جستجوی مقالات مرتبط با کلیدواژه « آنزیم های آنتی اکسیدانی » در نشریات گروه « زیست شناسی »

In order to investigate the effect of using salicylic acid, antifreeze and soybean oil, on the cold resistance of the flower of the sweet cherry tree cultivar "Siah Tak Daneh Mashhad", a factorial experiment in the form of a randomized complete block design with 3 factors (salicylic acid: zero, 1.5 and 3 mM), (natural antifreeze: zero, 2.5 and 5 per 1000) and (soybean oil: zero, 2.5 and 5 per 1000) and in 4 repetitions was conducted in a commercial garden located in Sarein city in 2018 and 2019. The results of the variance analysis of the data showed that the three-way effects of factors on proline are significant at the 5% probability level and on soluble carbohydrates and protein at the 1% probability level. The highest amount of proline (70.85% compared to the control) was observed in the treatment of salicylic acid foliar spraying 3 mM along with soybean oil (5/1000) and Thiofer antifreeze (5/1000 foliar treatment). The bilateral effects of salicylic acid and soybean oil on glycine betaine were different at the 1% probability level and on the activity of the catalase enzyme at the 5% probability level. The highest accumulation of glycine betaine (27.27% compared to the control) and also the highest activity of the antioxidant enzyme catalase (36.84% compared to the control) in salicylic acid (1.5 mM) foliar treatment with soybean oil (5 in 1000) were obtained. According to the observations of this research, it can be concluded that the use of salicylic acid foliar treatment (3 mM) along with soybean oil (5/1000) and 5/1000 foliar treatment of Thiofer natural antifreeze in flower buds. It is a suitable solution to increase the cold resistance indices of cherries against cold stress.

Japanese barberry or ornamental barberry (Berberis thunbergii) belongs to the Berberidaceae family. This family have several properties, including antioxidant, antimicrobial and anticancer activities. The healing properties of barberry have been known and studied for thousands of years. In order to study the changes in the physiological-biochemical characteristics of Japanese barberry under the influence of abiotic elicitors, an experiment was conducted in the form of a completely randomized design in the greenhouse and laboratory of the Faculty of Agriculture and Natural Resources of Imam Khomeini International University in 2018-2019. The treatments included methyl jasmonate elicitors, salicylic acid, titanium dioxide and no elicitor (control) in four replications. In this research, the amount of leaf photosynthetic pigments and antioxidant enzymes of leaf and root tissues of Japanese barberry plant were extracted and measured. The results showed that the effect of the experimental treatments on the amount of photosynthetic leaf pigments and antioxidant enzymes in the two studied tissues was significant at the 1% probability level. Comparison of the means showed that salicylic acid treatment increased the amount of chlorophyll a and total leaf chlorophyll compared to the control by 20.9% and 21.3%, respectively. Salicylic acid and methyl jasmonate increased 29.9 and 19.1 percent of carotenoid content in leaves, respectively, compared to the control. The highest protein content of the root was produced with the use of salicylic acid, which increased by 38.6% compared to the control. The activity of catalase enzyme in the root increased by salicylic acid and titanium dioxide elicitors by 76.8 and 52.2%, respectively, compared to the control. In leaves, salicylic acid and methyl jasmonate elicitors increased catalase enzyme activity by 104.1% and 57.1%, respectively. From this research, it was concluded that salicylic acid had the greatest effect in increasing the amount of pigments and the activity of antioxidant enzymes of the Japanese barberry plant, which can be used for medicinal products.

Salinity is one of the most important environmental stresses, the increasing spread of which reduces the growth and yield of agricultural plants, in this regard, identifying sugar beet cultivars tolerant to salinity stress to improve quantitative and qualitative yield is of particular importance. For this purpose, research was conducted to investigate the physiological characteristics of some sugar beet genotypes under salt stress in 2019. This experiment was carried out factorially in the form of randomized complete blocks with three replications in Mohaghegh Ardabili University under greenhouse conditions. The experimental factors included different genotypes of sugar beet (9 genotypes) as the first factor and salinity stress as the second factor at four levels (control and 4, 8 and 12 dS/m). The results showed that the effects of salinity stress on chlorophyll content, soluble protein, proline content, soluble sugars and the activity of antioxidant enzymes (catalase, peroxidase and polyphenol oxidase) of different sugar beet cultivars were significant. Higher levels of salinity stress (12 dS/m) caused a significant increase in soluble protein, proline content, soluble sugars and activity of catalase, peroxidase and polyphenol oxidase enzymes compared to other levels of salinity stress and the control treatment. Whereas, the highest content of chlorophyll a, b and total chlorophyll was observed in cultivars number 15 and 4 in the treatment of not applying salt stress. Among the studied genotypes, genotypes No. 6, 15 and 20 had the highest activity of antioxidant enzymes under the condition of 12 dS/m salinity stress. Therefore, at higher levels of salinity stress, resistant sugar beet cultivars prevent the reduction of photosynthetic pigment content by improving the content of compatible osmolytes and antioxidant activities through correct membrane structure.

