Endogenous Caulimovirids: Fossils, Zombies, and Living in Plant Genomes

The Caulimoviridae is a family of double-stranded DNA viruses that infect plants. The genomes of most vascular plants contain endogenous caulimovirids (ECVs), a class of repetitive DNA elements that is abundant in some plant genomes, resulting from the integration of viral DNA in the chromosomes of germline cells during episodes of infection that have sometimes occurred millions of years ago. In this review, we reflect on 25 years of research on ECVs that has shown that members of the Caulimoviridae have occupied an unprecedented range of ecological niches over time and shed light on their diversity and macroevolution. We highlight gaps in knowledge and prospects of future research fueled by increased access to plant genome sequence data and new tools for genome annotation for addressing the extent, impact, and role of ECVs on plant biology and the origin and evolutionary trajectories of the Caulimoviridae.

Automated summary

The Caulimoviridae is a family of DNA viruses that infect plants, and their integration into plant genomes has resulted in the presence of endogenous caulimovirids (ECVs). Research on ECVs over the past 25 years has revealed the ecological diversity and macroevolution of Caulimoviridae, highlighting the need for further investigation into the impact of ECVs on plant biology and the evolutionary history of this viral family. The availability of plant genome sequences and new tools for genome annotation will greatly contribute to future research in this field.