Identification of viral domains integrated into Arabidopsis proteome.

Horizontal gene transfer (HGT) contributes to the genome evolution of living organisms. In particular, several recent studies provide convincing data on the integration of viral sequences into diverse organisms. Here, we identified 101 viral domains integrated into the model plant Arabidopsis proteome. Functional analysis based on gene ontology (GO) terms indicates that viral domains in the Arabidopsis proteome were involved in various stress responses with binding functions. Protein interaction networks support the strong protein interactions of viral domains with other Arabidopsis proteins. A proteome-wide analysis gave a comprehensive evolutionary view of viral domains integrated into 41 plant proteomes, revealing the specific and conserved integration of viral domains into plant proteomes. Phylogenetic analyses revealed the possible HGT between viral domains and plant proteomes. Our results provide an overview of the integration of viral domains into plant proteomes and their possible functional roles associated with plant defense mechanisms.