Growing the Next Generation in Plant Genomics
Coate, Jeremy , Owens, Thomas , Doyle, Jeff .
Transcriptomic perspectives on the evolution of allopolyploidy in Glycine (Leguminosae).
In the legume genus, Glycine, a recent (ca.50,000 years) burst of allopolyploid speciation in Australia has produced a group of inter-related polyploids that combine the genomes of still-extant diploid progenitors. Several of the resulting polyploids were able to colonize islands of the Pacific Ocean, unlike any diploid perennial Glycine, and we are seeking to understand the physiological and molecular basis for this ecological phenomenon, with particular interest in identifying commonalities between independently formed allopolyploid species.We have begun with photosynthesis and photoprotection (specifically,non-photochemical quenching, NPQ), because both are potentially of adaptive significance. We have complemented physiological studies with transcriptomic analyses in an effort to identify the underlying genetic basis for the enhanced performance observed in allopolyploids. Illumina RNA-seq data provide information on levels of gene expression that can be dissected to identify the contribution of both homoeologous genomes of an allopolyploid. For both photosynthesis and NPQ, the best-studied allopolyploid, G. dolichocarpa, shows transgressive physiological phenotypes that appear to be produced by combining the best-performing features of its two diploid progenitors. For example, G. dolichocarpa achieves greater levels of NPQ by increasing the rapidly inducible,energy-dependent quenching component relative to one progenitor while increasing the more slowly inducible, zeaxanthin-dependent quenching component relative to the other. Analysis of transcriptomic data suggests that, relative to its diploid progenitors, G. dolichocarpa is better able to generate a strong proton gradient across the thylakoid membrane under stress conditions, resulting in enhanced NPQ. Similar trends in photosynthesis and NPQ occur in other allopolyploids of the complex.
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1 - Cornell University, Plant Biology, 412 Mann Library Building, Ithaca, NY, 14850, USA
2 - Cornell University, 412 Mann Library Building, ITHACA, NY, 14853-4301, USA
homoeologous gene expression
Presentation Type: Symposium or Colloquium Presentation
Location: Franklin C and D/Hyatt
Date: Monday, July 9th, 2012
Time: 4:00 PM