In our studies on the interaction between barley and the bird cherry oat aphid (Rhopalosiphum padi L.), we have suggestive evidence that at least one salicylic acid (SA) regulated gene might be involved in defence in resistant barley genotypes With
this background, it was of interest to investigate whether thiamine treatments would induce increased resistance towards R. padi aphids in barley and whether any such effects would be related to SA regulated signal transduction.