Verticillium manipulates RNA silencing to suppress host immunity

RNA silencing is a eukaryotic mechanism that exploits small non-coding RNAs (small- RNAs) to regulate gene expression in a sequence-specific manner in many cellular processes, including innate immunity. The plant immune system against viruses and bacteria is a well-known target of RNA silencing. Data from our laboratory indicate that the fungus Verticillium dahliae also targets the plant RNA silencing pathway, presumably by secreted effectors, to suppress host defence (Ellendorff et al., 2009). How Verticillium manipulates the RNA silencing pathway to suppress host immunity is still unknown. Arabidopsis is susceptible towards Verticillium, and a model plant to study epigenetics. We plan to identify the secreted Verticillium effectors and the Arabidopsis components that play a role in RNA silencing and are essential for Verticillium wilt disease. We have identified Verticillium regulated gene transcripts and small-RNAs of the host by combining transcriptomics and small-RNA profiling. We are currently investigating if the identified small-RNAs and putative gene targets are contributing to Verticillium immunity, the obtained results will be presented. References Ellendorff U., Fradin E.F., de Jonge R., Thomma B.P. 2009: RNA silencing is required for Arabidopsis defence against Verticillium wilt disease. J Exp Bot. 60(2):591-602.