The adaptor protein ECAP, the corepressor LEUNIG, and the transcription factor BEH3 interact and regulate microsporocyte generation in Arabidopsis

Plant Cell. 2024 Jul 2;36(7):2531-2549. doi: 10.1093/plcell/koae086.

Abstract

Histospecification and morphogenesis of anthers during development in Arabidopsis (Arabidopsis thaliana) are well understood. However, the regulatory mechanism of microsporocyte generation at the pre-meiotic stage remains unclear, especially how archesporial cells are specified and differentiate into 2 cell lineages with distinct developmental fates. SPOROCYTELESS (SPL) is a key reproductive gene that is activated during early anther development and remains active. In this study, we demonstrated that the EAR motif-containing adaptor protein (ECAP) interacts with the Gro/Tup1 family corepressor LEUNIG (LUG) and the BES1/BZR1 HOMOLOG3 (BEH3) transcription factor to form a transcription activator complex, epigenetically regulating SPL transcription. SPL participates in microsporocyte generation by modulating the specification of archesporial cells and the archesporial cell-derived differentiation of somatic and reproductive cell layers. This study illustrates the regulation of SPL expression by the ECAP-LUG-BEH3 complex, which is essential for the generation of microsporocytes. Moreover, our findings identified ECAP as a key transcription regulator that can combine with different partners to regulate gene expression in distinct ways, thereby facilitating diverse processes in various aspects of plant development.

MeSH terms

  • Arabidopsis Proteins* / genetics
  • Arabidopsis Proteins* / metabolism
  • Arabidopsis* / genetics
  • Arabidopsis* / metabolism
  • Co-Repressor Proteins / genetics
  • Co-Repressor Proteins / metabolism
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism
  • Gene Expression Regulation, Plant*
  • Nuclear Proteins
  • Pollen / genetics
  • Pollen / growth & development
  • Pollen / metabolism
  • Repressor Proteins / genetics
  • Repressor Proteins / metabolism
  • Transcription Factors / genetics
  • Transcription Factors / metabolism

Substances

  • Arabidopsis Proteins
  • BES1 protein, Arabidopsis
  • Co-Repressor Proteins
  • DNA-Binding Proteins
  • LUG protein, Arabidopsis
  • Nuclear Proteins
  • Repressor Proteins
  • SPL protein, Arabidopsis
  • Transcription Factors
  • AT3G58110 protein, Arabidopsis
  • AT4G18890 protein, Arabidopsis