FT-like proteins induce transposon silencing in the shoot apex during floral induction in rice
FT-like proteins induce transposon silencing in the shoot apex during floral induction in rice
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DOI：
10.1073/pnas.1417623112
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发表时间：
2015-02-24
影响因子：
11.1
通讯作者：
Shimamoto, Ko
中科院分区：
文献类型：
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作者：
Tamaki, Shojiro;Tsuji, Hiroyuki;Shimamoto, Ko
成花诱导是高等植物发育的关键步骤。成花素是一种移动的成花激活剂，在叶片中合成并运输到茎尖，最近被鉴定为由FLOWERLOCUS T（FT）及其直系同源物编码的蛋白;水稻成花素是抽穗期3a（Hd 3a）蛋白。14-3-3蛋白介导Hd 3a与转录因子OsFD 1相互作用，在水稻APETALA 1同源基因OsMADS 15的启动子上形成一个三元结构，称为成花素激活复合物。然而，关键的信息，包括FT样蛋白和成花素激活复合物和下游基因的组分之间的时空重叠，仍然不清楚。在这里，我们证实，Hd 3a共存，在相同的区域的水稻茎尖，与成花素激活复合物的其他组件及其转录靶点。然而，出乎意料的是，来自野生型和RNA干扰植物的茎尖的RNA测序分析显示，4，379个转座因子（TE;所有可分类的水稻TE的58%）在营养和生殖茎尖中共同表达。此外，在生殖枝顶端，214个TE被成花素沉默。我们的研究结果表明，成花诱导和调节TE之间的联系。
Floral induction is a crucial developmental step in higher plants. Florigen, a mobile floral activator that is synthesized in the leaf and transported to the shoot apex, was recently identified as a protein encoded by FLOWERING LOCUS T (FT) and its orthologs; the rice florigen is Heading date 3a (Hd3a) protein. The 14-3-3 proteins mediate the interaction of Hd3a with the transcription factor OsFD1 to form a ternary structure called the florigen activation complex on the promoter of OsMADS15, a rice APETALA1 ortholog. However, crucial information, including the spatiotemporal overlap among FT-like proteins and the components of florigen activation complex and downstream genes, remains unclear. Here, we confirm that Hd3a coexists, in the same regions of the rice shoot apex, with the other components of the florigen activation complex and its transcriptional targets. Unexpectedly, however, RNA-sequencing analysis of shoot apex from wild-type and RNA-interference plants depleted of florigen activity revealed that 4,379 transposable elements (TEs; 58% of all classifiable rice TEs) were expressed collectively in the vegetative and reproductive shoot apex. Furthermore, in the reproductive shoot apex, 214 TEs were silenced by florigen. Our results suggest a link between floral induction and regulation of TEs.