[Ultrastructural differences of RMV and TMV infected Nicotiana tabacum mesophyll cells for distinguishing virus strains].
Nine strains of ribgrass mosaic virus (RMV) and tobacco mosaic virus(TMV) from cruciferous and solanaceous plants in different geographic regions of China were used to inoculate 4-leave-old plants of Nicotiana tobacum for observation of ultrastructually pathological changes due to infection of different strains. The samples of the mesophyll cells of the plants 15 d after inoculation were prepared in a routine and examined using transmission electronic microscopy. Characteristic virion arrangement, inclusion forms, and cell structural aberrations were found different among the various strains. The virions were accumulated in cluster, arranged in ring scattered, irregularly congregated with membrane, and aggregated in angle layer or parallel layer in cytoplasm and vacuoles whereas they were not found in organelles including nuclei, chloroplasts, and mitochondria. The inclusions with bacilliform, club-shaped or granulous X-tubule varied in number and form among the viral strains investigated. The abnormality of cell wall including thickening, collapsing and distortions were also observed among the cells infected by the strains. Other distinguishable changes attributed to the strains included the number, size, shape, and clumping pattern of chloroplasts, and of starch grains and osmiphilic globules chroloplasts of mesophyll cells infected only by two of the 9 strains examined. Additionally, the increased numbers of mitochondria and endoplasmic reticulum were observed in the cells infected by some of the strains. The results indicate that the ultrastructural changes due to viral infection may be useful for distinguishing various RMV and TMV strains.
Xu
J
J
Department of Biological Sciences, Zhejiang Agricultural University, Hangzhou 310029.
Feng
M
M
D008854:Microscopy, Electron; D010935:Plant Diseases / Q000821:virology*; D014026:Nicotiana / Q000648:ultrastructure* / Q000821:virology; D017898:Tobamovirus