In this research, the effect of foliar spraying of brassinosteroid (0, 0.077 and 0.384 mg/liter) on grain yield and some physiological characteristics of wheat (Sirvan cultivar) under drought stress conditions (100% control) and 50% F.C.) was investigated in a factorial arrangement based on a randomized complete design with four replications at the research greenhouse of the Agriculture faculty, Shahid Bahonar University of Kerman on 2016. The results showed that drought stress caused a significant reduction in the biomass, yield and yield components of wheat and the decrease of these traits compared to the control was 31.7%, 29.6% and 20.3% respectively. On the other hand, brassinosteroid foliar spraying caused a significant increment of biomass, yield and yield components by approximately 22.7%, 22.4% and 12.5%, respectively, compared to the plants which were treated with distilled water under stress conditions. Drought stress had a significant effect on increasing of antioxidant enzymes activity (peroxidase, ascorbate peroxidase, catalase and superoxide dismutase) and the concentration of malondialdehyde, hydrogen peroxide, as well as the accumulation of carbohydrates and proline in wheat leaves. Spraying of brassinosteroid in both stress and non-stress conditions increased the activity of antioxidant enzymes and osmolytes accumulation (protein, carbohydrate and proline) and conversely reduced the amount of hydrogen peroxide and malondialdehyde, and this effect was more noticeable under drought stress condition. It seems that the effect of brassinosteroid application on modulating drought stress and improving wheat yield can be related to enhancement of osmotic regulation (through the accumulation of osmolytes) and increasing the activity of the antioxidant defense system mechanism in wheat.

Henna plants (Lawsonia inermis) and copper sulfate (CuSO4.5H2O) are used for healing and repairing skin wounds due to their antibiotic and antifungal properties. For this purpose, 500 pieces of Siberian sturgeons with an average weight of 15±1.2g were used. First, the acute toxicity (LC50) and then the maximum permissible concentration (MAC) were determined. To experiment, five treatments with three replications were designed. In treatments 1 to 4, doses equal to henna MAC value and amounts equal to 25%, 50%, and 75% of MAC were used. In treatment 5, copper sulfate at the concentration of 0.07 mg/L was used to compare. Fish were affected by compounds with determined concentrations for 4 days (96 hours). The results showed that henna plant extract performed better than copper sulfate in indicators such as white blood cell count, stress reduction, and liver enzyme activity. Finally, the present study showed that henna plant extract performed better and can be used as a suitable substitute for copper sulfate for disinfection in Siberian sturgeon farms. Also, the results showed that henna plant extract has negative effects on the blood and biochemical indices of Siberian sturgeon.

Carbon tetrachloride (CCl4) is a common chemical solvent that causes oxidative stress and brain damage. Alpha-pinene with antioxidant properties plays an important role in reducing oxidative stress and improving inflammation. However, Alpha-pinene has low bioavailability due to low solubility. The purpose of this study is to investigate the protective effects of Alpha-pinene nanophytosome on brain damage caused by CCl4 in male rats.

Metods:

 In this research, 35 male Wistar rats were divided into five groups control, Alpha-pinene nanophytosome (50 mg/kg ) for 14 days, CCl4 (1 mg/kg) twice a week for 14 days and two CCl4 treated groups with Alpha-pinene and Alpha-pinene nanophytosome (50 mg/kg ) for 14 days. Finally, the levels of malondialdehyde (MDA) and glutathione (GSH) as well as the activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) enzymes were investigated.

