مجله تحقیقات گیاهان دارویی و معطر ایران
سال چهل و یکم شماره 3 (پیاپی 125، پاییز 1404)

Due to the scorching desert environment and frequent severe droughts, residents of the rural districts of Zabol County have suffered significant losses to their livelihoods in recent years. As a result, identifying climate-resilient income sources and strategies to improve the county's economic prospects has become crucial. The cultivation of medicinal plants, with their extensive value chain, income-generating potential, and resilience to environmental challenges, stands out as a highly promising livelihood option. It can play a pivotal role in creating employment opportunities and reducing poverty in rural areas. This study was conducted to assess the feasibility of cultivating selected medicinal plants in the rural areas of Zabol County. The statistical population consisted of 25 specialists, including researchers from the Agricultural and Natural Resources Research Center, staff from the Agricultural Jihad Organization in Zabol County, and medicinal plant experts from the private sector. Participants were selected purposefully. Data were collected through interviews and a researcher-designed questionnaire. The data analysis was conducted using the Analytic Hierarchy Process (AHP) method. Medicinal plants were selected based on a literature review and expert interviews. Ten species were identified as having the most extensive history of cultivation in the study area: Cuminum cyminum, Nigella sativa, Plantago psyllium, Trigonella foenum-graecum, Trachyspermum ammi, Hibiscus sabdariffa, Linum usitatissimum, Matricaria chamomilla, Cyamopsis tetragonoloba, and Rosa damascena. The average age of the experts surveyed was approximately 55 years, with a standard deviation of 10.9 years. Most of the participants held bachelor's or master's degrees in fields related to agriculture. Their average work experience in the agricultural sector was about 15 years, with a standard deviation of 8.6 years. All respondents had prior experience in medicinal plant activities, including production, research, or trade. According to the experts, the most important criteria for selecting medicinal plants for cultivation were: economic factors, technical and climatic features, infrastructural and technological aspects, policy and management, and knowledge and attitudes. Based on these criteria, Rosa damascena (3.32), Hibiscus sabdariffa (3.12), and Cuminum cyminum (3.05) were identified as the top three priority species for cultivation in Zabol County. The findings further revealed that among the various sub-criteria affecting the development of medicinal plant cultivation, the most critical were technical aspects and climatic conditions, infrastructure, and appropriate technology. Additionally, the sub-criteria of compatibility with the regional climate, marketability, and ease of harvesting, processing, and storage were identified as the top three factors requiring special attention. Climate change and its adverse effects, combined with limited economic opportunities in rural areas, pose significant challenges to the livelihoods of villagers. One strategy to address these issues is to identify income sources that are compatible with both the climatic conditions and the economic potential of rural communities. Expanding the cultivation of medicinal plants, given their high income-generating potential and notable adaptability to environmental stresses, can be an effective approach to creating employment opportunities, increasing income, reducing poverty, and preventing rural migration. However, not all medicinal plants are equally suitable for cultivation in every region. It is therefore essential to evaluate these species based on a range of characteristics before recommending them for cultivation, to ensure the success and long-term sustainability of their development.

