Figure 6.
Processing of TBSV dsRNA by DCL4, but not DCL2, in A. thaliana. (A) Northern blot analysis of high molecular weight RNA to detect TBSV in systemically infected rosette leaves, 9 dpi, of A. thaliana mutant lines. Quantification of signal intensity is provided. Each sample is a pool of 4–5 plants. (B) Northwestern blot to detect dsRNA in the samples described in (A). The black arrow indicates the dsRNA band observed upon genetic knock-out of DCL4. In (A,B) EtBr gel staining was used as loading control. (C) Northern blot analysis of low molecular weight RNA to detect TBSV-derived siRNA, using two separate probes. TBSV-mid detects siRNA derived from the 3′ end of the P92 ORF, while TBSV-P19 detects siRNA derived from the P19 ORF. As a loading control, the membrane was separately hybridized to a snU6-specific probe. In all the blots a non-infected control (n.i.) was included on the far left.