Unraveling the Developmental and Genetic Mechanisms Underpinning Floral Architecture in Proteaceae

Autor(en)
Catherine Damerval, Hélène Citerne, Natalia Conde e Silva, Yves Deveaux, Etienne Delannoy, Johann Joets, Franck Simonnet, Yannick Staedler, Jürg Schönenberger, Jennifer Yansouni, Martine Le Guilloux, Hervé Sauquet, Sophie Nadot
Abstrakt

Proteaceae are a basal eudicot family that with a highly conserved floral groundplan but which displays a considerable variation in other aspects of floral and inflorescence morphology. Their morphological diversity and phylogenetic position make them good candidates for understanding the evolution of floral architecture, in particular the question of the homology of the undifferentiated perianth with the differentiated perianth of core eudicots, and the mechanisms underlying the repeated evolution of zygomorphy. In this paper, we combine a morphological approach to explore floral ontogenesis and a transcriptomic approach to access the genes involved in floral organ identity and development, focusing on Grevillea juniperina, a species sampled from subfamily Grevilleoideae. We present developmental data for Grevillea juniperina and three additional four species that differ in their floral symmetry using stereomicroscopy, SEM and High Resolution X-Ray Computed Tomography. We find that the adnation of stamens to tepals takes place at early developmental stages, and that the establishment of bilateral symmetry coincides with the asymmetrical growth of the single carpel. To set a framework for understanding the genetic basis of floral development in Proteaceae, we generated and annotated de novo a reference leaf/flower transcriptome from Grevillea juniperina. We found Grevillea homologs of all lineages of MADS-box genes involved in floral organ identity, with the notable exception of one of the two B-class lineages. Using Arabidopsis thaliana gene expression data as a reference, we found homologs of other genes involved in floral development in the transcriptome of G. juniperina. We also found at least 21 class I and class II TCP genes, a gene family involved in the regulation of growth processes, including floral symmetry. The expression patterns of a set of floral genes obtained from the transcriptome were characterized during floral development to assess their organ specificity and asymmetry of expression.

Organisation(en)
Department für Botanik und Biodiversitätsforschung
Externe Organisation(en)
Université Paris XI - Paris-Sud, Université Paris VII - Paris-Diderot, AgroParis Tech, National Herbarium of New South Wales
Journal
Frontiers in Plant Science
Band
10
Anzahl der Seiten
14
ISSN
1664-462X
DOI
https://doi.org/10.3389/fpls.2019.00018
Publikationsdatum
2019
Peer-reviewed
Ja
ÖFOS 2012
106042 Systematische Botanik, 106008 Botanik, 106012 Evolutionsforschung
Schlagwörter
Link zum Portal
https://ucris.univie.ac.at/portal/de/publications/unraveling-the-developmental-and-genetic-mechanisms-underpinning-floral-architecture-in-proteaceae(2e2dbbc8-8ec0-4168-af0f-433e86697bda).html