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 crop grasses and resurrection plants in order to identify genes and cellular pathways that distinguish typical drought responses, from those associated with desiccation. The interdisciplinary genomic, genetic, and evolutionary aspects of this project immerse high school, undergraduate, and graduate students in the leading frontiers of plant science research. Projects in collaboration with the Michigan State University 4H Children's Garden teach students and citizen scientists about the impact of drought on agriculture.
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, epigenome, and chromatin dynamics are surveyed at high temporal resolution during the desiccation and rehydration processes. From these datasets, a comprehensive atlas of the genes and regulatory elements controlling desiccation tolerance in grasses is developed. Finally, transcriptome and metabolite data are collected from six grass species that evolved desiccation tolerance independently to test for convergent evolution and conserved pathway rewiring. A series of educational outreach activities and teaching modules are developed to explore drought and water relations in plants. Large-scale datasets from this project are disseminated through peer-reviewed publications, presentations, and deposition at the NCBI sequence archives and CyVerse.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
