Acyl carrier protein (ACP) is a small acidic protein with a conservative serine residue. In the de novo synthesis of fatty acid in plastid, ACP carrying acyl-chains with different lengths takes part in the cycles of condensation, reduction, and dehydration steps. ACP is also a cofactor for desaturation and acyl-transfer reaction of fatty acid with different chains catalyzed by stearoyl-ACP desarurase and acyl transferase .It has much to do with the species and differential expression of the isomer o...