eCite Digital Repository

Stomata: the holey grail of plant evolution


McAdam, SAM and Duckett, JG and Sussmilch, F and Pressel, S and Renzaglia, KS and Hedrich, R and Brodribb, TJ and Merced, A, Stomata: the holey grail of plant evolution, American Journal of Botany, 108, (3) pp. 366-371. ISSN 0002-9122 (2021) [Refereed Article]

PDF (Author manuscript)

Copyright Statement

Copyright 2021 Botanical Society of America

DOI: doi:10.1002/ajb2.1619


The greatest cost associated with terrestrial photosynthesis is maintaining hydration in the presence of phenomenal evaporative forces from the atmosphere. Without the capacity to maintain internal water reserves, vascular plants (tracheophytes) would never have escaped the soil boundary layer. Two key adaptations enable homoiohydry in vascular land plants: (1) a means to rapidly conduct water over long distances via xylem and (2) the ability to regulate water use by stomata. Xylem alone has long been credited for the evolutionary success of tracheophytes. Trees are only found in this clade, with most "nonvascular" land plants (bryophytes) confined to the soil boundary layer and relying on vegetative desiccation tolerance to survive drought. In contrast, stomata, which predate xylem in the fossil record and are found in most extant land plant clades, are often relegated to a level of lesser importance for driving the evolution of homoiohydric land plants. We would argue that physiological data, particularly from bryophytes, challenge this conventional wisdom rooted in morphological observation and suggest that the evolution of stomatal function was a critical innovation for the evolution of large plants.

Item Details

Item Type:Refereed Article
Keywords:bryophytes, evolution, Polytrichum, PAP, 3'-phosphoadenosine 5'-phosphate, plant height, Sphagnum, stomata
Research Division:Biological Sciences
Research Group:Evolutionary biology
Research Field:Biological adaptation
Objective Division:Expanding Knowledge
Objective Group:Expanding knowledge
Objective Field:Expanding knowledge in the biological sciences
UTAS Author:McAdam, SAM (Dr Scott McAdam)
UTAS Author:Sussmilch, F (Dr Frances Sussmilch)
UTAS Author:Hedrich, R (Professor Rainer Hedrich)
UTAS Author:Brodribb, TJ (Professor Tim Brodribb)
ID Code:144968
Year Published:2021
Funding Support:Australian Research Council (DE200101133)
Web of Science® Times Cited:10
Deposited By:Plant Science
Deposited On:2021-06-23
Last Modified:2022-08-18
Downloads:16 View Download Statistics

Repository Staff Only: item control page