The pyruvate dehydrogenase complex (PDC) is subjected to multiple interacting levels of control in plant cells. The first level is subcellular compartmentation. Plant cells are unique inhaving twodistinct, spatially separated forms of the PDC; mitochondrial (mtPDC) and plastidial (plPDC). The mtPDCis the site of carbon entry into the tricarboxylic acid cycle, while the plPDCprovides acetyl-CoAandNADHfor de novofatty acid biosynthesis.