Abstract Detail

Genetics Section

Latvis, Maribeth [1], Moore, Michael [2], Wicke, Susann [3], Soltis, Pamela S. [4], Soltis, Douglas E.  [5].

How do different forms of parasitism within a family affect plastid genome structure? A comparison of the complete plastid genomes of Lindenbergia, Agalinis, and Epifagus (Orobanchaceae).

With few exceptions, chloroplast genome structure is remarkably conserved across the diversity of angiosperms, in part due to strong selective pressures on the photosynthetic machinery housed in these organelles. Parasitic plants, in deriving some or all of their nutrition from other plants, provide a well-documented exception to this rule because of relaxed functional constraints. The family Orobanchaceae has long been recognized as an ideal system to explore these modifications associated with the acquisition of a parasitic lifestyle, as the clade contains species of all trophic levels, including the autotroph Lindenbergia, facultative and obligate hemiparasites, and several independently derived holoparasitic lineages. The majority of research in Orobanchaceae has focused on chloroplast genome reduction and modification in holoparasites, which lack chlorophyll, have reduced leaves, and represent the non-photosynthetic extreme of parasitic ability. In contrast, little is known about hemiparasites of this clade, those that retain chlorophyll, are photosynthetic, and otherwise appear “normal.” Here, we present the complete chloroplast genome sequences of the hemiparasite Agalinis fasciculata and autotrophic Lindenbergia philippensis, in comparison with previously published data for the holoparasite Epifagus virginiana, and characterize patterns of gene loss, modification and nucleotide substitution. As the only autotrophic lineage of Orobanchaceae and sister to the rest of the family, Lindenbergia is crucial for rooting further comparative genomic studies in the clade.

Broader Impacts:

1 - University of Florida, Florida Museum of Natural History, Dickinson Hall, Gainesville, Florida, 32611, USA
2 - Oberlin College, Biology Department, 119 Woodland Street, Science Center K111, Oberlin, Ohio, 44074-1097, USA
3 - University of Vienna, Department of Biogeography, Rennweg 14, Vienna, Vienna, A-1030, Austria
4 - University of Florida, Florida Museum of Natural History, Museum Road and Newell Drive, Dickinson Hall, Gainesville, FL, 32611-7800, USA
5 - University of Florida, Department of Biology, 220 Bartram Hall, P.O. Box 118526, Gainesville, FL, 32611, USA

Keywords:
Orobanchaceae
chloroplast genome
Parasitism
Agalinis
Lindenbergia
Epifagus
next-generation sequencing.

Presentation Type: Oral Paper:Papers for Sections
Session: 1
Location: 556A/Convention Center
Date: Monday, August 2nd, 2010
Time: 8:30 AM
Number: 1003
Abstract ID:511