The multifunctional protein At MFP2 is co-ordinately expressed with other genes of fatty acid β-oxidation during seed germination in Arabidopsis thaliana (L.) Heynh

In germinating oilseeds peroxisomal fatty acid β-oxidation is responsible for the mobilization of storage lipids. This pathway also occurs in other tissues where it has a variety of additional physiological functions. The central enzymatic steps of peroxisomal β-oxidation are performed by acyl-CoA oxidase (ACOX), the multifunctional protein (MFP) and 3-ketoacyl-CoA thiolase (thiolase). In order to investigate the function and regulation of β-oxidation in plants it is first necessary to identify and characterize genes encoding the relevant enzymes in a single model species. Recently we and others have reported on the cloning and characterization of genes encoding four ACOXs and a thiolase from the oilseed Arabidopsis thaliana. Here we identify a gene encoding an Arabidopsis MFP (AtMFP2) that is induced transiently during germination. The pattern of AtMFP2 expression closely reflects changes in the activities of 2-trans-enoyl-CoA hydratase and l-3-hydroxyacyl-CoA dehydrogenase. Similar patterns of expression have previously been reported for ACOX and thiolase genes. We conclude that genes encoding the three main proteins responsible for β-oxidation are co-ordinately expressed during oilseed germination and may share a common mechanism of regulation.