Our results revealed that, the level of GSH (P<0.001) and the activity of antioxidant enzymes (P<0.01) in the brain of rats receiving CCl4 significantly decreased compared to the control group, while Alpha-pinene nanophytosome increased significantly. The level of MDA in the brain of rats receiving CCl4 increased significantly (P<0.001) compared to the control group, while Alphapinene nanophytosome significantly reduced MDA level. The findings of this research show that Alpha-pinene nanophytosome can protects the brain against oxidative stress and damage caused by CCl4.

Citrus sinensis cv Thomson Navel and Citrus limon cv Lisbon are known as relatively resistant and cold-sensitive garden products. Thus, in the present study attempts are made to investigate the vulnerability of Thomson oranges and Lisbon lemons to cold stress under controlled environmental conditions compared to treatment temperatures (4, -4 and -8 °C). This factorial experiment was conducted according to a completely randomized design. The ANOVA results showed that the temperature/cultivar interaction can significantly affect some traits such as lipid peroxidation, superoxide dismutase, ascorbate peroxidase, total flavonoids, ion leakage, chlorophyll a, carotenoids, total chlorophyll and LT50 (P> 0.001). However, the catalase/chlorophyll b interaction was found to be significant at p= 5%. The highest levels of ion leakage (59.65%), lipid peroxidation reaction (0.77 µg g−1 FW MDA) in lemon and catalase and superoxide dismutase (33.43 µmol•g−1 FW and 160.3.3 μmol g −1FW min respectively) in orange was recorded at -8 °C. In contrast, the highest levels of ascorbate peroxidase (39.7 µg g−1 FW) was recorded in lemon and total flavonoids (32.48 mg g−1 FW of catechin) was recorded in oranges at 4 °C. in the present study, different reactions were also observed at different temperatures. Oranges showed higher resistance to cold compared to lemons. As for the measured traits, however, oranges were mostly ranked higher than lemons. Exposure of genotypes to cold stress led to an increase in malondialdehyde.

Drought is one of the most threats in agricultural production worldwide, and climate change exacerbates this threat. Introducing drought tolerant cultivars and stocks is a fundamental solution. In order to evaluate the tolerance to drought of some economical rootstocks and varieties of Prunus spp., a factorial experiment was conducted in a completely randomized block design with three replications at the Horticultural Research Institute, Kamalshahr, Karaj, Iran, in 2021–2022. The first factor included vegetative rootstocks of Myrobalan C29, Penta, Tetra, St. Julien, Mariana 2624, GF677 and GN15, along with seed rootstocks of plum as a control; the second factor was varieties of Japanese plum (Simka and NO16), European plum (Zuchelo) and Greengag Prunus and the third factor was drought stress (with interruption of irrigation for 14 days) and control (without interruption of irrigation). Evaluated biochemical traits included the activity of the antioxidant enzymes catalase, peroxidase and polyphenol oxidase, proline content, soluble protein, total antioxidant, ionic leakage and relative water content. The results showed that the activity of antioxidant enzymes under drought stress conditions in Zuchelo on GN15 rootstock, were increased compared to the control. The highest proline content was observed in the NO16 variety and GF677 rootstock. According to the results, in terms of the studied traits, Zuchelo, NO16, GF677, and GN15 were introduced as drought tolerant varieties and rootstocks.

Due to the environmental effects of the widespread use of conventional chemical fertilizers, foliar application of nutrients can prevent an increase in chemical fertilizer use and pollution of surface and groundwater. Therefore, in the present study, the effect of foliar application of nano-chelate zinc (0, 1 and 1.5 g/l) under low fertigation conditions (90, 110 and 130 ml) on strawberry fruit C.V. Sabrina was performed in greenhouse conditions. The measured traits included antioxidant activity, vitamin C content, total phenol, flavonoids, anthocyanin content, antioxidant enzymes, and the content of iron and zinc elements. The results showed that the application of zinc chelate leads to increased yield, vitamin C, phenol and flavonoid content, and antioxidant capacity compared to control. The highest fruit yield (550.39 g) and iron element content (289.2 mg/kg DW) were observed in low fertigation of 130 ml and nano chelate zinc of 1.5 g/l, whereas the lowest yield (123.56 g) and iron element content (123.92 mg/kg DW) were obtained in low fertigation of 90 ml and nano chelate zinc at 0 g/l. Also, the highest activity of catalase enzyme (3.25 units/g FW) was obtained in 1.5 g/l of nano zinc chelate and low fertigation of 90 ml treatments. In general, it can be concluded that zinc chelate nano-fertilizer at a 1.5 g/l is suitable for improving the yield and quality of Sabrina cultivar strawberries under low fertigation conditions. Therefore, based on the results of this study, it is possible to suggest the use of a low fertigation treatment of 110 ml along with 1.5 g/L of zinc chelate nano to reduce the consumption of nutrient solution and water for strawberry hydroponic cultivation.

