Potential impact of TE-derived sRNA on gene regulation in the grassBrachypodium distachyon

Abstract

In plants, the transcriptional and post-transcriptional repression of TEs involved the production of small interfering RNAs (siRNAs) that guide the de novo methylation and transcriptional silencing of TEs. Because siRNAs act via sequence complementarity, they indiscriminately target TEs and possible non-TE transcripts. TEs and their derived siRNAs might thus provide a reservoir for long-distance gene regulation. To test this hypothesis, we infected Brachypodium distachyon with Mangnaporte oryzae, the agent of Rice Blast. The infection caused the differential expression of multiple TE copies as well as a global change in gene expression. By sequencing the small RNA fraction, we identified TE-derived sRNA that are identical in sequence to motifs contained in the UTR region of differentially expressed genes. Our study opens new avenues of research to further investigate to what extent TEs may serve as a source for in trans gene regulation.