Dual Function of the Cytochrome P450 CYP76 Family from Arabidopsis thaliana in the Metabolism of Monoterpenols and Phenylurea Herbicides

Abstract

Comparative genomics analysis unravels lineage-specific bursts of gene duplications related to the emergence of specialized pathways. The CYP76C subfamily of cytochrome P450 enzymes is specific to Brassicaceae. Two of its members were recently associated with monoterpenol metabolism. This prompted us to investigate the CYP76C subfamily genetic and functional diversification. Our study revealed high rates of CYP76C gene duplication and loss in Brassicaceae, suggesting the association of the CYP76C subfamily with species-specific adaptive functions. Gene differential expression and enzyme functional specialization in Arabidopsis thaliana, including metabolism of different monoterpenols and formation of different products, support this hypothesis. In addition to linalool metabolism, CYP76C1, CYP76C2, and CYP76C4 metabolized herbicides belonging to the class of phenylurea. Their ectopic expression in the whole plant conferred herbicide tolerance. CYP76Cs from A. thaliana. thus provide a first example of promiscuous cytochrome P450 enzymes endowing effective metabolism of both natural and xenobiotic compounds. Our data also suggest that the CYP76C gene family provides a suitable genetic background for a quick evolution of herbicide resistance.Although extensive monoterpenol (especially linalool) oxidative metabolism has been described in many plant species, leading to fragrant and bioactive compounds as diverse as alcohols, aldehydes, acids, and epoxides

CYP76C1 (Cytochrome P450)-Mediated Linalool Metabolism and the Formation of Volatile and Soluble Linalool Oxides in Arabidopsis Flowers: A Strategy for Defense against Floral Antagonists

“…The levels of 8-OH-linalool and 9-OH-linalool, also formed by the CYP76C2 and CYP76C3 enzymes Höfer et al, 2014), were moderately reduced in the cyp76c1 flowers compared with the wild type, but almost completely abolished in the complemented/35S:CYP76C1 line. The levels of lilac aldehydes and alcohols conjugates were strongly reduced in the cyp76c1 flowers and partially restored in the complemented/35S: CYP76C1 line.…”

“…This study also suggested the presence of partially redundant P450 enzymes that may contribute to floral linalool metabolism. The hypothesis of the involvement of other P450 oxygenases in floral linalool metabolism was then further supported by a systematic functional exploration of the expression patterns and in vitro activities of the CYP76C3 paralogs present in Arabidopsis (Höfer et al, 2014), which revealed floral expression of CYP76C2 and CYP76C1, two other monoterpenol-metabolizing oxygenases. CYP76C1 emerged as the best candidate due to its high and selective linalool oxygenase activity, which is 10 times higher than the activity of CYP76C2.…”

“…Successive Oxides to Form Lilac Aldehydes/Alcohols and 8-COOH-Linalool CYP76C1 was previously shown to metabolize (2)-(3R)-linalool into 8-OH-linalool and small amounts of 9-OH-linalool (Höfer et al, 2014). To determine if CYP76C1 was selectively metabolizing R-linalool or both the (2)-(3R) and (+)-(3S) enantiomers, which are respectively produced by TPS10 and TPS14 , the conversion of both of these enantiomers by yeastexpressed CYP76C1 was investigated (Supplemental Figure 3; Figure 3).…”

“…The Plant Cell Extensive gene expression analysis of the CYP76C1 insertion and complemented lines did not reveal any changes in expression for the genes known to be involved in linalool metabolism (TPS10, TPS14, CYP71B31, and CYP76C3) nor for P450s belonging to the same cluster as CYP76C1 and known to be active on linalool (CYP76C2, CYP76C3, and CYP76C4) (Höfer et al, 2014) (Supplemental Figure 9C). This ensured that any change in linalool metabolism would be the result of CYP76C1 activity.…”

Biosynthesis of geranial, a potent aroma compound in ginger rhizome (<i>Zingiber officinale</i>): Molecular cloning and characterization of geraniol dehydrogenase

“…10-Hydroxygeraniol is an important precursor for the biosynthesis of (seco) iridoids, which are pharmaceutically important compounds and include the anticancer agents vincristine and vinblastine (O'Connor and Maresh 2006). Cytochrome P450 enzymes, especially CYP76 family members such as CYP76B6 from Catharanthus roseus and CYP76C1 from Arabidopsis thaliana, were reported to catalyze the hydroxylation of geraniol (Collu et al 2001;Hofer et al 2014;Hofer et al 2013).…”