فصلنامه فرآیند و کارکرد گیاهی
سال دهم شماره 4 (پیاپی 44، مهر و آبان 1400)

This study was conducted to investigate the combined and independent effects of drought stress and copper on vegetative traits (root length, stem length, fresh and dry weight of seedling), essential oil content and copper accumulation in roots, shoots and distilled plant material of Fumaria parviflora Lam. In this study, different concentrations of copper (control, 50, 150, 300 and 400 mg /kg) and different levels of drought stress (control, 50% and 75% based on soil moisture percentage discharge) on seeds collected from two mineral regions in Kerman province (Askari and Rabar) and in each region four zones (Z1, Z2, Z3 and Z4) were used. The results showed that in all treatments, the concentration of 50 (mg / kg) copper without drought stress (control) led to the highest value in terms of vegetative traits.The highest percentage of essential oil (0.45) in the treatment with concentration 150 (mg / kg) of copper and medium drought stress in zone 3 of Askari copper mine and the highest concentration of copper in roots, shoots and distilled plant material in treatment with 400(mg /kg) copper and severe drought stress in zone 3 of Askari mine were observed. In this study, the Cu remained in the plant tissue during the distillation process and the concentration of copper in the distilled plant material was almost similar to the concentration of plant shoots before the distillation process. The best treatment for f. parviflora cultivation in terms of plant essential oil, 150 (mg / kg) copper and medium drought stress was evaluatedthese findings support the use of F. parviflora as an acceptable species for soils that are in moderation contaminated with copper. behaviors such as slow growth and severe decline in biomass at high concentrations of Cu, it is concluded that the F. parviflora cannot be a candidate species for the phytoremediation of copper contaminated soil.

A pot experiment was conducted to evaluate the effects of inoculation with different mycorrhizal species (Funneliformis mosseae, Rhizophagus irregularis, Claroideoglomus. claroideum, Cl. etanicatum, Glomus fasciculatum, G. caledonium, G. versiform and G. geosporum) on the growth parameters of two sesame cultivars (Yekta and Nas takshakheh). In this experiment treatments were arranged as factorial based on a completely randomized design with three replications. Results showed that the the effects of the interaction between mycorrhizal species and cultivars were significant on colonization rate, the contents of  phosphorus, potassium, iron, zinc, chlorophyll, carotenoids and soluble carbohydrates and also on shoot dry weight. The highest colonization rates in both cultivars were obtained in the plants inoculated by Cl. claroideum. Mycorrhizal inoculation in most cases increased the concentrations of phosphorus, potassium, iron and zinc in the treated plants. Maximum increases in the contents of  phosphorus (72%), iron (126%) and Zinc (54%) were achieved in the plants of Yekta inoculated by G. fasciculatum, G.caledonium and G.geosporum, respectively, while the highest content of potassium (38%) was obtained in the plants of Nas takshakheh inoculated by G. fasciculatum, Cl.etanicatum and Funneliformis mosseae. Mycorrhizal inoculation, depending on the used cultivar and mycorrhizal species, increased or decreased shoot dry weight and the contents of chlorophyll, carotenoids and soluble carbohydrates. Shoot dry weight was increased by 20 and 23% in the plants of Yekta inoculated by Rhizophagus irregularis and Funneliformis mosseae and by 17 and 41% in the plants of Nas takshakheh inoculated by G. fasciculatum and Cl.clarodoium, respectively, and therefore, these four mycorrhizal species were recognized as the most compatible species with sesame plants.

