The CYP450 Multigene Family of Fontainea and Insights Into Diterpenoid Synthesis

Abstract

Background: Cytochrome P450s (CYP450s) are enzymes that play critical roles in the biosynthesis of physiologically important compounds across all organisms. Although they have been characterised in a large number of plant species, no information relating to these enzymes are available from the genus Fontainea (family Euphorbiaceae). Fontainea is significant as the genus includes species that produce medicinally significant epoxy-tigliane natural products, one of which has been approved as an anti-cancer therapeutic. Results: A metabolome analysis showed that Fontainea species possess a chemical profile different from various other plant species. The diversity and expression profiles of Fontainea CYP450s were investigated from leaf and root tissue. A total of 103 and 123 full-length CYP450 genes in Fontainea picrosperma and Fontainea venosa, respectively (and a further 127/125 partial-length) that were phylogenetically classified into clans, families and subfamilies. The majority of CYP450 identified are most active within root tissue (66.2% F. picrosperma, 65.0% F. venosa). Fontainea CYP450 associated with diterpenoid biosynthesis were classified into 2 subfamilies (CYP71D and CYP726A), of which CYP726A1, CYP726A2 and CYP71D1 appear to be exclusive to Fontainea species, and significantly more highly expressed in root tissue compared to leaf tissue. Conclusion: This study presents a comprehensive overview of the CYP450 gene family in Fontainea that may provide important insights into the biosynthesis of the medicinally significant epoxy-tigliane diterpenes found within the genus.