https://jrpsm.asnrukh.ac.ir/ Research in Plant Metabolites en daily 1 Wed, 21 Jan 2026 00:00:00 +0330 Wed, 21 Jan 2026 00:00:00 +0330 https://jrpsm.asnrukh.ac.ir/article_242976.html Plant secondary metabolites are recognized as bioactive and valuable compounds in the pharmaceutical, food, and cosmetic industries. Limitations in the natural production of these metabolites, along with ecological risks associated with the overharvesting of medicinal plants, have made the application of biotechnological approaches, such as plant tissue and cell culture and elicitation of biosynthetic pathways, a research and industrial necessity. This study aimed to investigate the effects of concentration and incubation time of green‑synthesized copper oxide nanoparticles on oxidative responses and the accumulation of phenolic and flavonoid compounds in Artemisia annua L. cell suspension cultures. Cells were treated with three nanoparticle concentrations (0, 20, and 40 µg ml⁻¹) for three incubation periods (24, 48, and 72 h), and H₂O₂ content, activities of catalase, ascorbate peroxidase, and guaiacol peroxidase, as well as total phenolic and flavonoid contents, were quantified. Results demonstrated that 20 µg ml⁻¹ induced a controlled increase in H₂O₂, enhanced catalase and ascorbate peroxidase activities, and led to the highest accumulation of phenolics and flavonoids at 72 h. Treatment with 40 µg ml⁻¹ had a stimulatory effect at 24 h; however, prolonged exposure intensified oxidative stress, resulting in marked reductions in phenolic and flavonoid contents. The observed patterns suggest that oxidative stress and H₂O₂ accumulation may contribute to defense responses and regulation of biosynthetic pathways. These findings highlight the importance of precisely controlling nanoparticle concentration and treatment duration to harness stimulatory effects while avoiding oxidative damage, and underscore the potential of plant cell culture systems for secondary metabolite production. https://jrpsm.asnrukh.ac.ir/article_242977.html Soil contamination with heavy metals, particularly lead, represents a significant environmental challenge that reduces plant growth and performance by inducing oxidative stress and disrupting physiological processes. The present study aimed to investigate the effects of different concentrations (0, 2.5, 5, 7.5, and 10% v/v) of the green seaweed Ulva fasciataL. extract as a natural biostimulant on selected physiological and biochemical traits of Triticum aestivum under lead stress (0, 15, 45, and 75 ppm). The experiment was conducted as a factorial arrangement in a completely randomized design with three replications. The obtained data were subjected to statistical analysis using SAS software, and mean comparisons were performed using Duncan’s multiple range test at a significance level of P < 0.01. Treatment with lead nitrate resulted in decreased leaf area, photosynthetic pigment content, and total protein, along with increased levels of malondialdehyde (MDA), proline, and soluble carbohydrates, indicating the occurrence of oxidative stress. In contrast, application of the seaweed extract, particularly at 10% concentration, mitigated the adverse effects of lead and enhanced photosynthetic pigments, total protein, and the activities of antioxidant enzymes, including catalase, peroxidase, and ascorbate peroxidase. These findings suggest that the bioactive compounds in the seaweed extract play a crucial role in enhancing plant tolerance to heavy metal stress through stimulation of the antioxidant system and improvement of photosynthetic processes. Accordingly, U. fasciata extract can be utilized as an environmentally friendly biostimulant to improve growth and resistance of crop plants in heavy metal-contaminated soils. https://jrpsm.asnrukh.ac.ir/article_242978.html In order to investigate the effect of foliar application of humic acid and silicon on some quantitIn order to investigate the effect of foliar application of humic acid and silicon on some quantitative and qualitative characteristics of Matricaria chamomilla L. under salt stress, an experiment was conducted as a factorial based on a completely randomized design with three replications in research greenhouse of Nahavand Higher Education Complex during 2024. Experimental factors included salinity stress at three levels (0, 50, 100 mM), foliar application of humic acid at three levels (0, 0.5 and 1.5 g.L-1) and silicon foliar application at three levels (0, 1.5 and 3 mM). Chlorophyll a, b content, fresh and dry weight of