The development of multicellular organisms depends on a delicate balance between gene activation and repression, which is controlled by epigenetic marks* on chromatin. In plants, this regulation is essential for coordinating key developmental stages, such as flowering.
For the first time, IBS researchers, in collaboration with the Cell & Plant Physiology Laboratory, the iGReD and the Institut Curie, have demonstrated that the ULTRAPETALA1 (ULT1) protein performs a dual role as a gene regulator. Known for activating the expression of certain genes, ULT1 can also act as a repressor by directly interacting with enzymes of the PRC2 complex (, a protein complex that acts as a molecular switch by repressing the expression of certain genes through modifications to chromatin structure).
The discovery of this new mechanism sheds new light on how plants regulate their flowering and could, in the long term, facilitate the development of biotechnological approaches aimed at enhancing crop resilience to environmental changes. Détails
The dual trxG/PcG protein ULTRAPETALA1 modulates H3K27me3 and directly enhances POLYCOMB REPRESSIVE COMPLEX 2 activity for fine-tuned reproductive transitions. Geshkovski V, Engelhorn J, Izquierdo JB, Laroussi H, Thouly C, Turchi L, Wouters M, Le Masson M, Thévenon E, Petitalot A, Simon L, Verdier M, Desset S, Michl-Holzinger P, Bruckmann A, Parrinello H, Grasser KD, Probst AV, Margueron R, Vachon G, Kadlec J, Carles CC. Nature Plants 2026 ; 2(8):1561-1578. https://doi.org/10.1038/s41477-026-02363-z
Contact IBS : Jan Kadlec (IBS/Epigenetics and molecular pathways Group)