The use of Abiotic elicitors is very important in biosynthetic pathways that lead to the formation and regulation of secondary metabolites. The aim of this study was to investigate the effect of Low temperature elicitors on the amount of hypericin, flavonoids, phenol, antioxidant capacity and dry weight of ).Seeds of Topaz cultivar, Pharmasat Germany, with 99% purity and 85% potency, were prepared for the ability to produce secondary metabolites. Seeds were grown in MS medium in sterile containers and stored in a growth chamber at 25±1 ° C with light rotation for 8 hours in the dark and 16 hours of light with fluorescent light. This study was performed as a factorial study in a completely randomized design with three replications and the effect of temperatures of 4, 8, 16 and 25 ° C for 24 hours, 72 hours and one week. The highest amount of hypericin at 4 ° C for one week and 72 hours with 0.59 and 0.55 μg / g dry matter, respectively, and the highest antioxidant capacity at 4 ° C for one week at 0.87% was observed. With increasing temperature to 16 degrees (for 24 hours) the lowest amount of hypericin and antioxidant capacity was observed. Applying a temperature of 4 degrees for a week increased the amount of flavonoids. The highest amount of phenol was obtained in the samples treated at 4 ° C for one week and 72 hours with the amount of 5.65 and 5.03 mg / g dry matter, respectively. Applying 4 ° C for one week had the greatest effect on the dry weight of the plant. Due to the increase in secondary metabolites of hypericin, phenol, flavonoids and antioxidant capacity of H. perforatum after application of 4 ° C treatment (for one week and 72 hours), the use of this elicitor to increase secondary metabolites of H. perforatum Recommended.

In the present study to investigate the effect of melatonin on morphological and physiological parameters of Agastache under different water-deficit stresses used factorial experiment in the form of Randomized Completely Block Design with three replications in the commercial greenhouse, Urmia in 2019. The first factor was the levels of water deficit stress (non-stress, water deficit stress with depletion 40% and 70% FC) and the second factor was the different concentrations of melatonin (0, 50, and 100 µM) on Agastache. Results indicated that Applying stress, especially moderate stress, increases plant pigments, proline content, total sugar, number and length of lateral branches , and ultimately increases the dry weight of shoot. Foliar application of various melatonin concentrations, especially 100 μM, caused an increase of 11.58% in carotenoids and 43.35% in shoot proline content, and a decrease of 29.23% H2O2 contents. Melatonin may have increased Agastache tolerance to water deficit stress by protecting against oxidative damage and scavenging free radicals through stimulating the enzymatic and non-enzymatic systems, resulting in increased growth and yield.

Water stress is one of the most important environmental stresses that reduces the growth and yield of crops. Organic fertilizers such as compost and mineral compounds such as zeolite can reduce the negative impact of water stress on plants. The aim of this study was to investigate the effect of irrigation levels (irrigation after depletion of 25, 50 and 75% of field capacity (FC)) and compost treatments (control, 4 ton ha-1, 8 ton ha-1, 4 ton ha-1 compost +10 ton ha-1zeolite and 8 ton ha-1 compost +10 ton ha-1 zeolite) on yield and some physiological traits of quinoa. This study was done in three replications and split plot experiment based on a randomized complete block design at the research farm of Azarbijan shahid Madany University in 2019. In this study, water stress reduced seed yield, minimum seed yield was obtained in irrigation after depleting 75% of FC (2024 kg ha-1), which was 29.8% less than the control. This reduction was partly due to a decrease in the 1000-seed weight. Among enriched compost with zeolite treatments, application of 8 ton ha-1compost, application of 4 ton ha-1compost + 10 ton ha-1 zeolite and application of 8 ton ha-1 compost + 10 ton ha-1 zeolite had a significant effect and increased this trait by 28.9, 36.2 and 32.9%, respectively. Enriched compost with zeolite increased grain yield by increasing the number and weight of seeds. Due to the economic importance of grain yield and quality characteristics and overall plant growth, application of 4 ton ha-1compost + 10 ton ha-1 zeolite can optimally increase grain yield in both low water and full irrigation conditions.

