2025-12-08 ニューヨーク大学 (NYU)
Mangroves have evolved nearly 30 times over the last roughly 200 million years and can survive in saltwater. Photo credit: Pat Josse, CC0, via Wikimedia Commons
<関連情報>
- https://www.nyu.edu/about/news-publications/news/2025/december/scientists-find-cellular-key-to-helping-plants-survive-in-saltwa.html
- https://www.cell.com/current-biology/abstract/S0960-9822(25)01543-X
細胞サイズの収斂進化によりマングローブの生息地への適応が可能になる Convergent evolution of cell size enables adaptation to the mangrove habitat
Guo-Feng Jiang ∙ Bo-Tao Qin ∙ Long-De Luo ∙ … ∙ Arezoo Dastpak ∙ Kevin A. Simonin ∙ Adam B. Roddy
Current Biology Published:December 8, 2025
DOI:https://doi.org/10.1016/j.cub.2025.11.036
Highlights
- Salinity tolerance requires cells that can tolerate high turgor pressures
- Mangroves have evolved repeatedly to have smaller cells with thicker cell walls
- Smaller cells among mangroves are independent of genome size variation
Summary
Mangroves have evolved at least 27 times across ∼20 plant families to survive coastal environments characterized by high salinity, inundation, intense light, and strong winds.1,2 To survive these extreme conditions, mangroves exhibit a variety of physiological strategies to tolerate the low osmotic potentials associated with saltwater inundation.3,4,5,6,7,8 Because low osmotic potentials are counterbalanced by high turgor pressure, saltwater exposure exerts mechanical demands on cells. Analyzing 34 mangrove species and 33 closely related inland taxa from 17 plant families, we show that compared with their inland relatives, mangroves have unusually small leaf epidermal pavement cells and thicker cell walls, which together confer greater mechanical strength and tolerance to low osmotic potentials. However, mangroves do not exhibit smaller, more numerous stomata that enable higher photosynthetic rates,9,10,11 suggesting selection on biomechanical integrity rather than on gas exchange capacity. Notably, mangroves break the allometric scaling between the sizes of epidermal pavement cells and stomata typically seen in land plants,3,12 highlighting that strong selection in saline habitats can override genome size-mediated scaling rules. Phylogenetic comparative analyses revealed repeated convergent evolution of cell traits across independent transitions from inland to coastal habitats. These anatomical changes constitute a simple but effective adaptation to salt stress. Our findings underscore the role of biomechanics in driving convergent evolution of cell traits and suggest that manipulating cell size and wall properties could be a promising strategy for engineering salt-tolerant plants.
