A defect in beta-oxidation causes abnormal inflorescence development in Arabidopsis

The abnormal inflorescence meristem1 (aim1) mutation affects inflorescence and floral development in Arabidopsis. After the transition to reproductive growth, the aim1 inflorescence meristem becomes disorganized, producing ab normal floral meristems and resulting in plants with severely reduced ferti lity. The derived amino acid sequence of AIM1 shows extensive similarity to the cucumber multifunctional protein involved in beta-oxidation of fatty a cids, which possesses L-3-hydroxyacyl-CoA hydrolyase, L-3-hydroxyacyl-dehyd rogenase, D-3-hydroxyacyl-CoA epimerase, and Delta(3), Delta(2)-enoyl-CoA i somerase activities. A defect in beta-oxidation has been confirmed by demon strating the resistance of the aim1 mutant to 2,4-diphenoxybutyric acid, wh ich is converted to the herbicide 2,4-D by the beta-oxidation pathway. In a ddition, the loss of AIM1 alters the fatty acid composition of the mature a dult plant.