Highly conserved progesterone 5β-reductase genes (P5βR) from 5β-cardenolide-free and 5β-cardenolide-producing angiosperms

Several progesterone 5β-reductase (P5βR) orthologues from 5β-cardenolide-free and 5β-cardenolide-producing plant species were isolated and expressed in Escherichia coli. The specific role of progesterone 5β-reductases of P5βRs in cardenolide metabolism is challenged because this class of enone reductases seems to be widespread in higher plants.