Maize necrotic streak virus (MNeSV) has 32 nm isometric particles that encapsidate a single stranded RNA genome ca. 4.3 kb in size and is a tentative member of the genus Tombusvirus. Since tombusviruses elicit the formation of cytopathological structures known as "multivesicular bodies" that assist in their classification at genus level, the cytology of thinsectioned maize leaf tissues 7, 15 and 45 days after inoculation was investigated. The prominent cytopathological features were: (i) extensive accumulation of virus particles scattered throughout cytoplasm or in crystalline arrays in cytoplasm or, occasionally, in intercellular spaces; (ii) extensive plasmolysis and appearance of small patches of amorphous, dark-staining material in cytoplasm; (iii) proliferation of membranes and presence of empty double membrane-bound vesicular structures of various sizes. No apparent connection between these membranous elements and the nuclear envelope was detected, even when large clusters of vesicles were adpressed to the nuclei. Some of the largest doublemembrane bound structures had rows of small vesicles located inside peripheral dilations of the bounding membrane. Although most of these structures appeared to originate from disintegrating mitochondria, they bore little resemblance to genuine multivesicular bodies like those arising from the modified mitochondria that follow infection by certain members of Tombusviridae, i.e. Carnation Italian ringspot virus, Pelargonium necrotic spot virus (PNSV), Galinsoga mosaic virus (GaMV) and Turnip crinkle virus (TCV). Immunogold labelling using antibodies to virus particles was detected over cytoplasm, associated with virus particles and patches of electrondense amorphous material, suggesting that this material consists of virus coat protein
AGRIS-FAO dbase: Ultrastructure of Maize necrotic streak virus infections [Zea mays L.]
DE STRADIS A;
2005
Abstract
Maize necrotic streak virus (MNeSV) has 32 nm isometric particles that encapsidate a single stranded RNA genome ca. 4.3 kb in size and is a tentative member of the genus Tombusvirus. Since tombusviruses elicit the formation of cytopathological structures known as "multivesicular bodies" that assist in their classification at genus level, the cytology of thinsectioned maize leaf tissues 7, 15 and 45 days after inoculation was investigated. The prominent cytopathological features were: (i) extensive accumulation of virus particles scattered throughout cytoplasm or in crystalline arrays in cytoplasm or, occasionally, in intercellular spaces; (ii) extensive plasmolysis and appearance of small patches of amorphous, dark-staining material in cytoplasm; (iii) proliferation of membranes and presence of empty double membrane-bound vesicular structures of various sizes. No apparent connection between these membranous elements and the nuclear envelope was detected, even when large clusters of vesicles were adpressed to the nuclei. Some of the largest doublemembrane bound structures had rows of small vesicles located inside peripheral dilations of the bounding membrane. Although most of these structures appeared to originate from disintegrating mitochondria, they bore little resemblance to genuine multivesicular bodies like those arising from the modified mitochondria that follow infection by certain members of Tombusviridae, i.e. Carnation Italian ringspot virus, Pelargonium necrotic spot virus (PNSV), Galinsoga mosaic virus (GaMV) and Turnip crinkle virus (TCV). Immunogold labelling using antibodies to virus particles was detected over cytoplasm, associated with virus particles and patches of electrondense amorphous material, suggesting that this material consists of virus coat proteinI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
