In general, the
diversity of thousands of plant terpenoid structures originates
from many pathway combinations of TPS and terpenoid-
modifying enzymes. TPS and terpenoid-modifying
P450 enzymes exist as large and diverse gene families in
plants, and the same may be true for other terpenoidmodifying
enzymes. As there are only a few biologically
relevant isoprenyl diphosphate substrates for TPS, basic
characterization of these enzymes is relatively straightforward.