Plants recognize invading pathogens and trigger an array of signalling events eventually leading to a resistance response that prevents or limits pathogen growth in planta. One signalling event upon pathogen infection is the formation of lipid derived oxylipins. In the animal physiology a broad signalling role of fatty acid derived molecules (eicosanoid family of lipid signals) have been well established. Increasing evidence is emerging that plant oxylipins have a similar complex and vital biological role as signalling molecules contributing to resistance. In an in vitro assay, application of the oxylipin 9-hydroxyoctadecatrienoic acid (9-HOT) triggered potent effects in Arabidopsis wild-type seedlings like a root waving phenotype and the induction of hallmarks of plant defence. From a forward genetic screen approximately 30 mutants were identified that were non responsive to the oxylipin 9-HOT (noxy mutants) . A subset of these mutants has been tested in pathogen assays and revealed altered defence responses (enhanced or decreased resistance). The task will now be to identify the mutated genes and to perform their functional characterisations. I expect to identify genes that are of central importance for the perception and transduction of oxylipin signals in plant immunity.