Pharmacognostic standardization and DNA fingerprinting of leaves of Datura stramonium, growing naturally in Asir region of Saudi Arabia.

Evaluation of the various pharmacognostic quality parameters and DNA fingerprint of Saudi Arabian medicinal plant namely Datura stramonium growing in Asir region was the objective of the study. The pharmacognostical parameters were done in terms of macroscopic characters, microscopic details, physico-chemical evaluations, phytochemical analysis, fluorescence analysis and DNA fingerprint by using standard techniques and random polymorphic DNA primer. The detailed microscopy of the leaf revealed the presence of pre-medullary phloem, xylem, endodermis, parenchymatous pericycle, lower epidermis and calcium oxalate crystals. There are various amounts of foreign material, ash values, moisture content and extractive values, found after estimations. Preliminary phytochemical screening exhibited the presence of alkaloids, flavonoids, glycosides, tannins and sterols in variable amounts. Random amplified polymorphic DNA (RAPD) showed there are a prominent scorbale DNA bands. These evaluations provided referential information for correct authentication and quality standardization of the important medicinal plant material. These information will also be supportive to differentiate Datura stramonium from the closely related other species.

Effects of light conditions on growth and defense compound contents of Datura inoxia and D. stramonium.

We examined the effects of light conditions on plant growth and production of defense compounds in the toxic species Datura inoxia and D. stramonium. Specifically, we investigated morphological and physiological traits, including the contents of nitrogen-based tropane alkaloids (atropine and scopolamine) as defense compounds, under three light conditions: 100%, 80%, and 50% of full sunlight. Both species showed similar morphological and physiological responses to exposure to different intensities of light. Although the total plant mass decreased under lower light conditions, the total leaf area per plant increased. The reason being that the leaf mass per plant did not decrease, while the leaf mass per unit area decreased. Leaf nitrogen and chlorophyll concentrations and the chlorophyll/nitrogen ratio increased under lower light conditions, whereas the chlorophyll a/b ratio decreased. These morphological and physiological changes may be seen as ways to increase light acquisition under low light conditions. Leaf atropine and scopolamine concentrations did not differ among the three light conditions for both species. In conclusion, both Datura species underwent morphological and physiological changes under low light conditions, enabling them to use carbon and nitrogen to increase light acquisition while maintaining their chemical defense capability.

Sulfonate-Functionalized Mesoporous Silica Nanoparticles as Carriers for Controlled Herbicide Diquat Dibromide Release through Electrostatic Interaction.

Environmental stimuli-responsive pesticide release is desirable for enhanced efficiency and reduced side effects. In most cases, the loading and release of pesticides mainly depends on hydrophobic interactions and hydrogen bonding. Electrostatic interaction is less investigated as a weapon for achieving high loading content and controlled pesticide release. In this work, negative-charge decorated mesoporous silica nanoparticles (MSNs) were facilely fabricated by introducing sulfonate groups onto MSNs through a post-grafting method. Sulfonate-functionalized MSNs (MSN-SO3) were synthesized by conversion of epoxy group into sulfonate group using a bisulfite ion as a ring opening reagent. Diquat dibromide (DQ), one of the globally used quaternary ammonium herbicides, was efficiently loaded into these negatively charged MSN-SO3 nanoparticles. The loading content was increased to 12.73% compared to those using bare MSNs as carriers (5.31%). The release of DQ from DQ@MSN-SO3 nanoparticles was pH and ionic strength responsive, which was chiefly governed by the electrostatic interactions. Moreover, DQ@MSN-SO3 nanoparticles exhibited good herbicidal activity for the control of Datura stramonium L., and the bioactivity was affected by the ionic strength of the release medium. The strategy of cargo loading and release dependent on the electrostatic interactions could be generally used for charge-carrying pesticides using carriers possessing opposite charges to mitigate the potential negative impacts on the environment.

Flower-level developmental plasticity to nutrient availability in Datura stramonium: implications for the mating system.