In view of limitation of water resources in Iran, screening drought-tolerant watermelon genotypes and evaluate their response to drought stress conditions has been a research priority in country. In order to study the physiologic an agronomic response of indigenous accessions of Aliabad, Sistani and Torbat to water stress, a field study was carried out as a randomized complete block design with split plot arrangement of treatments under three water regimes, 100, 70 and 40% of required water, representing non-stress, mild stress and severe stress treatments, respectively, at Jiroft region in the spring and summer of 2017 growing seasons. The highest fruit weight and yield were at 100 and 70% required water whereas the lowest was achieved at 40% treatment. There were no remarkable differences among accessions under non-stress and 70% required water treatments while Sistani accession showed a better physiological and agronomic yield in response to increase water stress level to 40% required water. The increase of water stress led to an increase of proline concentration and activity of antioxidant enzymes of superoxide dismutase and catalase in all accessions, as this increase was higher in Sistani in comparison to other accessions. Based on the results obtained from this research, it could be state that Sistani accession with maintaining its physiological and agronomic yield showed a better tolerant under adverse condition in compared to other accessions. The utilization of indigenous and tolerant watermelon genotypes in breeding programs and irrigation managements might help in overcoming water shortage.

In order to investigate the effect of humic acid on the physiological characteristics, antioxidant activity and yield of Cape gooseberry (Physalis peruviana L.) under deficit irrigation conditions, a split plot experiment based on randomized complete block design with three replications was conducted in 2021. Treatments consisted of the arrangement of three levels of irrigation (starting irrigation at 100, 80 and 60% ETc (crop evapotranspiration)) and three levels of humic acid (0, 1.5 and 3 kg ha-1). The results showed that deficit irrigation significantly reduced fruit yield. The soil application of humic acid significantly increased leaf relative water content, antioxidant capacity, fruit yield, and decreased leaf electrolyte leakage under normal and deficit irrigation. The highest value of total phenol (18.1 mg gFW-1), flavonoid (0.47 mg gFW-1), antioxidant activity (90.06 %), proline (5.91 mg gFW-1) and catalase (0.81 μmol H2O2 g-1 FW min-1) and peroxidase (1.92 units g-1 FW min-1) enzymes activity were obtained with 3 kg ha-1 soil application of humic acid under deficit irrigation 60% ETc. The maximum fruit yield (4793.3 kg ha-1) was observed in plants treated with 3 kg ha-1 humic acid under 100% ETc irrigation. According to these results, the application of 3 kg ha-1 humic acid is suggested to improve the antioxidant capacity and fruit yield of Cape gooseberry under normal and deficit irrigation conditions.

In order to study foliar application of amino acids on morphophysiological properties and thyme essential oil under different irrigation regimes, an experiment was conducted as a split plot based on a randomized complete block design with three replications in the Research Farm of Tarbiat Modares University Faculty of Agriculture in the year 2020 crop season. Experimental factors were irrigation regimes at three levels including normal irrigation, moderate water stress, severe water stress (withholding irrigation until  25%, 45% and 65% of soil available water depletion in the root zone respectively and then irrigation up to field capacity from plant establishment to harvest time), were randomized to the main plot units and spraying at 6 kinds (aspartic acid, tyrosine, proline, commercial amino acids, distilled water and without spraying) were located in subplot units. The results showed that with reduction of irrigation to the level of severe water stress, plant height, fresh and dry weight of leaves, leaf area, total chlorophyll, percentage of essential oil decreased, and glycol peroxidase and proline showed a significant increase compared to optimal irrigation. Catalase activity also increased under moderate water stress and decreased under severe water stress. Foliar application of amino acids had a positive additive effect on the studied traits. The highest essential oil yield (about 11.20 kg/ha) was assigned to plants under commercial and proline amino acid foliar application under full irrigation conditions. Based on the general results of proline foliar application, increasing the concentration of osmolites such as proline under water stress conditions was able to help the plant withstand drought stress by helping to maintain osmotic pressure and compensate for part of the reduction in growth and dry weight. Therefore, consumption of this type of amino acid under stress conditions is recommended to reduce the effects of drought stress. Under non-stress conditions, foliar application of this type of amino acid had the greatest effect on plant growth and yield.

