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Strictosidine‐related enzymes involved in the alkaloid biosynthesis of Uncaria tomentosa root cultures grown under oxidative stress
Author(s) -
VeraReyes Ileana,
HuertaHeredia Ariana A.,
PonceNoyola Teresa,
FloresSanchez Isvett Josefina,
EsparzaGarcía Fernando,
CerdaGarcíaRojas Carlos M.,
TrejoTapia Gabriela,
RamosValdivia Ana C.
Publication year - 2013
Publication title -
biotechnology progress
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.572
H-Index - 129
eISSN - 1520-6033
pISSN - 8756-7938
DOI - 10.1002/btpr.1723
Subject(s) - biochemistry , oxidative stress , buthionine sulfoximine , enzyme , glutathione , hydrogen peroxide , biology , glutathione reductase , alkaloid , chemistry , stereochemistry , glutathione peroxidase
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 (H 2 O 2 ) 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 H 2 O 2 elicited cultures respect to the control. Production of monoterpenoid oxindole alkaloids (MOA), 3α‐dihydrocadambine, and dolichantoside was stimulated after H 2 O 2 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 H 2 O 2 ‐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 H 2 O 2 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. H 2 O 2 ‐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. © 2013 American Institute of Chemical Engineers Biotechnol. Prog ., 29:621–630, 2013