Retroviroids are very similar to viroids in size and structure but differ in that there exists a DNA form, generated by RNA-dependent DNA polymerase. Currently, only one type is known.


  • Daros, J. A., & Flores, R. (1995). Identification of a retroviroid-like element from plants. Proceedings of the National Academy of Sciences, 92(15), 6856–6860.
  • Vera, A., Daròs, J.-A., Flores, R., & Hernández, C. (2000). The DNA of a Plant Retroviroid-Like Element Is Fused to Different Sites in the Genome of a Plant Pararetrovirus and Shows Multiple Forms with Sequence Deletions. Journal of Virology, 74(22), 10390–10400.
  • Hegedűs, K., Dallmann, G., & Balázs, E. (2004). The DNA form of a retroviroid-like element is involved in recombination events with itself and with the plant genome. Virology, 325(2), 277–286.