Effect of tobacco mosaic virus strains on the ultrastructure of tobacco leaf parenchymal cells

Accumulation of considerable amounts of viral particles has been demonstrated in parenchymal cells of young leaves in tobacco cultivar Samsun systemically infected with any of studied tobacco mosaic virus (TMV) strains isolated from pepper (TMV-p), tomato (TMV-t), and eggplant (TMV-e). Abnormal (swollen and thin) virions were found, which points to their destruction. Cell infection with all studied strains was accompanied by the activation of the lysosomal compartment manifested as formation of nascent dictyosomes, elements of smooth endoplasmic reticulum, cytoplasmic vacuoles, various vesicles, invaginated mitochondria, and multivesicular bodies. The studied viral strains could be arranged in the following sequence according to the degree of lysosomal compartment stimulation and induction of intracellular lytic processes mediating the destruction of viral particles and cell structures: TMV-p > TMV-e > TMV-t.