Salinity stress can affect the growth and composition of secondary metabolites in medicinal plants. Salvia is an important medicinal and economic plant in the world. Different species of Salvia are grown in Iran. In the present study, a factorial experiment was conducted in a completely randomized design with ten replications. The effects of different salinity concentrations including 0, 50, 100 and 150 mM sodium chloride on the performance of the photosynthetic electron transport chain in two sensitive and resistant species of salvia were investigated by JIP-test method. The results of this study showed that with increasing salinity concentration, the activity of oxygen evolving complex (Fv / Fo) decreased in both species, but this decrease was more in susceptible species (Salvia officinallis) than resistant species. Salinity also reduced electron transfer to electron acceptors (φPo, ψo and φEo), electron transfer to photosystem I (φRo), active reaction centers (RC/CS), and performance index for transfer of electrons from photosystem II to I (PI total) decreased with increasing salinity concentration. The results of this study also showed that the negative effects of salinity stress on these parameters in the susceptible species (Salvia officinalis) were more than the resistant species (Salvia verticillata).

Common boxwood (Buxus sempervirens auct non L.) is a hard-rooted shrub with slow propagation rate. This plant species is in danger of extinction due to invasion of a type of fungus named Calonectria pseudonaviculata. The purpose of this research was investigation of the effect of different concentrations of BAP and NAA (0, 0.5, 1, 1.5 and 2 mg/L form each two) on micropropagation of B. sempervirens. Sterilization of explants of this species is very difficult. Combined application of disinfectants is proposed. Results of micropropagation showed that the largest number of shoots (6.60/plantlet) was obtained in apical buds expalnts treated with 1 mg l-1 BAP. Maximum number of node (5.50/plantlet) and number of leaf (8.10/plantlet) were obtained in media enriched with 1 mg l-1 BAP along with 0.5 and 2 mg l-1 NAA, respectively. The highest root length (10.15 cm/plantlet) was obtained in explants treated with 1 mg l-1 BAP along with 1 mg l-1 NAA. Also, the largest number of root (8.20/plantlet) was calculated in explants treated with 0.5 mg l-1 BAP together with 1 mg l-1 NAA. After propagation, plantlets were transferred to a bed containing peat and perlite with ratio of 1:1 for acclimatization. About 90% of them were recovered and survived. These survived plantlets were morphologically similar to the mother plants.

In this study, to investigate the effect of ploidy level changing on morphological and physiological traits and the amount of essential oil  of Lavandula stricta as a Iranian  native medicinal plant. In this experiment, gel containing colchicine at five concentrations (0, 0.05, 0.1, 0.2, and 0.4 %) and four times (8, 16, 24 and 48 h) in the final meristem in the four-leaf growth stage of the potted plant under greenhouse conditions. The results of flow cytometry showed that the genome size in all diploid and treated plants with colchicine were in the same range (0.55 and 0.57 pg, respectively), but, it was obtained 0.73 pg for treated plant with 0.4% colchicine in 48 hours and SEM images showed an increase in the density of glandular trichomes and stomata size in them. Also, the results showed that the concentration of colchicine and the time of treatment had no significant effect on chlorophyll and carotenoid, but increasing the concentration of colchicine and the application time increased the weight of 1000-seed, weight of seed with cover, peroxidase, polyphenol oxidase, catalase and percentage and yield of essential oil. According to the obtained results, it can be stated that the application of colchicine at 0.4% for 48 hours has the ability to increase ploidy level of Lavandula stricta plant and increase medicinal value of this plant.

Although phosphorus owns the lowest amount between essential elements in the plant, but due to its important role in the vital processes of the plant, its supply during the growing period of wheat is essential. This study was conducted to investigate the response of wheat to the use of phosphorus in different stages of its growth and in different conditions of water salinity in pots and in soilless culture system. This experiment were performed in the factorial experiment in a completely randomized design with three factors of irrigation water quality (2 and 8 dS / m), phosphorus concentration (30 and 45 mg/l) and the stage of growth of wheat that receives phosphorus (seedling stage, tillering stage, elongation stage of Stem, flowering and seed filling) and three replications. Plants were harvested at the end of the physiological maturation phase. Root and shoot dry weight, shoot phosphorus concentration, chlorophyll and catalase and peroxidase enzymes were measured. Increased salinity decreased 48% phosphorus concentration of shoots, 40% dry weight of roots and shoots and 100 and 50% increase of catalase and peroxidase, respectively. Increasing the concentration of phosphorus from 30 to 45 mg/l caused 10 and 36% increase in dry weight of roots and shoots, respectively. The highest amount of chlorophyll, root and shoot dry weight due to the use of phosphorus was observed in the stem elongation stage and the lowest values were related to the application of phosphorus in the seedling stage. Based on this research, it seems that fertilization is necessary during the wheat growth period, especially in the stage of elongation of the stem and flowering.

