Sun, Y, Harpazi, B, Wijerathna-Yapa, A et al. (7 more authors) (2019) A ligand-independent origin of abscisic acid perception. Proceedings of the National Academy of Science, 116 (49). pp. 24892-24899. ISSN 0027-8424
Abstract
Land plants are considered monophyletic, descending from a single successful colonization of land by an aquatic algal ancestor. The ability to survive dehydration to the point of desiccation is a key adaptive trait enabling terrestrialization. In extant land plants, desiccation tolerance depends on the action of the hormone abscisic acid (ABA) that acts through a receptor-signal transduction pathway comprising a PYRABACTIN RESISTANCE 1-like (PYL)–PROTEIN PHOSPHATASE 2C (PP2C)–SNF1-RELATED PROTEIN KINASE 2 (SnRK2) module. Early-diverging aeroterrestrial algae mount a dehydration response that is similar to that of land plants, but that does not depend on ABA: Although ABA synthesis is widespread among algal species, ABA-dependent responses are not detected, and algae lack an ABA-binding PYL homolog. This raises the key question of how ABA signaling arose in the earliest land plants. Here, we systematically characterized ABA receptor-like proteins from major land plant lineages, including a protein found in the algal sister lineage of land plants. We found that the algal PYL-homolog encoded by Zygnema circumcarinatum has basal, ligand-independent activity of PP2C repression, suggesting this to be an ancestral function. Similarly, a liverwort receptor possesses basal activity, but it is further activated by ABA. We propose that co-option of ABA to control a preexisting PP2C-SnRK2-dependent desiccation-tolerance pathway enabled transition from an all-or-nothing survival strategy to a hormone-modulated, competitive strategy by enabling continued growth of anatomically diversifying vascular plants in dehydrative conditions, enabling them to exploit their new environment more efficiently.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2019 Published under the PNAS license. This is an author produced version of a paper published in Proceedings of the National Academy of Science. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | PYL; receptor basal activity; Zygnema; abscisic acid; streptophyte algae |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Biological Sciences (Leeds) > School of Biology (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 01 Nov 2019 15:11 |
Last Modified: | 03 Jan 2020 16:18 |
Status: | Published |
Publisher: | National Academy of Sciences |
Identification Number: | 10.1073/pnas.1914480116 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:152957 |