Fig. 4: VIR1 is a negative regulator of antiviral RNAi.

a–d Accumulation of CMV-2aT∆2b (a, b) or CMV-∆2b (c, d) detected in wild-type (Col-0), single, double or triple mutant plants as indicated at 2 weeks post-infection by RT-qPCR analysis of the viral RNA3 (a, c), Northern blotting of the viral RNAs 1–4 (b, d), or Western blotting of the viral CP (b, d). The vsiRNAs and plant endogenous small RNAs were also detected by Northern blotting (b, d). Note the reduced sample loading (to ½) for total proteins and total RNAs from dcl2/4 double mutant plants and vir1/dcl2/4 triple mutant plants (b, d). e RT-qPCR analysis of DCL1, DCL2, DCL3 and DCL4 mRNA levels in wild-type (Col-0), single or double mutant plants without infection or one week post-infection with CMV-2aT∆2b as indicated. A. thaliana EF1α (At5g60390) mRNA was used as internal control. Data in (a), (c) and (e) are means ± SEM from three independent experiments, letters indicate groups with significant differences (one-way ANOVA, Duncan, p < 0.05) and green dots represent the individual values. ND not determined. The source data underlying blots in (b) and (d), and qRT-PCR data in (a), (c) and (e) are provided as a Source Data file.