TY - JOUR T1 - ARGONAUTE5 Mediates Fine-Tuning of Vegetative-to-Reproductive Phase Transition Through Its Interaction with miR156 in <em>Arabidopsis</em> JF - bioRxiv DO - 10.1101/640680 SP - 640680 AU - Charles Roussin-Léveillée AU - Guilherme Silva-Martins AU - Peter Moffett Y1 - 2019/01/01 UR - http://biorxiv.org/content/early/2019/05/16/640680.abstract N2 - Vegetative-to-reproductive phase change is a finely tuned process in plants, largely controlled by the age-regulated microRNA156 (miR156), which functions by suppressing the transcripts of SQUAMOSA-PROMOTER BINDING LIKE (SPL) transcription factors. ARGONAUTE proteins (AGO) are essential effectors of miRNA-mediated gene regulation. However, which AGO(s) mediate(s) the control of flowering time remains unclear. Here, we demonstrate a role for AGO5 in vegetative-to-reproductive phase transition through the modulation of SPL transcription factors. We show that AGO5 interacts physically and functionally with miR156 and that ago5 mutants present an early flowering phenotype in Arabidopsis. Furthermore, in ago5 mutants, the repression of flowering caused by miR156 overexpression is largely reversed, whereas leaf morphology remains unaffected. Our results thus indicate a specific role for AGO5 in mediating miR156 activity in meristematic, but not vegetative, tissue. As such, our data suggest a spatiotemporal regulation of the miR156 aging pathway, mediated through different AGO proteins in different tissues. ER -