Time course analysis of TuMV-induced membranous aggregates in mesophyll cells. (A to C) N. benthamiana leaf midribs systemically infected with TuMV/6K2:GFP were chemically fixed, processed, and observed by TEM. Higher-magnification images of the areas in the white rectangles are shown in the panels below. (A) TuMV-induced CM structures amid SMVL structures were connected with several rERs in a mesophyll cell at 6 dpi. (B) TuMV-induced heterogeneous SMVL structures close to the rER in a mesophyll cell at 7 dpi. (C) TuMV-induced aggregates contain both SMVL structures and DMVL structures with an electron-dense core in a mesophyll cell at 8 dpi. CW, cell wall; M, mitochondrion; CL, chloroplast; V, vacuole; CI, cytoplasmic inclusion body; rER, rough endoplasmic reticulum; CM, convoluted membranes; SMVL, single-membrane vesicle-like structure; DMVL, double-membrane vesicle-like structure.