GENOMERGE · Role of genome merger and redundancy in plant evolution and adaptation

Genome merger has played a central role in the origin, evolution and diversification of eukaryotes with critical impact on species ecology and adaptation. The GENOMERGE project will explore the consequences of genome merger in two contexts that played a major role in angiosperm evolution: lateral gene transfer through endosymbiosis and allopolyploid speciation. While the merging of two lineages through endosymbiosis or allopolyploidy results in the combination of two genetic repertoires, it also creates many opportunities for evolutionary novelties and new phenotypes. This increased dynamics derives mainly from the diverse evolutionary fates of the duplicated genes. GENOMERGE will integrate various dimensions of the evolutionary consequences of genome merger on biodiversity, from molecular mechanisms to functions of adaptive interests. The first part aims at characterizing the immediate evolution of genes duplicated by endosymbiosis or polyploidy via an innovative experimental method using transgenic lines. The second part corresponds to the analyses of the evolution of duplicated genes in natural allopolyploids from genus Spartina (Poaceae) that contains a textbook example of recent allopolyploid speciation and invasiveness (S. anglica). This evolution of gene expression will be analysed in natural and various ecological conditions via transcriptome analyses involving Next Generation Sequencing. The genes associated with new biochemical pathways or with phenotypic features that have facilitated the invasiveness of S. anglica will be identified. Finally, particular attention will be paid to a physiological trait that evolved with hexaploidy in Spartina, namely the rare ability in angiosperms to produce an osmoprotectant and ecologically important molecule: Dimethyl Sulfopropionate (DMSP). As a Career Integration Grant project, GENOMERGE will considerably improve the prospects for the permanent integration of its principal investigator in the European research area.