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Leaves, not roots or floral tissue, are the main site of rapid, external pressure-induced ABA biosynthesis in angiosperms

Citation

Zhang, F-P and Sussmilch, F and Nichols, DS and Cardoso, AA and Brodribb, TJ and McAdam, SAM, Leaves, not roots or floral tissue, are the main site of rapid, external pressure-induced ABA biosynthesis in angiosperms, Journal of Experimental Botany, 69, (5) pp. 1261-1267. ISSN 0022-0957 (2018) [Refereed Article]


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Copyright 2018 The Authors. Licensed under Creative Commons Attribution 4.0 International (CC BY 4.0) https://creativecommons.org/licenses/by/4.0/

DOI: doi:10.1093/jxb/erx480

Abstract

Rapid biosynthesis of abscisic acid (ABA) in the leaf, triggered by a decrease in cell volume, is essential for a functional stomatal response to vapour pressure deficit (VPD) in angiosperms. However, it is not known whether rapid biosynthesis of ABA is triggered in other plant tissues as well. Through the application of external pressure to flower, root and leaf tissues, we test whether a reduction in cell volume can trigger rapid increases in ABA levels across plant body in two species Solanum lycopersicum and Passiflora tarminiana. Our results show that, in contrast to rapid ABA synthesis in the leaf, flower and root tissue did not show a significant, rapid increase in ABA level in response to a drop in cell volume over a short time-frame, suggesting that fast ABA biosynthesis occurs only in leaf, not in flower or root tissues. A gene encoding the key, rate-limiting carotenoid cleavage enzyme (9`-cis-epoxycarotenoid dioxygenase, NCED) in ABA biosynthetic pathway in S. lycopersicum, NCED1, was unregulated to lesser degree in flowers and roots compared to leaves in response to applied pressure. In both species, floral tissues contained substantially lower levels of NCED substrate 9`-cis-neoxanthin than leaves, and this ABA precursor could not be detected in roots. Slow and minimal ABA biosynthesis was detected after 2 h in petals, indicating that floral tissue is capable of synthesising ABA in response to sustained water deficit. Our results indicate that rapid ABA biosynthesis predominantly occurs in the leaves, and not in other tissues.

Item Details

Item Type:Refereed Article
Keywords:abscisic acid, 9`-cis-epoxycarotenoid dioxygenase, stomata, cell volume, flowers, roots
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
Author:Sussmilch, F (Dr Frances Sussmilch)
Author:Nichols, DS (Dr David Nichols)
Author:Cardoso, AA (Ms Amanda Cardoso)
Author:Brodribb, TJ (Professor Tim Brodribb)
Author:McAdam, SAM (Dr Scott McAdam)
ID Code:123713
Year Published:2018
Web of Science® Times Cited:1
Deposited By:Tasmanian Institute of Agriculture
Deposited On:2018-01-20
Last Modified:2018-08-09
Downloads:22 View Download Statistics

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