flower, height of the plant, capitulum diameter, total phenol and flavonoid contents were measured traits in this experiment. The results indicated a positive effect of the application of humic acid and silicon on most of the studied traits, so that the highest amount of chlorophyll a (1.04 mg.g-1) and chlorophyll b (0.55 mg.g-1) was observed at 50 mM salinity and using 0.5 g.L-1 humic acid and without the use of silicon. The highest values ​​of plant height (41 cm) and capitulum diameter (8.28 mm) were obtained by applying 50 mM salinity and the simultaneous use of 0.5 g.L-1 humic acid and 3 mM silicon. The increase percentage of these traits compared to the absence of humic acid and silicon at the same salinity level were 24.39 and 23.55%, respectively. The highest levels of total phenols (13.07 mg gallic acid.g-1 extract) and total flavonoids (26.66 mg rutin.g-1 extract) were obtained at a salinity level of 100 mM, 1.5 mM silicon, and without the use of humic acid. With simultaneous application of humic acid and silicon, the adverse effects of salt stress on some traits such as plant height and capitulum diameter were reduced. Therefore, the use of humic acid and silicon can be suggested as an effective method to reduce the destructive effects of salinity stress.ative and qualitative characteristics of Matricaria chamomilla L. under salt stress, an experiment was conducted as a factorial based on a completely randomized design with three replications in greenhouse research of Nahavand Higher Education Complex during 2024. Experimental factors included salinity stress at three levels (0, 50, 100 mM), humic acid foliar application at three levels (0, 0.5 and 1.5 g/L) and silicon foliar application at three levels (0, 1.5 and 3 mM). The results indicated a positive effect of the application of humic acid and silicon on most of the studied traits, so that the highest amount of chlorophyll a (1.04 mg/g) and chlorophyll b (0.55 mg/g) was observed at 50 mM salinity and using 0.5 g/L humic acid and without the use of silicon. The highest values of plant height (41 cm) and capitulum diameter (8.28 mm) were obtained by applying 50 mM salinity and the simultaneous use of 0.5 g/L humic acid and 3 mM silicon. The increase percentage of these traits compared to the absence of humic acid and silicon at the same salinity level were 24.39 and 23.55%, respectively. The highest levels of total phenols (13.07 mg gallic acid/g extract) and total flavonoids (26.66 mg rutin/g extract) were obtained at a salinity level of 100 mM, 1.5 mM silicon, and without the use of humic acid. https://jrpsm.asnrukh.ac.ir/article_242980.html Melatonin is known as one of the endogenous cellular regulators that can improve the quantity and quality of the product by affecting the growth and development processes of plants. Considering the importance of secondary plant compounds and their role in physiological characteristics, the aim of this study was to investigate the effects of foliar spraying of melatonin on the contents of total anthocyanins, total phenolics, total flavonoids, and free radical scavenging capacity of safflower petals (Carthamus tinctorius). A field study was started in March 2025 in Shahdad region, Kerman province. Foliar spraying was performed on safflower plants twenty days after planting and at the stage of capitulum completion and before the opening of flowers. Experimental treatments included distilled water (control), melatonin at a concentration of 0.25 mM, and melatonin at a concentration of 0.5 mM. Data analysis was performed using a completely randomized design with three replications. The results showed that foliar application of melatonin at concentrations of 0.25 and 0.5 mM significantly increased the levels of various compounds measured in safflower petals (P<0.001). The highest levels of these compounds were observed in samples treated with 0.5 mM melatonin, which was significantly higher than the control. Also, samples treated with 0.25 mM melatonin increased the contents of each compound compared to the control (P<0.001). Based on the findings of this study, foliar application of melatonin at a concentration of 0.5 mM is recommended as an effective method for increasing phenolic, flavonoid, anthocyanin compounds and antioxidant capacity in safflower petals. The results showed that foliar application of melatonin at concentrations of 0.25 and 0.5 mM significantly increased the levels of various compounds measured in safflower petals (P<0.001). The highest levels of these compounds were