[Observation of cells tolerant of tobacco mosaic virus in virus-induced local lesions in Datura stramonium L. leaves].

Ultrastructural examination of tobacco mosaic virus-induced local lesions developing in leaves of Datura stramonium plants demonstrated that, in the central area of the lesions, the cell response to viral invasion was not uniform. Most cells exhibited an acute hypersensitive reaction 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 did not change essentially. These data suggest that the absence of hypersensitive response 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.

[Ultrastructure of parenchymal leaf cells of different soybean varieties systemically infected with soybean mosaic virus].

A comparative study was made of the ultrastructure of parenchyma leaf cells of different soybean varieties systemically infected with soybean mosaic virus (SMV). It has been shown that virus accumulation and formation of virus-specific cylindrical inclusions (CIs) occur in the infected cells, in addition to intracellular changes showing stimulation of lytic processes, such as activation of smooth endoplasmic reticulum and Golgi apparatus, formation of cytoplasmic vacuoles, cytosegresomes, myelin-like bodies, different disturbances in the structure of cell organelles. Many infected cells demonstrated microbodies with invagination in which cylindrical inclusions were often found showing signs of destruction. It is suggested that such microbodies possess autophagic activity towards CIs. A possible relation of the observed virus-induced ultrastructural cell changes with the degree of SMV affection of investigated varieties is discussed

[Ultrastructural study of local lesions and surrounding tissues in Gomphrena globosa L. leaves infected by tobacco mosaic virus]. / Ul'trastrukturnoe izucheniie lokal'nykh porazhenii i prilegaiushchikh k nim tkanei na infitsirovannykh virusom tabachnoi mozaiki list'iakh Gomphrena globosa L..

The cells in the local chlorotic areas of Gomphrena globosa L. leaves infected with tobacco mosaic virus (TMV) accumulate a significant amount of viral particles. The cells in the surrounding tissue have a relatively low number of virions, which are often degraded. The cells surrounding the forming local lesion have pronounced signs of activated autolysis. We believe that lysis activation provides for the viral particles destruction and is an important factor limiting TMV accumulation in the cells outside the chlorotic areas.