Background and Aims: Studies of phenotypic plasticity in plants have mainly focused on (1) the effect of environmental variation on whole-plant traits related to the number of modules rather than on (2) the phenotypic consequences of environmental variation in traits of individual modules. Since environmental and developmental factors can produce changes in traits related to the mating system, this study used the second approach to investigate whether within-individual variation in herkogamy-related traits is affected by the environment during plant development in two populations of Datura stramonium , an annual herb with a hypothesized persistent mixed mating system, and to determine which morphological traits may promote self-fertilization. Methods: Full-sib families of two Mexican populations of D. stramonium , with contrasting ecological histories, were grown under low, mid and high nutrient availability to investigate the effects of genetic, environmental and within-plant flower position on flower size, corolla, stamen and pistil lengths, and herkogamy. Key Results: Populations showed differences in familial variation, plasticity and familial differences in plasticity in most floral traits analysed. In one population (Ticumán), the effect of flower position on trait variation varied among families, whereas in the other (Pedregal) the effect of flower position interacted with the nutrient environment. Flower size varied with the position of flowers, but in the opposite direction between populations in low nutrients; a systematic within-plant trend of reduction in flower size, pistil length and herkogamy with flower position increased the probability of self-fertilization in the Pedregal population. Conclusions: Besides genetic variation in floral traits between and within populations, environmental variation affects phenotypic floral trait values at the whole-plant level, as well as among flower positions. The interaction between flower position and nutrient environment can affect the plant's mating system, and this differs between populations. Thus, reductions in herkogamy with flower positions may be expected in environments with either low pollinator abundance or low nutrients.

[Effects of methyl jasmonate on accumulation and release of main tropane alkaloids in liquid cultures of Datura stramonium hairy root].

OBJECTIVE: To study the effects of methyl jasmonate (MJ) on the accumulation and release of main secondary metabolites i. e. scopolamine and hyoscyamine in liquid cultures of Datura stramonium hairy roots. METHOD: After 18 days liquid culture of D. stramonium hairy roots induced by agrobacterium rhizogenes C58C1, the chemical elicitor methyl jasmonate was added into 1/2 MS liquid cultures and scopolamine and hyoscyamine on the day 0, 3, 6, 9 and 12, after dealing with MJ, was determined by HPLC. RESULT: After dealing with MJ on the day 3, 6, 9 and 12,the concentration of scopolamine reached to 0.419, 0.439, 0.431, 0.374 mg x g(-1), respectively, the increase of scopolamine were 1.36, 1.42, 1.17 and 1.12 fold higher than that of the control, respectively. And hyoscyamine reached 1.493, 0.817, 0.723 and 0.698 mg x g(-1), respectively, the increase of hyoscyamine were 2.28, 1.11, 0.63 and 0.70 fold higher than that of the control, respectively. CONCLUSION: MJ could stimulate the accumulation of scopolamine and hyoscyamine (3,6 d) in D. stramonium hairy root and have released them into the culture medium.

Optimization of the culture medium composition to improve the production of hyoscyamine in elicited Datura stramonium L. hairy roots using the Response Surface Methodology (RSM).

Traditionally, optimization in biological analyses has been carried out by monitoring the influence of one factor at a time; this technique is called one-variable-at-a-time. The disadvantage of this technique is that it does not include any interactive effects among the variables studied and requires a large number of experiments. Therefore, in recent years, the Response Surface Methodology (RSM) has become the most popular optimization method. It is an effective mathematical and statistical technique which has been widely used in optimization studies with minimal experimental trials where interactive factors may be involved. This present study follows on from our previous work, where RSM was used to optimize the B5 medium composition in [NO(3-)], [Ca(2+)] and sucrose to attain the best production of hyoscyamine (HS) from the hairy roots (HRs) of Datura stramonium elicited by Jasmonic Acid (JA). The present paper focuses on the use of the RSM in biological studies, such as plant material, to establish a predictive model with the planning of experiments, analysis of the model, diagnostics and adjustment for the accuracy of the model. With the RSM, only 20 experiments were necessary to determine optimal concentrations. The model could be employed to carry out interpolations and predict the response to elicitation. Applying this model, the optimization of the HS level was 212.7% for the elicited HRs of Datura stramonium, cultured in B5-OP medium (optimized), in comparison with elicited HRs cultured in B5 medium (control). The optimal concentrations, under experimental conditions, were determined to be: 79.1 mM [NO(3-)], 11.4 mM [Ca(2+)] and 42.9 mg/L of sucrose.

