Lay summary
Syringolin A, a product of a mixed non-ribosomal peptide/poyketide synthetase that is secreted by the phytopathogenic bacterium Pseudomonas syringae pv. syringae, triggers hypersensitive cell death at infection sites in compatible powdery mildew interactions both in wheat and Arabidopsis. Transcriptome analysis in infected and uninfected wheat and Arabidopsis showed that syringolin appears to have a conserved mode of action as similar groups of genes are activated. Analysis of the results lead to a working hypthesis about how cell death might be triggered at infection sites, according to which cell death at infection sites may result from a parasite-induced suppression of the transcriptional response which in turn would lead to insufficient production of proteins necessary for the recovery of these cells from the insult that is imposed by syringolin A. The results can be interpreted to suggest a mode of action of syringolin that will be tested. Interestingly, syringolin A was also shown to inhibit cell proliferation and to induce apoptosis in mammalian neuroblastoma and ovarian cancer cells.