FIGURE 1.

The capsid protein (CP) from Tomato yellow leaf curl virus (TYLCV) localizes to the nucleolus and the nucleoplasm, and this localization is changed in the presence of the virus. Nicotiana benthamiana leaves were infiltrated with Agrobacterium tumefaciens carrying constructs to express CP-GFP and GFP-CP alone (A) or co-infiltrated with A. tumefaciens carrying a TYLCV infectious clone or an empty vector (EV) as control (B). The subcellular localization of CP-GFP or GFP-CP was observed under the confocal microscope 2 days after infiltration. Five subcellular localization stages of GFP-fused CP were defined. Stage I: GFP-fused CP localizes strongly to the nucleolus and more weakly to the nucleoplasm, and only occasionally forms a few speckles in a few cells (<5%); Stage II: GFP-fused CP shows a similar localization similar to that of Stage I, but forms numerous speckles in the nucleoplasm; Stage III: GFP-fused CP shows a localization similar to that of Stage II, but it is absent from the nucleolus; Stage IV: GFP-fused CP localizes to the nucleoplasm only, where it is unevenly distributed; Stage V: GFP-fused CP is uniformly distributed in the nucleoplasm. This experiment was done three times; more than 20 cells were observed per sample and replicate. (C) Tomato leaves were co-infiltrated with A. tumefaciens carrying a construct to express RFP-CP, and a TYLCV infectious clone or empty vector (EV) as control. The subcellular localization of RFP-CP was observed under the confocal microscope 2 days after infiltration. This experiment was repeated three times; more than 15 cells were observed per sample and replicate. BF, Bright field. Scale bar: 10 μm.