Caulimoviridae

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Caulimoviridae
Systematics
Classification : Viruses
Area : Riboviria
Empire : Pararnavirae
Phylum : Artverviricota
Class : Revtraviricetes
Order : Ortervirales
Family : Caulimoviridae
Taxonomic characteristics
Genome : dsDNA circular
Baltimore : Group 7
Cover : unavailable
Scientific name
Caulimoviridae
Left
NCBI  Taxonomy: 186534
ViralZone ( ExPASy , SIB): 96

The Caulimoviridae is a family of Pararetroviruses that primarily damage plants . The representatives of the Caulimoviridae can be divided into two genera : The genus Caulimovirus has an icosahedral symmetry of its protein shell ( capsid ). In contrast, the representatives of the genus Badnavirus have a bacillus-like shape ( bacilliform ), that is, rod-shaped. Representatives of this family are responsible for viral diseases of economic importance in cultivated plants. As one of the badnaviruses , the tungro virus is the cause of severe epidemics in rice ( Oryza sativa ), which are responsible for high yield losses worldwide. Other crop plants damaged by representatives of the Caulimoviridae are, for example, sugar cane , cocoa trees or bananas .

morphology

The representatives of the Caulimoviridae can be divided into two larger groups, which differ morphologically: The representatives of the genus Caulimovirus have a three-layer protein shell ( capsid ) with icosahedral symmetry . The shell designed in this way surrounds an interior space of around 25 nm in diameter.

The representatives of the Badnavirus group, on the other hand, have a bacillus- like structure and are rod-shaped. Their length can vary between 60 and 900 nm, but is on average 130 nm with a diameter of 90 nm. The structure of the Badnavirus is also based on an icosahedral symmetry.

Genome

The differences between the two main groups mentioned also continue in terms of genome organization. Common to all representatives is a double-stranded DNA (dsDNA) with about 7000 to 8000 base pairs. The genome of the caulimovirus consists of a molecule of a double-stranded dsDNA of 7.2 to 8.2 kbp , which is present in the virus particles in an openly circular manner. The genome of the cauliflower mosaic virus (CaMV) contains seven so-called open reading frames (ORF), Petunia vein clearing virus-like only two ORF. The genome of the Badnavirus genus and its type species , the Commelina yellow mottle virus (ComYMV), is also available as a circular dsDNA with 7.5 kbp and three ORFs. After successful entry into the host organism, the viral dsDNA genome of the Caulimoviridae must be transcribed into RNA using a reverse transcriptase . This is done in the same way for the aforementioned representatives of both groups.

transmission

In the cauliflower mosaic virus (CaMV) and probably other caulimoviruses, aphids , especially the green peach aphid ( Myzus persicae ) and the cauliflower louse ( Brevycorine brassicae ), play an important role as animal vectors . In Badnaviren also play leafhoppers or scale insects a role as an intermediary animals. The transmission takes place semi-persistently and not circularly. Further spreading possibilities are given by the common methods of generative and vegetative propagation such as seed sowing or cuttings .

Systematics

literature

Individual evidence

  1. ↑ a b c d ICTV: ICTV Taxonomy history: Commelina yellow mottle virus , EC 51, Berlin, Germany, July 2019; Email ratification March 2020 (MSL # 35)
  2. ↑ SIB: Badnavirus , on: ViralZone
  3. ↑ SIB: Caulimovirus , on: ViralZone
  4. ↑ SIB: Cavemovirus , on: ViralZone
  5. ↑ SIB: Petuvirus , on: ViralZone
  6. ↑ SIB: Soymovirus , on: ViralZone
  7. ↑ SIB: Tungrovirus , on: ViralZone

Web links

Commons : Caulimoviridae  - collection of images, videos and audio files
  • University of Hamburg (PDF; 4.9 MB) - General Genetics script, overview of caulimoviruses with illustrations from p. 15–25.