glutathione s-transferase (gst) activity pattern was determined in tolerant (cv. sumai#3) and susceptible (cv. falat) wheat heads inoculated with fusarium graminearum, the causal agent of head scab disease (fhb), during various developmental stages. gst specific activity exhibited a transient pattern in sumai#3 reaching a maximum level at the milk stage and declining thereafter. gst level in su...