Database Research Summaries2018 Blocking Production of Non-metabolizable Carbohydrates by Altering Carbon Partitioning in Developing Soybean Seeds
Research Focus
The focus of this project is to confirm the source of carbon for carbohydrate production and identify regulated enzymatic steps that are engineering targets to enhance final seed quality and composition.
Objectives
- Track carbon partitioning with isotopes through metabolism including glycolysis/gluconeogenesis, glyoxylate cycle, beta oxidation, lipid production and turnover, and dietary fiber-carbohydrate production pathways.
- In concert with labeling studies, identify the enzymatic steps through monitoring targeted RNA and key enzyme activity levels over development.
- Development of soybean lines with altered carbon partitioning to non-digestible carbohydrates by targeting the suppression (through RNAi) or mutation (through characterization of FN mutant lines) of genes encoding key enzymatic steps.
Results
- Lipids, protein and sugars were quantified at five stages over development in wild type and 31 mutant lines. Both positive and inverse correlations between these components were further assessed.
- A method for accurate protein quantification was developed and used to assess biomass.
- A method for sugar quantification was developed that can also indicate isotopic labeling and was used to examine dynamic production of carbohydrates at different stages of development.
- Levels of primary intermediates were quantified over five stages in metabolism.
- Levels of seed coat exudates from five developmental stages were measured.
- 3C-glycerol, glucose, alanine, acetate, sucrose and aspartate labeling experiments were performed and analyzed by mass spectrometry to assess dynamics of metabolism over the course of development.
- Expression levels for genes in central carbon metabolism were quantified over development
- Five transgenic lines were generated and are being grown to obtain homozygous plants for further characterization.
Importance
Farmers will benefit by the improved value of soybeans that will occur when carbon is repartitioned away from non-metabolizable oligosaccharides towards protein and oil.
For more information about this research project, please visit the National Soybean Checkoff Research Database.
Funded in part by the soybean checkoff.
