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Shots Series: Virus Multiply(Viruses that multiply only in Plants)

Article No. 1

Photo/Unsplash 

Viruses are primarily classified based on their morphology, which includes the physical and chemical characteristics of their virion components as well as their genetic relationships.

List of selected viruses that multiply only in plants 

1. Caulimoviridae

• Open circular dsDNA with single-strand discontinuities, like the hepadnavirus.
• Molecular weight 4 to 5 × 10⁶
• Iso metric 50 nm particles.
• It contains reverse transcriptase.
• Aphid vector in nature.
• It is included in the cauliflower mosaic virus.

2. Germniviridae

• Circular single-stranded DNA.
• Molecular weight 0.7 to 0.8 x10⁶
• Germniviridae has two incomplete icosahedral particles joined as a pair.
• This virus is usually found in the nucleus.
• One to two molecules of DNA per pair of particles.
• It is persistent in whitefly or leafhopper vectors.

3. Luteoviridae 

• Single-stranded, positive-sense RNA.
• Molecular weight 2x 10⁶
• Isometric 25 to 30 nm.
• Persistent retention by aphid vectors.
• It includes barley yellow dwarf virus.

4. Tombusviridae

• Single-stranded, linear, positive-sense RNAs.
• Molecular weight 1.5x 10⁶
• Not polyadenylated.
• Particle 32 to 35 nm in diameter.
• Location -Cytoplasmic, nuclear, and sometimes mitochondrial.
• Transmitted through the soil, mechanical, inoculation, contact, and seeds.
• It includes tobacco necrosis virus and tomato bushy stunt virus.

5. Bromoviridae 

• Three single-stranded, linear, positive-sense RNAs.
• Icosahedral particles 26 to 35 nm in diameter.
• Bacilliform particles ( 18 to 26 nm x 30 to 85 nm).
• Infectively requires the three RNAs.
• It is assembled in the cytoplasm.
• It includes brome mosaic, cucumber mosaic virus, and alfalfa mosaic virus.

6. Comoviridae

• Two 28 to 30 nm non-enveloped particles containing single-stranded, linear, positive-sense RNA.
• Molecular weight 2.4 or 1.4 x 10⁶
• Two coat polypeptides are encoded by the smaller RNA.
• Transmitted by beetles or seed.
• It included cowpea mosaic virus and tobacco ringspot virus.

7. Tobamovirus

• Single-stranded, linear, positive-sense RNA.
• Molecular weight 2x10⁶
• Rigid Cylindrical particles 300x18nm.
• It is transmitted mechanically or by seed.

8. Potyviridae

• Single-stranded, linear, positive-sense RNA.
• Molecular weight 3.0 to 3.5 x10⁶
• Particle is a flexuous rod with helical symmetry, usually 650 to 900 x 11 to 15 nm.
• Cytoplasmic, but some have nuclear inclusions.
• Nonpersistent in aphid vectors includes potato virus y.

Stay connected for our upcoming shots series, and happy reading! 

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