Disclosed are plants that have been genetically modified to express a PKS-like system for the production of PUFAs (a PUFA PKS system), wherein oils produced by the plant contain at least one PUFA produced by the PUFA PKS system and are free of the mixed shorter-chain and less unsaturated PUFAs that are fatty acid products produced by the modification of products of the FAS system in standard fatty acid pathways. Also disclosed are the oil seeds, oils, and products comprising such oils produced by this system, as well as methods for producing such plants.