Abstract Detail

Comparative Genomics/Transcriptomics

Banerjee, Arjan [1], Stefanović, Saša [2].

Plastome evolution across the phylogenetic backbone of the parasitic plant genus Cuscuta (Convolvulaceae).

Parasitic plants have reduced to completely absent ability to conduct photosynthesis, and are usually characterized by sweeping morphological, physiological and genomic changes. The plastid genome (or plastome) is highly conserved in autotrophic plants and houses many key photosynthetic genes. This molecule is thus a useful system for documenting the genomic effects of a loss of autotrophy. Cuscuta (dodders) represents one of 13 independent transitions to a parasitic lifestyle within angiosperms. This near-cosmopolitan genus contains more than 200 obligate parasitic species circumscribed in four subgenera: Grammica, Pachystigma, Cuscuta, and Monogynella. Because plastomes in this group have been reported to show a substantial degree of diversification in terms of length and gene composition, they present an opportunity for fine-scale comparisons among closely related species of heterotrophic plants. In addition, with respect to photosynthesis, Cuscuta is a heterogenous group containing both hemi- and holoparasitic members that are, respectively, partially or entirely reliant on parasitism to meet their carbon budget. This research compares plastid genomes across the phylogenetic backbone of Cusucta to identify the changes in sequence composition and structure that have occurred as these plants have evolved along the trophic spectrum. By utilizing multiple whole-plastome assemblies from each of four subgenera, we are able to phylogenetically triangulate the positions of genomic changes and to construct a step-by-step model of plastome evolution in these plants.

1 - University of Toronto, Ecology and Evolutionary Biology, 3359 Mississauga Road N, DV4078/4090A, Mississauga, ON, L5C1Y9, Canada
2 - University Of Toronto Mississauga, Department Of Biology, 3359 Mississauga Rd. N., Mississauga, ON, L5L 1C6, Canada

Parasitic Plants

Presentation Type: Oral Paper
Abstract ID:639
Candidate for Awards:Margaret Menzel Award

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