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, flowers and leaves. Repressed by herbicides such as flufenacet and benfuresate (PubMed:12916765). Up-regulated by osmotic stress and down-regulated by low temperature, salt and drought (PubMed:18465198). Belongs to the thiolase-like superfamily. Chalcone/stilbene synthases family.