Identification of water deficit tolerance plants with a high economic efficiency can led to increase in production under rainfed conditions. Satureja is one of the most widely used medicinal plants belonged to Lamiaceae family which has high species diversity. In this research, dry matter yield, essential oil content and water deficit tolerance in some of Iranian native Satureja species including Satureja bachtiarica Bunge, Satureja sahendica Bornm., Satureja spicigera (K.Koch) Boiss., Satureja macrantha C.A. Mey. and Satureja mutica Fisch. & C.A.Mey. were evaluated under irrigated and rainfed conditions using stress tolerance indices as split plots based on RCB design in 2018, at Kurdistan Agricultural and Natural Resources Research and Education Center. Plants were harvested in flowering stage and essential oil was extracted using Clevenger apparatus for three hours. Results indicated that irrigation treatment had significant effect only on dry matter yield. Interaction effect of species and irrigation treatment was significant only on essential oil content, but both mentioned traits were affected by species type. The highest (2.12 %) and the lowest (0.48 %) essential oil content were belonged to S. mutica and S. macrantha species under rainfed condition, respectively. The highest (482.72 g) and the lowest (44.4 g) dry matter yield per plant were obtained from S. spicigera and S. sahendica species, respectively. Based on factor analysis and correlation results, MP, GMP, STI and HAM indices were considered the best indices for identification of tolerant species to rainfed condition and based on mentioned indices, S. spicigera was identified the most tolerable and suitable species for cultivating under rainfed condition of Kurdistan province.

This experiment was conducted to investigate the effect of drought stress and vermicompost biofertilizer on some morphological, physiological and biochemical characteristics of Thymus vulgaris in greenhouse of Khorramabad Agricultural and Natural Resources Research and Training Center in a completely randomized design with three replications. The pot experiment was performed. Factors included vermicompost fertilizer levels at 0, 30, 50 and 70% of pot volume and water stress including post-discharge irrigation (85 (control), 70 (moderate stress), and 55 (severe stress). The moisture content was the field capacity. The results showed that with increasing drought stress, the amount of photosynthetic pigments (chlorophyll a and chlorophyll b), antioxidant enzyme catalase, protein, secondary metabolites of alpha-terpinene, thymol and carvacrol and morphological traits of plant height, number of sub-branches, fresh weight and dry weight of plants decreased significantly, but drought stress of antioxidant enzymes and hydrogen peroxidase significantly increased the amount of unstructured soluble sugars and amino acid proline. Increased consumption of vermicompost significantly increased chlorophyll b, hydrogen peroxidase, alphaterpinene, thymol, carvacrol, essential oil percentage, plant height, number of sub-branches, fresh weight and dry weight of plant, but chlorophyll a and unstructured soluble sugars reduced. According to the results of this experiment, with increasing the severity of drought stress, despite the plant's antioxidant defense and osmotic regulation, the production of most secondary metabolites and the growth of the thyme stress-sensitive plant decreased significantly; However, consumption of vermicompost increased secondary metabolites, growth and fresh and dry weight of the plant.

