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Carbon nanotubes as novel plant elicitors are intensively studied in biotechnology due to their concentration-dependent effects on plant health. This emphasizes the importance of studying nanomaterials in the field of plant nanotoxicology and enables a better understanding of their advantages and disadvantages for plant health. Researchers examined how various concentrations of multi-walled carbon nanotubes (MWCNTs) affect growth and polyphenolic accumulation in the medicinal herb, Melissa officinalis. Two-month-old plant shoots were sprayed with various concentrations (0–250 mg L−1) of COOH- functionalized MWCNTs and harvested two and three weeks after elicitation. TEM images confirmed MWCNTs uptake into the mesophyll and the vessels of leaves. Low to moderate MWCNT concentrations (50–100 mg L−1) boosted growth indices and increased total amount of phenols, flavonoids, and phenolic acids, peaking three weeks after treatment with 100 mg L−1 MWCNTs, without destroying the cells and subcellular organelles. HPLC analysis showed this treatment yielded the highest content of rosmarinic acid, salvianolic acid B, apigenin, and kaempferol. However, 250 mg L−1 MWCNTs damaged cells without boosting metabolite production. We suggest that elicitation with low to moderate MWCNT concentrations can be a useful tool for laboratory-scale production of phenolic metabolites in M. officinalis. [ABSTRACT FROM AUTHOR]

The medicinal properties of narcissus plants are attributed to the presence of Amaryllidaceae alkaloids. Elicitors, such as nanoparticles, are employed to enhance the production of secondary metabolites through signaling and the generation of reactive oxygen species. We investigated the effects of Fe3O4 nanoparticles (Fe3O4-NPs), trans-cinnamic acid (tCA), and L-phenylalanine (L-Phe) precursors on various physiological and biochemical parameters in Narcissus tazetta L., with a particular focus on alkaloid content. Fe3O4- NPs treatment significantly increased photosynthetic pigments, secondary metabolites (including alkaloids, phenolic compounds), total soluble carbohydrates, and polysaccharides. The activities of antioxidant enzymes (SOD, CAT, POD), phenylalanine ammonia-lyase (PAL), and tyrosine ammonia-lyase (TAL) enhanced under Fe3O4-NPs treatment. While tCA treatment led to an increase in H2O2 level, L-Phe treatment decreased it. Both elicitors influenced the plant's metabolism, promoting primary and secondary metabolites. The augmentation of photosynthetic pigment content and antioxidant enzyme activity induced by tCA and L-Phe treatments appeared to improve alkaloid production. Furthermore, in silico studies using Molegro Virtual Docker (MVD) software were conducted. The third structures of PAL and N4OMT enzymes were designed by Modeler software and the ligand structures were designed using ChemDraw® (Fe3O4) and Atomsk (precursors) software. Docking results revealed that the Fe3O4-NPs and precursors interacted with the active sites of PAL and N4OMT, two enzymes involved in alkaloid biosynthesis in narcissus, exhibiting varying binding energies and impacting their activities. The Fe3O4/N4OMT and L-phenylalanine/PAL complexes had higher free energies of binding. Our results indicated that Fe3O4-NPs and precursors significantly affected the gene expressions of PAL and N4OMT. The highest levels of PAL (after 96 h) and N4OMT (after 24 h) expressions were obtained in tCA + Fe3O4-NPs and L-Phe + Fe3O4-NPs treatments. In summary, the application of Fe3O4-NPs, tCA, and L-Phe demonstrated the potential to activate the production of secondary metabolites, including alkaloids, by modulating the plant's metabolic pathways. [ABSTRACT FROM AUTHOR]

