جستجوی مقالات مرتبط با کلیدواژه « سوپراکسید دیسموتاز » در نشریات گروه « باغبانی »

Grasses are narrow-leaved plants that are used as cover plants in landscape. These plants are one of the basic and necessary components of the green cover of most gardens, parks and as the background color of landscape. In Iran, due to the high costs of planting and management of grass, high water requirements, climatic incompatibility and damage to water and soil salinity, it is recommended to remove from the green space in some cities, especially in areas with low water and water and soil saline. If it is possible to benefit from the role and influence of these plants by observing the technical points and choosing the best species for each area. Salinity stress is the second limiting factor for the growth of plants in the world after drought, which affects the efficiency and performance of plants. Increase in salinity causes a decrease in the water potential in the soil. In this condition, the plant spends most of its energy to maintain the water potential, cell mass, and water absorption to have minimal growth. The aim of this research is the effect of external application of glycine betaine on the accumulation of osmolality compounds and the antioxidant system of sports grass under salt stress.

This research was done in factorial form in completely randomized design with 3 replications on Rashid variety cucumber. The factors included 4 levels of temperature (25, 30, 35 and 40 degrees Celsius) and 3 levels of salicylic acid (0, 0.5 and 1 mM). When the seedlings reached the two-leaf stage, they were sprayed with different concentrations of salicylic acid two times with an interval of five days. One week after the application of salicylic acid, temperature treatment was gradually applied. After applying each heat treatment, the corresponding pots were transferred to the greenhouse with a temperature of 25 degrees Celsius. Then, fresh and dry weight of root and shoot, leaf surface, chlorophyll index, electrolyte leakage, proline, polyphenol oxidase enzyme activity and superoxide dismutase enzyme activity were measured.

Results and Discussion  :

The results showed that salinity stress decreased all the study morphological, physiological and biochemical parameters including plant height, shoot fresh and dry weight, number of tiller, leaf area, chlorophyll content, protein and total antioxidant capacity in the studied plants. It also increased peroxidase enzyme, H2O2 and proline in plants, but glycine betaine application significantly improved the morpho-physiological characteristics of plants compared to the control under salt stress conditions. Thus, the highest height, shoot fresh and dry weight, leaf area, number of tiller, chlorophyll content, and protein and antioxidant capacity were observed in plants sprayed with glycine betaine. Also, the highest content of glycine betaine and activity of catalase and peroxidase enzymes and the lowest content of glycine betaine and H2O2 were observed in in plants sprayed with glycine betaine and 10 mM glycine betaine was more effective than 5 mM. The occurrence of salinity in plants disrupts the absorption of ions and causes the reduction of nutrients and increases sodium ions. One of the effects of salinity in plants is the reduction of photosynthetic activity, which results in the reduction of chlorophyll, carbon dioxide absorption, photosynthetic capacity, plant height, shoot fresh and dry weight, number of tiller and leaf area. One of the most strategies to deal with stress is accumulation of osmolyte and increasing the antioxidant activity, which makes plants resistant to environmental stresses. Salinity, through the toxic effect of Na+ and Cl- ions, affects the growth and performance of the plant by reducing the soil water potential, disrupting water absorption and imbalance of nutrients in the plant. The results obtained from comparing the average results of glycine betaine show that glycine betaine increased plant height, shoot fresh and dry weight, number of tiller, leaf area, chlorophyll content, total protein and antioxidant capacity, but on the other hand, it increased proline and H2O2 decreased, which is due to the accumulation of glycine betaine as a protector in plants under salt stress conditions. In stress conditions, glycine betaine can protect photosynthetic activities including photosynthetic enzymes, proteins and lipids in thylakoid membranes in the combination of photosystem II, and also the task of protecting cell membranes against osmotic stresses in the plant.

The results obtained from this research showed that salinity stress reduced all the morphological, physiological and biochemical characteristics in the sport grass plants, but glycine betaine application played a positive role in reducing salinity damage and maintaining plant quality. Glycine betaine is known as one of the effective molecules in stress signaling, so it can protect the plant cells against stress by reducing the destruction of the membrane and by increasing the salt tolerance mechanisms. Also, glycine betaine 10 mM is introduced as the best treatment to reduce salinity damage in sport grass during present study.

