Only a trace amount of the (Z)-isomer of b-ocimene (5% of the total b-ocimene products, Figure 1B) was included in all the headspace volatiles, and this percentage corresponded to the composition of b-ocimene isomers generated from the recombi-nant PlOS protein expressed in Escherichia coli using geranyl diphosphate as a substrate [23]. A similar result was also observed in a preliminary study in transgenic torenia plants expressing PlOS (Shimoda et al. unpublished).