An important phytochemical compound with bioactive properties is artemisinin, which is extracted from Artemisia annua L.. Frontline malaria treatments are artemisinin-based combination therapies (ACTs). The expression of key genes in the biosynthesis pathway of artemisinin can be regulated through metabolic engineering. In this study, we evaluated changes in the mRNA levels of the AaWRKY1, AaMYB2, HMGR, and CYP71A1 genes following the application of iron oxide nanoparticles (Fe3O4-NPs) after 0, 4, 8, 24, 48, and 96 h of spraying at concentrations of 0, 50, 100, and 200 mg L−1 on the leaves of 6-week-old A. annua plants. The total protein contents and the activity of the CAT, POX, SOD, and PAL enzymes were increased by Fe3O4-NP, which triggered an enzymatic defense system associated with reactive oxygen species (ROS). This ROS-related defense mechanism was activated by Fe3O4-NPs, which significantly stimulated the expression of those target key genes and raised the artemisinin levels in A. annua. The artemisinin content increased after 96 h by 98.5%, 76.3%, and 77% in plants treated with the three Fe3O4-NP concentrations, respectively compared to the control. These findings can help the commercial production of this important medicinal compound both in vivo and in vitro.Key message: Elicitation of A. annua using Fe3O4-NPs increased activity of CAT, POX, SOD, and PAL, significantly stimulated overexpression of AaWRKY1, AaMYB2, CYP71A1 and HMGR genes, leading to notable raise artemisinin levels notably. [ABSTRACT FROM AUTHOR]

Introduction: Khabr National Park is one of the valuable natural resources in Iran, and its cyanobacterial population has not been studied yet. Cyanobacteria are the most important nitrogen-fixing bacteria in all aquatic and terrestrial environments, playing a vital role in arid and semi-arid ecosystems. The present study aimed to determine the role of different cyanobacterial species isolated from the grazed and not grazed areas in two cold and warm steppes of Khabr National Park on some soil properties and the effect of the selected cyanobacteria on Secale montanum growth. Materials and Methods: In the present study, cyanobacteria were isolated from a harsh terrestrial ecosystem and cultured on a BG11 medium. Next, the expression of the nifH gene was assayed in all nitrogen fixing isolates using the Real Time-PCR. Then, the best nitrogen-fixing cyanobacteria (Nodularia. sp.) was selected and its activity was investigated in pot experiments alone and in combination with chemical fertilizer. Three different soils in terms of physical and chemical properties were analyzed. Results: The results indicated that the treated soils with Nodularia sp. as a biofertilizer can significantly increase nitrogen content of both agricultural soil and mixed soil. Consequently, Nodularia sp. has the ability to promote some characteristics of the studied soil through improving TN, SOC, SOM, and enzyme activities. Discussion and Conclusion: It can be concluded that the selected cyanobacterium increase soil stability in terms of mechanical fracture and resistance to desiccation and improve soil structure, which is very important, especially in arid and desert soil. [ABSTRACT FROM AUTHOR]

The medicinal properties of the Narcissus genus are due to the presence of alkaloids known as Amaryllidaceae Alkaloids (AA). The presence of nanoparticles causes oxidative stress and stimulates production of secondary metabolites. Useing specific precursors in AA biosynthetic pathways can be effective on cumulative production of these compounds. In this study, the effect of iron oxide nanoparticles (Fe3O4-NPs), trans-cinnamic acid (tCA), and L-phenylalanine (L-Phe) as precursors has been investigated on changes in some biochemical parameters of Narcissus tazetta L. callus, especially alkaloid content. Treatment of calli generated from bulb explants in Morashig-Skoog (MS) media containing 2,4-D and BAP and Fe3O4-NPs, increased alkaloids, flavonoids, and phenolic compounds. Also, the activity of antioxidant enzymes (SOD, CAT and POD), and activity of phenylalanine ammonia-lyase (PAL) and tyrosine ammonia-lyase (TAL) increased under Fe3O4-NPs treatments alone and in combination with tCA or L-Phe precursors. The evaluation of the studied parameter changes showed that both tCA and L-Phe treatment can change the plant's metabolism to improve the production of secondary metabolites. This was especially evident with the simultaneous application of Fe3O4-NPs and these precursors. Application of precursors in the culture medium increased H2O2 content under tCA treatment and decreased it under L-Phe treatment. Increased activity of the antioxidant enzymes caused by nanoparticle treatments along with the nutritional effect of tCA and L-Phe precursors, progressed signaling pathway of antioxidant responses by affecting the activity of biosynthetic enzymes and increases production of some secondary metabolites including alkaloids and phenolic compounds. Considering various properties of Amaryllidaceaea alkaloids, optimizing, and increasing the production of these alkaloids is important from a commercial and medical point of view. [ABSTRACT FROM AUTHOR]

