Ca2+ signature gates responsiveness to exogenous auxin in Arabidopsis roots
Abstract Plants must continually balance growth with arrest, especially under stress. Auxin signaling acts as a central regulatory hub in this process, yet the mechanisms that dynamically tune early auxin signalling in real time remain unknown. Here, we used the light-gated, Ca 2+ -permeable Channelrhodopsin 2 variant XXM2.0 to optogenetically impose defined Ca 2+ signatures on Arabidopsis root cells. Repetitive light activation triggered cytosolic Ca 2+ signals that in turn suppressed auxin-induced membrane depolarization and Ca 2+ transients. Moreover, prolonged optogenetic Ca 2+ stimulation affects auxin-responsive transcriptional reprogramming. As phenotypic output, reversible inhibition of root growth by suppressing cell division and elongation was observed. We further identify a candidate CaM7–CNGC14 module that likely mediates Ca 2+ -dependent gating of early auxin signalling. Our study thus introduces a synthetic biology approach to decompose calcium–auxin crosstalk in plant cells, and demonstrates that optogenetically imposed cytosolic Ca 2+ signals act as dynamic regulators of auxin susceptibility in roots.
Authors
- Ondřej Novák (ORCID: https://orcid.org/0000-0003-3452-0154)
- Matthias Freund (ORCID: https://orcid.org/0000-0002-5683-6275)
- Shouguang Huang (ORCID: https://orcid.org/0000-0001-7007-0301)
- Jiřı́ Friml (ORCID: https://orcid.org/0000-0002-8302-7596)
- Matthew Gilliham (ORCID: https://orcid.org/0000-0003-0666-3078)
- Kerstin Kaufmann (ORCID: https://orcid.org/0000-0001-7960-6256)
- Rainer Hedrich (ORCID: https://orcid.org/0000-0003-3224-1362)
- Marek Randuch (ORCID: https://orcid.org/0000-0002-8108-0158)
- Angel Baudon (ORCID: https://orcid.org/0000-0003-4125-9476)
- Aleš Pěnčík (ORCID: https://orcid.org/0000-0002-1314-2249)
- Zhaohui He (ORCID: https://orcid.org/0000-0002-8976-9494)
- Huifang Song (ORCID: https://orcid.org/0000-0003-1567-6882)
Institutions
- Institute of Science and Technology Austria (AT)
- Chinese Academy of Sciences (CN)
- University of Würzburg (DE)
- Humboldt-Universität zu Berlin (DE)
- Shenzhen Institutes of Advanced Technology (CN)
- Czech Academy of Sciences, Institute of Experimental Botany (CZ)
- Shenzhen University of Advanced Technology (CN)
- Shenzhen Institute of Synthetic Biology (CN)
- The University of Adelaide (AU)
- Palacký University Olomouc (CZ)
Publication Details
- Journal
- Nature Communications
- Published
- 2026-11-03
- DOI
- https://doi.org/10.1038/s41467-026-78361-8
- Citations
- 2
- Primary Topic
- Plant Molecular Biology Research
- Type
- article
- Field-Weighted Citation Impact
- 3.05