Medicinal Plants
S. Samavat; M. Salehi Vozhdehnazari; M. Yahyazadeh Balalami; M. Rahimifard
Abstract
Introduction
So far, more than 40 different types of alkaloids have been known in poppy (Papaver somniferum L.) as a valuable medicinal plant, the most important of which are morphine, codeine, thebaine, noscapine, and papaverine. The biosynthesis of these alkaloids may be strongly influenced by a variety ...
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Introduction
So far, more than 40 different types of alkaloids have been known in poppy (Papaver somniferum L.) as a valuable medicinal plant, the most important of which are morphine, codeine, thebaine, noscapine, and papaverine. The biosynthesis of these alkaloids may be strongly influenced by a variety of biotic and abiotic elicitors. In fact, microbes as biotic elicitors can affect the production of poppy alkaloids. Among them, plant growth promoting rhizobacteria (PGPR) can be noticed, which stimulate and improve plant growth through various mechanisms such as mineral phosphate solubilization, plant hormone production, siderophores secretion, nitrogen fixation, etc. The use of PGPR agents can not only lead to an increase in plant biomass, but simultaneously, due to their role as biotic elicitors, they cause to an increase in the biosynthesis of secondary metabolites in plants. These biotic elicitors target plants’ defense mechanisms and result in triggering a series of metabolic changes throughout the plant. The use of PGPR agents to stimulate the plant to produce secondary metabolites has several advantages: First, in some plants, defensive metabolites are active biological compounds that lead to the induction of food production with high added-value in the plants. Secondly, physiologically, with the increase in the synthesis of secondary metabolites, the resistance of the plant against pathogens also increases. Accordingly, the present study was performed with the aim of investigating the effects of bacterial strains with the ability to solubilize inorganic phosphate as biotic elicitors on the amount of morphine, papaverine, and noscapine alkaloids in P. somniferum.
Materials and Methods
In this research, the solubility of inorganic phosphate by four bacterial strains including Enterobacter xiangfangensis S2, Pantoea dispersa S7, Pantoea stewartii S25, and Pseudomonas canadensis S36 was evaluated quantitatively using Sperber broth medium. Under greenhouse conditions, the effect of foliar spraying of P. somniferum plants with a suspension of the bacterial strains (108 CFU.ml-1) on the amount of morphine, papaverine, and noscapine in the plants’ capsules, stems, and leaves was investigated. About three weeks after the appearance of capsules in poppy plants, the aerial parts of the plants (stems, leaves, and capsules) were sprayed with the bacterial suspensions. One week after foliar spraying, poppy plants were harvested in order to determine the amount of the desired alkaloids. Three pots were considered for each treatment and there were three poppy plants in each pot. Alkaloids were extracted based on an alcoholic method and detected using HPLC. Morphine and noscapine standards were prepared at a concentration of 1000 μg.ml-1 and papaverine standard at a concentration of 250 μg/ml. Then the mixture was prepared in proportions of 1, 1:50, 1:10, 1:50 and 1:100 and injected into the HPLC set to draw the calibration curve. All the experiments were conducted in a form of completely randomized design with three replications for each treatment (P<0.05).
Results and Discussion
The results showed that the highest (458.67 µg.ml-1) and the lowest (130.47 µg.ml-1) phosphate solubility were related to S2 and S36 strains, respectively. S7 and S25 strains were not statistically significantly different from each other and after S2 strain, they were placed in the second statistical position. In the bacterial strains’ treatments, the level of morphine in the stems and leaves as well as the capsules increased significantly in most cases compared to the control. The amount of papaverine in the stems and leaves decreased significantly, but it had no significant changes in the capsule. Also, noscapine showed a significant increase in the stems and leaves and reached from 0.8 mg.g-1 DW in the control to 8.12 in the S2 treatment. While, the amount of noscapine increased significantly in the capsules, only in the S2 and S36 treatments. Other strains did not show significant differences with the control for noscapine content in the capsules. The results showed that the interaction effects of the type of the alkaloids and the use of phosphate solubilizing bacterial strains on the concentration of the studied alkaloids in poppy stems, leaves and capsules are significant (P<0.01).
Conclusion
It can be concluded that there is no need to apply genetic engineering to increase the production of valuable secondary metabolites by medicinal plants. Rather, this goal can be achieved much cheaper by using bacterial elicitors. Accordingly, by selecting compatible and efficient bacterial strains with phosphate solubilizing activity, the amounts of morphine, papaverine, and noscapine alkaloids in the aerial parts of P. somniferum as a valuable medicinal plant can be noticeably increased.
