How do stomata grow to just the right size?


Cell size strongly affects cellular functions. In plants, this is exemplified by stomatal guard cells, which form valves that regulate the exchange of water and carbon dioxide between the leaf and the atmosphere. The size of guard cells affects the efficiency of photosynthesis and the speed at which it adjusts to changes in environmental conditions. Despite the importance of stomatal cell size, little is known about how guard cells form with predictable and uniform sizes.

We have found that a different type of plant cell regulates its own size using DNA contents as an internal reference ( This recent work also gave us clues about how the size of stomatal cells may be regulated. In this project, the student will test hypotheses on how cell cycle or cell fate decisions are linked to cell size during stomatal development, using a combination of molecular genetics, live imaging and quantitative image analysis.

The physiological consequences of changes in cell size will also be examined. The work is expected to illuminate a fundamental aspect of plant development and cell biology. Ultimately, knowledge of how stomatal cell size is regulated will be valuable to improve crop water use efficiency in an increasingly unpredictable environment.

The successful applicant will join the Sablowski team, which is part of a lively department with multidisciplinary interactions, with strength in predictive, quantitative approaches, and supported by state-of-the-art facilities, particularly for bioimaging.


1. D’Ario, M., and Sablowski, R. (2019). Cell Size Control in Plants. Annu. Rev. Genet. 53, 45-65.

2. Faizullah, L., Morton, J.A., Hersch-Green, E.I., Walczyk, A.M., Leitch, A.R., and Leitch, I.J. (2021). Exploring environmental selection on genome size in angiosperms. Trends Plant Sci. 10 1039-1049.

3. Zuch, D.T., Doyle, S.M., Majda, M., Smith, R.S., Robert, S., and Torii, K.U. (2022). Cell biology of the leaf epidermis: Fate specification, morphogenesis, and coordination. The Plant Cell 34, 209-227.

4. D’Ario, M., Tavares, R., Schiessl, K., Desvoyes, B., Gutierrez, C., Howard, M., and Sablowski, R. (2021). Cell size controlled in plants using DNA content as an internal scale. Science 372, 1176-1181.