Background: Rhodotorula is characterized by the absence of ballistoconidia, fermentation ability, and starch-like compounds. Biology of the species is not well-identified; therefore molecular identification is required. Sequence analysis of the D1/D2 region can be used for the identification of the majority of Basidiomycetous species. Carotenoids which are natural pigments can be synthesized by some genera of yeasts such as Rhodotorula. The increase of demand for carotenoids obtained from natural sources has promoted major efforts to recognize potential microbial sources. The aims of this study were to identify a strain isolated from leather wastewater and to investigate its carotenoid production ability. The effect of 2 different medium (Semi-synthetic medium (MMS) and yeast malt extract medium (YM)) on biomass and carotenoid production was studied. Materials and Methods: In this experimental study, sequence analysis of the D1/D2 region in addition to morphological and biochemical characterization to identify the strain was carried out. To isolate the carotenoid pigment, cells were suspended in acetone and broken using a homogenizer, followed by centrifugation and supernatant was separated; thus pigments were measured spectrophotometrically at 450 nM using the extinction coefficient E1% 450=2500. Results: Identification processes represented strain SG006 as a Rhodotorula slooffiae. The sequence was deposited in the Gene Bank database with accession number JX997835. The results showed that SG006 are able to produce carotenoid and MMS medium promoted carotenoid production. Conclusion: We found that Rhodotorula slooffiae showed the ability to produce carotenoid. However, further work is needed to optimize of the amount of product and to characterize the carotenoids. [ABSTRACT FROM AUTHOR]

Introduction: Infections caused by Pseudomonas aeruginosa biofilm are the major causes of death in patients with cystic fibrosis (CF). Some studies revealed that biofilms are resistant to several antibiotics because of their impermeable structures. In order to resensitize bacteria to different antibiotics, biofilm formation should be inhibited. In this research, evaluation of antibiofilm activity of n-butanolic Cyclamen coum extract as a medicinal plant from Myrsinaceae family, in combination with ciprofloxacin was carried out. Materials and methods: The biofilm formation ability by P. aeruginosa PAO1 and one clinically isolated P. aeruginosa (PA214) was confirmed by microtiter plate method. Extraction of the tubers of Cyclamen coum was done by fractionation method. The antibiofilm and antibacterial properties of n-butanolic C. coum extract (which includes saponin compounds) alone and in combination with ciprofloxacin by using microdilution and crystal violet methods were examined. The cytotoxicity effect of the n-butanolic extract on HT-29 cells was assayed by MTT (3- (4,5-dimethylthiazol-2-yl) -2,5-diphenyltetrazolium bromide) test. Results: The biofilm formation ability by P. aeruginosa strains was quantitatively confirmed. Saponin content of the n-butanolic C.coum extract was 156 µg/mL. The extract revealed antibacterial activity against the growth of planktonic P. aeruginosa strains. The combination of n-butanolic C.coum extract and ciprofloxacin significantly inhibited P.aeruginosa biofilm formation (ΣFBIC = 0.5). The n-butanolic C.coum extract showed insignificant cytotoxic effect against HT-29 human cancer cell line after 48 hours and 72 hours incubation. Discussion and conclusion: It can be concluded that n-butanolic C.coum extract in combination with ciprofloxacin significantly revealed antibiofilm activity against P. aeruginosa biofilm however, further clinical investigations are required. [ABSTRACT FROM AUTHOR]

