A subset of cells in tobacco mosaic virus (TMV)-induced local lesions in Datura stramonium leaves are tolerant to TMV

Ultrastructural examination of tobacco mosaic virus-induced local lesions growing in Datura stramonium leaves is carried out. It is demonstrated that, in the central area of the lesions, the cell response to viral invasion is not uniform. Most cells exhibited an acute hypersensitive reaction (HR) and underwent rapid and complete necrosis. However, some cells, despite considerable virus accumulation and immediate contact with completely collapsed cells, maintained a certain degree of structural integrity. Analysis performed showed that the proportion of collapsed and uncollapsed cells in the lesion centre 3 to 5 days after infection essentially did not change. These data suggest that the absence of HR in some cells in the lesion centre is not due to an early stage of infection but is likely caused by cell tolerance of the virus.