Florigen FT: a Signaling Hub Connecting Environmental Cues and Developmental Regulation

FLOWERING LOCUS T (FT) is a signaling protein synthesized in leaves and transported to the shoot apical meristem, where it functions as florigen, a key inducer of flowering and developmental transitions. Substantial progress has been made in elucidating the mechanisms underlying FT synthesis, transport, and the assembly and regulation of the florigen activation complex (FAC), providing a solid foundation for understanding plant developmental regulatory networks. Recently, a study integrated multiple regulatory layers, including protein-DNA interactions, liquid-liquid phase separation, and spatiotemporal expression patterns, thereby extending the traditional static FAC model into a dynamic and multilayered assembly framework. This work offers new molecular insights into how plants integrate environmental cues to regulate reproductive development. In this review, we summarize recent advances in FT and FAC research, highlight key outstanding questions, and discuss future directions, aiming to provide fresh perspectives for elucidating plant developmental regulation and for potential applications in crop improvement.