Redistribution of 14C label from [2-14C]acetate (a,b) and [U-14C]alanine (c,d) into sugars and CO2 in 2-day-old seedlings. Data are means±s.e. from four separate pools of 100 seedlings and asterisks represent a statistical difference from WT (P<0.05, LSD test, n=4). (e) Schematic outlining PPDK- and PCK-dependent gluconeogenesis from lipids and amino acids during early seedling growth. Note that glycerol is also a minor product of lipid breakdown (∼5% of the carbon in storage oil) and enters gluconeogenesis downstream of PEP. A minimum of two moles of pyruvate are required to form one mole of PEP via pyruvate dehydrogenase (PDH) and the glyoxylate or tricarboxylic acid cycle, while the molar ratio is 1:1 using PPDK. However, when employing PPDK an additional ATP is necessary to regenerate ADP from AMP.