An ancient alkalinization factor informs Arabidopsis root development

Xhelilaj, K.; von Arx, M.; Biermann, D.; Parvanov, A.; Faiss, N.; Monte, I.; Klingelhuber, F.; Zipfel, C.; Timmermans, M.; Oecking, C.; Gronnier, J.

doi:10.64898/2025.12.22.695669

bioRxiv · 10.64898/2025.12.22.695669

An ancient alkalinization factor informs Arabidopsis root development

Xhelilaj, K.·von Arx, M.·Biermann, D.·Parvanov, A.·Faiss, N.·Monte, I.·Klingelhuber, F.·Zipfel, C.·Timmermans, M.·Oecking, C.·Gronnier, J.

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Abstract

The power of hydrogen (pH) regulates virtually all cellular activities. In both plants and animals, cell-to-cell variations in pH correlate with key developmental transitions1-5, yet the underlying regulators and associated functions remain elusive. Here, we report that members of the REMORIN (REM) protein family function as inhibitors of the H+-ATPases thereby promoting extracellular pH (pHe) alkalinization. This, in turn, regulates various cell surface processes, including steroid hormone signaling, and coordinates developmental transitions in the Arabidopsis thaliana root. Inhibition of H+-ATPases by REMs represents an evolutionary innovation that predates the origin of the root system itself. This study thus uncovers an ancient alkalinization mechanism co-opted by the root developmental program and infers that pHe patterning may have shaped morphogenesis evolution.

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Xhelilaj, K., von Arx, M., Biermann, D., Parvanov, A., Faiss, N., Monte, I., Klingelhuber, F., Zipfel, C., Timmermans, M., Oecking, C., Gronnier, J.. 2025-12-23. An ancient alkalinization factor informs Arabidopsis root development. https://doi.org/10.64898/2025.12.22.695669

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