show Abstracthide AbstractWe report new insight of non-coding RNA degradation mediated by XRN exoribonucleases and FRY1 in Arabidopsis thaliana. We suggest that XRN3, in combination with FRY1, is required to prevent the accumulation of 3’ extensions that arise from thousands of mRNA and miRNA precursor transcripts. Overall design: Examination of genome-wide transcriptomes of Arabidopsis genotypes such as fry1-6, xrn3-3, xrn2-1xrn3-3, xrn2-1xrn4-6 and xrn3-3xrn4-6 using directional RNA-Seq method.