Physalis (Physalis peruviana L.) is a popular fruit, which has received great attention due to its nutritional and medicinal properties. This valuable fruit has a short shelf life and so far, very little research has been done on postharvest physiology of shelf life. For this purpose, a factorial experiment was conducted based on a completely randomized design with three replications. The first factor was the different levels of γ- aminobutyric acid (GABA) concentrations (0, 5, 10 and 15 mM), the second factor was the storage time in three levels (7, 14 and 21 days) and the third factor was the harvesting stage (based on the appearance color of the fruit into two levels: yellowish green and orange). The obtained results showed that the weight loss in fruit treated with GABA at the end of the storage period was lower than untreated fruit, and the most weight loss (12.62%) was found in fruit harvested in the orange stage without any treatment. At the end of the storage period, the fruit firmness in fruit treated with GABA showed a lower decrease compared to the untreated fruit, so that the maximum decrease was observed in the orange stage after 21 days of storage in the untreated fruits. The application of GABA significantly reduced the fruit decay. The highest fruit decay (43.83%) was observed in the fruit harvested at the orange stage without GABA at the end of storage. The results showed that the application of GABA increased the activity of antioxidant enzymes during the storage period compared to untreated fruit. The highest activity of superoxide dismutase (SOD), catalase (CAT), guaiacol peroxidase (GPX) and ascorbate peroxidase (APX) enzymes was observed in fruit treated with 15 mM GABA compared to untreated fruit. Overall, application of GABA after harvesting at a concentration of 15 mM is recommended to maintain the quality of physalis fruit.

 Portulaca oleraceae is used in many countries for a variety of purposes, including human nutrition and the conversion and pharmaceutical industries. The edible parts of Portulaca oleracea are the young organs, especially the brittle leaves and stems. Over time, this medicinal herb has been forgotten. Drought, on the other hand, is a factor in the decline of crops and horticulture around the world. Given the vastness of arid and semi-arid regions in Iran and also the reduction of access to water resources, appropriate arrangements should be made for the optimal use of water in the agricultural sector. Changing the planting pattern and using useful and resistant alternative species such as drought-tolerant medicinal plants can enable the optimal use of limited water resources. GABA is an important non-protein amino acid that plays a positive role in increasing plant resistance to stress.
 This experiment was carried out in 2020 as a factorial based on a completely randomized design with three replications in the vegetable research greenhouse of the Faculty of Agriculture, Shahid Bahonar University of Kerman. Experimental treatments included different levels of GABA (0, 20, and 40 mM). Treatment with different concentrations of GABA was done in two stages of 6 and 12 leaves of portulaca oleracea and foliar application and application of dehydration stress in three levels of control, medium and severe at irrigation intervals of 7, 14, and 21 days from 6 leaf stage of plants to the end.
 According to the analysis of variance, the effect of GABA at different concentrations and dehydration stress on plant height was significant at the level of 5% probability. Based on the mean comparison test, the highest plant height was obtained in GABA treatment of 40 mM and irrigation intervals of 7 days (control), and the lowest of this trait was obtained in GABA zero treatment and irrigation intervals of 21 days (highest stress level). The results of analysis of variance showed that the effect of GABA at different concentrations and dehydration stress on vegetative yield was significant, the interaction between irrigation intervals and GABA was significant at 5% level. Based on the mean comparison test, the highest vegetative yield was obtained in GABA treatment of 40 mM and irrigation intervals of 7 days and the lowest in control treatment and irrigation intervals of 21 days. According to the results of the analysis of variance table, the effect of GABA at different concentrations and dehydration stress on the amount of malondialdehyde was significant at the level of 1% probability. Based on the means comparison test, the highest amount of this trait was obtained in the control treatment. Comparison of the mean of the data showed that the effect of GABA at different concentrations and dehydration stress caused a significant difference in the probability level of 1% in the proline content of the data. Based on the mean comparison test, the highest amount of proline was observed in GABA treatment of 40 mM and irrigation intervals of 21 days and the lowest amount was observed in control treatment and irrigation intervals of 7 days. As can be seen in the comparison table of means, the highest activity of superoxide dismutase enzyme was obtained in GABA treatment at 40 mM and irrigation intervals of 14 days and the lowest in control treatment and irrigation intervals was 7 days (Table 2). The results of this study showed that the effect of GABA at different concentrations and dehydration stress on the activity of catalase was significant at the level of 1% probability. As can be seen in the comparison table of means, the highest level of catalase activity was 40 mM in GABA treatment and 21 days irrigation intervals and the lowest in GABA treatment was 40 mM and irrigation intervals were 7 days.
 The results of this study indicate that GABA is able to greatly alleviate the oxidative stress caused by dehydration in Portulaca oleracea. This effect is quite evident in oxidative parameters, especially the activity of antioxidant enzymes. The concentration of 40 mM GABA was the most effective treatment in mitigating the effects of irrigation. The results show that the use of GABA makes Portulaca oleracea tolerant to dehydration stress.