observed in samples treated with 0.5 mM melatonin, which was significantly higher than the control. Also, samples treated with 0.25 mM melatonin increased the contents of each compound compared to the control (P<0.001). Based on the findings of this study, foliar application of melatonin at a concentration of 0.5 mM is recommended as an effective method for increasing phenolic, flavonoid, anthocyanin compounds and antioxidant capacity in safflower petals. https://jrpsm.asnrukh.ac.ir/article_242982.html Licorice (Glycyrrhiza glabra L.) is valued in various industries for its secondary metabolites. UV-B radiation stress can impair plant growth and metabolism, while salicylic acid, as a growth regulator, enhances plant tolerance to stress. This study was conducted to investigate the effects of UV-B and salicylic acid on growth and non-enzymatic antioxidant characteristics of licorice in a completely randomized factorial design with three replications during 2023–2024 at Urmia University. Seeds were prepared, germinated, and planted in pots, and at the 5–6 leaf stage, plants were treated with salicylic acid (0, 1, and 2 mM) via foliar application and UV-B stress (30 minutes daily) for two weeks. Growth traits (fresh and dry weight of roots and leaves) and biochemical traits (total phenol, flavonoid, anthocyanin content, and FRAP antioxidant activity) were evaluated. The results showed that UV-B significantly reduced the fresh weight of roots and leaves and dry weight of roots and leaves (by 67%, 68%, 64.6%, and 37.5% compared to the control, respectively) but increased total phenol and flavonoid content. Application of salicylic acid, particularly at 2 mM, mitigated these effects and improved the fresh and dry weight of leaves and roots. Additionally, salicylic acid combined with UV-B significantly increased phenol content in roots (130%), which led to an increase inFRAP antioxidant activity. The antioxidant activity of leaves (158%) and roots (130%) significantly increased under combined treatment of salicylic acid and UV compared to the control. Leaf anthocyanin content significantly increased under salicylic acid treatment. These findings highlight the role of salicylic acid in alleviating the negative effects of UV-B and enhancing the antioxidant defense system of licorice. https://jrpsm.asnrukh.ac.ir/article_242983.html Indigofera tinctoria L. is one of the most important medicinal-industrial plants, valued for its indigo carmine pigments and valuable phenolic compounds, which have extensive applications in the pharmaceutical and dyeing industries. As a natural source of plant-based dyes, it holds high economic value & exhibits moderate tolerance to environmental stresses such as drought and heat. This study was conducted in Shahid Bahonar Agricultural High School, Shushtar with the aim of evaluating the effects of planting date and plant density on photosynthetic traits and indigo carmine content of Indigo plant, using a split-plot design based on a randomized complete block design with three replications over two consecutive growing seasons (2022–2023). Treatments in the first year included six planting dates (April 29, May 19, June 8, June 28, July 17 and August 6) and four plant densities (30, 40, 50 and 60 plants per square meter). In the second year, two planting dates (July 17 and August 6) were excluded, and only four planting dates (April 29, May 19, June 8 and June 28) along with the same four plant densities were tested. Analysis of variance revealed that planting date, plant density, and their interaction significantly affected all qualitative traits at the 1% probability level. Mean comparison results showed that early planting in spring (April 29) yielded the highest values for chlorophyll a, chlorophyll b and total chlorophyll (1.82, 0.73 and 2.55 mg/g, respectively), as well as indigo carmine content (5.91 g/m²). Delaying planting, especially during the hotter months, significantly reduced all qualitative traits. A plant density of 40 plants per square meter was identified as the optimal level, at which the highest photosynthetic indices and indigocarmine content were observed. A significant positive correlation between chlorophyll content and indigocarmine concentration indicated a direct relationship between photosynthetic activity and secondary metabolite production in this plant. Overall, early planting in April and a plant density of 40 plants/m² are recommended as the best treatments for maximizing both the quality and quantity of indigo carmine in the indigo plant.