FIERY1 promotes microRNA accumulation by suppressing rRNA-derived small interfering RNAs in Arabidopsis

Arabidopsis AGO1 binds both microRNA (miRNA) and endogenous small interfering RNA (siRNA). Here the authors show that 5′−3′ RNA degradation suppresses siRNA biogenesis from ribosomal RNA to prevent overloading of AGO1 with ribosomal siRNA and maintain miRNA-directed post translational gene silencing.