Identification of cambium stem cell factors and their positioning mechanism

Eswaran, G.; Rutten, J. P.; Han, J.; Iida, H.; Lopez Ortiz, J.; Makila, R.; Wybouw, B.; Vainio, L.; Porcher, A.; Leal Gavarron, M.; Zhang, J.; Blomster, T.; Wang, X.; Dolan, D. W. P.; Smetana, O.; Brady, S.; Kucukoglu Topcu, M.; ten Tusscher, K. H.; Etchells, P.; Mahonen, A. P.

doi:10.1101/2023.07.20.549889

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bioRxiv · 10.1101/2023.07.20.549889

Identification of cambium stem cell factors and their positioning mechanism

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Abstract

Wood constitutes the majority of terrestrial biomass. Composed of xylem, it arises from one side of the vascular cambium, a bifacial stem cell niche that also produces phloem on the opposing side. It is currently unknown which molecular factors endow cambium stem cell identity. Here we show that TDIF ligand-activated PXY receptors promote the expression of CAMBIUM AINTEGUMENTA-LIKE (CAIL) transcription factors to define cambium stem cell identity in the Arabidopsis root. By sequestrating the phloem-originated TDIF, xylem-dependent PXY confines the TDIF signaling front, resulting in the activation of CAIL expression and stem cell identity in only a narrow domain. Our findings show how signals emanating from cells on opposing sides ensure robust yet dynamically adjustable positioning of a bifacial stem cell.

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Eswaran, G., Rutten, J. P., Han, J., Iida, H., Lopez Ortiz, J., Makila, R., Wybouw, B., Vainio, L., Porcher, A., Leal Gavarron, M., Zhang, J., Blomster, T., Wang, X., Dolan, D. W. P., Smetana, O., Brady, S., Kucukoglu Topcu, M., ten Tusscher, K. H., Etchells, P., Mahonen, A. P.. 2023-07-21. Identification of cambium stem cell factors and their positioning mechanism. https://doi.org/10.1101/2023.07.20.549889

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