title: Transcriptomic insight into terpenoid and carbazole alkaloid biosynthesis, and functional characterization of two terpene synthases in curry tree (Murraya koenigii).
abstract: Curry tree (Murraya koenigii L.) is a rich source of aromatic terpenes and pharmacologically important carbazole alkaloids. Here, M. koenigii leaf transcriptome was generated to gain insight into terpenoid and alkaloid biosynthesis. Analysis of de novo assembled contigs yielded genes for terpene backbone biosynthesis and terpene synthases. Also, gene families possibly involved in carbazole alkaloid formation were identified that included polyketide synthases, prenyltransferases, methyltransferases and cytochrome P450s. Further, two genes encoding terpene synthases (MkTPS1 and MkTPS2) with highest in silico transcript abundance were cloned and functionally characterized to determine their involvement in leaf volatile formation. Subcellular localization using GFP fusions revealed the plastidial and cytosolic localization of MkTPS1 and MkTPS2, respectively. Enzymatic characterization demonstrated the monoterpene synthase activity of recombinant MkTPS1, which produced primarily (-)-sabinene from geranyl diphosphate (GPP). Recombinant MkTPS2 exhibited sesquiterpene synthase activity and formed (E,E)-α-farnesene as the major product from farnesyl diphosphate (FPP). Moreover, mRNA expression and leaf volatile analyses indicated that MkTPS1 accounts for (-)-sabinene emitted by M. koenigii leaves. Overall, the transcriptome data generated in this study will be a great resource and the start point for characterizing genes involved in the biosynthetic pathway of medicinally important carbazole alkaloids.
authors.affiliation: Molecular Plant Biology and Biotechnology Laboratory, CSIR-Central Institute of Medicinal and Aromatic Plants Research Centre, GKVK Post, Bengaluru - 560065, India.
authors.forename: Seema
authors.initials: S
authors.lastname: Meena
authors.affiliation: Molecular Plant Biology and Biotechnology Laboratory, CSIR-Central Institute of Medicinal and Aromatic Plants Research Centre, GKVK Post, Bengaluru - 560065, India.
authors.forename: Sarma
authors.initials: S
authors.lastname: Rajeev Kumar
authors.affiliation: Molecular Plant Biology and Biotechnology Laboratory, CSIR-Central Institute of Medicinal and Aromatic Plants Research Centre, GKVK Post, Bengaluru - 560065, India.
authors.forename: Varun
authors.initials: V
authors.lastname: Dwivedi
authors.affiliation: Molecular Plant Biology and Biotechnology Laboratory, CSIR-Central Institute of Medicinal and Aromatic Plants Research Centre, GKVK Post, Bengaluru - 560065, India.
authors.forename: Anup
authors.initials: A
authors.lastname: Kumar Singh
authors.affiliation: Laboratory of Aromatic Plants and Chiral Separation, CSIR-Central Institute of Medicinal and Aromatic Plants, P.O. CIMAP, Lucknow - 226015, India.
authors.forename: Chandan S
authors.initials: CS
authors.lastname: Chanotiya
authors.affiliation: Biotechnology Division, CSIR-Central Institute of Medicinal and Aromatic Plants, P.O. CIMAP, Lucknow - 226015, India.
authors.forename: Md Qussen
authors.initials: MQ
authors.lastname: Akhtar
authors.affiliation: Molecular Plant Biology and Biotechnology Laboratory, CSIR-Central Institute of Medicinal and Aromatic Plants Research Centre, GKVK Post, Bengaluru - 560065, India.
authors.forename: Krishna
authors.initials: K
authors.lastname: Kumar
authors.affiliation: Biotechnology Division, CSIR-Central Institute of Medicinal and Aromatic Plants, P.O. CIMAP, Lucknow - 226015, India.
authors.forename: Ajit
authors.initials: A
authors.lastname: Kumar Shasany
authors.affiliation: Molecular Plant Biology and Biotechnology Laboratory, CSIR-Central Institute of Medicinal and Aromatic Plants Research Centre, GKVK Post, Bengaluru - 560065, India.
authors.forename: Dinesh A
authors.initials: DA
authors.lastname: Nagegowda
mesh_terms: D000470:Alkaloids / Q000096:biosynthesis*; D019883:Alkyl and Aryl Transferases / Q000235:genetics / Q000378:metabolism*; D002227:Carbazoles / Q000378:metabolism*; D020869:Gene Expression Profiling; D032101:Murraya / Q000235:genetics / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D013729:Terpenes / Q000378:metabolism*
chemical_list: D000470:Alkaloids; D002227:Carbazoles; D010940:Plant Proteins; D013729:Terpenes; C041514:carbazole; D019883:Alkyl and Aryl Transferases; C108877:terpene synthase