Monitoring of the pollutant effects in the biological environment requires the identification of a suitable biomarker. In this study, the efficacy of the expression of the CYP1 gene and the antioxidant enzymes in the Scatophagus argus were studied as biomarker of oil pollutants at three stations (Bandargah, Solhabad and Jofreh) and the control samples. CYP1A gene expression in liver was significantly different from control samples in all regions. The highest CYP1 gene expression was measured in Solhabad station. CYP1A gene expression in the gills of green scat fish showed a significant increase compared to control samples. The highest and lowest CYP1A gene expression was observed in the gills in Solhabad and Bandargah samples, respectively. The amount of superoxide dismutase and catalase of liver tissue in Jofrah and Solhabad stations were significantly lower than the control (P<0.05). In contrast, the rate of lipid peroxidation and GST were directly correlated with the amount of polycyclic aromatic hydrocarbons (P<0.05, R=0.96). Due to the relationship between CYP1A gene expression and antioxidant markers and the level of contamination, CYP1A gene expression and antioxidant markers can be used as a suitable biomarker for PAH contaminants in this species.

Arbuscular mycorrhizas are able to reduce the adverse effects of biotic and abiotic stresses on crops. To investigate the effect of inoculation with Glomus mosseae on physiological characteristics of two rice cultivars under water deficit conditions, an experiment was conducted in a randomized complete block design in the greenhouse. Irrigation conditions included flooding, stop irrigation up to 70% and 50% of field capacity. In general, in both groups of plants, inoculated and control plants (non-inoculated), increased levels of phenol, tannin, glycine and betaine, as well as polyphenol oxidase and guaiacol peroxidase enzymes were observed under water deficit conditions. However, the change amount of each trait in inoculated plants was significantly higher than the non-inoculated plants. In case of stopped irrigation up to 70% of field capacity, the amount of proline, antioxidant enzymes in Nemat cultivar was higher than Tarom Hashemi, while Glycine betaine, tannin and phenol content was higher in Tarom Hashemi than Nemat cultivar. In case of stopped irrigation up to 50% of field capacity, the amount of phenol, tannin, glycine and betaine as well as antioxidant enzymes in Nemat cultivar was higher than Tarom Hashemi, which can be a reason for different effects of arbuscular mycorrhizal colonization on the response of rice cultivars to water deficit conditions. Based on the results, it seems that inoculation of rice plant with mycorrhizal fungus can play a role in reducing the adverse effects of water deficit in case of water shortage conditions during the critical stages of plant growth.

In this study, the effect of drought stress on morphological and physiological characteristics of two forest species: Alnus subcordata and Acer velutinum, which are used in natural forest restoration and afforestation, was evaluated. A factorial experiment was conducted based on a completely randomized design with two factors (two species and four levels of drought stress: (25% (severe stress), 50% (moderate stress), 75% (mild stress), and 100% (no stress) percentage of field capacity). The results showed that drought stress significantly reduced the height, basal diameter, Leaf, and root biomass in both species, Whereas A. subcordata showed more stem biomass reduction. Root to shoot ratio showed a noticeable and slight increase in A. subcordata in A. velutinum respectively. Both species experienced a significant decrease in leaf area in drought conditions. Meanwhile, the specific leaf area decreased in A. subcordata as the degree of water stress increased, but it increased under mild and moderate treatment in A. velutinum seedlings. Total chlorophyll and chlorophyll a decreased in A. subcordata more than A. velutinum. Also, chlorophyll b decrease was similar in both species, while, carotenoids content decreased significantly in A. subcordata and increased insignificantly in A. velutinum. Drought stress showed a significant effect on the relative water content and proline in both species. There were no differences between the two species in proline content. furthermore,  A. velutinum had more relative water content than A. subcordata seedlings under moderate treatment. These findings suggested that the two species did not show similar responses to drought stress. Also, based on the measured characteristics A. velutinum may maintain stronger drought tolerance. The malondialdehyde content and antioxidant enzymes activities in both species increased with increasing stress. A. subcordata had a more increase in malondialdehyde content in drought treatment compared to the control treatment. The activity of antioxidant enzymes in both species increased in moderate and mild stress treatment and A. velutinum showed higher enzyme levels. Our results highlighted that the two species did not show similar responses to drought stress and A. velutinum maintained stronger drought tolerance based on the measured parameters. According to these findings and based on more ability of A. velutinum to cope with drought, it is recommended that A. velutinum plantation has more priority compared to A. subcordata in water deficit regions.

