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Combining Analysis of DNA in a Crude Virion Extraction with the Analysis of RNA from Infected Leaves to Discover New Virus Genomes
Published on: July 27, 2018
Three seedborne cryptic viruses containing double-stranded RNA isolated from white clover.
G Boccardo1, R G Milne, E Luisoni
1Istituto di Fitovirologia applicator del C.N.R., via O. Vigliani 104, 10135 Torino, Italy.
Virology
|November 1, 1985
Summary
White clover cryptic viruses (WCCV) 1 and 2 were purified and characterized. These dsRNA viruses are seed-transmitted and multiply within their host plants.
Area of Science:
- Plant Virology
- Molecular Biology
- Microbiology
Background:
- White clover cryptic viruses (WCCV) are poorly understood viruses affecting clover health.
- Previous research on WCCV is limited, necessitating further characterization.
Purpose of the Study:
- To purify and characterize WCCV 1, 2, and 3.
- To investigate the transmission and multiplication of these viruses in white clover.
Main Methods:
- Virus purification and isopycnic centrifugation in CsCl.
- Electron microscopy for particle morphology and size determination.
- dsRNA analysis and antiserum production.
- Grafting, mechanical inoculation, and seed transmission assays.
- Thin section electron microscopy for cellular localization.
Main Results:
- WCCV 1 and 2 were purified with yields of ~200 µg/kg, banding at densities of 1.392 and 1.375 g/ml, respectively. WCCV 3 was not recovered.
- Particle sizes were 34 nm for WCCV 1 and 3, and 38 nm for WCCV 2, with distinct morphologies.
- Both WCCV 1 and 2 contain two linear dsRNA segments and elicited antisera with high titers.
- Virus particles were observed in the cytoplasm of parenchyma cells in carrier plants.
- WCCV 1 and 2 were not transmitted by grafting or mechanical inoculation but were seed-transmitted.
Conclusions:
- WCCV 1 and 2 are distinct viruses characterized by their dsRNA genomes and specific particle properties.
- Seed transmission is the primary mode of WCCV 1 and 2 spread.
- These viruses multiply within white clover plants and are not associated with other organisms.
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