The control of flowering time is essential for reproductive success and has a major effect on seed and fruit yield and other important agricultural traits in crops. Nuclear Factors Y (NF-Ys) are transcription factors that form heterotrimeric protein complexes to regulate gene expression required for diverse biological processes including flowering time control in plants. However, to our knowledge, there has been no report on mutants of individual NF-YA subunits that promote early flowering phenotype in plants. In this study, we identified SlNF-YA3b, encoding a member of the NF-Y transcription factor family, as a key gene regulating flowering time in tomato. Knockout of NF-YA3b resulted in an early flowering phenotype in tomato, whereas overexpression of NF-YA3b delayed flowering in transgenic tomato plants. NF-YA3b was demonstrated to form heterotrimeric protein complexes with multiple NF-YB/NF-YC heterodimers in yeast three-hybrid assays. Biochemical evidence indicated that NF-YA3b directly binds to the CCAAT cis-elements of the SINGLE FLOWER TRUSS (SFT) promoter to suppress its gene expression. These findings uncovered a critical role of NF-YA3b in regulating flowering time in tomato and could be applied to the management of flowering time in crops.

中文翻译：

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核因子 Y-A3b 与单花桁架启动子结合并调节番茄的开花时间

控制开花时间对于繁殖成功至关重要，并且对种子和果实产量以及农作物的其他重要农业性状具有重大影响。核因子 Y (NF-Y) 是形成异三聚体蛋白复合物的转录因子，可调节多种生物过程（包括植物开花时间控制）所需的基因表达。然而，据我们所知，目前还没有关于促进植物早期开花表型的单个 NF-YA 亚基突变体的报道。在这项研究中，我们确定了编码 NF-Y 转录因子家族成员的 SlNF-YA3b 是调节番茄开花时间的关键基因。 NF-YA3b 的敲除导致番茄提早开花表型，而 NF-YA3b 的过度表达则延迟转基因番茄植物的开花。在酵母三杂交测定中，NF-YA3b 被证明可与多个 NF-YB/NF-YC 异二聚体形成异三聚体蛋白复合物。生化证据表明 NF-YA3b 直接与单花桁架 (SFT) 启动子的 CCAAT 顺式元件结合以抑制其基因表达。这些发现揭示了 NF-YA3b 在调节番茄开花时间中的关键作用，可应用于作物开花时间的管理。