Abstract Detail

Systematics

Unruh, Sarah [1], McKain, Michael [2], Pires, Joseph Chris [3], Leebens-Mack, Jim [4].

Genome Evolution in Orchidaceae.

Orchidaceae is one of the largest families of flowering plants with an array of unique traits and adaptations. The recently published genomes of Phalaenopsis and Dendrobium have suggested a paleopolyploid event shared by these species, but the exact placement of this whole genome duplication (WGD) is currently unknown. We hypothesized that the event was shared by all orchids, and, may have facilitated the evolution of many adaptive traits found in the orchid family. We used transcriptome data to estimate a species tree and to investigate the incidence of WGD in the context of these relationships. We identified 777 single copy gene families and reconstructed species relationships. Our phylogeny recapitulated previously published relationships but increased support in areas with short branches, such as Cypripedioideae. We reconstructed gene trees for 3181 multi-copy gene families and used the PUG software to identify nodes of the trees with bursts of gene duplication. We identified two nodes of the tree with bursts of gene duplication, one that includes all orchids and one that include all sampled monocots (not including Alismatales). Ks frequency plots corroborated the gene trees, indicating one putative event shared by all orchids and one shared by sampled monocots, which has previously been identified as tau. The identification of an orchid-wide polyploid event has great implication for the role of WGD in the evolution of unique orchid biology. Additionally, the core ortholog set presented here represents a conservative list of single-copy genes that will be highly useful for target enrichment studies designed to shed light on the evolution of difficult to delineate orchid clades.

1 - University of Missouri, Biological Sciences, 1201 E Rollins St, 311 Bond Life Sciences Center, Columbia, MO, 65201, USA
2 - Donald Danforth Plant Science Center, Plant Biology, 975 N. Warson Rd., St. Louis, MO, 63132, USA
3 - University Of Missouri, 371 Bond Life Sciences Center, 1201 Rollins Street, Columbia, MO, 65211-7310, USA
4 - University of Georgia, Plant Biology, 3111 Carlton St, 4505 Miller Plant Sciences, Athens, GA, 30602

Keywords:
Orchidaceae
polyploidy
Transcriptomics
phylogenetics.

Presentation Type: Oral Paper
Session: 20, Basal Dicots/Monocots part A (Asparagales)
Location: 200/Savannah International Trade and Convention Center
Date: Tuesday, August 2nd, 2016
Time: 8:45 AM
Number: 20004
Abstract ID:653
Candidate for Awards:None