Figure 1.

Fluorescence micrographs of epidermal leaf cells of N. benthamiana (A) or N. benthamiana erGFP (B–H) infected with TMV or TMV-MP:GFP. (A1) Fluorescence surrounding the nucleus (n) due to MP-GFP early in infection (arrow). (A2) Fluorescent structures containing MP-GFP in cells early in infection. (A3) Cortical fluorescent bodies in early to mid stages of infection. (B) Noninfected epidermal cells of N. benthamiana erGFP. (B1) Perinuclear fluorescent halo of erGFP (arrow). (B2) Normal reticulate pattern of cortical ER. (B3) Fast-moving tracks of erGFP fluorescence (arrowheads). (C–F) Left panels excited with blue light, right panels excited with UV. Note: UV excitation exclusively excites erGFP, while excitation with blue light excites both MP-GFP and erGFP. (C, C′) Early stage of infection, showing small cortical aggregates formed at vortexes of ER network; much of the fluorescence is contributed by MP-GFP (arrows). (D, D′) Large cortical aggregates and disrupted cortical ER in mid-stages of infection. (E, E′) Recovery of tubular ER and dissociation of large cortical aggregates and development of filamentous fluorescence of MP-GFP colocalized with microtubules (arrows) as well as a punctate fluorescence on the cell surface (arrowheads) in mid to late stages of infection. (F, F′) Cortical aggregates decrease and filaments comprising MP-GFP on microtubules (arrows) are apparent in late stages of infection; punctate fluorescent structures often aligned with microtubules (arrows); ER has recovered to preinfection state. (G) Large cortical ER aggregates induced in N. benthamiana erGFP during infection by wild-type TMV. (H) Tubular cisternae of the cortical ER are disrupted and converted to lamellar aggregates. (Bars = 0.5 μm.)