A secoisolanciresinol dehydrogenase protein has been isolated from Forsythia
intermedia, together with cDNAs encoding secoisolariciresinol dehydrogenase
from this species. Accordingly, isolated DNA sequences are provided which code
for the expression of secoisolariciresinol dehydrogenase. In other aspects, the
present invention is directed to replicable recombinant cloning vehicles comprising
a nucleic acid sequence which codes for a secoisolariciresinol dehydrogenase protein,
or to a base sequence sufficiently complementary to at least a portion of a secoisolariciresinol
dehydrogenase DNA or RNA to enable hybridization therewith. Thus, systems and methods
are provided for the recombinant expression of secoisolariciresinol dehydrogenases
that may be used to facilitate the production, isolation and purification of significant
quantities of recombinant secoisolariciresinol dehydrogenase for subsequent use,
to obtain expression or enhanced expression of secoisolariciresinol dehydrogenase
in plants in order to enhance, or otherwise alter, lignan biosynthesis, or may
be otherwise employed for the regulation or expression of secoisolariciresinol dehydrogenase.
