Romera-Branchat Maida, Pocard Chloé, Vincent Coral, Cerise Martina, da Silveira Falavigna Vítor, Pajoro Alice, Ding Na, Gao He, Franzen Rainer, Coupland George
Department of Plant Developmental Biology, Max Planck Institute for Plant Breeding Research, Cologne 50829, Germany.
Development. 2025 May 15;152(10). doi: 10.1242/dev.204241. Epub 2025 May 22.
Arabidopsis florigen activation complex (FAC), formed by the interaction of the transcription factor FD and the florigen protein FT, activates gene expression in the shoot apical meristem to induce flowering. We show that FD and its paralog FDP are also expressed in partially overlapping patterns in the floral meristem and floral organs, and that FT is present in floral meristems. The flowers of mutants for FT and its paralog TSF (ft tsf), and of fd fdp mutants show variable numbers of sepals and petals, and larger floral meristems than wild type. In the floral meristem, fd fdp and ft tsf mutants show a significant reduction in the expression of SEP and AG genes, which encode MADS-domain transcription factors, as well as increased expression of the homeobox gene WUS. Binding of FD to SEP genes suggests that diminished SEP gene expression is a primary defect in the mutants. We conclude that, beyond their role in floral transition, FAC components regulate floral homeotic gene expression to control floral meristem size, and influence floral organ development and identity.
拟南芥成花素激活复合体（FAC）由转录因子FD和成花素蛋白FT相互作用形成，可激活茎尖分生组织中的基因表达以诱导开花。我们发现，FD及其旁系同源物FDP在花分生组织和花器官中也以部分重叠的模式表达，并且FT存在于花分生组织中。FT及其旁系同源物TSF（ft tsf）的突变体以及fd fdp突变体的花，其萼片和花瓣数量可变，且花分生组织比野生型大。在花分生组织中，fd fdp和ft tsf突变体中编码MADS结构域转录因子的SEP和AG基因的表达显著降低，同时同源异型框基因WUS的表达增加。FD与SEP基因的结合表明，SEP基因表达减少是突变体的主要缺陷。我们得出结论，除了在花转变中的作用外，FAC组件还调节花同源异型基因的表达，以控制花分生组织的大小，并影响花器官的发育和特征。
