德国马克斯·普朗克植物育种研究所George Coupland小组开发出拟南芥花原激活复合物通过多面组装形成。相关论文于2025年11月12日发表在《自然》杂志上。

本研究揭示了FAC的不同组装机制，14-3-3蛋白在复合物中的不同功能，以及FAC的意外时空分布。研究小组发现，FT不是由14-3-3单独招募的，而是通过两个界面与DNA - FD - 14-3-3复合物相互作用，其中一个通过FT的非结构化C端与DNA结合。研究小组还发现，14-3-3蛋白与磷酸化FD的C端相互作用减少了内在无序FD蛋白的液相冷凝，使其能够结合DNA，并且14-3-3蛋白通过促进二聚化来加强FD的DNA结合。最终导致FT的招募。出乎意料的是，该课题组人员还发现在FT移动到茎尖后，FT和FD在幼花原基中共同转录，与被抑制的苞片形成边界，从而在花发育的最初阶段形成FAC。他们的研究提出了花原FT转录复合物形成的新机制，并指出该复合物在SAM和花原基发育过程中具有不同的功能。

研究人员表示，花原（Florigen）由FT基因编码，在叶片中合成并转运到茎尖分生组织（shoot apical meriorganization， SAM）诱导花发育。在SAM上，14-3-3蛋白被认为是FT蛋白的受体，并介导FT与碱性亮氨酸拉链（bZIP）转录因子FD之间的间接相互作用，形成花原激活复合物（FAC），激活开花基因的转录。

附：英文原文

Title: Florigen activation complex forms via multifaceted assembly in Arabidopsis

Author: Gao, He, Ding, Na, Wu, Yuang, Yu, Dongli, Zhou, Shi-Zhao, Stolze, Sara Christina, Vincent, Coral, Rodrguez Maroto, Gabriel, de los Reyes, Pedro, Harzen, Anne, Cerise, Martina, da Silveira Falavigna, Vtor, Li, Ertong, Timmers, Ton, Neumann, Ulla, Nakagami, Hirofumi, Hu, Jin-Yong, Chai, Jijie, Coupland, George

Issue&Volume: 2025-11-12

Abstract: Florigen, encoded by FT genes, is synthesized in leaves and transported to the shoot apical meristem (SAM) to induce flower development1,2,3. At the SAM, 14-3-3 proteins are proposed to act as receptors for FT protein and to mediate the indirect interaction between FT and the basic leucine zipper (bZIP) transcription factor FD to form the florigen activation complex (FAC) that activates transcription of flowering genes4,5,6. Here we demonstrate a different mechanism of FAC assembly, diverse functions for the 14-3-3 proteins within the complex, and an unexpected spatiotemporal distribution of the FAC. We show that FT is not recruited by 14-3-3 alone, but that it interacts with the DNA–FD–14-3-3 complex through two interfaces, one of which binds DNA via the unstructured C terminus of FT. We also find that interaction of 14-3-3 proteins with the C terminus of phosphorylated FD reduces liquid phase condensation of the intrinsically disordered FD protein, allowing it to bind DNA, and that the 14-3-3 proteins strengthen DNA binding of FD by promoting dimerization, which ultimately results in the recruitment of FT. Unexpectedly, we also find that after FT movement to the shoot apex, FT and FD are co-transcribed in young floral primordia, forming a boundary with the suppressed bract and allowing formation of the FAC during the first stages of floral development. Our studies propose a new mechanism by which the florigen FT transcriptional complex is formed, and indicate distinct functions for the complex during SAM and floral primordium development.

DOI: 10.1038/s41586-025-09704-6

Source: https://www.nature.com/articles/s41586-025-09704-6