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One of the key factors affecting all aspects of the life of a plant is the ability that cells have to control how genes are expressed. Reflecting this importance, regulation of gene expression can occur at several stages, from transcription to protein degradation. Small RNAs (sRNAs) are crucial for this process, being involved in the downregulation of genes at both transcriptional and post-transcriptional levels. An important trigger for sRNA generation is the presence of aberrant transcripts, which can be used as a template by the RNA-DEPENDENT RNA POLYMERASE 6 (RDR6) to synthesize double-stranded RNA molecules that are later processed into sRNAs. Recent evidence shows that terminators can have a dramatic role in this mechanism, influencing the accumulation of sRNAs derived from genes and consequently, affecting their expression. Nonetheless, little is known about the molecular mechanisms involved in the regulation of gene expression associated with the terminator function in plants. Here, we identify a new element in the Arabidopsis HSP18.2 terminator (tHSP) that is essential for its efficiency in supporting high levels of gene expression. We show that this element acts to reduce the levels of aberrant transcripts originating from read-through transcription, inhibiting thus the generation of sRNAs that can cause downregulation of the gene expression. Our data also suggests that terminators carrying this new element have a positive impact on splicing, helping to increase the levels of gene expression. Finally, our results not only make an important contribution towards a better understanding of how plant terminators can impact sRNA …