OeBAS and CYP716C67 catalyze the biosynthesis of health‐beneficial triterpenoids in olive (Olea europaea) fruits

• Published in: The New phytologist Vol. 238; no. 5; pp. 2047 - 2063
• Main Authors: Alagna, Fiammetta, Reed, James, Calderini, Ornella, Thimmappa, Ramesha, Cultrera, Nicolò G. M., Cattivelli, Alice, Tagliazucchi, Davide, Mousavi, Soraya, Mariotti, Roberto, Osbourn, Anne, Baldoni, Luciana
• Format: Journal Article
• Language: English
• Published: England Wiley Subscription Services, Inc 01.06.2023; John Wiley and Sons Inc
• Subjects: Acids; Agribusiness; bioactive compound; Biochemical analysis; Biosynthesis; Breeding; Chromosomes; Cosmetics; Cytochrome; Cytochrome P450; Cytochromes; Cytochromes P450; Food industry; Fruit - metabolism; Fruits; Genes; Genetic markers; Genomes; Germplasm; maslinic acid; Olea - genetics; Olea europaea; oleanolic acid; Olive oil; Oxidation; Pharmaceutical industry; Plant Breeding; Scaffolds; terpene; trait‐associated marker; Triterpenes - metabolism; Triterpenoids; β‐amyrin synthase; trait-associated marker; maslinic acid; β-amyrin synthase; oleanolic acid; olive oil; terpene; cytochrome P450; bioactive compound
• ISSN: 0028-646X; 1469-8137
• DOI: 10.1111/nph.18863

Summary The bioactive properties of olive (Olea europaea) fruits and olive oil are largely attributed to terpenoid compounds, including diverse triterpenoids such as oleanolic, maslinic and ursolic acids, erythrodiol, and uvaol. They have applications in the agri‐food, cosmetics, and pharmaceutical industries. Some key steps involved in the biosynthesis of these compounds are still unknown. Genome mining, biochemical analysis, and trait association studies have been used to identify major gene candidates controlling triterpenoid content of olive fruits. Here, we identify and functionally characterize an oxidosqualene cyclase (OeBAS) required for the production of the major triterpene scaffold β‐amyrin, the precursor of erythrodiol, oleanolic and maslinic acids, and a cytochrome P450 (CYP716C67) that mediates 2α oxidation of the oleanane‐ and ursane‐type triterpene scaffolds to produce maslinic and corosolic acids, respectively. To confirm the enzymatic functions of the entire pathway, we have reconstituted the olive biosynthetic pathway for oleanane‐ and ursane‐type triterpenoids in the heterologous host, Nicotiana benthamiana. Finally, we have identified genetic markers associated with oleanolic and maslinic acid fruit content on the chromosomes carrying the OeBAS and CYP716C67 genes. Our results shed light on the biosynthesis of olive triterpenoids and provide new gene targets for germplasm screening and breeding for high triterpenoid content.