Auxin alone provokes retention of mRNA in mother cells.

The auxin-inducible degradation (AID) system can elicit conditional and reversible protein degradation as a tool to assess the role of essential proteins. Indeed, AID enables functional studies without the possibility of adaptation, which can occur with permanent gene deletions. The AID system relies on the addition of auxin molecules, such as indole-3-acetic acid (IAA), as a means to launch the degradation of the protein of interest. In this context, it is extremely important to control for the effect of auxin addition alone. To study the role of essential proteins in the process of selective mRNA delivery to daughter cells in , we first controlled for the effect of adding IAA to cells that cannot perform AID-mediated degradation. We found that auxin alone restricted delivery to daughter cells, as mRNA started being retained in the mother cell as soon as thirty minutes after IAA addition. Thus, our data warn about the danger of not systematically including auxin-treated cells incapable of degradation in every AID-related experiment. Furthermore, given previous data reporting the ability of auxin to inhibit the master growth regulator TORC1 in , our data suggest that TORC1 could control the selective delivery of mRNAs to daughter cells.