Cell surface and intracellular auxin signalling for H+ fluxes in root growth

Lanxin Li, Inge Verstraeten, Mark Roosjen, Koji Takahashi, Lesia Rodriguez, Jack Merrin, Jian Chen, Lana Shabala, Wouter Smet, Hong Ren, Steffen Vanneste, Sergey Shabala, Bert De Rybel, Dolf Weijers, Toshinori Kinoshita, William M. Gray, Jiří Friml

Research output: Contribution to journalArticlepeer-review

107 Scopus citations


Growth regulation tailors development in plants to their environment. A prominent example of this is the response to gravity, in which shoots bend up and roots bend down1. This paradox is based on opposite effects of the phytohormone auxin, which promotes cell expansion in shoots while inhibiting it in roots via a yet unknown cellular mechanism2. Here, by combining microfluidics, live imaging, genetic engineering and phosphoproteomics in Arabidopsis thaliana, we advance understanding of how auxin inhibits root growth. We show that auxin activates two distinct, antagonistically acting signalling pathways that converge on rapid regulation of apoplastic pH, a causative determinant of growth. Cell surface-based TRANSMEMBRANE KINASE1 (TMK1) interacts with and mediates phosphorylation and activation of plasma membrane H+-ATPases for apoplast acidification, while intracellular canonical auxin signalling promotes net cellular H+ influx, causing apoplast alkalinization. Simultaneous activation of these two counteracting mechanisms poises roots for rapid, fine-tuned growth modulation in navigating complex soil environments.

Original languageEnglish (US)
Pages (from-to)273-277
Number of pages5
Issue number7884
StatePublished - Nov 11 2021

Bibliographical note

Publisher Copyright:
© 2021, The Author(s), under exclusive licence to Springer Nature Limited.


Dive into the research topics of 'Cell surface and intracellular auxin signalling for H+ fluxes in root growth'. Together they form a unique fingerprint.

Cite this