Genetic and Genomic Approaches to Understanding Long-Distance Transport and Carbon Partitioning in Plants

University Of Missouri-Columbia, Columbia MO

Investigators

Abstract

PI: David Braun, University of Missouri - Columbia CoPIs: Karen Koch and Byung-Ho Kang (University of Florida - Gainesville), Clifford Weil and Rebecca Doerge (Purdue University), Jiri Adamec (University of Nebraska - Lincoln), and Mark Lubkowitz (Saint Michael's College) Key Collaborator: Judith Van Houten (University of Vermont - Burlington) Whole-plant carbohydrate partitioning is the process whereby carbon, assimilated through photosynthesis in leaves, is translocated through the veins, and imported into non-photosynthetic tissues like flowers, fruits, seeds and roots to sustain their growth and development. In most crop plants, sucrose is the principal carbohydrate translocated long-distance through the phloem tissue within veins. Although physiological studies have determined the site of sucrose synthesis and its translocation path through the phloem, very little is known about the genes that control the distribution of carbohydrates within plants. The objectives of this project are to provide a comprehensive understanding of the gene regulatory network controlling whole-plant carbohydrate partitioning in maize, a crop of vital significance to the agriculture and economy of the U.S. The project will use genetic and genomic experiments to identify the genes regulating carbon export from leaves and import into seeds, employ next generation sequencing to characterize genes expressed along the sucrose transport route through the phloem, and exploit the vast genetic diversity within maize to discover novel genetic modifiers of carbohydrate partitioning. Collectively, this knowledge will generate testable hypotheses about the functions of genes that underlie long-distance transport of carbohydrates, providing new insight that may translate into gains in food production, environmental stress tolerance, biomass accumulation for production of biofuels, and strategies to use plants for carbon sequestration. This project will help train and mentor the next generation of scientists by recruiting undergraduate students from a small liberal arts college and partnering them with undergraduate, graduate, and postdoctoral colleagues from major research universities. In coordination with the Vermont EPSCoR program, the project will develop a summer workshop for high school students and teachers that will focus on the research goals of the project and will help the participants develop a high school teaching module on plant genomics and carbohydrate partitioning. Community resources that include quality-controlled expression data will be deposited into public databases such as GenBank (www.ncbi.nlm.nih.gov/GenBank/), the Maize Genome Database (www.maizegdb.org/), and Gramene (www.gramene.org/). Genetic stocks will be made available through the Maize Genetics Cooperation Stock Center (www.maizecoop.cropsci.uiuc.edu/). A project website will be developed to communicate the research discoveries and educational outcomes of this project broadly to other scientists and to the public.