1. As a first achievement of TORPEDO, we have identified mutants that are either resistant or hypersensitive to induction of PD; and have mapped the causal mutations to a set of novel genes. As these are very likely to be involved in this pathway, we will currently focus on understanding the function and localization of these genes. A manuscript describing these results is currently being revised for publication (bioRxiv 483486).
2. Besides this, as a second achievement, we have set-up a high throughput cell-based chemical genetics screening system to identify small molecules affecting oriented cell division, and have identified a set of 3 small molecules which are indeed affecting cell division orientation in both the cell-culture based screening system and in in planta experiments. We are focussing follow-up work to one chemical molecule able to induce oriented divisions in both our high-throughput cell culture system and in Arabidopsis roots. By analysing the transcriptional changes in these tissues upon treatment with this molecule, we have identified a transcription factor as top induced gene. Overexpression of this novel factor leads to a strong induction of oriented divisions in the root meristem, suggesting this factor is causal to the effect of the small molecule. We are currently following up on the biological role of this novel transcription factor in controlling cell division orientation as a main topic in the group.
3. We have additionally found the one of the main factors involved in controlling oriented cell divisions in the primary root meristem has a similar role throughout plant development. However, depending on the organ, different homologous transcription factors play a more prominent role. This means that heterodimer variations define oriented cell divisions in all plant meristem regions. These results are meanwhile published in iScience (bioRxiv 494582).
4. As a forth achievement in TORPEDO, we have identified a novel regulator of cell division orientation. Unlike the function of known pathways switching cell division orientation from AD to PD; this factor causes oblique divisions to occur. As such, we now have the perfect tools in hand to understand the difference between switching perfectly controlled oriented divisions and non-controlled oblique divisions.Work on this is currently being continued in the group.
5. As a final achievement of TORPEDO, we have set up a plant specific single cell RNA-sequencing pipeline in the host institute and are providing this to the plant community. Besides this, it has resulted in several high impact publications using this technology both from our group (Wendrich et al., 2020 Science; Yang et al., 2021 Nature Plants) and in collaboration with other labs (Graeff et al., 2021 Molecular Plant).
Work related to the TORPEDO project has been widely disseminated using alternative funding sources, including core funding:
- organization of 5 Vascular Development meetings in 2017-2022 (about 35-40 participants each)
- presentation using posters or oral presentations at several international meetings (including ROOTING2017, SEB2017, ACPD2018, iPMB2018, FASEB2019, CSHA2019, ROOTING2021, SEB2021, AUXIN2022 and others) and on invited lectures (including lectures in Helsinki, Paris-Saclay, Lyon, Nottingham, Tübingen, Zurich, Copenhagen, Lausanne and others). For a detailed overview, see the dissemination and output section.
