The plant master photoperiodic regulator CONSTANS (CO) interacts with Nuclear Factor-Y subunits B2 (NF-YB2) and C9 (NF-YC9) and transcriptionally activates the florigen gene FLOWERING LOCUS T (FT), regulating floral transition. However, the molecular mechanism of the functional four-component complex assembly in the nucleus remains elusive. We report that co-phase separation of CO with NF-YB2/NF-YC9/FT precisely controls heterogeneous CO assembly and FT transcriptional activation. In response to light signals, CO proteins form functional percolation clusters from a diffuse distribution in a B-box-motif-dependent manner. Multivalent coassembly with NF-YC9 and NF-YB2 prevents inhibitory condensate formation and is necessary to maintain proper CO assembly and material properties. The intrinsically disordered region (IDR) of NF-YC9, containing a polyglutamine motif, fine-tunes the functional properties of CO/NF-YB/NF-YC condensates. Specific FT promoter recognition with polyelectrolyte partitioning also enables the fluidic functional properties of CO/NF-YB/NF-YC/FT condensates. Our findings offer novel insights into the tunable macromolecular condensation of the CO/NF-YB/NF-YC/FT complex in controlling flowering in the photoperiod control.

中文翻译：

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CO/NF-YB/NF-YC/FT 复合物的分子凝聚在拟南芥中门开花过渡。


植物主光周期调节因子 CONSTANS （CO） 与核因子-Y 亚基 B2 （NF-YB2） 和 C9 （NF-YC9） 相互作用，并转录激活 florigen 基因 FLOWERING LOCUS T （FT），调节花转换。然而，细胞核中功能性四组分复合物组装的分子机制仍然难以捉摸。我们报道了 CO 与 NF-YB2/NF-YC9/FT 的共相分离精确控制异质 CO 组装和 FT 转录激活。响应光信号，CO 蛋白以 B-box 基序依赖性方式从弥散分布形成功能性渗流簇。与 NF-YC9 和 NF-YB2 的多价共组装可防止抑制性冷凝水的形成，并且对于保持适当的 CO 组装和材料特性是必要的。NF-YC9 的本质无序区 （IDR） 包含聚谷氨酰胺基序，可微调 CO/NF-YB/NF-YC 缩合物的功能特性。通过聚电解质分配识别特异性 FT 促进子还可以实现 CO/NF-YB/NF-YC/FT 冷凝物的流体功能特性。我们的研究结果为 CO/NF-YB/NF-YC/FT 复合物的可调谐大分子缩合在光周期控制中控制开花提供了新的见解。