Compared with well-watered plants, drought-treated potatoes had smaller, more densely packed stomata. Their ratio to neighbouring pavement cells showed no significant change. Stomatalia’s AI analysed 192 leaf-print images across four cultivars, with three plants per treatment and cultivar.[1]
A density can change as cells expand
Stomata are pores that regulate gas exchange and water loss. Pavement cells form much of the surrounding leaf surface. As a developing leaf expands, the area occupied by its cells changes; counting pores per square millimetre therefore combines information about their production and their spacing.[2]
An earlier maize-and-soybean study measured both populations to separate those effects. Its stomatal index divided the number of stomata by the combined count of stomata and pavement cells. That denominator concerns the cellular population, whereas density uses surface area. Reduced expansion can change density without changing the proportion of cell types.[2]
The researchers maintained water treatments while new leaves developed, then measured the fully expanded leaves. That design follows a developmental response to growing conditions. It helps distinguish anatomy established during growth from the rapid opening and closing of pores that controls water loss.[2]
Measure the neighbourhood as well as the pore
Stomatalia delineates individual stomata and pavement cells in microscope images of leaf impressions, refining their irregular boundaries. The unchanged ratio supports reduced cell expansion as an explanation for crowding. Its strongest validation concerns clear potato and tomato images; transfer to other leaf architectures was uneven.[1]
Sources & further reading
- Stomatalia: a deep learning-based platform for quantitative stomata and pavement cell analysis Plant Methods · 7 Jul 2026 · Accessed 20 Oct 2026
- Different Leaf Anatomical Responses to Water Deficit in Maize and Soybean Life · 20 Jan 2023 · Accessed 20 Oct 2026