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Up-regulation of NCED3 and ABA biosynthesis occur within minutes of a decrease in leaf turgor but AHK1 is not required


Sussmilch, FC and Brodribb, TJ and McAdam, SAM, Up-regulation of NCED3 and ABA biosynthesis occur within minutes of a decrease in leaf turgor but AHK1 is not required, Journal of Experimental Botany, 68, (11) pp. 2913-2918. ISSN 0022-0957 (2017) [Refereed Article]


Copyright Statement

Copyright 2017 The Author. Licensed under Creative Commons Attribution 4.0 International (CC BY 4.0)

DOI: doi:10.1093/jxb/erx124


A major environmental signal influencing day-time stomatal aperture is the vapour pressure deficit between the leaf and atmosphere (VPD). In angiosperms, increased VPD triggers biosynthesis of abscisic acid (ABA), prompting rapid stomatal closure. Altered cell turgor has been proposed as the trigger for ABA biosynthesis, but the timing and nature of the genetic signals linking these processes have remained uncertain. We investigated this in Arabidopsis by examining changes induced by a decrease in leaf turgor, simulating a natural increase in VPD. We found that the rate-limiting gene within the de novo ABA biosynthesis pathway, 9-cis-epoxycarotenoid dioxygenase 3 (NCED3), was induced and ABA levels increased within just 5 min of decreased leaf turgor. This rapid induction matches the time-frame for initiation of stomatal closure in response to a doubling in VPD. We further examined Arabidopsis histidine kinase1 (AHK1) as the most likely candidate for the turgor-sensing receptor involved, but found no significant difference between wild-type and an ahk1 null mutant in the induction of ABA-biosynthetic genes, ABA production, or stomatal behaviour. We show that decreased leaf turgor triggers de novo ABA biosynthesis within the time-frame of the stomatal response to VPD, but that AHK1 does not fulfil a critical role as a turgor-sensing receptor within this pathway.

Item Details

Item Type:Refereed Article
Keywords:ABA, AHK1, leaf turgor, NCED, stomata, turgor sensor, VPD
Research Division:Biological Sciences
Research Group:Plant biology
Research Field:Plant physiology
Objective Division:Expanding Knowledge
Objective Group:Expanding knowledge
Objective Field:Expanding knowledge in the biological sciences
UTAS Author:Sussmilch, FC (Dr Frances Sussmilch)
UTAS Author:Brodribb, TJ (Professor Tim Brodribb)
UTAS Author:McAdam, SAM (Dr Scott McAdam)
ID Code:117159
Year Published:2017
Funding Support:Australian Research Council (DP140100666)
Web of Science® Times Cited:51
Deposited By:Plant Science
Deposited On:2017-06-01
Last Modified:2018-07-13
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