University Of Tasmania

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Evolution of stomatal closure to optimize water-use efficiency in response to dehydration in ferns and seed plants

journal contribution
posted on 2023-05-21, 02:38 authored by Yang, Y-J, Bi, M-H, Nie, Z-F, Jiang, H, Lui, X-D, Fang, X-W, Timothy BrodribbTimothy Brodribb
  • Plants control water-use efficiency (WUE) by regulating water loss and CO2 diffusion through stomata. Variation in stomatal control has been reported among lineages of vascular plants, thus giving rise to the possibility that different lineages may show distinct WUE dynamics in response to water stress.
  • Here, we compared the response of gas exchange to decreasing leaf water potential among four ferns and nine seed plant species exposed to a gradually intensifying water deficit. The data collected were combined with those from 339 phylogenetically diverse species obtained from previous studies.
  • In well-watered angiosperms, the maximum stomatal conductance was high and greater than that required for maximum WUE, but drought stress caused a rapid reduction in stomatal conductance and an increase in WUE in response to elevated concentrations of abscisic acid. However, in ferns, stomata did not open beyond the optimum point corresponding to maximum WUE and actually exhibited a steady WUE in response to dehydration. Thus, seed plants showed improved photosynthetic WUE under water stress.
  • The ability of seed plants to increase WUE could provide them with an advantage over ferns under drought conditions, thereby presumably increasing their fitness under selection pressure by drought.


Australian Research Council


Publication title

New Phytologist










School of Natural Sciences


Wiley-Blackwell Publishing Ltd.

Place of publication

United KIngdom

Rights statement

Copyright 2021 The Authors

Repository Status

  • Restricted

Socio-economic Objectives

Effects of climate change on Australia (excl. social impacts); Management of water consumption by plant production; Plant extract crops