Effect of L-tryptophan, tryptamine and indole-3 acetaldehyde on gene expression in Fusarium graminearum

Fusarium graminearum is a plant pathogen that can cause the devastating cereal grain disease fusarium head blight (FHB) in temperate regions of the world. Previous studies have shown that F. graminearum can synthetize indole-3-acetic acid (auxin) using L-tryptophan (L-TRP)-dependent pathways. In the present study, Gene expression profiles were obtained using microarray analysis of RNAs from F. graminearum cultures in auxin producing conditions, treated with L-TRP, tryptamine (TAM) and indole-3 acetaldehyde (IAAld). A comparative expression profiling of all treatments identified candidate genes for auxin production in F. graminearum. Additional analysis of the expression profiling between L-TRP-treated and control cultures showed that L-TRP treatment induce the up-regulation of a series of genes with predicted function in the metabolism of L-TRP via anthranilic acid and catechol towards the tricarboxylic acid cycle. F. graminearum stain DAOM180378 mycelia samples in 2nd stage media were treated with either 2 mM L-TRP, 0.2 mM TAM, 0.2 mM IAAld or were untreated (NT). Dual-channel, three biological replicated for each treatment with two technical replicates (dye-swaps) for each sample.