Caulimoviridae (Plant Pararetroviruses)


Family Caulimoviridae comprises eight genera of plant viruses whose members replicate by reverse transcription and whose virions contain double‐stranded deoxyribonucleic acid. In a recent survey of the international scientific community, Cauliflower mosaic virus (CaMV), the type species of the family, was ranked sixth in the world in a list of the most scientifically or economically important plant viruses. This notoriety is due purely to the major conceptual advances that have been made in plant virology using CaMV as a model pathogen. However, several relatively lesser known viruses in the family, such as rice tungro bacilliform virus and the cacao swollen shoot virus species complex, are very serious constraints to crop production in tropical regions of the world. In this article, information on the taxonomy, replication cycle, vector transmission, epidemiology and disease management of this important group of plant viruses is summarised.

Key Concepts

  • The Caulimoviridae is the only family of plant viruses with a double‐stranded deoxyribonucleic acid (dsDNA) genome, and in common with all viral retroelements, incorporates a reverse transcription step in the replication cycle.
  • Cauliflower mosaic virus is the type species of the family and has been a very important model plant virus for elucidating fundamental aspects of virus replication, cell‐to‐cell movement and aphid transmission.
  • Members of the Caulimoviridae are most prominent in tropical regions, where they cause serious diseases such as rice tungro, cacao swollen shoot and banana streak disease.
  • The most important component of a control programme for these viruses is to reduced inoculum levels by using clean planting material, avoiding overlapping crops, and removing diseased plants and alternative hosts of the virus.
  • In some host species, infection can arise as a consequence of activation of viral DNA that is integrated into the nuclear genome of the plant.

Keywords: plant viruses; retroelement; pararetrovirus; reverse transcription; Cauliflower mosaic virus; rice tungro; cacao swollen shoot; tropical crop

Figure 1. Electron micrographs of particles of (a) Cauliflower mosaic virus (bar, 50 nm) and (b) Rice tungro bacilliform virus (bar, 100 nm) negatively stained with 2% uranyl acetate.
Figure 2. Genome organisations of members of the Caulimoviridae; abbreviations of virus names are provided in Table . With the exception of SoyMV, the circular genomes have been linearised at the beginning of the tRNAMET binding site, represented by a black diamond. SoyMV is linearised at the beginning of ORF VII. Grey boxes are open reading frames and coloured boxes within are conserved protein domains: blue is the movement protein, green is the capsid protein, red is the aspartic protease, orange is the reverse transcriptase, yellow is the RNaseH1 and black is the transactivator protein.


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Further Reading

Hohn T (2013) Plant pararetroviruses: interactions of cauliflower mosaic virus with plants and insects. Current Opinion in Virology 3: 629–638.

Scholthof K‐BG, Adkins S, Czosnek H, et al. (2011) Top 10 plant viruses in molecular plant pathology. Molecular Plant Pathology 12: 938–954.

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How to Cite close
Geering, Andrew DW(Sep 2019) Caulimoviridae (Plant Pararetroviruses). In: eLS. John Wiley & Sons Ltd, Chichester. [doi: 10.1002/9780470015902.a0000746.pub4]