 In recent years, the collection of medicinal plants from rangelands in the Saral region of Divandarreh County, Kurdistan Province, has become an increasingly important livelihood strategy for rural communities. Although this activity contributes to household income, there remains a limited and often unclear understanding of its actual impact on the livelihoods of beneficiary households, as well as the challenges they encounter. Therefore, the main objective of this study is to assess the extent of the activity’s impact on rural livelihoods and to identify the key challenges associated with medicinal plant collection in the region, to propose appropriate strategies for sustainable development in this sector. This research employed a survey-based approach, with the statistical population comprising all rural households in the Saral region of Divandarreh County, totaling 2,519 households. Using Cochran's formula, a sample of 206 household heads was selected through stratified random sampling with proportional allocation. Data was collected from these beneficiaries using structured questionnaires. The validity of the questionnaire was confirmed through expert review, while its reliability was assessed using Cronbach’s alpha coefficient. Coefficients exceeding the 0.70 threshold indicated that the measurement tools used for the study variables were sufficiently reliable. Descriptive data analysis was conducted using mean values and the coefficient of variation. Descriptive statistical findings showed that 70% of the beneficiaries had an average age of 35 years, and their average experience in harvesting medicinal plants from rangelands was 4.65 years. The most common sales method was cash transactions with intermediaries, accounting for 43.5% of the total sales. In terms of harvest frequency, the top three medicinal plants collected were Ferula spp. (Kama), Thymus spp. (Avishan), and Mentha pulegium (Pooneh), while Achillea millefolium (Gole Maraneh), Hypericum perforatum (Alaf Chy) and Salvia officinalis (Maryam Gloe) were among the least harvested. Regarding income-generating potential (measured in thousand rials per liter or kilogram of product), Descurainia Sophia (1,097.60), Thymus spp. (794.89), and Mentha pulegium (506.99) had the highest average values, whereas Cichorium intybus (240.93), Achillea millefolium (214.19), and Salvia officinalis (117.53) had the lowest. The prioritization of challenges related to medicinal plant collection in the Saral region identified the following as the most pressing issues: (1) economic and livelihood pressures leading to overharvesting, (2) the risk of extinction of certain medicinal plant species due to excessive harvesting, and (3) reliance on local community motivation to prevent harvesting by non-local individuals. Moreover, beneficiaries' prioritization of strategies to enhance rural livelihoods, through sustainable medicinal plant collection, highlighted three key approaches: (1) developing grassroots organizations such as cooperatives and NGOs; (2) expanding public education on the importance of conserving natural resources as national and communal assets during collection; and (3) delegating oversight of medicinal plant collection to local communities to enable structured and limited resource management. Based on the findings, it can be concluded that the springtime collection of medicinal plants in the Saral region has a limited positive impact on household livelihoods. The absence of proper training and awareness regarding sustainable harvesting methods, combined with the issue of overharvesting, has resulted in negative consequences that outweigh the potential benefits. The analysis of livelihood improvement strategies revealed that the most critical approaches include the development of cooperatives and NGOs, the expansion of public education focused on protecting natural resources, and the delegation of oversight for medicinal plant collection to local communities. These strategies are essential for enhancing the sustainability of medicinal plant harvesting and improving rural livelihoods in the region.

In contemporary times, the importance of medicinal plants and their identification in advancing national, regional, and global objectives, such as achieving health, pharmaceutical self-sufficiency, fostering employment, and promoting economic development, is indisputable. Mentha suaveolens × Mentha piperita, commonly referred to as grapefruit mint, is recognized as a valuable medicinal plant within the Lamiaceae family. Drought stands out as a major limiting factor for global plant growth, constituting the most prevalent environmental stressor that disrupts the balance between reactive oxygen species and antioxidant defense mechanisms, thereby inducing oxidative stress. Nanotechnology emerges as a modern approach with notable potential to enhance plant resilience against drought stress. Among various nanomaterials, carbon quantum dots, discovered in 2004, possess distinctive characteristics, including dimensions below 10 nanometers, reduced toxicity, and superior biocompatibility compared to metal-based alternatives, owing to their carbonaceous structure. Due to these unique attributes, carbon quantum dots have attracted significant research interest in recent years. Therefore, this study aimed to evaluate the effects of carbon quantum dots on the growth, yield, and essential oil composition of grapefruit mint (Mentha suaveolens × piperita) under drought stress conditions.

This research was conducted as a factorial experiment in a completely randomized design with four replications in pots during the spring and summer of 2023 at the research greenhouse of Maragheh University, East Azerbaijan, Iran. The first factor was irrigation at 90% of field capacity (FC) as control (normal irrigation), irrigation at 70% FC (moderate stress), and irrigation at 50% FC (severe stress). The second factor consisted of different levels of carbon quantum dots (0, 5, 10, 15, and 20 parts per million). Data collected from sampling were analyzed using SAS statistical software, and means were compared using the least significant difference (LSD) test at the 5% level.

Analysis of variance indicated that the effects of different irrigation regimes, fertilizer treatments, and their interaction on all measured traits were significant. The findings revealed that the application of 15 ppm carbon quantum dots under normal irrigation increased fresh weight, dry weight, chlorophyll a, and chlorophyll b contents by 110%, 86%, 184%, and 163%, respectively, compared to no CQD application under severe drought stress. Under moderate stress, the use of 15 ppm carbon quantum dots increased essential oil content by 135% and essential oil yield by 298% compared to severe stress without CQD. Furthermore, the highest linalyl acetate content was obtained with 15 ppm carbon quantum dots under 50% FC, showing a 50.1% increase compared to the control treatment. Similarly, the highest linalool content was recorded under normal irrigation with 10 ppm carbon quantum dots, representing a 67.4% increase compared to no CQD application under 50% FC. Moreover, under normal irrigation, 15 ppm carbon quantum dots reduced malondialdehyde and hydrogen peroxide contents by 51% and 58%, respectively, compared to no CQD application under severe stress. Additionally, under mild stress, 15 ppm carbon quantum dots enhanced the activity of superoxide dismutase, guaiacol peroxidase, and ascorbate peroxidase enzymes by 123%, 111%, and 72%, respectively, compared to no fertilizer application under normal conditions.

