Regulatory dynamics of desiccation tolerance in c4 grasses.

Resurrection plants can survive near complete drying during periods of prolonged drought and resume normal growth with the return of water. Grasses provide the bulk of human nutrition, and discoveries in resurrection grasses can be translated to closely related crop species. The genetic mechanisms controlling desiccation tolerance are largely unknown, but may be useful for improving drought tolerance in crop plants. This research project focuses on resurrection plants within an economically important grass family. The project involves a detailed comparison between resurrection plants in order to identify genes and cellular pathways associated with desiccation.Desiccation tolerance in angiosperms likely evolved through rewiring pre-existing seed desiccation pathways, but the gene and pathway level changes underlying this transition are unknown. In this project, systems-level and comparative genomics approaches are used to understand the genetic basis of desiccation tolerance in C4 grasses. The project focuses on two species from independent lineages of resurrection plants: Oropetium thomaeum, an emerging model grass, and Eragrostis nindensis, a wild South African grass closely related to the orphan cereal tef (E. tef). In the first instance, the role of gene and genome duplication in the evolution of desiccation tolerance is explored and genes under adaptive evolution are identified. Second, transcriptome, and chromatin dynamics are surveyed during the desiccation and rehydration processes. From these datasets, a set of the genes and regulatory elements controlling desiccation tolerance in grasses is developed.