Figure 3. Degradation of miRNAs in plants.

The 3′ ends of plant miRNAs are 2′-O-methylated by HEN1, which recognizes fully-processed miRNA duplexes through its dsRNA binding domains. This prevents HESO1/URT1-mediated 3′ uridylation and subsequent degradation of miRNAs by an unknown nuclease(s). SDN proteins can remove the 2′-O-methyl group, triggering miRNA uridylation and degradation. Figure created with Biorender.com.