Abstract Detail

Molecular Ecology

Elphinstone, Cassandra [1], Todesco, Marco [2], Henry, Greg [3], Rieseberg, Loren [4].

Arctic plant epigenomics in response to warming.

The world’s climate is warming at an unprecedented rate. Can plants adapt fast enough to keep up? Will they adapt through the slow accumulation of favourable genetic changes or through more rapid, but less stable, changes in DNA methylation and related processes, broadly termed epigenetic adaptation? We used artificially warmed plots at International Tundra Experiment (ITEX) sites across the Arctic (Alaska, Sweden, Svalbard, Northern Canada) to determine the mechanisms and speed of plant adaptation to climate change. Experimental warming has been maintained in tundra communities for up to 28 years by ITEX participants. This provides a unique opportunity to study short-term adaptive responses to climate warming. Our focus is on Dryas octopetala and D. integrifolia, diploid plants with a small (460 Mb) genome, a circumpolar distribution, and well-studied responses to climate change. We ran Whole Genome Bisulphite Sequencing and RNAseq on plants from the warmed and control plots across the four ITEX sites to identify differences in DNA methylation and gene expression that are consistently associated with experimental warming. Initial results show several significantly differentially methylated regions (DMRs) associated with plants from the warming experiments. Many of these DMRs exist close to or are co-located with genes associated with abiotic stress resistance in other related species. To determine if these DMRs are heritable, we grew the seeds of all the Dryas plants that were sequenced in two different environmental conditions (growth chambers simulating high and low Arctic climates and light regimes). Survival, growth and DNA methylation data were collected for the seeds that germinated. We are investigating whether any DMRs of the parent plants, associated with warming, are present in their seedlings. DNA methylation is known to affect gene transcription when near gene regulatory regions. However, finding a direct link between the warming induced DMRs and physical differences, that we can measure in the field, is difficult. To begin to investigate a direct mechanism, we will measure the frequency of certain RNA transcripts and determine if they are affected by the DNA methylation.This unique study combining the genomics of a tundra plant with pre-existing warming experiments across the Arctic has enabled us to begin to test the mechanisms, inheritance, and speed of plant adaptation to climate change.

1 - University of British Columbia, Botany, 2212 Main Mall, Vancouver, BC, V6T 1Z4, Canada
2 - University of British Columbia, Department of Botany, 6270 University Boulevard, Vancouver, BC, V6T 1Z4, Canada
3 - University of British Columbia, Department of Geography, 1984 West Mall, Vancouver BC V6T 1Z2, Vancouver, BC, V6T 1Z2, Canada
4 - University Of British Columbia, Department Of Botany, 6270 University Blvd, Vancouver, BC, V6T 1Z4, Canada

Keywords:
tundra plants
climate change
DNA methylation
genomics
epigenetics
RNAseq.

Presentation Type: Oral Paper
Number: ME2003
Abstract ID:640
Candidate for Awards:None