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Evolution of stomatal closure to optimize water‐use efficiency in response to dehydration in ferns and seed plants
Author(s) -
Yang YuJie,
Bi MinHui,
Nie ZhengFei,
Jiang Hui,
Liu XuDong,
Fang XiangWen,
Brodribb Timothy J.
Publication year - 2021
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.17278
Subject(s) - water use efficiency , abscisic acid , stomatal conductance , dehydration , biology , photosynthesis , botany , drought tolerance , drought resistance , transpiration , horticulture , agronomy , biochemistry , gene
Summary Plants control water‐use efficiency (WUE) by regulating water loss and CO 2 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.