Effect of nutritional factors on AflR (AFLR) expression. A. parasiticus NRRL 2999 was grown in various media (PMS, GMS, GMS−Zn, GMS+NH4NO3, and GMS+NaNO3) for 70 h. Duplicate samples in each group were collected, subjected to sodium dodecyl sulfate–10% polyacrylamide gel electrophoresis (50 μg of protein/lane), and tested by Western blot analysis with anti-AflR antibodies. Results of the Western blot analysis for AflR are shown in the top panel. The accumulation of AFB1 and relative AflR levels in Western blots are shown in the bottom panel. The intensity of the AflR signal for the GMS medium culture was considered 100%.