Abstract Detail

Comparative Genomics/Transcriptomics

Sipperly, Nicolette [1], Carlson, David [1], Tacatta, Jorgen [1], Davalos, Liliana [1], Bomblies, Kirsten [2].

Energy allocation and senescence in the transition between annual and perennial populations of Draba albertina.

Evolutionary theories of senescence, and in particular the disposable soma theory, predict the evolution of genetically controlled senescence because energy used for growth and reproduction cannot be used to produce structure related to survival or maintenance of tissues and cells, and thus reproduction signals a decline in commitment to the soma. But in plants the genetic mechanisms that determine longevity, and its variation among species, remain mysterious for most species. Here, I study how energetic trade-offs between reproduction and extended lifespan might contribute to an evolutionary transition between annual and perennial populations of Draba albertina (Brassicaceae). I do this by comparing phenotypes, and studying gene and gene expression differences in leaf and flower tissues from populations which differ in flowering time, lignin content, and root-shoot biomass ratios. After floral development and seed set, the leaves of annual D. albertina plants begin to senesce followed by whole plant death. In the perennial plants, however, only the flowering shoot senesces while and the leaves and roots persist. By comparing annual and perennial plants, I find the greatest differential expression in genes related to energy allocation, specifically in pathways involved in starch metabolism and cell wall rigidity. Further, differences in hormone signaling pathways suggest changes in coordination of development, which may correlate with observed differences in e.g., flowering time and root-shoot ratio. These within-species differences suggest the transition between annual and perennial life histories involves shifts in energy allocation and metabolism, in line with the disposable soma theory. More broadly, these data illuminate relationships among survival, reproduction and lifespan that constrain evolution of species with different life histories and help explain covariation in traits related to longevity.

1 - Stonybrook University, Department of Ecology and Evolution, 650 Life Sciences Building, Stonybrook, NY, 11794-5245, USA
2 - Institute of Molecular Plant Biology ETH Zürich, Department of Biology, LFW E56.1, Universitätsstrasse 2, Zürich, 8092, Switzerland

life history
Disposable soma
gene expression.

Presentation Type: Oral Paper
Number: CGT5003
Abstract ID:801
Candidate for Awards:Margaret Menzel Award

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