Skip to main content
. 2007 Apr 5;26(8):2169–2179. doi: 10.1038/sj.emboj.7601674

Figure 2.

Figure 2

Electron micrographs showing localization, morphology and structure of inclusions formed by ORF3-GFP or its mutants (RA-GFP and L149A-GFP) in palisade mesophyll cells of N. benthamiana plants. (A) Sections showing typical general views of healthy cells and cells infected with ORF3-GFP after IGL with antibodies against the ORF3 protein. Cells infected with the ORF3 mutants, RA-GFP and L149A-GFP, are essentially similar. All cells contain normal organelles such as nucleus (N) nucleolus (No), chloroplasts (Chl) and vacuole (V). In addition, virus-infected cells (exemplified by ORF3-GFP) also contain TMV-specific X-bodies (XB) containing electron-dense (gold-labelled) ORF3 protein-related inclusions (shown by arrows). Scale bars, 5 μm. (B) Higher magnification of X-bodies and cytoplasmic inclusions of ORF3-GFP and its mutants, RA-GFP and L149A-GFP. XB, X-bodies; arrows, inclusions. Scale bars, 2 μm. (C) High-resolution EM sections of cytoplasmic inclusions formed by ORF3-GFP, RA-GFP and L149A-GFP labelled with antibody against the ORF3 protein (IGL) and with an RNA probe specific for the positive strand of the ORF3 gene (ISH). ORF3-GFP inclusions are composed of complexes of filamentous RNP particles (c-RNP) containing the ORF3 protein and viral RNA. The inclusions of the ORF3 mutants, RA-GFP and L149A-GFP did not have a filamentous structure; they contained mutant ORF3 proteins (IGL) but did not contain viral RNA (ISH). All of the inclusions appear as large fluorescence masses (up to 10 μm) in confocal images (Figure 1D–G). Scale bars, 100 nm.