Real-time gene induction patterns upon CIT and OTA exposure. Yeast strains with genomic fusions of the indicated promoters with destabilized luciferase were used. a, dose-response profiles of PDR5, PDR15, SNQ2, and YOR1 upon the treatment with the indicated mycotoxin concentrations. The light emission from three independent culture aliquots was continuously measured. S.D. was <15% throughout the experiment but is not included in the graphs. b, comparison of the sensitivity of gene induction of the same four reporter genes. Shown are the mean values of three independent measurements including S.D. c, sensitivity assays of the indicated transporter mutants. Cells were treated in liquid culture aliquots with the indicated CIT concentrations. Cell growth was then assayed on YPD plates (left panel) and cfu determined (right panel). Significant differences according to the Student's t test are marked (*, p < 0.05; **, p < 0.01).