ATP citrate-lyase is the primary enzyme responsible for the synthesis of cytosolic acetyl-CoA, used for the elongation of fatty acids and biosynthesis of isoprenoids, flavonoids and malonated derivatives. May supply substrate to the cytosolic acetyl-CoA carboxylase, which generates the malonyl-CoA used for the synthesis of a multitude of compounds, including very long chain fatty acids and flavonoids. Required for normal growth and development and elongation of C18 fatty acids to C20 to C24 fatty acids in seeds. In contrast to all known animal ACL enzymes having a homomeric structure, plant ACLs are composed of alpha and beta chains. acetyl-CoA + ADP + oxaloacetate + phosphate = ATP + citrate + CoA Heterooctamer of 4 alpha and 4 beta chains. A number of isoforms are produced. According to EST sequences. Expressed in trichomes, epidermal leaf cells, anther tapetal cells, stigma and in young vascular bundles of expanding leaves, cotyledons, roots, pedicel of flowers and siliques. Expressed in flower buds at stage 6 of development in tapetal cells and at stage 10 in the epidermal cells of growing petals and ovaries. In young siliques, expressed transiently in the inner integument of the ovules just prior to testal deposition. Expressed in the developing embryo with a maximal level at the heart and torpedo stages. The expression then disappears in the mature embryo. During seed germination, expressed in the vascular bundles, apical meristem, epidermis of the seedling cotyledon, stem, and root. Highly expressed in the root tip of seedlings 4 days after imbibition. Plants silencing ACLA-1 show a severe dwarf and dark-green phenotype with some seedling lethal plants, reduced leaf cell size, altered cellular ultrastructure, altered plastid ultrastructure, hyperaccumulation of starch, increased accumulation of anthocyanins, chlorophylls and carotenoids in vegetative organs and decreased accumulation of epicuticular and cuticular waxes. These phenotypes can be complemented by exogenous supply of malonate. Belongs to the succinate/malate CoA ligase beta subunit family. Truncated N-terminus.