Transposable Element-Driven Expansion of Enhancer RNA Repertoires Underlies Regulatory Innovation and Polyploid Adaptation in Cereal Crops [CB RNA-seq]

The evolutionary trajectories and functional implications of these landscapes, however, remain largely unexplored. By employing chromatin-bound RNA sequencing across seven cereal species, we systematically mapped 45,952 regulatory element transcripts (RETs), including 32,867 distal RETs corresponding to enhancer RNAs (eRNAs).

Our analysis reveals that 56% of lineage-specific eRNAs originate from TE expansions, suggesting TEs as significant reservoirs of species-specific regulatory innovation in cereals. Notably, we uncovered a remarkable similarity in defense-related function, root-specific expression, and TE-derived origin of eRNAs across ancient and recent evolutionary layers of Triticeae, suggesting recurrent recruitment of TE-derived root-associated regulatory elements during Triticeae evolution.