Our work during the Ambizione project has provided pioneer insights into the regulation of signaling by the major plant hormone Auxin and its impact on plant development. We were the first to show that, during leaf development, the expression of TIR1/AFB2 Auxin Receptor (TAAR) genes is regulated by the miRNA miR393 and by secondary siRNAs, which we termed siTAARs. In another work, we have established that the levels of TAAR transcripts, the homeostasis of Auxin signaling and plant development are also regulated by the RNA decay pathway. The simultaneous regulation of transcript levels by RNA Silencing and by RNA decay has never been reported for natural regulatory system so far. Thus, the regulatory network that we have unraveled is unique. One major aim of the follow-up project will be to ch

aracterize in planta the modus operandi of this unique combination of pathways and to determine its biological significance.