Abstract Detail

Evolutionary Developmental Biology (Evo-Devo)

Little, Stefan Allan [1], Sauquet, Herve [1].

Evolution of floral transcriptomes in Magnoliidae.

Flowers are considered a key component to the success and diversification of angiosperms. Understanding of the genetic mechanisms underlying the diversity of floral morphology has been well-studied in several model organisms. However, the applicability of these mechanisms across angiosperms remains to be tested. Here, we focus on analyses of pre-anthetic bud transcriptomes for 20 exemplar magnoliid species. Magnoliidae, with four orders, twenty families, and ca. 10,000 species, are remarkably diverse in floral structure, representing a microcosm of floral evolution. Our sampling approach aims to represent the main phylogenetic lineages and morphological floral diversity of the clade. All four orders are represented by 13 families: Annonaceae, Aristolochiaceae, Calycanthaceae, Eupomatiaceae, Gomortegaceae, Himantandraceae, Lauraceae, Magnoliaceae, Monimiacae, Piperaceae, Saururaceae, Siparunaceae, and Winteraceae. RNA was extracted from 1-5 buds preserved in liquid nitrogen or in RNA-later. Extractions were sequenced using Illumina Hi-Seq with strand-specific paired-end reads, and Trinity was used to produce de novo assemblies. After quality filtering for sequences with high confidence and annotation, we approach the gene expression data with both qualitative and quantitative approaches. Transcripts with high sequence similarity to MADS-box genes, as well as TCP transcription factors with elevated expression are found in all samples. The MADS-box genes include those of B, C, and E function, central in floral organ identity in model organisms (i.e., AGAMOUS, APETALA3, PISTILLATA, SEPALLATA). We also relate expansion and contraction of gene families expressed in buds with ancestral state reconstructions of floral morphology. These transcriptomes represent a key resource for understanding floral gene expression, complementing current knowledge in ANA-grade, monocot, and eudicot angiosperms.

Related Links:
http://www.magniphy.org/

1 - Universite Paris-Sud, Laboratoire Ecologie, Systematique, Evolution, CNRS UMR 8079, bat. 360, Orsay, 91405, France

Keywords:
Magnoliidae
Transcriptome
transcription factor
gene duplication
character evolution.

Presentation Type: Oral Paper
Session: 2, Evolution and Development
Location: 200/Savannah International Trade and Convention Center
Date: Monday, August 1st, 2016
Time: 8:00 AM
Number: 2001
Abstract ID:719
Candidate for Awards:None