EIN3/EIN3-LIKE1 modulate FLC expression via histone demethylase interaction

Flowering time is determined by both endogenous factors and environmental cues to ensure successful reproduction. ETHYLENE INSENSITIVE 3 (EIN3) and EIN3 LIKE 1 (EIL1) are transcription factors which are the key downstream regulators of ethylene signal transduction. Rapid flowering is promoted by the repression of FLOWERING LOCUS C (FLC). It has been seen that FLOWERING LOCUS D (FLD), which encodes for a demethylase H3K4me1/H3K4me2, binds to FLC loci, and removes methylation marks to repress it.  Arabidopsis thaliana null mutants for EIN3 and EIL1 showed delayed flowering, however, the mechanism of this response is unknown. In this work, Xu et al., show how EIN3/EIL1 supress floral transition through the binding to the FLC loci and recruiting FLD. With a higher level of ethylene, FLD expression decreases which results in an hypermethylated H3K4me2 FLC locus, allowing its transcriptional activation and delaying flowering. (Summary by Eva Maria Gomez Alvarez, @eva_ga96) Plant Physiol. 10.1093/plphys/kiad131