Technological advances have enabled scientists to develop complete understanding of the genomes of many crop species. However, there are continued challenges in linking the differences in plant genomes to specific traits. The lack of tools to study epigenetic variation, heritable variation that is not due to changes in DNA sequence, limits our ability to predict plant traits such as seed size and yield. This project is developing novel tools and approaches for studying the role of epigenetic variation in corn. These tools require developing a system for targeted editing of genes that regulate epigenetic variation in plants, enabling insights into the role of epigenetic variation in crop development. The outcomes of this project will provide breakthrough technologies to improve corn and other crops.
The proposed research is focused on development of biological materials to study the role of DNA methylation in maize. Prior work has suggested that DNA methylation is required for proper development of maize. This project will characterize the genome-wide patterns of DNA methylation in callus of maize in order to document any changes in this cell type. Genome editing approaches will be utilized to create loss-of-function mutations in three key DNA methylation pathways in cell culture. These cell lines can then be used to document changes in gene or transposable element expression to provide insights into the roles of DNA methylation in regulation of expression. Several enzymes known to play roles in demethylation of DNA will also be over-expressed in callus tissue in an attempt to generate partial, or locus-specific, reductions in DNA methylation. Attempts will be made to recover plants containing the loss-of-function mutations or over-expressing DNA demethylases that would be used to study the effects of these changes in vegetative plant tissues. The materials generated by this project may provide novel resources for understanding the role of DNA methylation in a species with a large, complex crop genome.
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.