Environmental and endogenous stimuli determine plant developmental transitions including flowering through multiple signaling cascades

Environmental and endogenous stimuli determine plant developmental transitions including flowering through multiple signaling cascades. Although the key activators and repressors of flowering initiation are defined, the components and mechanisms integrating the flowering pathways are not established. This study shows that TANDEM ZINC-FINGER/PLUS3 (TZP) is a light signaling component that orchestrates the cross-talk between the autonomous and the photoperiodic flowering pathways by regulating the chromatin status of the flowering repressor FLOWERING LOCUS C (FLC). We discover that TZP associates with the promoters and upregulates the expression of genes operating at diverse flowering pathways, including the histone demethylase FLD, and the histone deacetylase HDA6 that modulate the transcriptional accessibility and epigenetic landscape of the FLC locus. These findings will help understand how environmental signals are integrated in the nucleus.