Figure 4: Pathogenicity and AAL-toxin production of the ALT7- disrupted strains. (A) Pathogenicity test by spore inoculation with A. alternata As-27 wild type (WT), ALT7-disrupted (T1) and ALT7- complemented (T1C) strains. The leaves were inoculated with a spore suspension (105 conidia/ml) and incubated in a moist chamber at 25C for 3 days. (B) Leaf necrosis bioassay for AAL-toxin production by WT, T1 and T1C. The leaves of the susceptible tomato cultivar Aichi-first were treated with culture filtrates of each strain at 25C for 3 days. (C) HPLC chromatograms of culture filtrates of WT, T1 and T1C. The strains were grown on rice for 15 days. Samples of each fungus were dried and extracted with CH3CN:H2O (1:1, v/v). The extracts were cleaned using a Sep-Pak C18 cartridge column with CH2CN:H2O (7:3, v/v) as a solvent. The OPA derivatization and HPLC analysis were described previously [12,28]. The peaks for AAL-toxin TA are indicated by arrows.