Transcriptional networks are crucial to integrate various internal and external signals into optimal responses during plant growth and development. Primary root vasculature patterning and proliferation are controlled by a network centred around the basic Helix-Loop-Helix transcription factor complex formed by TARGET OF MONOPTEROS 5 (TMO5) and LONESOME HIGHWAY (LHW), which control cell proliferation and division orientation by modulating cytokinin response and other downstream factors. Despite recent progress, many aspects of the TMO5/LHW pathway are not fully understood. In particular, the upstream regulators of TMO5/LHW activity remain unknown. Here, using a forward genetic approach to identify new factors of the TMO5/LHW pathway, we discovered a novel function of the MYB-type transcription factor MYB12. MYB12 physically interacts with TMO5 and dampens the TMO5/LHW-mediated induction of direct target gene expression as well as the periclinal/radial cell divisions. The expression of MYB12 is activated by the cytokinin response, downstream of TMO5/LHW, resulting in a novel MYB12-mediated negative feedback loop that restricts TMO5/LHW activity to ensure optimal cell proliferation rates during root vascular development.
|Original language||English (US)|
|Journal||Journal of Experimental Botany|
|State||Published - Jan 18 2023|
Bibliographical noteKAUST Repository Item: Exported on 2023-01-20
Acknowledgements: This work was funded by The Research Foundation - Flanders (FWO; Odysseus II G0D0515N and post-doc fellowship 1215820N); the Netherlands Organization for Scientific Research (NWO; VIDI 864.13.00); the European Research Council (ERC Starting Grant TORPEDO; 714055); the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 885979 “DIVISION BELL”; EMBO (long term fellowship ALTF 1005-2019); and ERC consolidator Grant T-REX; 682436 to DVD; ERC Starting Grant COSI; 949808 to I.D.C and the China Scholarship Council (PhD fellowship 201706910099) to X.L. The authors thank Ralf Stracke and Sofie Goormachtig for sharing the myb11myb12-1f,myb111 and myb12-f mutant seeds, respectively; Davy Opdenacker for help with the EMS mutagenesis and Frederik Coppens for help with the SHOREmap analysis. B.D.R. would like to thank T.G.A. and A.P.M. for helpful discussions completely unrelated to this work.
ASJC Scopus subject areas
- Plant Science