Regulation of FT splicing by an endogenous cue in temperate grasses.
Regulation of FT splicing by an endogenous cue in temperate grasses.
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温带草中内源信号对 FT 剪接的调节
DOI：
10.1038/ncomms14320
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发表时间：
2017-02-01
影响因子：
16.6
通讯作者：
Wu L
中科院分区：
文献类型：
--
作者：
Qin Z;Wu J;Geng S;Feng N;Chen F;Kong X;Song G;Chen K;Li A;Mao L;Wu L
适当的开花时间对植物繁殖成功至关重要。开花位点T （flower LOCUS T， FT）与14-3-3蛋白和bZIP转录因子FD相互作用，在多种开花途径的核心节点上发挥作用。在短柄基远隔体中有两个FT同源物FT1和FT2。在这里，我们发现FT2经历了年龄依赖性的选择性剪接（AS），导致两种剪接变体（FT2α和FT2β）。ft2 β编码的蛋白不能与FD或14-3-3相互作用，但能够与FT2α和FT1形成异源二聚体，从而干扰开花起始复合物的成花素介导的组装。值得注意的是，过量生产FT2β的转基因植株开花延迟，而通过人工microRNA沉默FT2β的转基因植株开花加速，表明FT2β在诱导开花中的主导负作用。此外，我们发现FT2的AS剪接在大麦和小麦等重要谷类作物中是保守的。总的来说，这些发现揭示了温带牧草中FT调控的一种新的转录后模式。
Appropriate flowering timing is crucial for plant reproductive success. The florigen, FLOWERING LOCUS T (FT), interacts with 14-3-3 proteins and the bZIP transcription factor FD, functioning at core nodes in multiple flowering pathways. There are two FT homologues, FT1 and FT2, in Brachypodium distachyon. Here we show that FT2 undergoes age-dependent alternative splicing (AS), resulting in two splice variants (FT2α and FT2β). The FT2β-encoded protein cannot interact with FD or 14-3-3s but is able to form heterodimers with FT2α and FT1, thereby interfering with the florigen-mediated assembly of the flowering initiation complex. Notably, transgenic plants overproducing FT2β exhibit delayed flowering, while transgenic plants in which FT2β is silenced by an artificial microRNA display accelerated flowering, demonstrating a dominant-negative role of FT2β in flowering induction. Furthermore, we show that the AS splicing of FT2 is conserved in important cereal crops, such as barley and wheat. Collectively, these findings reveal a novel posttranscriptional mode of FT regulation in temperate grasses.