The results indicate that applying 15 ppm carbon quantum dots can promote growth by modulating secondary metabolites and strengthening defense mechanisms through the activation of antioxidant enzymes and increasing the accumulation of osmolytes such as proline and total soluble sugars, thereby reducing malondialdehyde and hydrogen peroxide levels. This enhancement in grapefruit mint plants contributes to improved drought resilience, ultimately enhancing both the quantity and quality of the essential oil.

Marigold (Calendula officinalis L.) is a medicinal and ornamental herbaceous plant belonging to the Asteraceae family. Since ancient times, it has been valued for its leaves, roots, flowers, and seeds, owing to the presence of bioactive compounds such as flavonoids, carotenoids, steroids, terpenoids, phenolic acids, mucilages, and vitamin E. Salinity stress is among the most critical factors limiting plant production, particularly in arid and semi-arid regions. The present study aimed to evaluate the effect of foliar application of salicylic acid on the growth characteristics and photosynthetic pigment content of marigold under saline conditions.
This experiment was conducted as a factorial arrangement within a completely randomized design, with three replications, in pots at the research greenhouse of the University of Agricultural Sciences and Natural Resources, Sari. The treatments included salinity (sodium chloride) at five levels (0, 50, 100, 150, and 200 millimolar) as the first factor, and foliar application of salicylic acid at three levels (0, 1, and 2 millimolar) as the second factor. Planting was carried out on December 1, 2013, in pots measuring 25 cm × 25 cm, each containing four plants and irrigated with 200 milliliters every two days. Distilled water was used for the zero-millimolar treatment. Salinity stress was initiated at the four-leaf stage. Foliar application of salicylic acid was performed twice during the four-leaf stage. To facilitate acclimatization, the pots were placed outdoors before the experiment. Harvesting was conducted on February 28 at the full flowering stage. After harvest, measurements included plant height, the number of flowers, the dry weight of flowers, the dry weight of aerial parts, photosynthetic pigments, the relative water content of leaves, and electrolyte leakage. Data analysis was performed using SAS software.
The results indicated that foliar application of salicylic acid significantly improved plant height, dry weight of shoots, number of flowers, dry weight of flowers, chlorophyll a and b content, carotenoid levels, relative leaf water content, and electrolyte leakage. The highest values for these traits (excluding electrolyte leakage) were obtained with one mM salicylic acid treatment under control (0 mM) salinity. The lowest values were recorded in 0 mM salicylic acid and 200 mM salinity treatment, showing reductions of 193.3% in plant height, 70.8% in shoot dry weight, 332% in number of flowers, 430% in flower dry weight, 186.7% in chlorophyll a, 216.7% in chlorophyll b, 185.7% in carotenoids, and 215.9% in relative leaf water content compared to 1 mM salicylic acid treatment at zero salinity. The lowest electrolyte leakage occurred in treatments with 1 and 2 mM salicylic acid and irrigation with distilled water, representing a 481.5% reduction compared with the non-sprayed treatment at 200 mM salinity.
In general, foliar application of salicylic acid partially alleviated the adverse effects of salinity and had a significant positive influence on the evaluated traits up to a salinity level of 100 mM. Among the salicylic acid treatments, the one mM concentration exerted the highest effect in reducing stress impact, producing the highest values for the measured traits.

