Format

Send to

Choose Destination
Plant Cell. 2016 Jun;28(6):1310-27. doi: 10.1105/tpc.16.00091. Epub 2016 May 18.

Genetic Analysis of Physcomitrella patens Identifies ABSCISIC ACID NON-RESPONSIVE, a Regulator of ABA Responses Unique to Basal Land Plants and Required for Desiccation Tolerance.

Author information

1
Centre for Plant Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom.
2
Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom.
3
Department of Energy Joint Genome Institute, Walnut Creek, California 94598 HudsonAlpha Institute for Biotechnology, Huntsville, Alabama 35806.
4
Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831.
5
University of Marburg, Plant Cell Biology, D-35043 Marburg, Germany BIOSS Centre for Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany.
6
BIOSS Centre for Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany Plant Biotechnology, Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany.
7
Botanisches Institut, D-50674 Köln, Germany.
8
Department of Integrative Biology, University of California, Berkeley California 94720-3140.
9
Department of Biology, Duke University, Durham, North Carolina 27708.
10
Uppsala University, Systematic Biology, 752 36 Uppsala, Sweden.
11
Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada Department of Medicine, University of Alberta, Edmonton, Alberta T6G 2E1, Canada BGI-Shenzhen, Shenzhen 518083, China.
12
Centre for Plant Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom a.c.cuming@leeds.ac.uk.

Abstract

The anatomically simple plants that first colonized land must have acquired molecular and biochemical adaptations to drought stress. Abscisic acid (ABA) coordinates responses leading to desiccation tolerance in all land plants. We identified ABA nonresponsive mutants in the model bryophyte Physcomitrella patens and genotyped a segregating population to map and identify the ABA NON-RESPONSIVE (ANR) gene encoding a modular protein kinase comprising an N-terminal PAS domain, a central EDR domain, and a C-terminal MAPKKK-like domain. anr mutants fail to accumulate dehydration tolerance-associated gene products in response to drought, ABA, or osmotic stress and do not acquire ABA-dependent desiccation tolerance. The crystal structure of the PAS domain, determined to 1.7-Å resolution, shows a conserved PAS-fold that dimerizes through a weak dimerization interface. Targeted mutagenesis of a conserved tryptophan residue within the PAS domain generates plants with ABA nonresponsive growth and strongly attenuated ABA-responsive gene expression, whereas deleting this domain retains a fully ABA-responsive phenotype. ANR orthologs are found in early-diverging land plant lineages and aquatic algae but are absent from more recently diverged vascular plants. We propose that ANR genes represent an ancestral adaptation that enabled drought stress survival of the first terrestrial colonizers but were lost during land plant evolution.

PMID:
27194706
PMCID:
PMC4944411
DOI:
10.1105/tpc.16.00091
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center