Insights into the virulence role of Blumeria graminis f.sp hordei RNAse-like effector CSEP0264 (BEC1011)  
K. ORMAN (1), L. Bindschedler (1), C. Turnbull (2) (1) Royal Holloway University of London, United Kingdom; (2) Imperial College London, United Kingdom

Candidate secreted effector proteins (CSEPs), including CSEP0264 (synonym BEC1011) were identified through transcriptomic and proteomic studies following the publication of the Blumeria graminis f.sp hordei genome. Like many CSEPs, CSEP0264 contains an RNase fold, therefore is identified as an RNAse-Like-protein in haustoria (RALPH). The virulence function of CSEP0264 was confirmed using Host Induced Gene Silencing (HIGS) since its silencing led to significant reduction in haustorial formation. Similar results were obtained when using “Silencing Targeted Effectors in planta” (STEP) as an alternative approach involving the direct delivery of antisense oligonucleotides to the host to silence fungal effectors. Unlike HIGS, STEP allows silencing in each cell - rather than a limited number of cells. Therefore STEP is amenable to whole leaf downstream analyses. In particular, the decreased virulence phenotype was associated with a significant, although modest, reduction of CSEP0264 mRNA in STEP treated leaves. Multiple reaction monitoring-mass spectrometry (MRM-MS) is being used to measure the relative abundance of the CSEP0264 protein in an attempt to correlate protein amount with the decreased virulence phenotype and reduced mRNA. The reduced virulence in CSEP0264 silenced plant was also linked with an increase in H2O2 production around the papillae, at the sites of attempted penetration

Abstract Number: P9-292
Session Type: Poster