Anthraquinones are secondary plant metabolites that play a significant role in the treatment of certain diseases, such as hepatitis and cancer. Anthraquinones are utilized not only in textiles and food production but also in the cosmetics, perfume, and pharmaceutical industries due to their high antioxidant levels. In vitro culture of plants has provided a suitable alternative method for producing medicinal compounds under controlled conditions, not affected by environmental factors. The hairy root culture system, based on inoculation with Agrobacterium rhizogenes, has become an influential approach for producing secondary metabolites in plant roots, such as ginseng, over the last two decades. One of the advantages of in vitro production of these compounds is the possibility of increasing their yield through the use of influential nutrient elements, as well as inducing the production process and biosynthesis of secondary substances with various biological and non-biological elicitors. The objective of this research was to investigate the effect of salt concentration in the culture medium and sucrose levels on increasing hairy root biomass, and to examine the influence of different abiotic elicitors on enhancing anthraquinone production in madder hairy roots. For this purpose, in the first experiment, after inducing hairy roots, the effect of sucrose concentration (30, 45, and 60 g/L) in combination with basal medium salt strength (1/2 MS and MS) on root biomass enhancement was studied in a factorial experiment with a completely randomized design and four replications. In the second experiment, the effects of different elicitors, including titanium dioxide (50 and 100 mg/L), chitosan (100 and 150 mg/L), silver nitrate (50 and 100 mg/L), proline (250 and 500 mg/L), gibberellic acid (1 and 2 mg/L), and naphthalene acetic acid (1 and 2 mg/L), were investigated for their role in increasing anthraquinone (alizarin) production in hairy roots. In the first experiment, the 1/2 MS medium containing 45 g/L sucrose produced the highest biomass, followed by MS containing 45 and 60 g/L sucrose, MS with 30 g/L sucrose, and 1/2 MS containing 60 g/L sucrose. The best medium for biomass production from this experiment was selected for the subsequent experiment, in which the effect of different elicitor treatments for two days on the accumulation of the secondary metabolite (alizarin) was assessed. The results showed that the accumulation of the secondary metabolite in the medium containing 250 mg/L of proline exhibited a significant increase compared to other elicitors, followed by 50 mg/L of silver nitrate and 2 mg/L of gibberellic acid, respectively. The secondary metabolite content in media supplemented with two different levels of naphthalene acetic acid did not differ significantly from that of the control. Overall, this study demonstrated that the optimal root biomass production was achieved in 1/2 MS culture medium containing 45 g/L of sucrose, while the highest anthraquinone content was obtained in the presence of proline.

One of the most critical factors influencing the production of agricultural products is the proper nutrition of plants. In addition to its positive role in increasing quantitative yield, it also affects the quality of various products. Roselle (Hibiscus sabdariffa L.) is a medicinal plant and an annual, short-day, self-fertilizing species sensitive to cold and frost. More than 300 Roselle species exist worldwide; like other plants, their growth and yield, both quantitative and qualitative, can be influenced by genetic factors and environmental conditions. Moreover, due to the importance of the quality of extracted compounds in all types of medicinal plants, greater care is required when using chemical fertilizers. This study was conducted to develop a suitable integrated nutritional program using organic and biological fertilizers to replace chemical fertilizers in Roselle cultivation.

The field experiment was conducted using a randomized complete block design with three replications in Jiroft during the years 2021-2022 and 2022–2023. The experimental treatments included 14 nutritional sources: control (T1), inoculation with arbuscular mycorrhizal fungi (T2), application of Azospirillum (T3), simultaneous application of arbuscular mycorrhizal fungi + Azospirillum (T4), 100% recommended poultry manure (T5), 100% recommended chemical fertilizer (T6), 50% poultry manure + 50% recommended chemical fertilizer (T7), 50% poultry manure + arbuscular mycorrhizal fungi (T8), 50% poultry manure + Azospirillum (T9), 50% poultry manure + arbuscular mycorrhizal fungi + Azospirillum (T10), 50% chemical fertilizer + arbuscular mycorrhizal fungi (T11), 50% chemical fertilizer + Azospirillum (T12), 50% chemical fertilizer + arbuscular mycorrhizal fungi + Azospirillum (T13), and 25% poultry manure + 25% chemical fertilizer + arbuscular mycorrhizal fungi + Azospirillum (T14). Planting was done on June 12, and harvesting took place on December 1 in both years. Traits measured included wet and dry yield of Roselle sepals, anthocyanin content of sepals, and Hunter’s color indices (L*, a*, and b*). Additionally, to evaluate color quality and purity, three indices-hue angle (degrees), chroma, and redness—were assessed. Data analyses were performed using SAS v. 9.1, and means were compared with Duncan’s test.

