Expression profiles of three ALS genes in tomatoes upon powdery mildew attack. (A) NIL-Ol-1 and (B) Moneymaker (MM). Samples were harvested at 0 hpi (prior to inoculation), 8 hpi (hours post inoculation), 1 dpi (days post inoculation), 3 dpi and 5 dpi. For each biological replicate the 3rd and 4th leaves were pooled from three plants. Values are normalized relative to EF, and expression level at each time point after inoculation were calibrated to levels of counterpart plants without inoculation. Error bars represent standard deviation of three biological replicates. To test whether expressions of ALS1 and ALS2 were different between NL-Ol-1 and MM, two-way between groups ANOVA was used.