Viroids: sequence variability and evolution of pathogenic RNA

https://doi.org/10.17221/10348-PPSCitation:Matoušek J. (2002): Viroids: sequence variability and evolution of pathogenic RNA. Plant Protect. Sci., 38: 173-176.
download PDF
Viroids as the smallest pathogenic circular single-stranded pathogenic RNAs form populations of quasi-species, which
has been recently identified by thermodynamic methods like TGGE pre-selection and heteroduplex analysis. It was found
that replication under thermal stress led to enormously high level of viroid mutagenesis. Mostly multiple mutants having
non-random distribution of base changes were found. A specific “hot spots” were identified in the regions, where
a characteristic “pathogenicity domains” are localised in different viroids of the pospiviroidae family. Specific viroid
microevolution was observed upon artificial inoculation of non-host plant species. Our results suggest that viroid propagation
under physiological stress can be assumed as important factor, which is among others, responsible for an appearance
of viroid quasi-species in the nature. Evolution and new viroid patotypes could accumulate due to environmental stress
including various pollutants may be a potential danger for cultured plants.
download PDF

© 2020 Czech Academy of Agricultural Sciences