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Stomatal responses to vapour pressure deficit are regulated by high speed gene expression in angiosperms

journal contribution
posted on 2023-05-18, 12:54 authored by McAdam, SAM, Frances SussmilchFrances Sussmilch, Timothy BrodribbTimothy Brodribb
Plants dynamically regulate water use by the movement of stomata on the surface of leaves. Stomatal responses to changes in vapour pressure deficit (VPD) are the principal regulator of daytime transpiration and water use efficiency in land plants. In angiosperms, stomatal responses to VPD appear to be regulated by the phytohormone abscisic acid (ABA), yet the origin of this ABA is controversial. After a 20 minute exposure of plants, from three diverse angiosperm species, to a doubling in VPD, stomata closed, foliar ABA levels increased and the expression of the gene encoding the key, rate-limiting carotenoid cleavage enzyme (9-cis-epoxycarotenoid dioxygenase, NCED) in the ABA biosynthetic pathway was significantly upregulated. The NCED gene was the only gene in the ABA biosynthetic pathway to be upregulated over the short time scale corresponding to the response of stomata. The closure of stomata and rapid increase in foliar ABA levels could not be explained by the release of ABA from internal stores in the leaf or the hydrolysis of the conjugate ABA-glucose ester. These results implicate an extremely rapid de novo biosynthesis of ABA, mediated by a single gene, as the means by which angiosperm stomata respond to natural changes in VPD.

Funding

Australian Research Council

History

Publication title

Plant, Cell and Environment

Volume

39

Pagination

485-491

ISSN

0140-7791

Department/School

School of Natural Sciences

Publisher

Blackwell Publishing Ltd

Place of publication

9600 Garsington Rd, Oxford, England, Oxon, Ox4 2Dg

Rights statement

Copyright 2015 John Wiley & Sons Ltd

Repository Status

  • Restricted

Socio-economic Objectives

Expanding knowledge in the biological sciences

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