The findings showed significant differences among fertilizer treatments for all traits. The highest Roselle sepal yield was obtained from 50% poultry manure + Azospirillum (T9) and 50% poultry manure + 50% chemical fertilizer (T7), with a 55% increase compared to the control (T1). The highest dry sepal yield was also observed in 50% poultry manure + 50% chemical fertilizer (T7), with no significant difference from 50% poultry manure + Azospirillum (T9). The highest anthocyanin content, with increases of 36.26% and 34.97% over the control, was recorded in poultry manure + arbuscular mycorrhizal fungi + Azospirillum (T10) and 50% poultry manure + Azospirillum (T9), respectively. These two treatments also produced the maximum red-green color index values (25.292 and 24.960), color saturation (39.980 and 39.403), and redness (10.769 and 10.282), respectively.

The results indicate that combined nutritional treatments containing poultry manure and biofertilizers can enhance both the quality and quantity of Roselle sepal yield. Sepals from these treatments exhibited the highest values for the measured quantitative traits. In color attributes, the highest values were also obtained from poultry manure and biofertilizer combinations. Therefore, integrated nutritional treatments involving these fertilizers appear to be a suitable alternative for reducing chemical fertilizer use while improving both the quantitative and qualitative yield of Roselle

The cultivation of medicinal plants, including savory (Satureja), is increasing worldwide. Savory, containing thymol and carvacrol in its essential oil, holds significant importance. This study aims to investigate the effects of planting density and soil fertility on the physiological traits and antioxidant enzyme activities of savory under rainfed conditions. Considering the importance of these factors in enhancing plant resistance to stress, this research was conducted to determine the optimal planting density and soil fertility for boosting antioxidant activities and promoting the sustainable development of savory. This study was conducted as a field experiment at the Hamand Absard Research Station in Damavand during the 2017–2018 and 2018–2019 growing seasons. The experiment was arranged in a split-plot design within a randomized complete block design (RCBD) with two factors. The main factor consisted of three fertilizer levels: (1) control (no fertilizer), (2) decomposed cattle manure (30 tons per hectare), and (3) straw enriched with ammonium sulfate (10 tons per hectare). The sub-factor included three planting densities: 2.67, 4, and 8 plants per square meter. Planting was performed using standard savory seeds. Land preparation involved plowing, disking, and leveling. Fertilizers were applied according to the treatments before planting. Irrigation was limited to rainfed conditions only. Leaf samples were collected at the full flowering stage. The measured physiological traits included relative leaf water content, total chlorophyll, proline content, electrolyte leakage, ion leakage, malondialdehyde content, and antioxidant enzyme activities (catalase, peroxidase, and superoxide dismutase). Samples were analyzed in the laboratory after harvest to evaluate the effects of treatments on the studied parameters. Data was analyzed using SAS software, and mean comparisons were performed using Duncan’s multiple range test at a 5% significance level. This study demonstrated that planting density and organic fertilizer treatments significantly influenced the physiological traits and antioxidant defense responses of Satureja spicigera under rainfed conditions. The highest relative water content (87.67%) and the lowest electrolyte leakage (47.19%) were recorded in the treatment with cow manure and a low planting density of 2.67 plants per square meter, indicating improved water status and membrane stability. In contrast, increasing planting density reduced chlorophyll content and relative water content, while levels of proline, electrolyte leakage (ELI), and malondialdehyde (MDA) increased, reflecting greater stress intensity under high-density conditions. The application of cow manure and ammonium sulfate-enriched straw improved physiological performance and significantly reduced oxidative stress markers. These treatments promoted better osmotic regulation and membrane protection, contributing to greater stress tolerance. Interestingly, the highest activities of antioxidant enzymes, catalase, peroxidase, and superoxide dismutase were observed in the unfertilized control under high-density planting. This suggests that the plant naturally boosts its enzymatic antioxidant defenses under more stressful conditions, particularly when nutrients are limited. In conclusion, the results highlight that integrating organic fertilization with optimal planting density can enhance drought resilience by maintaining physiological stability and reducing oxidative damage. These practices not only support the sustainable cultivation of Satureja spicigera in water-limited environments but also improve the plant’s overall functional and medicinal quality. The results of this study show that savory (Satureja spicigera) has a good ability to grow and develop under rainfed conditions and demonstrates significant capacity to enhance its antioxidant activity. The combined use of organic fertilizers, especially cow manure, along with an appropriate planting density, is practical in improving physiological traits, increasing resistance to environmental stresses, and strengthening the plant’s enzymatic defense system. Implementing these findings can be valuable in enhancing productivity, ecological sustainability, and food security in areas with limited water resources.

