FT-like proteins induce transposon silencing in the shoot apex during floral induction in rice

Shojiro Tamaki, Hiroyuki Tsuji, Ayana Matsumoto, Akiko Fujita, Zenpei Shimatani, Rie Terada, Tomoaki Sakamoto, Tetsuya Kurata, Ko Shimamoto
Proceedings of the National Academy of Sciences, 2015, 112(8): E901-E910  DOI: 10.1073/pnas.1417623112;      追溯原文......本站官方QQ群:62473826

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.



  成花素基因;抽穗期基因;生育期基因;光周期敏感基因;感光基因 Hd3a; FT