The miRNome function transitions from regulating developmental genes to transposable elements during pollen maturation

Plant Cell. 2022 Feb 3;34(2):784-801. doi: 10.1093/plcell/koab280.


Animal and plant microRNAs (miRNAs) are essential for the spatio-temporal regulation of development. Together with this role, plant miRNAs have been proposed to target transposable elements (TEs) and stimulate the production of epigenetically active small interfering RNAs. This activity is evident in the plant male gamete containing structure, the male gametophyte or pollen grain. How the dual role of plant miRNAs, regulating both genes and TEs, is integrated during pollen development and which mRNAs are regulated by miRNAs in this cell type at a genome-wide scale are unknown. Here, we provide a detailed analysis of miRNA dynamics and activity during pollen development in Arabidopsis thaliana using small RNA and degradome parallel analysis of RNA end high-throughput sequencing. Furthermore, we uncover miRNAs loaded into the two main active Argonaute (AGO) proteins in the uninuclear and mature pollen grain, AGO1 and AGO5. Our results indicate that the developmental progression from microspore to mature pollen grain is characterized by a transition from miRNAs targeting developmental genes to miRNAs regulating TE activity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / genetics*
  • Arabidopsis / growth & development
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism
  • Argonaute Proteins / genetics
  • Argonaute Proteins / metabolism
  • DNA Transposable Elements / genetics*
  • Gene Expression Regulation, Plant
  • Germination / genetics
  • MicroRNAs / genetics*
  • MicroRNAs / metabolism
  • Plants, Genetically Modified
  • Pollen / genetics*
  • Pollen / growth & development*
  • RNA, Plant / genetics
  • RNA-Binding Proteins / genetics
  • RNA-Binding Proteins / metabolism


  • AGO1 protein, Arabidopsis
  • Arabidopsis Proteins
  • Argonaute Proteins
  • DNA Transposable Elements
  • MicroRNAs
  • RNA, Plant
  • RNA-Binding Proteins
  • argonaute 5 protein, Arabidopsis