Oil is the primary seed storage reserve in many higher plants. After germination, this reserve is mobilized in order to support growth during early seedling development. The glyoxylate cycle is instrumental in this metabolic process. It allows acetyl-CoA derived from the breakdown of storage lipids to be used for the synthesis of carbohydrate. Recently, Arabidopsis mutants have been isolated that lack key glyoxylate cycle enzymes. An isocitrate lyase mutant has provided the first opportunity to test the biochemical and physiological functions of the glyoxylate cycle in vivo in an oilseed species.