Hyoscyamine biosynthesis in Datura stramonium hairy root in vitro systems with different ploidy levels.

Hyoscyamine biosynthesis in Datura stramonium hairy roots with different ploidy levels was investigated. For the first time, we report that hairy roots undergo endoreduplication and therefore consist mainly of cells with doupled sets of chromosomes of primary plant tissues, used for Agrobacterium transformation. The alkaloid profiles of hairy roots obtained from diploid and tetraploid plants were similar in terms of the major compounds, but they differed significantly with respect to the minor compounds (here defined as those that accounted for <1% of the total ion current of the alkaloid mixture in gas chromatography-mass spectrometric analyses). Significant differences in the effects of the main nutrients on the growth of the hairy roots obtained from diploid and tetraploid plants and their hyoscyamine contents were observed. The maximal yield of hyoscyamine (177 mg/L) was obtained when hairy roots from tetraploid plants were cultivated in Murashige-Skoog nutrient medium supplemented with 6% sucrose. Time courses of utilization of the main nutrients in the medium during cultivation of D. stramonium hairy root cultures are also presented.

Growth and production optimization of tropane alkaloids in Datura stramonium cell suspension culture.

Abstract: A number of physicochemical conditions such different concentration of glucose, sucrose, potassium nitrate, ammonium nitrate, calcium chloride and temperatures were tested to optimize growth and production of tropane alkaloids from Datura stramonium (Solanaceae) plants. Cell suspension from semi-clear calli of leave explants developed in MS medium containing kinetin (0.5 mg L(-1)) and NAA (2 mg L(-1)) hormones was used to measure biomass and total alkaloids and comparison of treatments. The results showed that 30 and 40 g L(-1) glucose led to the highest level of alkaloids and biomass productions, respectively. 20 and 40 g L(-1) sucrose concentrations resulted in order the most rates of alkaloids and biomass productions. The results showed that increasing of nitrate concentration led to the reduction of the alkaloids. The best concentration of potassium nitrate for the production of tropane alkaloids and biomass were in order 9.4 and 3.76 mM. Also it was evinced that the optimized concentration of ammonium nitrate for alkaloids production was 10.3 mM and for the biomass was 41.22 mM. The best concentration of calcium chloride for growth and production of the alkaloids was 7.92 mM. Testing different temperature specified that the best condition for production of the alkaloids was 20 degrees C whereas it was 25 degrees C for biomass production. The results of this study could be recommended to farmers involved in production of D. stramonium for tropain alkaloids at industrial and semi-industrial scales.

Host tolerance does not impose selection on natural enemies.

Coevolution between hosts and their natural enemies is believed to operate through the evolution of resistance traits. Although the importance of tolerance to natural enemies as an alternative defensive strategy has been recognized, there is still no consensus about the possible role of host tolerance in the evolutionary outcome of the interaction. Here, using bioassay experiments, we tested the hypothesis that variation in host tolerance among selected plant genotypes could impose a selection pressure upon a specialist herbivore. Tolerance did not affect herbivore larvae survival, weight gain, efficiency of food consumption, total food consumption, developmental time and adult mass. These results therefore do not support the hypothesis that host tolerance could affect natural enemy performance. However, resistance did negatively affect herbivore larva survival. Genetic variation in herbivore larva survival was detected, thus suggesting the potential for a coevolutionary response. Our results indicate that host tolerance would reduce opportunities for a coevolutionary response by the natural enemies of the host. Contrary to predictions from previous models, our results suggest that host tolerance may constitute an evolutionarily unstable defensive strategy.

Distribution of hyoscyamine and scopolamine in Datura stramonium.

The production of hyoscyamine and scopolamine in Datura stramonium has been investigated in the different plant parts, at different stages of their life cycle. Maximum contents were found in the stems and leaves of young plants, hyoscyamine being always the predominant component.

