Whole transcriptome analysis in nicotiana benthamiana WT and transgenic lines presenting spontaneous systemic posttranscriptional silencing (PTGS) of a GFP transgene (line GFP6.4 described in Kalantidis Plant J 2006). Change in gene expression was analysed in WT versus GFP6.4 before initiation, during spreading and maintenance of GFP-PTGS.

Detect the global transcriptional changes occuring during spreading and maintenance of systemic post transcriptional silencing . Test the hypothesis that activation of systemic PTGS induces parallel antiviral defense pathways. Gene expression was analysed by MACE method (Massive Analysis of cDNA Ends) on total RNA extracted from leaf tissues of WT plants (WT), and GFP6.4 presenting no-silencing (NS sample), ongoing spreading of silencing (OS) and maintenance of silencing (SS). Plants were grown in parallel, and silencing state was monitored under UV. After 3 weeks of growth, total RNAs were extracted using the Trizol method from leaf tissues of 2-3 leaf stage plants. A total of 4 plants were sampled per variable (WT/NS/OS/SS). RNA from 4 plants were pooled and sequenced.