Medicinal Plants
M. Sohrabei; D. Samsampoor; A. Bagheri
Abstract
Introduction Medicinal plants have historically been one of the main sources of medicine and pharmacy in most parts of the world, that among these plants, we can mention the species Citrullus colocynthis L. Schrad. Cell suspension culture is a widely used method to increase the rate of secondary ...
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Introduction Medicinal plants have historically been one of the main sources of medicine and pharmacy in most parts of the world, that among these plants, we can mention the species Citrullus colocynthis L. Schrad. Cell suspension culture is a widely used method to increase the rate of secondary metabolites. The secondary metabolites of plants, are species compounds often produced during a certain period of growth and development and have important ecological functions in plants. They induce the ability of plants to cope with herbivores, microbial pathogens, adsorbents, and seed-spreading organisms. Also, due to the role of fungal elicitors to increase the rate of secondary metabolites in plants, in this study, we studied the role of the endophytes Alternaria solani. Fusarium sp. and Setosphaeria rostrata extracted from Citrullus colocynthis L. Schrad were collected from different regions of Hormozgan province as bio-elicitors in a cell suspension culture medium.Materials and Methods The study was performed based on a factorial experiment in a completely randomized design with two factors (the first factor had two levels of different hormonal composition and the second factor had eight levels of endophytic fungal extracts) with three replications in the biotechnology laboratory of Hormozgan University and the results were analyzed statistically using SAS 9.4 software. To produce the callus and culture of cell suspension under hormone treatment, watermelon seeds were first disinfected for a period of time and then the seeds were transferred to a culture medium containing MS and placed in a suitable incubator for seed germination. After germination and leaflet production, pieces with an area of approximately 1 mm2 were separated from the primary leaves and for callus formation were transferred to Petri dishes containing MS medium (3% sucrose, 0.8% agar), with two levels of 1mg 2,4-D + 1mg BA and 1mg 2,4-D + 1mg kin and placed in a suitable incubator for three weeks. Three fungal endophytes Alternaria solani, Setosphaeria rostrata, and Fusarium sp. were transferred separately to PDA (Potato Dextrose Agar) culture medium to prepare the bio elicitor and placed at 30 ° C for 7 days. From 7-day cultures, 1 cm2 of mycelium was isolated and inoculated into 150 ml of PDB (Potato Dextrose Broth) culture medium. The cultured cells were stored at 30 ° C in a 500 ml Erlenmeyer flask and placed on a shaker for 7 days at 120 rpm. The fungal cells were isolated and dried at 65 ° C for 24 hours. The powder from the dried cells was dissolved in water (10 g / l) and autoclaved for 20 minutes at 121 ° C. The extracts of these cells were finally used as a bio elicitorto study the change in the number of secondary metabolites. After that, the growth rate of cells in cell suspension culture was measured before and after the application of fungal extract. Parameters such as total phenol content, antioxidant activity, and flavonoids were also studied.Results and DiscussionThe results showed that the treatment combinations of 1mg 2,4-D + 1mg BA and inoculation of the plant with three fungi, the amount of phenol and flavonoids increased by 62.11% and 49.18%, respectively, compared to the control and at the levels of 1% and 5% probability were significant and was observed in the combination of hormonal treatment 1mg 2.4-D + 1mg Kin and inoculation of three fungi, the amount of antioxidant production increased by 62.78% compared to the control and at the levels of 1% probability was significant. The results indicated that the cell extraction of the fungal endophyte Alternaria solani, Fusarium sp., and Setosphaeria rostrata under condition hormonal treatment can be used as an effective stimulant in increasing the amount of secondary metabolites (phenol, flavonoids and antioxidant) of Citrullus colocynthis L. Schrad. Conclusion It was revealed that by adding the elicitor to the culture medium, cell growth was increased. The results showed that the combination of three types of endophytic fungi Alteynaria solani, Setosphaeria rostrata and Fusarium sp. led to a significant increase in cell dry weight compared with the control treatment. Also, an increase in cell growth was observed even when a fungal extract was used alone. The amount of metabolites in cells treated with fungal extracts (fungal elicitors) was significantly higher than metabolites produced in the control. According to the results of this experiment, using a combination of three fungal extracts was the best treatment to increase the metabolite production in the culture of cell suspension of Citrullus colocynthis L. Schrad.