Viola odorata L. and Hymenocrater longiflorus Benth., two wild medicinal plants from the Kosalan region of Kurdistan Province, are recognized for their promising health-related effects. Viola is the largest genus in the Violaceae family, with 30 out of its 525-600 species identified in Iran. V. odorata (sweet violet) is widely used in the perfume industry and contains secondary metabolites with anti-inflammatory, sedative, detoxifying, and antiviral properties. Its various plant parts are known for medicinal uses, and local ecotypes have been documented. Hymenocrater, from the Lamiaceae family, includes 24 species found in Iran and neighboring countries; nine are reported in Iran, and H. longiflorus has ornamental and medicinal properties. Located in northwestern Iran, including Kosalan, H. longiflorus has no dedicated medicinal studies, although the genus exhibits sedative, anti-inflammatory, antispasmodic, and antipyretic activities. Both families are valued for their high antioxidant and phenolic content, driving pharmaceutical interest. This study focuses on assessing the antioxidant capacity, phenolic and flavonoid composition, and antibacterial properties of flower and leaf methanolic extracts from both plants, to highlight their medicinal potential.
Plant samples were collected from the Kosalan region, and herbarium samples were prepared. Extraction from the aerial parts (flowers and leaves) was performed using methanol as a solvent. Antioxidant capacity was measured using the Ferric Reducing Antioxidant Power (FRAP) method and DPPH radical activity at different extract concentrations. Additionally, phenolic content was measured using the Folin-Ciocalteu method, and flavonoid content was assessed using the aluminum chloride colorimetric method. The antibacterial properties of the samples were evaluated using disk diffusion and tube dilution methods against Gram-positive and Gram-negative bacterial strains.
According to the results, the flowers of H. longiflorus exhibited the highest reducing power and free radical inhibition (IC50 = 851.4 µg.ml-1) compared to the standard Trolox (IC50 = 612.35 µg.ml-1). The leaves of V. odorata contained the highest amount of flavonoids, with 58.21 mg of quercetin per gram of dry extract, while the flowers of this species had the lowest amount of flavonoids (3.37 mg QE/Ex). The phenolic content of the samples ranged from 30 to 33 mg of gallic acid per gram of extract. Antimicrobial tests indicated that the flower extract of V. odorata had no effect on the proliferation of the strains, but its leaves created a 7 mm zone of inhibition at a concentration of 200 µg/mL against E. coli. The leaves of H. longiflorus exhibited a significant inhibitory effect only on S. aureus, while its flowers demonstrated inhibition against S. aureus at all concentrations tested (18 mm). This species also inhibited the growth of E. coli at a concentration of 200 µg.ml-1 (13 mm). Results from the tube dilution tests indicated a MIC of 25 µg.ml-1 and MBC of 50 µg.ml-1 for the flowers and leaves of H. longiflorus against S. aureus, and a MIC of 200 µg.ml-1 for E. coli. The flower extract of V. odorata was ineffective against both strains, while its leaf extract confirmed a MIC of 200 µg/ml. The results of this test were consistent with the antibiogram test. GC analysis confirmed the presence of terpenoids, sesquiterpenoids, alkaloids, sugars, and esters in these species, suggesting potential antidiabetic and anticancer properties.
This study concludes that the flower methanolic extract of H. longiflorous has significant antioxidant and antimicrobial activities. These findings highlight the potential of this species as a source of natural antioxidants and antimicrobial agents, which could be utilized in food preservation, pharmaceuticals, and natural product-based industries. Further research is required to isolate and identify the specific bioactive compounds responsible for these effects.

