Components of the autonomous flowering pathway form a complex that suppresses FLC transcription by regulating multiple histone modifications
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ABSTRACT:
ORGANISM(S): Arabidopsis thaliana
PROVIDER: GSE193253 | GEO | 2022/06/25
REPOSITORIES: GEO
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Project description: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.
2022-06-25 | GSE193251 | GEO
Project description: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.
2022-06-25 | GSE193252 | GEO
Project description:Components of the autonomous flowering pathway form a complex that suppresses FLC transcription by regulating multiple histone modifications
| PRJNA795493 | ENA
Project description:Components of the autonomous flowering pathway form a complex that suppresses FLC transcription by regulating multiple histone modifications [RNA-seq]
| PRJNA795495 | ENA
Project description:Components of the autonomous flowering pathway form a complex that suppresses FLC transcription by regulating multiple histone modifications [ChIP-seq]
| PRJNA795496 | ENA
Project description:The developmental transition to flowering is timed by endogenous and environmental signals through multiple genetic pathways. In Arabidopsis, the MADS-domain protein FLOWERING LOCUS C is a potent flowering repressor. Here, we report that the FLOWERING LOCUS C clade member MADS AFFECTING FLOWERING3 acts redundantly with another clade member to directly repress expression of the florigen FLOWERING LOCUS T and inhibit flowering. FLOWERING LOCUS C clade members act in partial redundancy in floral repression and mediate flowering responses to temperature, in addition to their participation in the flowering-time regulation by vernalization and photoperiod. We show that FLOWERING LOCUS C, MADS AFFECTING FLOWERING3 and three other clade members can directly interact with each other and form nuclear complexes, and that FLOWERING LOCUS C-dependent floral repression requires other clade members. Our results collectively suggest that the FLOWERING LOCUS C clade members act as part of several MADS-domain complexes with partial redundancy, which integrate responses to endogenous and environmental cues to control flowering.
| S-EPMC3709509 | biostudies-literature
Project description:Several pathways control time to flowering in Arabidopsis thaliana through transcriptional and posttranscriptional gene regulation. In recent years, mRNA processing has gained interest as a critical regulator of flowering time control in plants. However, the molecular mechanisms linking RNA splicing to flowering time are not well understood. In a screen for Arabidopsis early flowering mutants we identified an allele of BRR2a. BRR2 proteins are components of the spliceosome and highly conserved in eukaryotes. Arabidopsis BRR2a is ubiquitously expressed in all analyzed tissues and involved in the processing of flowering time gene transcripts, most notably FLC. A missense mutation of threonine 895 in BRR2a caused defects in FLC splicing and greatly reduced FLC transcript levels. Reduced FLC expression increased transcription of FT and SOC1 leading to early flowering in both short and long days. Genome-wide experiments established that only a small set of introns was not correctly spliced in the brr2a mutant. Compared to control introns, retained introns were often shorter and GC-poor, had low H3K4me1 and CG methylation levels, and were often derived from genes with a high-H3K27me3-low-H3K36me3 signature. We propose that BRR2a is specifically needed for efficient splicing of a subset of introns characterized by a combination of factors including intron size, sequence and chromatin, and that FLC is most sensitive to splicing defects.
| S-EPMC4839602 | biostudies-literature
Project description:Although previous studies have identified several autonomous pathway components that are required for the promotion of flowering, little is known about how these components cooperate. Here, we identified an autonomous pathway complex (AuPC) containing both known components (FLD, LD and SDG26) and previously unknown components (EFL2, EFL4 and APRF1). Loss-of-function mutations of all of these components result in increased FLC expression and delayed flowering. The delayed-flowering phenotype is independent of photoperiod and can be overcome by vernalization, confirming that the complex specifically functions in the autonomous pathway. Chromatin immunoprecipitation combined with sequencing indicated that, in the AuPC mutants, the histone modifications (H3Ac, H3K4me3 and H3K36me3) associated with transcriptional activation are increased, and the histone modification (H3K27me3) associated with transcriptional repression is reduced, suggesting that the AuPC suppresses FLC expression at least partially by regulating these histone modifications. Moreover, we found that the AuPC component SDG26 associates with FLC chromatin via a previously uncharacterized DNA-binding domain and regulates FLC expression and flowering time independently of its histone methyltransferase activity. Together, these results provide a framework for understanding the molecular mechanism by which the autonomous pathway regulates flowering time.
| S-EPMC9303297 | biostudies-literature
Project description:Flowering locus C (FLC), a floral repressor, is a critical factor for the transition from the vegetative to the reproductive phase. Here, the mechanisms regulating the activity and stability of the FLC protein were investigated. Bimolecular fluorescence complementation and in vitro pull-down analyses showed that FLC interacts with the E3 small ubiquitin-like modifier (SUMO) ligase AtSIZ1, suggesting that AtSIZ1 is an E3 SUMO ligase for FLC. In vitro sumoylation assays showed that FLC is modified by SUMO in the presence of SUMO-activating enzyme E1 and conjugating enzyme E2, but its sumoylation is inhibited by AtSIZ1. In transgenic plants, inducible AtSIZ1 overexpression led to an increase in the concentration of FLC and delayed the post-translational decay of FLC, indicating that AtSIZ1 stabilizes FLC through direct binding. Also, the flowering time in mutant FLC (K154R, a mutation of the sumoylation site)-overexpressing plants was comparable with that in the wild type, whereas flowering was considerably delayed in FLC-overexpressing plants, supporting the notion that sumoylation is an important mechanism for FLC function. The data indicate that the sumoylation of FLC is critical for its role in the control of flowering time and that AtSIZ1 positively regulates FLC-mediated floral suppression.
| S-EPMC3883301 | biostudies-literature
Project description:Adenosine bases of RNA can be transiently modified by the deposition of a methyl-group to form N6-methyladenosine (m6A). This adenosine-methylation is an ancient process and the enzymes involved are evolutionary highly conserved. A genetic screen designed to identify suppressors of late flowering transgenic Arabidopsis plants overexpressing the miP1a microProtein yielded a new allele of the FIONA1 (FIO1) m6A-methyltransferase. To characterize the early flowering phenotype of fio1 mutant plants we employed an integrative approach of mRNA-seq, Nanopore direct RNA-sequencing and meRIP-seq to identify differentially expressed transcripts as well as differentially methylated RNAs. We provide evidence that FIO1 is the elusive methyltransferase responsible for the 3'-end methylation of the FLOWERING LOCUS C (FLC) transcript. Furthermore, our genetic and biochemical data suggest that 3'-methylation stabilizes FLC mRNAs and non-methylated FLC is a target for rapid degradation.
| S-EPMC9543952 | biostudies-literature