Transposable Elements Direct The Coevolution between Plants and Microbes

Transposable elements are powerful drivers of genome evolution in many eukaryotes. Although they are mostly considered as 'selfish' genetic elements, increasing evidence suggests that they contribute to genetic variability; particularly under stress conditions. Over the past few years, the role of transposable elements during host-microbe interactions has been recognised. It has been proposed that many pathogenic microbes have evolved a 'two-speed' genome with regions that show increased variability and that are enriched in transposable elements and pathogenicity-related genes. Plants similarly display structured genomes with transposable-element-rich regions that mediate accelerated evolution. Immune receptor genes typically reside in such regions. Various mechanisms have recently been identified through which transposable elements contribute to the coevolution between plants and their associated microbes. Transposable elements are powerful drivers of adaptive genome evolution in plants and in symbiotic microbes, and contribute to their coevolution.Analysis of large next-generation sequencing datasets fuels a better understanding of the precise role of transposable elements in genome evolution, revealing active as well as passive contributions.Transposable elements contribute to genome evolution through diverse mechanisms, by mediating structural variations, gene inactivation, gene copy variation, but also by affecting gene expression.Further mechanistic understanding of the role of transposable elements in genome evolution will come from detailed structural analysis of chromatin