Medicinal plant Plantago ovata is effective in treating gastrointestinal disorders and improving intestinal function due to its bioactive compounds, such as mucilage. Given the importance of psyllium as a valuable medicinal plant and the water resource limitations in many regions, this study aimed to investigate the effect of sowing date on the growth and yield characteristics of psyllium under different irrigation regimes in the climatic conditions of Rafsanjan, Iran. This experiment was conducted during the 2022–2023 growing season in Rafsanjan, Iran, at a farm located at 30°24′N latitude, 55°59′E longitude, with an elevation of 1467 meters above sea level. The area has an annual average rainfall of 120 mm and maximum and minimum temperatures of 43°C and -5°C, respectively. The experiment was laid out in a strip-plot design based on a randomized complete block design (RCBD) with three replications. Irrigation treatments, applied in the horizontal strips, included four levels: 40%, 60%, 80%, and 100% of the crop water requirement. Sowing dates (March 10, 2023, March 25, 2023, April 10, 2023, and April 25, 2023) were assigned to vertical strips. Irrigation treatments were initiated after complete seedling establishment (3–4 leaf stage) and continued until physiological maturity. The irrigation water requirement was calculated using AGWAT software, with water volumes of 1430, 1144, 858, and 572 cubic meters per irrigation for 100%, 80%, 60%, and 40% water requirement levels, respectively. Data analysis was performed using SAS 9.4 software, and means were compared using Duncan's test at the 5% probability level. The results showed that the highest plant height (24.1 cm), number of tillers (6), spike length (14.3 cm), and number of spikes per plant (27.7) were achieved under the 100% water requirement treatment and the March 25 sowing date. Additionally, the highest number of seeds per plant (1245), seed yield (1876 kg. ha-1), and biological yield (5357 kg. ha-1) were observed under the same treatment. The highest harvest index (35.9%) was recorded with the 100% irrigation treatment and the March 10 sowing date. Furthermore, the maximum thousand-seed weight was obtained under the 80% water requirement (1.94 g) and the March 25 sowing date (1.88 g). Moreover, the highest mucilage content was reported under the 100% water requirement (23.9%) and the March 10 sowing date (22.4%). Overall, the findings demonstrated that sowing date and irrigation level significantly affect the growth and yield characteristics of psyllium. Delayed sowing and reduced irrigation levels led to significant declines in plant height, yield components, seed yield, biological yield, and harvest index. Therefore, selecting an optimal sowing date and ensuring adequate water supply can improve the performance of this medicinal plant.

Nepeta binaludensis Jamzad is a rare, aromatic, and endemic species known for its antibacterial activity, attributed to its phenolic and flavonoid content. Given the rising issue of antibiotic resistance, exploring innovative therapeutic approaches, such as utilizing plant-derived components in conjunction with nanoparticles, is essential. These methods enhance plants' antibacterial properties while reducing the quantity of these valuable resources needed, thereby contributing to their conservation. The current study investigated the antimicrobial properties of a silver nanoemulsion derived from Nepeta binaludensis extract. It also investigated its effect on the expression of the toxA gene, which is involved in Toxin A secretion, and the algD gene, which plays a role in biofilm formation, in Pseudomonas aeruginosa. The Nepeta binaludensis flowering aerial parts were collected from Binaloud Mts in the northeast of Razavi Khorasan Province at an altitude of 2517 m. The ethanolic extract of the species was obtained from 40 g of the plant-dried powder using the maceration method. The extract's flavonoid and phenolic content were measured using an HPLC apparatus. This study used a silver nanoemulsion-loaded plant extract that was previously prepared by the high-energy method. The synthesis accuracy of the nanoemulsion was evaluated using FTIR, SEM, DLS, Zeta potential, and XRD techniques. The antibacterial effects of varying concentrations of silver nanoparticles, crude extract, and silver nanoemulsion were assessed against the standard bacterial strain Pseudomonas aeruginosa using the Kirby-Bauer disk diffusion test and the microdilution plate technique. RNA extraction from the bacteria was performed utilizing treatments that included the minimum inhibitory concentration (MIC) and sub-minimum inhibitory concentration (subMIC) of silver nanoparticles, the crude extract, and the silver nanoemulsion containing the extract. Following cDNA synthesis, the expression changes of the toxA and algD genes were analyzed using Real-time PCR. The outcomes of the Real-time PCR were assessed with REST software. The results were analyzed using one-way ANOVA with Microsoft Excel 2016 and GraphPad Prism 9.5.1, with a P value of less than 0.05. The HPLC analysis of the extract composition indicated that the plant extract did not contain gallic acid, catechin, rutin, or quercetin. Among the phenolic constituents, including chlorogenic acid, caffeic acid, salicylic acid, and rosmarinic acid, rosmarinic acid exhibited the highest abundance, measuring 20.82 mg/g. The evaluation of the synthesized nanoemulsion confirmed that the particles are spherical with a diameter of 270 nm. The surface charge is negative, and the particles are non-crystalline, and the presence of water and ester bonds has been detected. The Kirby-Bauer disk diffusion test results indicated that the smallest inhibition zone (12 mm) was associated with silver nanoparticle treatment. Conversely, the largest inhibition zone (21 mm) was observed with the treatment involving silver nanoemulsion of the extract, which was approximately equivalent to the inhibition zone induced by the antibiotic ceftazidime (CAZ, 30µg). The minimum values for MBC, MIC, and Sub MIC were 80, 40, and 20 µg/ml, respectively, corresponding to the silver nanoemulsion containing the extract. The algD gene expression level decreased by a factor of 0.87 when treated with silver nanoemulsion of the extract (40µg/ml), compared to the control group (P < 0.01). The toxA gene expression level was reduced by a factor of 0.78 following treatment with the silver nanoemulsion of the extract (P < 0.05). The changes in gene expression induced by varying concentrations of plant crude extract and silver nanoparticles did not show a significant difference when compared to the control group. The nanoemulsion of the plant extract exhibits a greater growth inhibitory effect and enhanced bactericidal activity. Given that the algD gene plays a crucial role in biofilm formation and the toxA gene is responsible for the secretion of the endotoxin A, it appears that the silver nanoemulsion may effectively inhibit growth by influencing the expression of genes in Pseudomonas aeruginosa. The reduction in droplet size within the nanoemulsion enhances the concentration of bioactive compounds and antibacterial properties compared to the crude extract. Consequently, this makes it suitable for applications in the pharmaceutical and food industries.

