Location: Plant Genetics Research
Project Number: 3622-21000-039-00
Start Date: Jul 23, 2013
End Date: Jul 22, 2018
Goal 1.1.A: Identify genes controlling elemental accumulation in many different environments. Goal 1.1.B: Identify elemental signatures of plant responses to stressful environments. The ionome is a highly sensitive probe of the processes that allow plants to adapt to the soil environment. The mechanisms that plants use to adapt to different soil environments will affect how they take up elements and different mechanisms will have different effects on the ionome. By identifying the genes responsible for elemental accumulation, we will also be identifying the genes responsible for adapting to the environment. Additionally, it may be possible to identify elemental signatures of different mechanisms of adaptation to the environment. Goal 1.2.: Identify and test candidate genes in soybeans and the oilseed model Camelina. The results from Approach 1 will give us a large number of genomic regions that control ionomic traits. For most of these regions, we will not be able to identify the causative loci directly in soybean. Instead, we will need to employ a variety of computational methods to identify candidate genes. The most powerful methods are likely to be comparative genomics efforts leveraging the large amount of ionomic data from other organisms to identify candidates that can then be addressed directly in soybean. Goal 2.1.A: Determine the contribution of glutamine carbon to the production of pyruvate-derived amino and fatty acids through the use of malic enzyme. Goal 2.1 B: Determine the carbon sources for citrate biosynthesis in seeds and its subsequent use for oil and or protein amino acid production. We will pursue a more explicit understanding of the role for carboxylic acids and related enzymes by i) developing methods for transient isotopic labeling of embryos with organic acids or amino acids and ii) analyzing labeled products with LC-MS/MS and scintillation counting to assess the redistribution of the label over time, quantifying metabolic fluxes when applicable. Goal 2.2: Demonstrate that oxidative and non-oxidative pathways within PPP maintain the production of erythrose-4-phosphate and ribulose-5-phosphate, necessary for amino acid and nucleotide production under different reduced/oxidized status. We will investigate the operational status of pentose phosphate pathway (PPP) metabolism in developing soybeans. The organization of PPP in soybeans is structured to produce aromatic amino acid precursors and nucleotides under changing redox conditions while fixing carbon or additionally producing NADPH depending upon development and the environment. The current investigations will also utilize isotopic labeling investigations and potentially flux analysis with paralleled technique developments.