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.
Subject(s)
Arabidopsis Proteins , Arabidopsis , Gene Expression Regulation, Plant , Arabidopsis/genetics , Arabidopsis/metabolism , Arabidopsis Proteins/metabolism , Arabidopsis Proteins/genetics , Co-Repressor Proteins/metabolism , Co-Repressor Proteins/genetics , DNA-Binding Proteins/metabolism , DNA-Binding Proteins/genetics , Nuclear Proteins , Pollen/genetics , Pollen/metabolism , Pollen/growth & development , Repressor Proteins/metabolism , Repressor Proteins/genetics , Transcription Factors/metabolism , Transcription Factors/geneticsABSTRACT
Jasmonate (JA) is a well-known phytohormone essential for plant response to biotic stress. Recently, a crucial role of JA signaling in salt resistance has been highlighted; however, the specific regulatory mechanism remains largely unknown. In this study, we found that the NUCLEAR FACTOR-Y (NF-Y) subunits NF-YA1, NF-YB2, and NF-YC9 form a trimeric complex that positively regulates the expression of salinity-responsive genes, whereas JASMONATE-ZIM DOMAIN protein 8 (JAZ8) directly interacts with three subunits and acts as the key repressor to suppress both the assembly of the NF-YA1-YB2-YC9 trimeric complex and the transcriptional activation activity of the complex. When plants encounter high salinity, JA levels are elevated and perceived by the CORONATINE INSENSITIVE (COI) 1 receptor, leading to the degradation of JAZ8 via the 26S proteasome pathway, thereby releasing the activity of the NF-YA1-YB2-YC9 complex, initiating the activation of salinity-responsive genes, such as MYB75, and thus enhancing the salinity tolerance of plants.