Search

This study reported the inducing effect of Aspergillus flavus fungal elicitor on biosynthesis of terpenoid indole alkaloids (TIAs) in Catharanthus roseus cambial meristematic cells (CMCs) and its inducing mechanism. According to the results determined by HPLC and HPLC-MS/MS, the optimal condition of the A. flavus elicitor was as follows: after suspension culture of C. roseus CMCs for 6 day, 25 mg/L A. flavus mycelium elicitor were added, and the CMC suspensions were further cultured for another 48 h. In this condition, the contents of vindoline, catharanthine, and ajmaline were 1.45-, 3.29-, and 2.14-times as high as those of the control group, respectively. Transcriptome analysis showed that D4H, G10H, GES, IRS, LAMT, SGD, STR, TDC, and ORCA3 were involved in the regulation of this induction process. The results of qRT-PCR indicated that the increasing accumulations of vindoline, catharanthine, and ajmaline in C. roseus CMCs were correlated with the increasing expression of the above genes. Therefore, A. flavus fungal elicitor could enhance the TIA production of C. roseus CMCs, which might be used as an alternative biotechnological resource for obtaining bioactive alkaloids. [ABSTRACT FROM AUTHOR]

Four new compounds obtained from cultured cells of Artemisia annua were reported. Products were detected by HPLC-ELSD/GC-MS and isolated by chromatographic methods. The structures of four new compounds, namely 6-hydroxy arteannuin I ( 1 ), 1-hydroxy arteannuin I ( 2 ), 2-hydroxy arteannuin J ( 3 ), and 14-hydroxy arteannuin J ( 4 ), were elucidated using their physico-chemical properties by NMR and MS data analyses. The results from the spontaneous oxidative experiment indicated that the biosynthesis of the new compounds was enzyme-catalyzed. Interestingly, the enzymes in the cultured cells of A. annua showed the abilities of substrate-selective and region-selective hydroxylation of the sesquiterpene lactone. Furthermore, the artemisinin contents were increased by 50% and 80% compared to the control group after the addition of arteannuin I/J to the suspension-cultured cells of A. annua under light and dark culture conditions, respectively., Competing Interests: The authors declare no conflicts of interest.