RESEARCH-PGR: Anchoring phenotypes to gene networks for embryo formation in maize

University Of Florida, Gainesville FL

Investigators

Abstract

Corn is among the world's most productive crops and provides food for a growing population. The United States is the largest producer and exporter of corn. Every corn kernel contains an embryo that will grow into a plant if the kernel is planted. A vigorous embryo is critical for establishing the healthy stand of corn plants needed to maximize yield. The embryo also supplies valuable nutrients including unsaturated corn oil, vitamin E, and other anti-oxidants. Despite the importance of this embryo, the genes that control its formation and interaction with other organs of the kernel are not well understood. Planned work will identify networks of interacting genes that control growth of the embryo as the kernel develops on the ear. Genes involved in embryo growth will be identified by analyzing genomes of individual plants that carry heritable defects in embryo formation. This research will use and augment the UniformMu national public resource for corn genetics developed for systematic analysis of gene function. Genes revealed by this genetic analysis are in turn compared to networks of genes identified by correlations in timing of action during embryo development. Results will delineate new sources of natural genetic variation for improving quality and quantity of maize. The project will also connect with the public via museum programs, and will train students in application of genomics technologies to problems with both fundamental and practical importance. The maize embryo dramatically impacts resource partitioning between embryo and endosperm during kernel growth. A striking feature of the cereal-grain embryo is its unique organ-- the scutellum. In addition to well-known roles of the scutellum in germination, it is also the storage site for lipid-soluble vitamins and unsaturated oils that impact nutritional quality of the grain. Surprisingly, the processes involved in formation and growth of the scutellum remain largely unknown. Planned work targets the developmental control of this distinctive organ: Objective 1 will implement high-throughput, phenotype-to-genotype analysis for 86 embryo mutants isolated from the UniformMu maize population. Objective 2 will delineate and genetically anchor gene networks for embryogenesis by combining transcriptome-network analysis with in-depth morphological, metabolic, and molecular analysis of embryo phenotypes identified in Objective 1. Objective 3 will enhance the UniformMu national public resource for genetic research by replenishing and improving depleted seed stocks to aid their availability and accessibility via the Maize Cooperation Genetics Stock Center and MaizeGDB.org. The project will reach out to diverse communities through public museum programs, resource workshops, proactive engagement, and user support. 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.