The role of mobile DNA elements in the dynamics of plant genome plasticity

Plants host a range of DNA elements capable of self-replication. These molecules, usually associated with the activity of transposable elements or viruses, are found integrated in the genome or in the form of extrachromosomal DNA. The activity of these elements can impact genome plasticity by a variety of mechanisms, including the generation of structural variants, the shuffling of regulatory or coding DNA sequences across the genome, and DNA endoduplication. This plasticity can dynamically alter gene expression and genome stability, ultimately affecting plant development or the response to environmental changes. While the activation of these elements is often considered deleterious to the genome, their role in creating variation is important in adaptation and evolution. Moreover, the mechanisms by which mobile DNA proliferates have been exploited for plant engineering, or contributed to understand how desirable traits can be generated in crops. In this review, we discuss the origins and the roles of mobile DNA element activity on genome plasticity and plant biology, as well as their potential function and current application in plant biotechnology. A range of DNA elements can autonomously propagate into plant cells, either integrated in the genome or as extrachromosomal DNA. We discuss the impacts these viral and transposable elements have on host genome plasticity.