Pospiviroid pathogenesis as "regulatory disorder" mediated by viroid-specific small RNAs

• Applicants: Professor Dr. Jörg Schubert; Professor Dr. Gerhard Steger
• Subject Area: Organismic Interactions, Chemical Ecology and Microbiomes of Plant Systems
• Term: from 2009 to 2013
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 159036268

We will analyze mechanisms of pathogenesis of two viroids (small, infectious, single-stranded, circular, non-coding and autonomously replicating RNAs) from Pospiviroidae family: potato spindle tuber viroid (PSTVd) infecting various vegetables and ornamentals and highly expansive hop stunt viroid (HSVd) that, in particular, represents a danger to hops in Europe. Based on our previous study, we aim to verify the hypothesis that pathogenesis caused by pospiviroids involve viroid-specific (vs) small RNAs, misregulation of host-encoded microRNAs and plant transcription factors (TFs). In order to analyze the mechanism(s) of viroid pathogenesis we perform: 1. “deep” sequencing of small RNAs; 2. prediction of vsRNA targets in silico including the whole genome data of PSTVd-sensitive tomato becoming available; 3. verification of vsRNA molecular targets, components of silencing mechanisms and TFs involved in pospiviroid pathogenesis by quantitative RNA expression assays, promoter activity assays and by virusinduced gene silencing technology (VIGS) using N. benthamiana, tomato and hop.

• DFG Programme: Research Grants
• International Connection: Czech Republic
• Participating Person: Dr. Jaroslav Matousek