Commentary: Primary Transcripts of microRNAs Encode Regulatory Peptides.

Noncoding RNAs (ncRNAs), including microRNAs (miRNAs) and long noncoding RNAs (lncRNAs), were assumed to be incapable of encoding proteins (Mercer et al., 2009; Rogers and Chen, 2013; Patil et al., 2014). miRNAs that derived from the primary miRNAs (pri-miRNAs) play crucial roles in post-transcriptional gene regulation by either repressing translation or guiding the degradation of complementary mRNA targets (Rogers and Chen, 2013). Transcriptome and high-throughput sequencing analyses have revealed a large number of ncRNAs in various organisms (Kapusta and Feschotte, 2014). It was found that ncRNAs were implicated in a variety of biological processes, including plant growth and development, and responses to environmental stresses (Mercer et al., 2009; Zhang et al., 2013; Kapusta and Feschotte, 2014).