To study the effects of differential habitat Masjed-Solieyman and Izeh (Khuzestan province) and phenological stages (vegetative, flowering and seeding stages) on essential oil components of shoot plant of Artemisia sp. belong to the Asteraceae family, this research was carried out in spring of 2020. The most essential oil compounds in three species were Alpha-pinene, Camphene, Sabinene, Limonene, Artemisia-ketone, Borneol, Caryophyllene, Germacrene-D and Beta-eudesmol. The highest content (2.57 %) of essential oil was obtained from Masjed-Solieyman and in flowering stage and smallest content (1.61 %) of essential oil was obtained from Izeh and in seeding stage. The most of compounds such as Alpha-pinene, Sabinene and Borneol as volatile components (monoterpene hydrocarbons) and Caryophyllene (sesquiterpene hydrocarbons) as an important constitute in pharmaceutical industry obtained from end of vegetative stage. In addition, the amounts of volatile components and monoterpene hydrocarbons such as Alpha-pinene and Limonene on essential oils decreased from Masjed-Solieyman (tropical) to Izeh (temperate), however the percentage of sesquiterpene hydrocarbons such as Caryophyllene in the oils increased. The results showed significant effects of phenological stages and habitats on essential oil content and composition in three species.

Hormonal changes of Aeluropus littoralis (Gouan) Parl. halophyte under none- stress, moderate and severe salinity stress condition (0, 250, and 600 mM NaCl, respectively) at four time-courses (3, 6, 12, 24 h) were studied. The results showed that the Abscisic acid (ABA) content increased after one day at all stress levels, however, Gibberellic acid (GA3) levels also significantly decreased under severe stress compared to mild stress. The level of Salicylic acid (SA) decreased slightly compared to the control at the beginning of mild stress condition, but in severe stress, this decrease was more noticeable. Jasmonic acid (JA) content was not different at the first of stress, but with increased stress time, its content increased and in severe stress, it was more than mild stress and in mild stress, it was more than the control. It seems that the plant needs at least 24 hours to respond to stress because in the first time (3 hours) the content of hormones changed compared to the control, which indicates the perception of stress, but in continues the levels of the hormone had limited changes, and within 24 hours, the plant produced a completely different response to its hormonal content than the control. In conclusion, the results of this study will be useful in providing a deeper understanding of the hormonal mechanism of salinity tolerance.

In the last two decades, soil contamination with heavy metals has increased in many agricultural areas. Therefore, in order to investigate the interaction of mycorrhiza and putrescine on physiological characteristics, lead content, and yield of Lallemantia iberica under lead (Pb) stress, a factorial experiment was conducted in a randomized complete block design in the Research Greenhouse of the Faculty of Agriculture, University of Zanjan in 2018. Experiment consisted of Pb in four levels (0, 300, 600, and 900 mg Pb/kg soil) from the source of Pb(NO3)2, mycorrhiza at three levels (no inoculation, Funneliformis mosseae, and Rhizophagus intraradices), and putrescine in three levels (0, 0.5, and 1 mM). The results showed that among the Pb levels, 900 mg/kg caused the greatest decrease in the greenness index, relative water content, height, plant dry weight, root length, and grain yield, and increased electrolyte leakage, plant Pb concentration, colonization, and proline content. At all Pb levels, both fungi, especially F. mosseae, increased greenness index, relative water content, height, plant dry weight, root length, and yield, and decreased plant Pb concentration. At all Pb levels, the concentration of 0.5 mM putrescine decreased electrolyte leakage and plant Pb concentration, and increased proline content, plant dry weight, yield, and colonization. In all traits, putrescine had a synergistic effect with F. mosseae, but only 0.5 mM putrescine had a synergistic effect with R. intraradices. In general, the interaction of 0.5 mM putrescine with F. mosseae had an additive effect on plant growth, especially under Pb stress conditions.

