title: Strictosidine-related enzymes involved in the alkaloid biosynthesis of Uncaria tomentosa root cultures grown under oxidative stress.
abstract: The activity and gene expression of strictosidine-related enzymes in Uncaria tomentosa root cultures exposed to oxidative stress were studied. Elicitation with 0.2 mM hydrogen peroxide (H2 O2 ) or a combination of 0.8 mM buthionine sulfoximine and 0.2 mM jasmonic acid (BSO-JA) increased peroxidase activities by twofold at Day 8 and glutathione reductase by 1.4-fold at Day 5 in H2 O2 elicited cultures respect to the control. Production of monoterpenoid oxindole alkaloids (MOA), 3α-dihydrocadambine, and dolichantoside was stimulated after H2 O2 elicitation, reaching levels of 886.4 ± 23.6, 847.7 ± 25.4, and 87.5 ± 7.2 µg/g DW, at Day 8 which were 1.7-, 2.1-, and 2.3-fold higher relative to control. BSO-JA elicited cultures produced about twice alkaloids than H2 O2 -treated cultures, following a biphasic pattern with maxima at 0.5 and 8 days. Alkaloid production was preceded by increase in strictosidine synthase (STR) and strictosidine glucosidase (SGD) activities. After elicitation with H2 O2 or BSO-JA, the STR activity (pKat/mg protein) increased by 1.9-fold (93.8 ± 17.8 at 24 h) or 2.5-fold (102.4 ± 2.2 at 6 h) and the SGD activity (pKat/mg protein) by 2.8-fold (245.2 ± 14.4 at 6 h) or 4.2-fold (421.2 ± 1.8 at 18 h) relative to control. STR and SGD transcripts were upregulated after elicitation. H2 O2 -treated roots showed higher levels of STR at 48-192 h and SGD at 24-48 h, while BSO-JA treatments showed STR increased at 12 h and SGD at 24 h. Also, LC/ESI-MS confirmed the biosynthesis of dolichantoside from N-ω-methyltryptamine and secologanin by U. tomentosa protein extracts.
authors.affiliation: Depto. de Biotecnología y Biongeniería, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), A. P. 14-740, México, D. F. 07000, Mexico.
authors.forename: Ileana
authors.initials: I
authors.lastname: Vera-Reyes
authors.forename: Ariana A
authors.initials: AA
authors.lastname: Huerta-Heredia
authors.forename: Teresa
authors.initials: T
authors.lastname: Ponce-Noyola
authors.forename: Isvett Josefina
authors.initials: IJ
authors.lastname: Flores-Sanchez
authors.forename: Fernando
authors.initials: F
authors.lastname: Esparza-García
authors.forename: Carlos M
authors.initials: CM
authors.lastname: Cerda-García-Rojas
authors.forename: Gabriela
authors.initials: G
authors.lastname: Trejo-Tapia
authors.forename: Ana C
authors.initials: AC
authors.lastname: Ramos-Valdivia
mesh_terms: D000470:Alkaloids / Q000032:analysis / Q000378:metabolism*; D000704:Analysis of Variance; D019328:Buthionine Sulfoximine / Q000494:pharmacology; D019759:Carbon-Nitrogen Lyases / Q000235:genetics / Q000378:metabolism; D020948:Cat's Claw / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism; D003517:Cyclopentanes / Q000494:pharmacology; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D005959:Glucosidases / Q000235:genetics / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007211:Indoles / Q000378:metabolism; D053858:Metabolic Networks and Pathways; D009005:Monosaccharides / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects* / Q000502:physiology; D000078183:Oxindoles; D054883:Oxylipins / Q000494:pharmacology; D018517:Plant Roots / Q000737:chemistry / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology
chemical_list: D000470:Alkaloids; D003517:Cyclopentanes; D007211:Indoles; D009005:Monosaccharides; D000078183:Oxindoles; D054883:Oxylipins; D012333:RNA, Messenger; C432871:dolichantoside; C022960:2-oxindole; D019328:Buthionine Sulfoximine; C011006:jasmonic acid; D006861:Hydrogen Peroxide; D005959:Glucosidases; C456847:strictosidine glucosidase; D019759:Carbon-Nitrogen Lyases; C022684:strictosidine synthetase