PT  - JOURNAL ARTICLE
AU  - Yan Gong
AU  - Renee Dale
AU  - Hannah F. Fung
AU  - Gabriel O. Amador
AU  - Margot E. Smit
AU  - Dominique C. Bergmann
TI  - A cell size threshold triggers commitment to stomatal fate in <em>Arabidopsis</em>
AID  - 10.1101/2022.10.09.510391
DP  - 2022 Jan 01
TA  - bioRxiv
PG  - 2022.10.09.510391
4099  - http://biorxiv.org/content/early/2022/10/10/2022.10.09.510391.short
4100  - http://biorxiv.org/content/early/2022/10/10/2022.10.09.510391.full
AB  - How flexible developmental programs integrate information from internal and external factors to modulate stem cell behavior is a fundamental question in developmental biology. Cells of the Arabidopsis stomatal lineage modify the balance of stem cell proliferation and differentiation to adjust the size and cell type composition of mature leaves. Here, we report that meristemoids, one type of stomatal lineage stem cell, trigger the transition from asymmetric self-renewing divisions to commitment and terminal differentiation by crossing a critical cell size threshold. Through computational simulation, we demonstrate that this cell size-mediated transition allows robust, yet flexible termination of stem cell proliferation and we observe adjustments in the number of divisions before the differentiation threshold under several genetic manipulations. We experimentally evaluate several mechanisms for cell size sensing, and our data suggest that cell size is sensed via a chromatin ruler acting in the nucleus.Competing Interest StatementThe authors have declared no competing interest.