Auxin and nano-humic acid are among the vital compounds for improving the growth and performance of plants, especially medicinal plants. Auxins are plant hormones that play a role in plant growth and development processes, including rooting, stem elongation, and regulating responses to environmental conditions. These hormones help regulate hormonal balance in plants and can help increase the quality and quantity of plant products. Nano-humic acid is also an organic compound that is obtained from the decomposition of organic matter in the soil and, due to its nano-sized dimensions, has better absorption capacity in plants. This compound helps improve soil properties, increase water retention capacity, facilitate nutrient absorption, and strengthen the plant's defense system. The use of nano-humic acid in combination with auxin can have positive effects on the growth and quality of medicinal plants, including increasing the content of active pharmaceutical ingredients. Therefore, this study investigated the effect of auxin hormone and nano-humic acid on the physiological and morphological characteristics of the medicinal plant Valerian. The treatments included different concentrations of auxin (0, 15, 30, and 45 ppm) and different concentrations of nano-humic acid (2, 4, and 6 g/l). Both treatments were applied as a foliar spray. This study was conducted in two years as a split-plot in a randomized block design. The dry weight of roots and shoots, and the content of auxin, cytokinin, and carbohydrates in roots and shoots were measured. In this study, the effect of auxin hormone and nano-humic acid on the physiological and morphological characteristics of the medicinal plant Valerian was investigated. The results showed that the application of auxin at concentrations of 30 and 45 ppm significantly increased the dry weight of leaves, so that in the first year, foliar spraying of auxin at a concentration of 30 ppm increased the dry weight of leaves by 15.1%, and in the second year, this increase reached 40%. Furthermore, in nano-humic acid treatments, foliar spraying at a concentration of 6 g/L significantly increased the dry weight of leaves, and it increased by 12.8% compared to not using nano-humic acid. The effect of auxin hormone also increased the chlorophyll content index, so that in the treatment with a concentration of 30 ppm, this index increased by 13.9%. In addition, the use of nano-humic acid at a concentration of 6 g/L also increased the chlorophyll index of leaves by 8%. Regarding root growth, the application of auxin, especially at concentrations of 30 and 45 ppm, increased the dry weight of roots by 33 to 39%, and nano-humic acid at a concentration of 6 g/L increased the dry weight of roots by 19.1%. Moreover, both auxin and nano-humic acid treatments increased the content of soluble sugars in leaves and roots, by 21.7% in the case of nano-humic treatment and by 14.6% in the case of auxin treatment. In general, the results of this study showed that both auxin and nano-humic acid compounds, by affecting the hormonal and metabolic processes of the plant, can significantly enhance the growth and yield of medicinal plants such as valerian and increase the indices of chlorophyll, soluble sugars, and root growth. Both auxin and nano-humic acid treatments enhance leaf and root growth and increase the yield of the medicinal plant valerian by increasing photosynthetic capacity, cytokinin content, and plant source power.