Due to the dry climate and water shortage in Iran, the use of substances that can increase the plant's tolerance to water stress is very important. In this study, the effects of exogenous application of salicylic acid (SA) and kaolin (KL) on drought stress tolerance of tomato plants was evaluated in field conditions. Experimental factors included foliar application (including control, 0.5 mM SA, 2.5% KL and simultaneous application of SA + KL) and irrigation intervals (at four levels of 2, 4, 6 and 8 days). The results showed that increasing the irrigation interval in tomato plant led to a decrease in growth and yield in this plant. As compared to the controls, irrigation intervals of 4, 6 and 8 days decreased total yield as much as 9, 11 and 21%, respectively. The relative water content, total chlorophyll, transpiration and photosynthesis decreased while malondialdehyde, proline, peroxidase and hydrogen peroxide increased with the increase of irrigation intervals. Both SA and KL were effective in reducing the adverse effects of drought stress on plant growth and productivity.  Application of SA and KL improved plant growth and yield by increasing chlorophyll, relative water content, peroxidase activity, photosynthesis rate and transpiration. The highest effect of foliar spraying was observed at irrigation intervals of 6 and 8 days. The results also showed that the simultaneous application of SA + KL did not have a synergistic effect on plant growth and productivity in comparison to their separate application. According to the obtained results, the use of KL or SA is recommended to reduce the effects of prolonged irrigation on the tomato plant.

In order to evaluation the effects of arbuscular mycorrhizal fungi (AMF) and harvesting time on the macro- and micronutrients and antioxidant enzymes activity of thyme (Thymus Vulgaris L.) in different irrigation levels, a field experiment study was carried out as Split plot in time and place with 12 treatments and three replications at the faculty of Agriculture, University of Maragheh, Iran, in 2019. The first factor was three irrigation levels included irrigation after depletion of 20% maximum allowable depletion (W20), depletion of 50% of maximum allowable depletion (W50) and depletion of 80% of maximum allowable depletion (W80) as severe stress. The sub factor was application and non-application of mycorrhiza and sub sub factor was harvesting time (first and second harvest). The results demonstrated that the highest and lowest content of N, P, K, Zn, Fe and Ca was observed in W20 and W80 irrigation levels, respectively. Also, with application of AMF, the content of N, P, K, Fe, Zn and Mn increased by 17.4, 24.7, 20.9, 20.6, 11.8 and 18.2% compared with untreated control. Among different irrigation levels, the highest content of Chlorophyll a (0.8 mg/g fresh weight), b (0.48 mg/g fresh weight) and total (1.28 mg/g fresh weight) was achieved in the non-stress conditions (W20). Also, the highest antioxidant enzymes activity such as superoxide dismutase, ascorbate peroxidase and guaiacol peroxidases was achieved in the moderate and severe water stress conditions with application of AMF. Generally, the results showed that application of AMF play a main role in improving plant nutrient absorption and increasing resistant to drought stress conditions.

Melatonin plays important and different roles in many aspects of plant growth and development. Recently it has been shown that melatonin has antioxidant properties and plays in processes of germination, maturation, senescence, cytoprotection, resistance to biotic and abiotic stress and etc. However, its role in post-harvest processes and water relations cut flowers has not yet been determined. In this study, the effects of different concentrations of melatonin on five levels (0, 50, 100, 250 and 500 µM) and three times (2, 4 and 6 hours) on the cut tuberose cv. Pearl were investigated as pulse treatments. cut flowers were then transferred to distilled water and evaluated daily for vase life and water relations. However, pulse treatments for 4 h with 250 µM melatonin solutions extended vase life and suppressed a reduction in fresh weight during the post-harvest period. The amounts of water uptake and water loss by the cut flowers decreased upon melatonin treatment. The results showed that melatonin treatment resulted in prolonged vase life, increasing the number of opened florets in the inflorescence, reducing water loss and maintaining the water balance in cut tuberose. Treatment of 250 µM melatonin resulted in a 1.5-fold increase in vase life of cut tuberose compared to control treatment. The highest water uptake and water loss were observed in control treatment and the lowest water uptake and water loss were observed in treatment with 500 µM melatonin. As the melatonin concentration increased, endogenous melatonin levels increased. Melatonin application caused a positive change in chlorophyll and carotenoid levels. The role of melatonin at high concentrations (500 µM) may be similar to the abscisic acid in stomata closure and reduced transpiration, or at concentrations of 100 and 250 µM melatonin, possibly maintaining cells membrane integrity, may cause turgidity of cells