Objective(s): Carotenoids which are naturally synthesized by fungi such as yeasts can act as an antioxidant which is closely related to their ability to decrease the risk of a variety of degenerative diseases. In recent years, the increase of demand for carotenoids obtained from natural sources has promoted major efforts to improve carotenoid production from biological sources such as pigmented yeasts. The aim of this study was comparing incubation time and carotenoid production in Rhodotorula slooffiae and R. mucilaginosa isolated from leather tanning wastewater. Materials and Methods: To isolate the carotenoid pigment, cells were suspended in acetone and broken using a homogenizer, followed by centrifugation and separation of supernatant. In order to study the effect of incubation time, samples were held at 30 C in a shaker at 150 rpm for 24, 48, 72, 96, and 120 hr. For analytical evaluation, pigments were measured spectrophotometrically at 450 nm using the extinction coefficient E1% 450=2500. Results: The results showed that the content of total carotenoid in R. slooffiae was the highest when samples were incubated for 72 hr. Overall, R. mucilaginosa had more potential to produce carotenoid. The best incubation periods for R. slooffiae and R. mucilaginosa were 72 hr and 48 hr, respectively. Conclusion: It seemed that the maximum rate of total carotenoid was not directly associated with the maximum amount of cell biomass and the type of carotenoid and their relative amount may vary depending on genus of yeast. [ABSTRACT FROM AUTHOR]

Salvia L. is a large genus of the Lamiaceae family with high medicinal value. Pharmaceutical properties of Salvia species are mainly due to their secondary metabolites, especially phenolic compounds. This study was focused on identification and determination of five bioactive phenolic compounds (rosmarinic acid, carnosic acid, caffeic acid, salvianolic acids A and B) in the 41 populations from 27 wild Salvia species of Iran using a simple and reliable HPLC-UV method. The principal component analysis (PCA) technique was used to study differentiation among species according to their phenolic compound profiles. Significant intra- and interspecific variations were observed in the distribution patterns and contents of phenolic compounds in the studied Salvia species. As a result of this study, it was found that leaves had greater amounts of phenolic compounds as compared to the roots. The highest content of rosmarinic acid (41.53±0.88 mg/g DW) and salvianolic acid A (8.10±0.35 mg/g DW) were found in the leaves of S. verticillata. The leaves of S. syriaca and S. sharifii were rich in salvianolic acid B (54.47±2.00 mg/g DW) and carnosic acid (34.05±1.18 mg/g DW), respectively. The PCA results revealed chemical variations in the Salvia species collected from different regions and could fully distinguish between them based on the phenolic compounds concentrations. The present study demonstrated that apart from S. officinalis, some wild species such as S. verticillata, S. hypoleuca, S. leriifolia and S. virgata can be introduced as potent natural sources for medicinal and industrial purposes. [ABSTRACT FROM AUTHOR]

Objective(s): Carotenoids which are naturally synthesized by fungi such as yeasts can act as an antioxidant which is closely related to their ability to decrease the risk of a variety of degenerative diseases. In recent years, the increase of demand for carotenoids obtained from natural sources has promoted major efforts to improve carotenoid production from biological sources such as pigmented yeasts. The aim of this study was comparing incubation time and carotenoid production in Rhodotorula slooffiae and R. mucilaginosa isolated from leather tanning wastewater., Materials and Methods: To isolate the carotenoid pigment, cells were suspended in acetone and broken using a homogenizer, followed by centrifugation and separation of supernatant. In order to study the effect of incubation time, samples were held at 30 ˚С in a shaker at 150 rpm for 24, 48, 72, 96, and 120 hr. For analytical evaluation, pigments were measured spectrophotometrically at 450 nm using the extinction coefficient E(1%) 450=2500., Results: The results showed that the content of total carotenoid in R. slooffiae was the highest when samples were incubated for 72 hr. Overall, R. mucilaginosa had more potential to produce carotenoid. The best incubation periods for R. slooffiae and R. mucilaginosa were 72 hr and 48 hr, respectively., Conclusion: It seemed that the maximum rate of total carotenoid was not directly associated with the maximum amount of cell biomass and the type of carotenoid and their relative amount may vary depending on genus of yeast.