14-3-3 proteins act as intracellular receptors for rice Hd3a florigen

Florigen, a plant hormone that translocates from leaves to the shoot apex to induce flowering, is encoded by the FLOWERING LOCUS T (FT) gene. The detailed molecular mechanism for florigen action and the identity of its receptors remained unknown. Ko Shimamoto and colleagues show that in rice, florigen binds to 14-3-3 proteins, a type of regulatory molecule present in all eukaryotic cells, and to the transcription factor OsFD1. The crystal structure of the resulting florigen activation complex (FAC) has been determined, providing a mechanistic basis for florigen function in flowering. This work offers clues for improving agriculturally important traits by manipulating florigen and its regulators.