Infection by Grapevine fanleaf nepovirus (GFLV), a bipartite RNA virus of positive polarity belonging to the Comoviridae family, causes extensive cytopathic. The specific transmission of Grapevine fanleaf virus by its nematode vector Xiphinema index is solely determined by the viral coat protein. There are plenty of plant viruses that no one has heard of, but few are as widely known as grapevine fanleaf virus. Learn how to identify a sick.

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Cowpea mosaic virus infection induces a massive proliferation of endoplasmic reticulum but not Golgi membranes and is dependent on de novo membrane synthesis.

Formvar-coated electron microscopic grids were first coated with affinity immunopurified anti-VPg antibodies and then floated on aliquots of the gradient fractions combined three by three. These contained VPg either as polyprotein precursors involved in RNA replication or as a final maturation product associated with viral RNA and also double-stranded grapevinee replicative forms and neosynthesized viral RNA, which confirmed their direct involvement in GFLV replication.

Please review our privacy policy. Viral proteins involved in replication were immunodetected on these vesicles in CPMV-infected cells Frapevine of tobacco mosaic falneaf on endoplasmic reticulum and role of the cytoskeleton and virus movement protein in intracellular distribution of viral RNA. Small vesicles were specifically immunotrapped by anti-VPg from ER-enriched bottom fractions of the sucrose gradient fnaleaf infected protoplasts.

Cellular COPII proteins are involved in production of the vesicles that form the poliovirus replication complex. No electron-dense structures similar to those described in CPMV-infected cells 15 were observed.


BFA and cerulenin treatment.

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Control experiments were performed with healthy protoplasts treated similarly or by using infected protoplasts incubated in the absence of primary antibodies to verify the specificity of the labeling. Consistent with its function in cell-to-cell movement, the movement protein was generally detected at the cell periphery at 48 hpi, probably after its release from the precursor polyprotein.

Also, the productive life of GFLV-infected vineyards is significantly reduced. This hypothesis is further substantiated by the fact that BFA, a drug known to disrupt COP vesiculation in animals 2133 and plants 52 and to inhibit poliovirus replication 123242also inhibited that of GFLV. Immunocytochemical localization of TYMV-coded structural and non-structural proteins by the protein A-gold technique.

Fanleaf Degeneration of Grape

Unlike VPg labeling, the intracellular coat protein distribution was not homogeneous in between cells. Photo courtesy of William M. Nepoviruses Viral grape diseases Viral plant disease stubs. Upon uptake of the virus, a nematode can remain viruliferous for nearly a year.

Similarity in gene organization and homology between proteins of animal picornaviruses and a plant comovirus suggest common ancestry of these virus families. Occasionally, very fanlefa CP-labeled spike-like structures were detected within the cytoplasm Fig. Four bands of VPg-containing precursors that migrated in the gel with apparent molecular masses of ca. In other projects Wikimedia Commons Wikispecies. Using epifluorescence microscopy, we have previously described the formation of a perinuclear complex where viral RNA was synthesized and viral proteins accumulated 23but this could not be further analyzed due to technical limitations.


Open in a separate window. Differential interference contrast observations were superimposed in panels C, D, F, and M for visualization of the cell and its nucleus.

Formation of plant RNA virus replication complexes on membranes: To demonstrate whether the ER-derived aggregates were involved in viral replication, double-labeling experiments were performed with anti-dsRNA and anti-VPg antibodies. No significant signal was observed in similarly processed healthy protoplasts Grapeevine. The cell lines used were: The results were expressed as the ratio between the percentage of infection and the percentage of viable cells.

Detection of viral proteins in cytopathic structures in cowpea protoplasts infected with cowpea mosaic virus. Cells were harvested at 48 h p. When detected in the nuclear periphery, the MP signal appeared as small, round aggregates Fig. The VPg-containing perinuclear aggregates and punctate dsRNA labeling are indicated in panel N by full arrowheads and in panel O by arrows. Ultrathin sections 90 nm were stained with uranyl acetate and ffanleaf citrate.

We are grateful to K. Laser scanning was performed by using the multitrack mode to avoid cross talk. Characterization of the poliovirus replication complex.

It is transmitted via a nematode vector, Xiphinema index. Support Center Support Center.

A human virus protein, poliovirus protein 2BC, induces membrane proliferation and blocks the exocytic pathway in the yeast Saccharomyces cerevisiae. They were used at a 1: