GSE193252
Components of the autonomous flowering pathway form a complex that suppresses FLC transcription by regulating multiple histone modifications [RNA-seq]
The autonomous flowering pathway promotes flowering in rapid-flowering accessions of Arabidopsis thaliana by reducing the expression of the key flowering repressor gene FLC. Although previous studies identified several autonomous pathway components, little is known about how these components cooperate in the regulation of flowering time. Here, we identified an autonomous pathway complex (APC) composed of three known autonomous pathway components (FLD, LD, and SDG26) and three previously uncharacterized components (EFL2, EFL4, and APRF1). Loss-of-function mutations of all of these components result in increased FLC expression and delayed flowering. The late-flowering phenotype is independent of photoperiod and can be overcome by vernalization, supporting the inference that the complex regulates flowering time specifically through the autonomous pathway. Our ChIP-seq analyses indicated that the APC components are required for the suppression of the histone modifications (H3Ac, H3K4me3, and H3K36me3) associated with the activation of gene expression and for the promotion of the histone modification (H3K27me3) associated with the repression of gene expression at FLC. We also found that the C-terminal coiled-coil domain of SDG26 binds to DNA in vitro and that the DNA-binding ability mediates the association of SDG26 with FLC chromatin in vivo. These results reveal the molecular basis of the autonomous pathway. Overall design: Examination of the mRNA expression of wild type and four mutants grown under long day condition.