Lysophosphatidylcholine 17:1 from the Leaf Surface of the Wild Potato Species <i>Solanum bulbocastanum</i> Inhibits <i>Phytophthora infestans</i>

Late blight, caused by the oomycete Phytophthora infestans, is economically most important foliar disease of potato. To assess importance leaf surface, as site first encounter pathogen and host, we performed untargeted profiling liquid chromatography–mass spectrometry surface metabolites susceptible cultivated potato Solanum tuberosum resistant wild species bulbocastanum. Hydroxycinnamic acid amides, typical phytoalexins potato, were abundant on S. tuberosum, but not One accumulating was identified lysophosphatidylcholine carrying heptadecenoic acid, LPC17:1. In vitro assays revealed that both spore germination mycelial growth P. infestans efficiently inhibited LPC17:1, suggesting from could contribute to early defense responses against infestans.