Antagonistic action of low-fluence and high-irradiance modes of response of phytochrome on germination and beta-mannanase activity in Datura ferox seeds.

Seed germination is often induced by a pulse of red light perceived by phytochrome and cancelled by a subsequent pulse of far-red light. When the pulse of red light is followed by several hours of darkness, a pulse of far-red light is no longer effective and prolonged far-red is necessary to block germination. The aim was to investigate whether the red light pulse and prolonged far-red light act on the same or different processes during germination of Datura ferox seeds. Forty-five hours after the inductive red light pulse, germination could not be blocked by one pulse or six hourly pulses of far-red light, but was significantly reduced by 6 h of continuous far-red light. The pulse of red light increased embryo growth potential and the activities of beta-mannanase and beta-mannosidase extracted from the micropylar region of the endosperm. Continuous far-red light had no effect on embryo growth potential or beta-mannosidase activity, but severely reduced the activity of beta-mannanase. The effect of far-red light had the features of a high-irradiance response of phytochrome. Both germination and beta-mannanase activity were restored by a pulse of red light given after the end of the continuous far-red treatment. It is concluded that the low-fluence response and the high-irradiance response modes of phytochrome have antagonistic effects on seed germination and that the control of beta-mannanase activity is one process where this antagonism is established.

Fumonisin B1 from the fungus Fusarium moniliforme causes contact toxicity in plants: evidence from studies with biosynthetically labeled toxin.

Fumonisin B1 (FB1) is the most abundant of a series of sphingosine analog mycotoxins produced by the fungus Fusarium moniliforme, a ubiquitous contaminant of stored corn (maize) worldwide. FB1 exhibits a variety of biological activities including phytotoxicity, which is of particular interest for its potential role as a virulence factor to facilitate invasion of plant tissues by the fungus. Droplets of FB1 solution applied to the leaf surface of jimsonweed, black nightshade, and susceptible tomatoes caused necrosis, growth inhibition, and death. With Arabidopsis thaliana grown on agar plates, an IC50 (concentration causing half maximal phytotoxicity) of less than 1 ppm was observed. [3H]FB1 was prepared by biosynthetic incorporation of commercially-available radiolabeled presumptive precursors into the toxin in rice medium solid cultures of F. moniliforme JW#1. The labeled toxin produced by incorporation of [9,10-3H]palmitate induced phytotoxic symptoms identical to unlabeled material, indicating it had full biological activity. The area of necrosis on treated leaves was similar in light and dark treated plants. Using liquid scintillation counting to quantify radioactivity in excised plant parts, over 95% of the [3H]FB1 radioactivity applied to leaves of light or dark-treated plants was recovered from the treated leaf. When [3H]FB1 was applied to a wound site on target plants, severe damage occurred at the site of FB1 application and in tissue above the site. These results indicate that FB1 applied to intact surfaces of target plants exhibits primarily contact activity. Translocation of FB1 is limited, occurring only when FB1 is applied to a wound site, and it results in damage to tissue above the point of application, indicating that FB1 is xylem mobile.

Growth and hyoscyamine production of 'hairy root' cultures of Datura stramonium in a modified stirred tank reactor.

The growth and hyoscyamine production of transformed roots of Datura stramonium have been examined in a modified 14-1 stirred tank reactor in both batch and continuous fermentations on media containing half or full strength Gamborg's B5 salts and at three different temperatures. Under a range of conditions, roots grown on half strength B5 salts with 3% w/v sucrose had a higher dry matter content (up to 8.3% w/w) and a higher hyoscyamine content (up to 0.52 mg.g-1 wet weight) than roots grown on full strength B5 salts with the same level of sucrose (up to 4.6% w/w dry matter and up to 0.33 mg hyoscyamine g-1 wet weight). Growth at 30 degrees C was initially faster than at either 25 degrees C or 35 degrees C and by day 12, the drained weight of roots in the fermentor at 30 degrees C was about fourfold greater than at 25 degrees C and twice that at 35 degrees C. The ultimate hyoscyamine levels attained (approximately 0.5 mg.g-1 wet weight) were similar at both 25 degrees C and 30 degrees C but some 40% lower at 35 degrees C. Final packing densities of 70% w/v were achieved for roots after 37 days growth at 25 degrees C and the highest production rate of 8.2 mg hyoscyamine 1(-1) per day was obtained for roots grown at 30 degrees C. In continuous fermentation at 25 degrees C, the release of hyoscyamine into the culture medium was low (less than 0.5% w/w of the total) but was up to sevenfold higher in fermentors operated at 30 degrees C or 35 degrees C.

