Nuclear factor Y-mediated H3K27me3 demethylation of the SOC1 locus orchestrates flowering responses of Arabidopsis

Abstract

Nuclear factor Y (NF-Y) is a conserved heterotrimeric transcription factor complex that binds to the CCAAT motifs within the promoter region of many genes. In plants, a large number of genes code for variants of each NF-YA, B or C subunit that can assemble in a combinatorial fashion. Here, we report the discovery of an Arabidopsis NF-Y complex that exerts epigenetic control over flowering time by integrating environmental and developmental signals. We show that NF-Y interacts with CONSTANS in the photoperiod pathway and DELLAs in the gibberellin pathway, to directly regulate the transcription of SOC1, a major floral pathway integrator. This NF-Y complex binds to a unique cis-element within the SOC1 promoter to modulate trimethylated H3K27 levels, partly through a H3K27 demethylase REF6. Our findings establish NF-Y complexes as critical mediators of epigenetic marks that regulate the response to environmental or intrinsic signals in plants.

Arabidopsis DPB3-1, a DREB2A Interactor, Specifically Enhances Heat Stress-Induced Gene Expression by Forming a Heat Stress-Specific Transcriptional Complex with NF-Y Subunits

“…The yeast three-hybrid analysis indicated that a H2A/H2B dimer is selective for NF-YA subunits, although the NF-YA subunits are highly similar to each other in Arabidopsis ( Figure 8D). A previous study suggested that the NF-YB6/NF-YC3 dimer did not form a trimer with NF-YA2 , although a recent study indicated that the NF-YB3/NF-YC9 dimer formed a trimer with NF-YA2 (Hou et al, 2014). Additionally, among the H2B-like proteins, DPB4, NC2b1, and NC2b2 did not form trimers with DPB3-1 and (E) Transactivation of the HsfA3 1-kb promoter:GUS reporter gene by various combinations of trimers and DREB2A CA.…”

“…Additionally, NF-Y trimers have been suggested to act in concert with a histone acetyltransferase (Li et al, 1998;Caretti et al, 2003;Peng et al, 2007), affecting the acetylation of histone H2A.Z on promoters (Li et al, 1998;Caretti et al, 2003;Peng et al, 2007;Gatta and Mantovani, 2011). Moreover, a recent study revealed that a NF-Y trimer is also involved in histone methylation to regulate the target gene expression of a transcription factor (Hou et al, 2014). Therefore, further study is required to reveal the regulation of histone modifications during drought or heat stress responses.…”

Arabidopsis LEAFY COTYLEDON1 Mediates Postembryonic Development via Interacting with PHYTOCHROME-INTERACTING FACTOR4

“…NF-Y subunits interact with other transcription factors to modulate gene expression in plant development and stress responses (Liu and Howell, 2010;Hou et al, 2014). LEC1 belongs to the NF-YB family; thus, we reasoned that LEC1 might function with other partners in the regulation of hypocotyl elongation during postembryonic development.…”

“…Full-length cDNAs of LEC1 and PIF4 were cloned into the pGreen binary vector HY105 containing C-or N-terminal fusions of EYFP to generate 35S: LEC1-EYFP C and 35S:PIF4-EYFP N , then cotransformed into tobacco (Nicotiana benthamiana) leaf epidermal cells by infiltration as previously published (Hou et al, 2014). After infiltration, tobacco was grown for 2 d and transferred to darkness for 24 h before detection of the YFP signals.…”

“…ChIP assays were performed as previously described (Hou et al, 2014). Briefly, for 35S:PIF4-HA, 3-d-old seedlings were transferred to darkness for additional 2 d and harvested for fixation.…”