Roy J. Carver Department of Biochemistry, Biophysics & Molecular Biology

"Compartment-Specific Acetyl-CoA and Acyl-Carrier Protein Metabolism in Arabidopsis"

Plants exhibit a highly dynamic metabolome in response to different developmental and environmental cues.  Determining the organization of metabolism in time and space, especially at the subcellular level, is fundamental to understand the metabolic phenotype of a cell and precise control of carbon fluxes for engineering plants for bio-based products.  However, understanding the compartment-specific metabolism in plants has been hampered by the limitations of current analytical methods to determine the subcellular locations of metabolites.

I will present our new findings of two key compartment-specific metabolic processes in plant cells using Arabidopsis as the model system.  Combining reverse genetics with stable isotope-assisted metabolomics, we have characterized two distinctly localized acetate-activating enzymes, the plastidic acetyl-CoA synthetase (ACS) and peroxisomal acetate non-utilizing 1 (ACN1).  The redundant acetate-activating routes are required for normal plant growth and preventing plants from accumulating toxic levels of acetate.

We have also genetically and metabolically characterized three mitochondrial acyl-carrier protein (ACP) isoforms that are important cofactors in fatty acid metabolism.  Our results address their unequal contributions to the physiology and metabolism in plant growth and development.