The P450 multigene family of Fontainea and insights into diterpenoid synthesis

<strong style="background-color:white;">Background:&lt;/strong&gt; Cytochrome P450s (P450s) 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 &lt;em&gt;Fontainea&lt;/em&gt; (family Euphorbiaceae). &lt;em&gt;Fontainea&lt;/em&gt; 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. </strong>&lt;strong&gt;Results:&lt;/strong&gt; A comparative species leaf metabolome analysis showed that &lt;em&gt;Fontainea&lt;/em&gt; species possess a chemical profile different from various other plant species. The diversity and expression profiles of &lt;em&gt;Fontainea&lt;/em&gt; P450s were investigated from leaf and root tissue. A total of 103 and 123 full-length &lt;em&gt;P450&lt;/em&gt; genes in &lt;em&gt;Fontainea picrosperma&lt;/em&gt; and &lt;em&gt;Fontainea venosa&lt;/em&gt;, respectively (and a further 127/125 partial-length) that were phylogenetically classified into clans, families and subfamilies. The majority of &lt;em&gt;P450&lt;/em&gt; identified are most active within root tissue (66.2% &lt;em&gt;F. picrosperma, &lt;/em&gt;65.0%&lt;em&gt; F. venosa&lt;/em&gt;). Representatives within the CYP71D and CYP726A were identified in &lt;em&gt;Fontainea &lt;/em&gt;that are excellent candidates for diterpenoid synthesis, of which CYP726A1, CYP726A2 and CYP71D1 appear to be exclusive to &lt;em&gt;Fontainea &lt;/em&gt;species and were significantly more highly expressed in root tissue compared to leaf tissue. &lt;strong&gt;Conclusion:&lt;/strong&gt; This study presents a comprehensive overview of the &lt;em&gt;P450&lt;/em&gt; gene family in &lt;em&gt;Fontainea &lt;/em&gt;that may provide important insights into the biosynthesis of the medicinally significant epoxy-tigliane diterpenes found within the genus.&lt;br&gt;