Viral sequences in the Arabidopsis genome ($) (Mol. Phylogenetics Evol.)

Numerous prokaryotic and eukaryotic genes have been identified as having homology to viral sequences. This phenomenon is the result of horizontal gene transfer (HGT) between viral pathogens and host cells. Chu and collaborators performed a proteome-wide analysis for the identification of viral domains in the Arabidopsis proteome. The study identified 101 plant viral peptide sequences that matched at least one Arabidopsis protein, and hundreds of Arabidopsis proteins predicted to be homologous to viral proteins. From the latter, the most abundant corresponded to heat shock 70 domains and RNA helicase proteins. The taxonomical classification of the 101 viral proteins resulted in the vast majority of the studied sequences attributed to ssRNA viruses, followed by dsDNA and dsRNA viruses. Interestingly, the distribution of viral-derived sequences in the Arabidopsis genome did not appear to be random, and several of these viral-like proteins were found in many other plant genomes, indicating the high evolutionary conservancy and specificity of HGT phenomena between viruses and plants.  (Summary by Juan S. Ramirez-Prado) Mol. Phylogenetics Evol. 10.1016/j.ympev.2018.08.009