mutant; Δacs2, ACS2 deletion mutant; Δacs1 Δacs2, double deletion mutant of ACS1 and ACS2; and ACS1c, ACS1- derived strain complemented with ACS1-GFP. Scale bar, 0.5 mm.