Contributes to cuticular wax and suberin biosynthesis (By similarity). Regulates negatively the stomatal development in elevated CO(2) conditions. a very-long-chain acyl-CoA + H(+) + malonyl-CoA = a very-long-chain 3-oxoacyl-CoA + CO2 + CoA Lipid metabolism; fatty acid biosynthesis. Expressed in siliques and flowers. Repressed by herbicides such as flufenacet and benfuresate. Belongs to the thiolase-like superfamily. Chalcone/stilbene synthases family.