Systematics Section / ASPT
Barkman, Todd J. , McNeal, Joel R. , Lim, Seok-Hong , Coat, Gwen , Croom, Henrietta , Young, Ned , dePamphilis, Claude W. .
Mitochondrial DNA suggests 12 origins of parasitism in angiosperms and implicates parasitic plants as vectors of horizontal gene transfer.
Analyses designed to infer the phylogenetic positions of all haustorial parasitic angiosperm lineages were performed on a data matrix of 103 seed plant species using 3 mitochondrial genes: atp1, coxI, and matR (4,019 aligned base pairs). Overall, the mtDNA phylogenetic tree agrees with independent analyses in terms of non-parasitic plant relationships and reveals 12 independent origins of parasitism in angiosperms, with four endoparasitic families formerly recognized as Rafflesiales (Cytinaceae, Rafflesiaceae, Mitrastemonaceae, and Apodanthaceae) being unrelated to one another. Cynomorium is unrelated to Balanophoraceae as has sometimes been suggested. In addition, results suggest multiple putative transfers of atp1 from host to parasite lineages, revealing for the first time a vector for horizontal gene transfer in angiosperms. Finally, the phylogenetic relationships inferred for parasites indicate that the origins of parasitism in angiosperms are very strongly correlated with gains of the mobile coxI group I intron. Evolutionary implications of the phylogeny and horizontal gene transfer events will be discussed.
1 - Western Michigan University, Department of Biological Sciences, 1903 West Michigan Ave, Kalamazoo, Michigan, 49008, USA
2 - University of the South, Department of Biology, Sewanee, Tennessee, 37383, USA
3 - Duquesne University, Department of Biological Sciences, Pittsburgh, Pennsylvania, 15219, USA
4 - Pennsylvania State University, Department of Biology and Institute of Molecular Evolutionary Genetics, University Park, Pennsylvania, 16802, USA
horizontal gene transfer
Presentation Type: Paper
Location: Cottonwood B (Snowbird Center)
Date: Wednesday, August 4th, 2004
Time: 2:30 PM