Efecto de la forma de cosecha en los rendimientos de Datura candida (Pers.) Safford / Effect of ways of harvesting in yields of Datura candida (Pers.) Safford

Tres formas de recolección en Datura candida (Pers). Safford fueron probadas en la Estación Experimental de Plantas Medicinales "Dr. Juan Tomás Roig" del MINSAP, ubicada en San Antonio de los Baños, provincia Habana. Los resultados indicaron que las recolecciones sucesivas de hojas produce mayores rendimientos con altos contenidos de alcaloides en menor período de tiempo que la cosecha tradicional de hojas, yemas terminales y tallos verdes

Efecto de la frecuencia de cosecha en los rendimientos de Datura candida (Pers.) Safford / Effect of harvest frequency in the yields of Datura candida (Pers.) Safford

En la Estación Experimental de Plantas Medicinales "Dr. Juan Tomás Roig" del MINSAP, se realizaron una serie de experimentos con vistas a determinar la mejor frecuencia de cosecha en Datura candida (Pers.) Safford, planta medicinal productora de alcaloides tropánicos, principalmente escopolamina. Los experimentos desarrollados fueron: diferentes edades de la planta en la primera cosecha (3,4,5 y 6 meses) y distintas frecuencias de corte en plantaciones de 12, 24 y 41 meses (2,3,4 meses). Los análisis estadísticos demostraron que los mayores valores para la primera cosecha se obtuvieron cuando los cortes se realizaron entre los 5-6 meses de edad y los subsiguientes a intervalos de 2 meses, tanto en la plantación de 12, como en las de 24 y 41 meses de edad, debiéndose considerar el que después de 5 a 6 cortes, las plantas se podarán a 20 cm del suelo. También se verificó que los cultivos pueden explotarse hasta aproximadamente 5 años de edad, aunque con una disminución gradual de los rendimientos

Efecto de la frecuencia de cosecha en los rendimientos de Datura candida (Pers.) Safford / Effect of harvest frequency in the yields of Datura candida (Pers.) Safford

En la Estación Experimental de Plantas Medicinales "Dr. Juan Tomás Roig" del MINSAP, se realizaron una serie de experimentos con vistas a determinar la mejor frecuencia de cosecha en Datura candida (Pers.) Safford, planta medicinal productora de alcaloides tropánicos, principalmente escopolamina. Los experimentos desarrollados fueron: diferentes edades de la planta en la primera cosecha (3,4,5 y 6 meses) y distintas frecuencias de corte en plantaciones de 12, 24 y 41 meses (2,3,4 meses). Los análisis estadísticos demostraron que los mayores valores para la primera cosecha se obtuvieron cuando los cortes se realizaron entre los 5-6 meses de edad y los subsiguientes a intervalos de 2 meses, tanto en la plantación de 12, como en las de 24 y 41 meses de edad, debiéndose considerar el que después de 5 a 6 cortes, las plantas se podarán a 20 cm del suelo. También se verificó que los cultivos pueden explotarse hasta aproximadamente 5 años de edad, aunque con una disminución gradual de los rendimientos

Efecto de la forma de cosecha en los rendimientos de Datura candida (Pers.) Safford / Effect of ways of harvesting in yields of Datura candida (Pers.) Safford

Tres formas de recolección en Datura candida (Pers). Safford fueron probadas en la Estación Experimental de Plantas Medicinales "Dr. Juan Tomás Roig" del MINSAP, ubicada en San Antonio de los Baños, provincia Habana. Los resultados indicaron que las recolecciones sucesivas de hojas produce mayores rendimientos con altos contenidos de alcaloides en menor período de tiempo que la cosecha tradicional de hojas, yemas terminales y tallos verdes