The Stable Association of Virion with the Triple-gene-block Protein 3-based Complex of Bamboo mosaic virus
Figure 9
The effects of Cys-to-Ala substitutions in TGBp3 on virus cell-to-cell movement and TGBp2- and TGBp3-dependent PD targeting of TGBp1.
(A) Diagrammatic representation of the infectious plasmid clones of wild-type (WT) and mutant BaMV. Each plasmid clone of BaMV contains a full-length BaMV genome inserted downstream the Cauliflower mosaic virus (CaMV) 35S promoter (as indicated by arrow). pCBG is the WT plasmid clone of BaMV derived from pCB; it has a green fluorescence protein (GFP) gene inserted between the coding sequences of TGBp3 and capsid protein (CP). pGC31A, pGC46A and PGC31, 46A are the three mutant BaMV with either one or both of the conserved cysteine residues (Cys-31 and Cys-46 are indicated by star) in the C-terminal tail of TGBp3 being replaced with alanine. (B) Effects of Cys-to-Ala substitutions in TGBp3 on cell-to-cell movement of BaMV. The fluorescence image of mesophyll cells of C. quinoa leaves inoculated with the WT plasmid clone of BaMV (pCB or pCBG) or either one of the mutant clones of BaMV ( pGC31A, pGC46A, and pGC31, 46A) was taken at 10 dpi. The white bar shown in bottom right corner of each panel is equal to 50 µm. (C) Effects of the Cys-to-Ala substitutions in TGBp3 on TGBp2- and TGBp3-dependent PD targeting of TGBp1. Co-expression of TGBp2 and either the WT or mutant TGBp3:HA with YFP:TGBp1 was conducted by introducing the plasmid (pBA-p2/p3HA, pBA-p2/P3C31AHA, pBA-p2/p3C46AHA or pBA-p2/p3C31, 46AHA) which expresses TGBp2 as well as the WT or mutant TGBp3:HA, and the plasmid (pBA-Y-p1) which expresses YFP:TGBp1 into N. benthamiana by agroinfiltration. The arrows point to the co-localized YFP:TGBp1 and callose in the PD. The white bar in the bottom right corner of each panel indicates the length of 10 µm.