 This study aimed to investigate the effect of microgravity and light spectral composition on the levels of antioxidant enzyme activity, minerals, and  some photosynthetic pigments in Physalis alkekengi.

This study was performed in vitro. Seedlings were exposed to the microgravity treatments under two different light conditions, including white (C) and red+blue (R+B).

 The microgravity treatments were more capable of rapidly influencing growth performance than the light spectrum quality. Red+blue light increased the amount of chlorophyll a and b. Antioxidant enzymes under microgravity stress showed an increase, while changing the quality of the light spectrum did not make a significant difference. An increase in malondialdehyde (MDA) was observed in the microgravity treatment compared to the light spectrum. The amount of Cu+2 and Zn+2 were increased by the R+B+microgravity treatment. However, Mn+2 was increased in the microgravity treatment. The highest uptake of Fe+2 and Ca+2 was recorded under microgravity conditions. R+B+Microgravity treatment increased K+ content compared to white control. The microgravity treatment increased Mg+2 in the root cell.

 In general, microgravity and light spectrum can increase biomass. Microgravity has little effect on photosynthetic pigments, but the R+B light spectrum increased the pigments. Microgravity increased the activity of antioxidant enzymes and the content of MDA. The concentration of some elements in roots and leaves can be modified by the light and microgravity conditions.

Sweet violet (Viola odorata) is a perennial herbaceous plant with ornamental and medicinal properties. The purpose of this study was to investigate the effect of different levels of water-deficit and spraying with salicylic acid, sodium nitroprusside and zinc Nano-oxide on physiological parameters, secondary metabolites and enzymatic activity of sweet violet. Factorial experiment in completely randomized design was performed with two factors; water-deficit stress at 3 levels (55, 65 and 85% of field capacity or FC of pot soil) and sprays including salicylic acid (200 and 300 mg/l), zinc Nano-oxide (1000 and 1500 mg/l) and sodium nitroprusside (200 and 300 μM) in three replications. The results showed that with increasing water-deficit stress, the amount of phenolic compounds, proline and phytol, as well as the percentage of secondary metabolites, antioxidant enzyme activity and plasma membrane stability increased. The highest phenolic compounds (57.07 mg/galic acid/g D.W.) and proline content (52.47 mg/kg F.W.) were obtained in the treatment of 300 μM sodium nitroprusside at 55% of field capacity. The highest activity of superoxide dismutase (1.94 EU/mg/pro./min), catalase (0.198 EU/mg/pro./min) and polyphenol oxidase (0.248 EU/mg/pro./min) were obtained in treatments of 200 mg/l salicylic acid and 200 and 300 μM sodium nitroprusside, respectively, in 55% FC. The highest amount of phytol (2.87%) belonged to the control treatment in 55% of FC. The highest amount of sodium (28.60 mg/kg) and phosphorus (0.60 mg/kg) in control plants in 55% stress and potassium (4.29 mg/kg), iron (306 mg/kg F.W.) and dry matter percentage of shoots (26.23) and roots (27.60) was observes in spraying with 1000 mg/l of zinc nanoparticles in stress 85%, 1500 mg/l zinc oxide in stress 65%, 200 μM salicylic acid in stress 85% and 1000 mg/l of zinc Nano-oxide in 55% stress, respectively. Totally, the use of 200 mg/l of salicylic acid as spray, in addition to improving the growth and developmental conditions of sweet violet, decreased the negative effects of water-deficit stress and increased plant resistance to water-deficit.

