(A) Growth of the parental strain and the mgtc mutant for 24 h at 37°C on Czapek agar medium without magnesium or supplemented with 20 μM, 100 μM, or 1,000 μM magnesium. (B) Expression levels of the AfuMGTC gene and the AfuTEF1 control gene after 32 h of growth at 37°C in Czapek liquid medium supplemented with 10 μM, 50 μM, 100 μM, or 1 mM magnesium.