In order to investigate the effect of biofertilizer on physiological characteristics and nutrient concentration in linseed under irrigation withholding at different growth stages, a farm experiment conducted as split plot base on randomized complete block design with three replication at research field of Yasouj University in 2017. Irrigation regimes (full irrigation, irrigation withholding at beginning of flowering until beginning of podding, irrigation withholding at beginning of podding to end of maturity) and bio-fertilizer application at four levels (mycorrhiza fungi, Phosphate Barvar2, mycorrhiza arbuscular fungi + Phosphate Barvar2 and non-application of bio-fertilizer) were considered as the main and the sub plots, respectively. The results showed that the highest concentration of phosphorus (8.27 g.kg-1) and potassium (4.20 g.kg-1) in the leaf was observed in the treatment of mycorrhiza bio-fertilizer. In both stages of flowering and seed filling, irrigation withholding compared to full irrigation increased the soluble sugars, malondialdehyde, but reduced the relative water content and soluble protein of leaf.  The highest leaf prolin cintent (11.63 µmol.g-1) was observed in both biofertilizer combination treatments in condition of Irrigation withholding at beginning of podding to end of maturity. Application of both type of biofertilizer increased soluble sugar concentration, soluble protein and reduced malondialdehyde levels. The highest grain yield was observed from application of mycorrhiza+ phosphate Barvar2.The results indicate that linseed is sensitive to drought stress in the encapsulation to ripening stage (58% reduction). This damage modified by application of biofertilizer trough improving the absorption of nutrients and changing the concentration of osmolites.

Increasing use of silver nanoparticles in agriculture and industry attracted more attention to the negative effects of their accumulation in environment. In this study, the effect of citric acid and hydrogen sulfide treatment on the morphological and physiological responses of green bean plants under silver nanoparticles stress was investigated. The results showed that nanosilver stress significantly reduced leaf area, plant height, leaf and pod dry weights and made a significant increase in total flavonoids and anthocyanins content and superoxide dismutase and glutathione-S transferase activities. Nanosilver stress increased malondialdehyde content and electrolyte leakage indicating a high oxidative and cell membrane damage, whereas these values ​​were lower in plants treated with citric acid and hydrogen sulfide. Furthermore, the highest growth indices were observed in control plants, plants treated with inducers and plants under stress, respectively, which indicates the effective role of inducers in stress relief. These results showed that citric acid and hydrogen sulfide mitigated the damage caused by nanosilver stress in green bean plants by reducing free oxygen species accumulation and preventing lipid peroxidation leading to increased growth rate in stressed plants. These findings can be used to reduce crop damages in regions contaminated with nanoparticles.

In order to investigate the effect of different carbon sources (ethanol and methanol) on some morphological and physiological characteristics of Melissa officianlis L., a pot experiment was conducted in factorial based on completely randomized design with three replications in the research greenhouse of Shahed University in 2018. Foliar treatments included different concentrations of 0, 15, 30 and 45% ethanol and methanol. The results showed that ethanol 15% had the most effect on leaf number per plant and total flavonoid. As ethanol concentration increased by 15%, the flavonoid content decreased, so that at 45% ethanol concentration, its inhibitory effects appeared. The highest plant height and protein percentage were obtained in 15% methanol and 45% ethanol treatments, respectively. The highest percentage and yield of essential oil were obtained from methanol treatment with 45%. The combined application of 15% ethanol and 45% methanol, produced the highest biological yield, chlorophyll a, chlorophyll b and total chlorophyll. Therefore, the use of alcoholic compounds such as methanol and ethanol is one of the appropriate strategies to improve the yield and quality of Melissa officianlis L.