Figure 1.

Toxin production assay of the various Fgp1 mutant strains with two independent parameters, carbon source (glucose and sucrose) and initial pHs (4 and 2.5), cultured on 30 mL of medium in a 100-mL Erlenmeyer flask with gyratory shaking (135 rpm) at 25°C. (A) Each of the four strains tested (wild-type, WT; complemented, C; overexpressor, O/E; phosphorylation site mutant, T67A) was cultured on the defined media with amino acids mixture nitrogen source (Supplementary Table 1), and the carbon source and initial pH as indicated at the top. Each culture was sampled on days 2, 3, 4 and 5 of incubation. TLC panels show the spots of 15-ADON extracted from 500 μL of the medium with ethyl acetate. (B) Time course of pH changes of each fungal culture. When cultured at initial pH of 4, the wild-type, complemented, and T67A strains exhibited similar pH profiles, while the overexpressor displayed an increase in pH and deviated from the other three strains (upper graphs). When cultured at initial pH of 2.5, all four strains exhibited similar pH profiles (lower graphs).