Abstract Detail

Evolutionary Developmental Biology (Evo-Devo)

Little, Stefan A. [1], Massoni, Julien [2], von Balthazar, Maria [3], Carrive, Laetitia [1], Couvreur, Thomas L. P. [4], Schoenenberger, Juerg [3], Staedler, Yannick [3], Sauquet, Herve [1].

Floral evolution in Magnoliidae: an integrated approach.

Although flowers are considered key to the success and diversification of angiosperms, there remain large gaps in our knowledge of floral evolution across angiosperm diversity. Magnoliidae are remarkably diverse in floral structure. As a large monophyletic group (ca. 10,000 spp.) comprised of four orders and 20 families, Magnoliidae represent a microcosm of the broad changes in floral evolution seen across the angiosperms. The MAGNIPHY project aims to study floral evolution in Magnoliidae, integrating molecular phylogenetics, morphology, paleobotany, and developmental genetics. In order to test hypotheses of floral evolution at the scale of the group as a whole, we generated a densely sampled, dated phylogeny (199 species; 75% of genera; all families), calibrated with 10 carefully reviewed fossil age constraints. Floral morphology for each sequenced species was compiled from literature and our own morpho-anatomical observations. Floral trait evolution was reconstructed under parsimony, maximum likelihood, and Bayesian approaches. Preliminary results suggest that the ancestral flower of Magnoliidae was probably trimerous, with a whorled and differentiated perianth. In addition, floral transcriptomes of one species from each of the 20 families are being sequenced to correlate floral gene expression patterns with floral morphology. So far, preliminary transcriptomic data from six families reveal several MADS-box genes as well as TCP transcription factors with elevated expression. The MADS-box genes show high sequence similarity with genes of B, C, and E function, central in floral organ differentiation (i.e., AGAMOUS, APETALA3, PISTILLATA, SEPALLATA). The integrative approach of the MAGNIPHY project should help us unravel the history and mechanisms of floral diversification in Magnoliidae, an enigmatic part of angiosperm evolution.

1 - Universite Paris-Sud, Laboratoire Ecologie, Systematique, Evolution, CNRS UMR 8079, bat. 360, Orsay, 91405, France
2 - University of Connecticut, Department of Ecology and Evolutionary Biology, Storrs, CT, USA
3 - University of Vienna, Department of Botany and Biodiversity Research, Rennweg 14, A-1030, Vienna, Austria
4 - Institut de Recherche pour le Developpement, UMR-DIADE, F-34394 Montpellier, Montpellier, France
5 - Universite Paris-Sud, Laboratoire Ecologie, Systematique, Evolution, CNRS UMR 8079, bat. 360, Orsay, 91405, France

Keywords:
eFLOWER
floral evolution
floral structure
ancestral traits
ancestral character reconstruction
flower
Magnoliidae
transcriptomics.

Presentation Type: Oral Paper:Papers for Topics
Session: 26
Location: Hall B/The Shaw Conference Centre
Date: Tuesday, July 28th, 2015
Time: 9:00 AM
Number: 26005
Abstract ID:597
Candidate for Awards:None