(A) V2-GFP and RFP-AGO4 co-localize in the Cajal body. CFP-Fibrillarin, V2-GFP and RFP-NbAGO4-1/2 or RFP-SlAGO4a/b/d were transiently co-expressed in N. benthamiana epidermal cells. CFP-Fibrillarin is used as nucleolus and Cajal body marker. Confocal images were taken at two days after infiltration. Arrowheads indicate the position of the Cajal body. Bar, 5 μm. This experiment was repeated more than three times with similar results. (B) V2 interacts with AGO4 in the Cajal body. The N-terminal half of the YFP fused to V2 (V2-nYFP) was transiently co-expressed with the C-terminal half of the YFP alone (cYFP, as negative control), or cYFP-NbAGO4, cYFP-SlAGO4, or cYFP-V2 (as positive control) in N. benthamiana leaves. CFP-Fibrillarin was used as nucleolus and Cajal body marker. Confocal images were taken at two days after infiltration. Yellow fluorescence indicates a positive interaction. Arrowheads indicate the position of the Cajal body. Bar, 5 μm. This experiment was repeated more than three times with similar results.