Characterizing the Role of Transcriptional Repression in Maize Development and Domestication

Most of the world's food supply is provided either directly or indirectly by a few cultivated cereal species. Cereals generate their main edible product, grains, through a reproductive process that takes place in specialized structures called spikelets, which eventually give rise to flowers. Spikelet formation is carefully regulated by a network of genes that function at specific times during development. This is achieved through precise control of gene activity, either by activating or repressing mechanisms. The maize REL2 protein is essential for repressing gene activity in many developmental processes, among which are those that regulate the formation of spikelets and flowers. In this proposal the role of REL2 and REL2-like proteins are investigated in the development of maize, an economically important crop species. Overall, this research will reveal the molecular mechanisms controlling spikelet and flower formation, and will have far-reaching ramifications for both basic and applied plant research in maize and other agronomically valuable species. This project will impact undergraduate students and a post-doctoral researcher, providing them with a broad range of genetic, developmental, and genomic skills. High-school students and teachers will also be trained and exposed to the importance of protein interaction networks in biological systems.

The proposed research integrates genetic, molecular and genomic approaches to dissect the role of REL2-mediated transcriptional repression during maize development and will ultimately lead to: i) the functional characterization of the REL2 corepressor gene family; ii) the development of an integrated model for spikelet and flower formation; iii) a mechanistic understanding of a key step in the domestication of maize spikelets; and iv) the discovery of new proteins mediating transcriptional repression in different developmental pathways.