In this research, to study the effect of drought stress on the morpho-physiological traits of two hybrid cultivars of lily, ʻMerluzaʼ and ʻNashvilleʼ, a factorial, completely randomized design-based experiment with four replicates was performed with potted plants in the experimental greenhouses of the department of Horticultural Science, Faculty of Agriculture, Agricultural Sciences and Natural Resources, University of Khuzestan. The experimental factors included four irrigation levels (irrigation at the rate of 100, 80, 60, and 40% rate of field capacity) and two lily cultivars, ʻNashvilleʼ with yellow, and ʻMerluzaʼ with white flowers. The results indicated that the reduction of irrigation rate had significant impact on the evaluated traits. Stalk height and the number of flowers reduced with the reduction of soil water content, whereas the fresh: dry weight ratio of petal increased. However, no significant difference was found in this trait between 80 and 100% rate of field capacity. The activity of catalase antioxidant enzyme, increased as the irrigation rate decreased, however, this increase in ʻNashvilleʼ was higher than ʻMerluzaʼ. Although with both cultivars, catalase activity and soluble carbohydrate level were higher under drought stress, severe stress at 40% rate of field capacity led to reduced protein content, ramped down catalase activity and diminished rate of soluble carbohydrates. Generally, the results of the present study indicated that although both cultivars well tolerated mild drought stress of 80% rate of field capacity, severe stress at 40% rate of field capacity led to serious damages in both lily cultivars. Also, lily ʻNashvilleʼ cultivar expressed more tolerance than ʻMerluzaʼ cultivar via the mechanisms such as increased carbohydrate content and peroxidase activity that resulted in the reduced peroxidation of lipids.

An experiment was performed to examine the effect of methyl jasmonate foliar spray with concentrations (10, 1, 0.1 mM and 0) and titanium nanoparticles with concentrations (40, 30, 20  µM and 0) on the physiological indices of Savory. The field experiment was carried out in Isfahan in the summer of 2019. This experiment was conducted in a factorial manner based on completely randomized design and 3 replications with 2 factors and 4 levels in two harvest times of 24 and 48 hours after the last treatment .According to the results of this research, compared to the control treatment, methyl jasmonate treatments result in a significant increase of 1 percent in leaf area, leaf fresh weight, leaf dry weight and length of aerial part in 48 hours after the last treatment. Titanium nanoparticle treatments result in a significant increase at the level of 1 percent in leaf width, leaf area, leaf dry weight, leaf fresh weight and length of the aerial part of the plant. Similarly, the flavonoid content increased significantly at a concentration of 30 μM at the level of 1 percent. In combined treatments that were conducted at 48 hours after the last treatment, there was a significant increase in leaf dry weight, leaf area, leaf fresh weight and length of aerial part at the level of 1 percent and a significant increase at the 5 percent level in flavonoid content and activity of dismutase enzyme. It was concluded from the current research that 48 hours after the last treatment is the best time for harvesting. The use of both concentrations of 1 or 0.1 mM methyl jasmonate with 40 μM nanoparticles and 10 mM methyl jasmonate with 30 μM nanoparticles affects the plant positively and can increase the growth and biochemical factors of Savory.

Soil and water salinity in semi-arid regions such as Iran have been a important threat for plant growth and agriculture. It is demonstrated that TiO2 nanoparticles can improve plant growth and increase stress tolerance in plants. Therefore, in current study, a pot experiment was conducted as factorial with completely randomized design to evaluate the effect of 3 levels of salinity (0, 50, 100 mg/L NaCl) and 5 levels nano- TiO2 (0, 10, 20, 40, 80 mg/L) on ajowan (Carum copticum). Results showed that with increasing salt concentration, fresh and dry weight of roots and shoots, content of chlorophyll a, b and relative water content (RWC) significantly reduced, but content of malon dialdehyde, carotenoids, proline content and the activities of SOD and APX increased in leaves. Foliar spray of nano- TiO2 concentrations influenced all the above mentioned parameters in a dose-dependent manner. Foliar spray with suitable nano- TiO2 concentrations (often 20 and 40mg/L) improved plant growth, content of chlorophyll a, b and carotenoids, RWC, proline accumulation and the activities of SOD and APX and reduced lipid peroxidation level. Impact of 80 mg/L nano- TiO2 on growth parameters and photosynthetic pigments contents was less than 20 and 40 mg/L and significantly increased lipid peroxidation under both normal and salinity stress conditions. In conclusion, it can said that appropriate nano-TiO2 concentrations protected ajowan against salt –induced osmotic- and oxidative stresses through increasing proline accumulation and enhancing the activities of antioxidant enzymes.