Publications

• Product profile of PEN3: the last unexamined oxidosqualene cyclase in Arabidopsis thaliana.

  Morlacchi P., Wilson W.K., Xiong Q., Bhaduri A., Sttivend D., Kolesnikova M.D., Matsuda S.P.T.

  The triterpene product profile is reported for At5g36150 (PEN3), the last unexamined oxidosqualene cyclase in the reference plant Arabidopsis thaliana. PEN3 makes tirucalla-7,24-dien-3beta-ol ( approximately 85%) and several minor products. Also discussed are the unexpectedly facile convergent evo ... >> More

  The triterpene product profile is reported for At5g36150 (PEN3), the last unexamined oxidosqualene cyclase in the reference plant Arabidopsis thaliana. PEN3 makes tirucalla-7,24-dien-3beta-ol ( approximately 85%) and several minor products. Also discussed are the unexpectedly facile convergent evolution of another Arabidopsis tirucalladienol synthase (LUP5), mechanistic origins of the 20S configuration, and active-site remodeling necessary to accommodate the 17alpha side chain. This work marks the first completed functional characterization of all triterpene synthases in a higher plant. << Less

  Org. Lett. 11:2627-2630(2009) [PubMed] [EuropePMC]

• Identification of key enzymes responsible for protolimonoid biosynthesis in plants: Opening the door to azadirachtin production.

  Hodgson H., De La Pena R., Stephenson M.J., Thimmappa R., Vincent J.L., Sattely E.S., Osbourn A.

  Limonoids are natural products made by plants belonging to the Meliaceae (Mahogany) and Rutaceae (Citrus) families. They are well known for their insecticidal activity, contribution to bitterness in citrus fruits, and potential pharmaceutical properties. The best known limonoid insecticide is azad ... >> More

  Limonoids are natural products made by plants belonging to the Meliaceae (Mahogany) and Rutaceae (Citrus) families. They are well known for their insecticidal activity, contribution to bitterness in citrus fruits, and potential pharmaceutical properties. The best known limonoid insecticide is azadirachtin, produced by the neem tree (<i>Azadirachta indica</i>). Despite intensive investigation of limonoids over the last half century, the route of limonoid biosynthesis remains unknown. Limonoids are classified as tetranortriterpenes because the prototypical 26-carbon limonoid scaffold is postulated to be formed from a 30-carbon triterpene scaffold by loss of 4 carbons with associated furan ring formation, by an as yet unknown mechanism. Here we have mined genome and transcriptome sequence resources for 3 diverse limonoid-producing species (<i>A. indica</i>, <i>Melia azedarach</i>, and <i>Citrus sinensis</i>) to elucidate the early steps in limonoid biosynthesis. We identify an oxidosqualene cyclase able to produce the potential 30-carbon triterpene scaffold precursor tirucalla-7,24-dien-3β-ol from each of the 3 species. We further identify coexpressed cytochrome P450 enzymes from <i>M. azedarach</i> (MaCYP71CD2 and MaCYP71BQ5) and <i>C. sinensis</i> (CsCYP71CD1 and CsCYP71BQ4) that are capable of 3 oxidations of tirucalla-7,24-dien-3β-ol, resulting in spontaneous hemiacetal ring formation and the production of the protolimonoid melianol. Our work reports the characterization of protolimonoid biosynthetic enzymes from different plant species and supports the notion of pathway conservation between both plant families. It further paves the way for engineering crop plants with enhanced insect resistance and producing high-value limonoids for pharmaceutical and other applications by expression in heterologous hosts. << Less

  Proc. Natl. Acad. Sci. U.S.A. 116:17096-17104(2019) [PubMed] [EuropePMC]

  This publication is cited by 2 other entries.

• Identification of early quassinoid biosynthesis in the invasive tree of heaven (Ailanthus altissima) confirms evolutionary origin from protolimonoids.

  Chuang L., Liu S., Biedermann D., Franke J.

  The tree of heaven, <i>Ailanthus altissima</i> (MILL.) SWINGLE, is a globally invasive plant known to secrete allelopathic metabolites called quassinoids. Quassinoids are highly modified triterpenoids. So far, nothing has been known about the biochemical basis of quassinoid biosynthesis. Here, bas ... >> More

  The tree of heaven, <i>Ailanthus altissima</i> (MILL.) SWINGLE, is a globally invasive plant known to secrete allelopathic metabolites called quassinoids. Quassinoids are highly modified triterpenoids. So far, nothing has been known about the biochemical basis of quassinoid biosynthesis. Here, based on transcriptome and metabolome data of <i>Ailanthus altissima</i>, we present the first three steps of quassinoid biosynthesis, which are catalysed by an oxidosqualene cyclase and two cytochrome P450 monooxygenases, resulting in the formation of the protolimonoid melianol. Strikingly, these steps are identical to the first steps of the biosynthesis of limonoids, structurally different triterpenoids from sister plant families within the same order Sapindales. Our results are therefore not only important to fully understand the biosynthesis of complex triterpenoids in plants, but also confirm the long-standing hypothesis that quassinoids and limonoids share an evolutionary origin. In addition, our transcriptome data for <i>Ailanthus altissima</i> will be beneficial to other researchers investigating the physiology and ecology of this invasive tree. << Less

  Front. Plant Sci. 13:958138-958138(2022) [PubMed] [EuropePMC]

  This publication is cited by 2 other entries.