The two plant-specific DREAM components FLIC and FLAC repress floral transition in Arabidopsis

The DREAM complex is a key transcriptional regulator especially involved in the control of the cell cycle and development. Here, we characterise two novel plant- specific DREAM components, FLIC and FLAC, which we identified through tandem affinity purification experiments as interactors of conserved core DREAM constituents. We demonstrate that plants lacking both FLIC and FLAC exhibit pleiotropic phenotypes, including stunted growth and reduced fertility. Notably, flic flac double mutants show an early-flowering phenotype, an aspect that we found to be shared with mutants of the core DREAM component LIN37, with which FLIC and FLAC interact in binary protein-protein interaction assays. Performing reverse affinity purification experiments, we detected the JMJ14/NAC050/NAC052 module, known for its involvement in flowering repression, in the interactome of both FLIC and FLAC. Subsequent binary interaction studies then link the JMJ14/NAC050/NAC052 module via LIN37 to the DREAM complex providing a mechanistic framework on how flowering time could be transcriptionally controlled by the DREAM complex. Summary blurbThis study identifies two plant-specific members of the DREAM complex, explores their roles by mutant analysis and protein interaction investigation, and links them and additional DREAM complex components to the regulation of floral transition.