The role of APETALA1 in petal number robustness
Abstract
Invariant floral forms are important for reproductive success and robust to natural perturbations. Petal number, for example, is invariant in Arabidopsis thaliana flowers. However, petal number varies in the closely related species Cardamine hirsuta, and the genetic basis for this difference between species is unknown. Here we show that divergence in the pleiotropic floral regulator APETALA1 (AP1) can account for the species-specific difference in petal number robustness. This large effect of AP1 is explained by epistatic interactions: A. thaliana AP1 confers robustness by masking the phenotypic expression of quantitative trait loci controlling petal number in C. hirsuta. We show that C. hirsuta AP1 fails to complement this function of A. thaliana AP1, conferring variable petal number, and that upstream regulatory regions of AP1 contribute to this divergence. Moreover, variable petal number is maintained in C. hirsuta despite sufficient standing genetic variation in natural accessions to produce plants with four-petalled flowers.
Data availability
All data generated or analysed during this study are included in the manuscript and supporting files.
Article and author information
Author details
Funding
Biotechnology and Biological Sciences Research Council (BB/H01313X/1)
- Angela Hay
Human Frontier Science Program (RGP0008/2013)
- Richard S Smith
Royal Society (University Research Fellowship)
- Angela Hay
Max Planck Society (W2 Minerva Fellowship)
- Angela Hay
European Molecular Biology Organization (Long Term Fellowship)
- Marie Monniaux
National Science and Engineering Research Council of Canada (Post-Doctoral Fellowship)
- Sarah M McKim
European Molecular Biology Organization (Long Term Fellowship)
- Sarah M McKim
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Reviewing Editor
- Sheila McCormick, University of California-Berkeley, United States
Version history
- Received: June 23, 2018
- Accepted: October 11, 2018
- Accepted Manuscript published: October 18, 2018 (version 1)
- Version of Record published: October 29, 2018 (version 2)
Copyright
© 2018, Monniaux et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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