McAdam et al 2015 AOBPlants.pdf (491.11 kB)
Molecular characterization of a mutation affecting abscisic acid biosynthesis and consequently stomatal responses to humidity in an agriculturally important species
journal contribution
posted on 2023-05-18, 12:53 authored by McAdam, SAM, Frances SussmilchFrances Sussmilch, Timothy BrodribbTimothy Brodribb, John RossJohn RossMutants deficient in the phytohormone abscisic acid (ABA) have been instrumental in determining not only the biosynthetic pathway for this hormone, but also its physiological role in land plants. The wilty mutant of Pisum sativum is one of the classic, well-studied ABA deficient mutants; however this mutant remains uncharacterised at a molecular level. Using a candidate gene approach, we show that the wilty mutation affects the xanthoxin dehydrogenase step in ABA biosynthesis. To date, this step has only been represented by mutants in the ABA2 gene of Arabidopsis thaliana. Functional ABA biosynthesis appears to be critical for normal stomatal responses to changes in humidity in angiosperms, with wilty mutant plants having no increase in foliar ABA levels in response to a doubling in vapour pressure deficit and no closure of stomata. Phylogenetic analysis of the ABA2 gene family from diverse land plants indicates that the evolution of an ABA-biosynthetic-specific short-chain dehydrogenase (ABA2) evolved in the earliest angiosperms. The relatively recent evolutionary origin of specificity in this step has important implications for both the evolution of ABA biosynthesis and action in land plants.
Funding
Australian Research Council
History
Publication title
AoB PlantsVolume
7Article number
plv091Number
plv091Pagination
1-11ISSN
2041-2851Department/School
School of Natural SciencesPublisher
Oxford University PressPlace of publication
United KingdomRights statement
Copyright 2015 The Authors Licenced under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/)Repository Status
- Open