DRP002453
Florigen-induced Transposon Silencing in the Shoot Apex during Floral Induction in Rice
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 FLOWERING LOCUS T and its orthologs; the rice florigen is Heading date 3a (Hd3a). Here we show that Hd3a co-exists, in the same regions of the rice shoot apex, with the other components of the florigen activation complex and its transcriptional targets. RNA-seq analysis of shoot apex from wild type and RNAi plants depleted of florigen activity revealed unexpectedly that 4354 transposable elements (58% of all classifiable rice TEs) were expressed collectively in the vegetative and reproductive shoot apex. Furthermore, in the reproductive shoot apex, 216 TEs were silenced by florigen. Although the biological significance of these findings remains to be studied, our results suggest a link between floral induction and regulation of TEs.