FIGURE 4.

AaSte12 plays no roles in the production of ACT toxin. Fungal strains: Z7 (wild type), ΔSte12, and ΔΔACTT6 (defective for both ACTT_6-1 and ACTT_6-2 genes involved in the biosynthesis of ACT) were grown in Richard’s solution for 14 days. ACT was extracted with Amberlite XAD-2 resins, dissolved in methanol, and analyzed by HPLC. Extracts purified from Richard’s medium alone (minus fungal strain) or the ΔΔACTT6 double mutation strain with a similar manner were used as negative controls. A distinct peak with the retention time of 36.5 min was detected in the extracts purified from wild type and ΔSte12. The peak was barely detectable in samples purified from medium alone or ΔΔACTT6.