A. Norozi; B. Hosseini; M. Jafari; M. Farjaminezhad
Abstract
Henabne(Hyoscyamus reticulatus L.) is a rich source of tropane alkaloids including hyoscyamine (Hyos) and scopolamine (SCP), widely used in pharmaceutical field. The aim of the present study was to assess the effect of different concentrations (0, 50, 100 and 200 µM) of methyl jasmonate (MeJA) ...
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Henabne(Hyoscyamus reticulatus L.) is a rich source of tropane alkaloids including hyoscyamine (Hyos) and scopolamine (SCP), widely used in pharmaceutical field. The aim of the present study was to assess the effect of different concentrations (0, 50, 100 and 200 µM) of methyl jasmonate (MeJA) at two different times of exposure (24 and 48 h) on growth, antioxidant enzymes activity, tropane alkaloids content, and the expression level of hyoscyamine-6-beta-hydroxylase (h6h) gene in H. reticulatus hairy root cultures. The results showed that MeJA at high concentration (200 µM) led to the decline of fresh and dry weight of hairy roots. Catalase (CAT), guaiacol peroxidase (GPX) and ascorbate peroxidase (APX) activities were significantly increased by MeJA, especially at 200 µM in elicited hairy roots. As well, CAT and GPX activities, but not of APX, were also affected by exposure time of MeJA. According to the GC/MS analysis, the highest percentage of SCP (13.96%) and Hyos (21.9%) were respectively obtained when hairy roots were exposed to MeJA at concentrations of 100 and 200 µM for 48 and 24 h, which were, respectively, 1.6- and 1.25-fold higher than those in the control roots. According to the results of semi-quantitative RT-PCR analysis, the highest expression of h6h gene (6-fold higher than in the control) was obtained after 24 h exposure to 100 µM MeJA. These results indicate that MeJA, due to stimulation of the expression of key genes involved in the biosynthetic pathway of tropane alkaloids, could be used as an effective elicitor for increased production of Hyos and SCP.
F. Moharrami; B. Hosseini; M. Farjaminezhad; A. Sharafi
Abstract
Hyoscyamus species such as Hyoscyamus reticulatus L. are rich sources of tropane alkaloids, mainly hyoscyamine and scopolamine, which are used for their mydriatic, antispasmodic, anticholinergic, analgesic and sedative properties. Due to complex chemical structures, these alkaloids are obtained from ...
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Hyoscyamus species such as Hyoscyamus reticulatus L. are rich sources of tropane alkaloids, mainly hyoscyamine and scopolamine, which are used for their mydriatic, antispasmodic, anticholinergic, analgesic and sedative properties. Due to complex chemical structures, these alkaloids are obtained from natural sources, mainly Solanaceae plants. Elicitation of secondary metabolites biosynthetic pathways by different kind of elicitors is an effective strategy to increase secondary metabolites productivity. In the present study, in order to increase production of tropane alkaloids, cotyledon-derived hairy root cultures transformed with Agrobacterium rhizogenes strain A7, were elicited with yeast extract (YE) as biotic elicitor. Effect of different concentrations (0, 125, 250, 500 and 1000mg/l) of YE elicitor at different exposure times (24, 48 and 72 h) were investigated. According to the results, YE at the concentration of 500 and 250 mg/l after 48 h treatment, significantly increased hyoscyamine (2-fold) and scopolamine (2.5-fold) production in comparison with control, respectively. The results showed that treatment with different concentrations of YE and also increasing the exposure time led to significant decrease in growth of hairy roots in comparison with control. The activity of antioxidant enzymes including catalase, guaiacol peroxidase, and ascorbate peroxidase was also elevated in treated hairy roots rather than of the control. Based on the results, it can be concluded that elicitation with YE leads to induce an oxidative stress. These results suggest that YE could be used as an effective elicitor in plant biotechnology for the production of plant secondary metabolites such as tropane alkaloids.