Three bacterial genes coding for the enzymes, 3-ketothiolase (bktB), acetoacetyl-CoA reductase (phaB) and PHB synthase (phaC), required for the synthesis of PHB from acetyl-CoA in bacteria were transformed into oil palm embryogenic calli. For the production of copolymer polyhydroxybutyrate–co-valerate (PHBV), the threonine dehydratase (tdcB) gene from Escherichia coli was also transformed into oil palm embryogenic calli for producing propionyl-CoA, the substrate for hydroxyvalerate. These genes were under the control of the maize ubiquitin promoter. Currently, many transformed embryogenic lines resistant to the herbicide Basta have already been produced. These transformed calli were later regenerated to produce a few hundred plantlets which are now growing in a biosafety screenhouse. Molecular analyses have demonstrated stable integration of the transgenes in their genome.