Salinity stress is one of the most important factors in reducing the crop yield in the world. The application of humic acid along with selenium can improve the plant yield under salinity stress conditions by increasing the antioxidant capacity. To evaluate the effects of humic acid and selenium application under salinity stress conditions in Calendula officinalis L., a factorial greenhouse experiment was conducted in a completely randomized design with three replications in Islamshahr city in 2018. The experimental treatments included sodium chloride (0, 50, and 100 mg l-1), humic acid (0, 100, and 200 mg l-1), and selenium (0, 5, and 10 mg l-1) and their combined effects. The results showed that increasing the salinity significantly reduced the fresh and dry weight of shoots and roots and number of flowers per plant. The foliar application of 200 mg l-1 humic acid and 10 mg l-1 selenium improved carotenoids content of the petals and total chlorophyll of the leaves at all salinity levels. Also, with increasing the sodium chloride level up to 100 mg l-1, the amount of proline increased significantly. Meanwhile, the interaction treatments of humic acid and selenium had significant effects (P≤0.0.1) on improving the activity of superoxide dismutase and peroxidase enzymes at different salinity levels. The highest amount of essential oil (1.37%) was obtained in the interaction treatment of 200 mg l-1 humic acid and 10 mg l-1 selenium under salinity stress of 50 mg l-1 sodium chloride. In general, the results of this study showed that the foliar application of 200 mg l-1 humic acid and 10 mg l-1 selenium could be effective in reducing the negative effects of salinity stress on  C. officinalis.

Drought is one of the most important abiotic stresses that have effect on growth and physiological aspect of grape. In this research effect of manganese sulfate on the morpho-physiological traits and superoxide dismutase enzyme activity in Thompson seedless and Rotabi grape cultivars under invitro at drought stress was evaluated. The manganese sulfate treatment was carried out across three levels, including MS without manganese (0 mg/L), MS with a standard manganese concentration (16.9 mg/L) and MS with twice the standard manganese concentration (33.8 mg/L), and the drought stress treatment was performed across four levels using 0, 3, 9 and 12% (w/v) solutions of polyethylene glycol (PEG) 6000 in two grape cultivars, namely seedless Thompson and Rotabi. The meristems of shoottip were used as explants. All growth parameters, including plant height, stem dry weight, leaf area, leaf number and relative water content (RWC) were reduced under the impact of drought. However, manganese sulfate treatment caused a significant increase in all these parameters at all concentrations. The highest amounts of superoxide dismutase enzyme activity was observed in 33.8 mg/L MnSO4 under drought stress with 12% PEG in the Rotabi cultivar (65.4 Umin-1g-1FW). The results of this research suggest that manganese sulfate treatment under invitro condition can improve water stress tolerance in both grapevines seedless Thompson and Rotabi cultivars.

Melatonin has different physiological functions in plants, such as active growth regulator signal. A factorial experiment, based on randomized complete blocks design, was carried out in order to evaluate of the effect of melatonin and sodium nitroprusside (SNP) on morpho-physiological traits of cut flower Gerbera (Gerbera jamesonii cv. Malibu) under salinity stress. The first factor in this experiment was melatonin and SNP at 5 levels (control (without melatonin and SNP), 0.1 mM melatonin + 0 SNP, 0.1 mM melatonin + 10 µM SNP, 0.2 mM melatonin + 0 SNP, 0.2 mM melatonin + 10 µM SNP) and the second factor consisted of irrigation water with two levels of electrical conductivity (i.e., 2 and 4 dS/m). The studied traits consisted of soluble solids, cell membrane stability, leaf, shoot and root water potential, water use efficiency, reduced glucose, different kinds of chlorophyll, carotenoid, proline, superoxide dismutase, catalase, ascorbate peroxidase, polyphenol oxidase and total protein content. Based on the means’ comparisons, 0.1 mM melatonin + 10 μM SNP, 0.2 mM melatonin + 0 SNP and 0.2 mM melatonin + 10 μM SNP treatments had the highest membrane stability at 2 dS/m salinity level, and with increasing the salinity level to 4 dS/m, the membrane stability decreased. The amounts of chlorophylls a, b and total in the 0.1 mM melatonin + 10 μM SNP, 0.2 mM melatonin + 0 SNP and 0.2 mM melatonin + 10 μm SNP were significantly higher than control and 0.1 mM melatonin treatments. The amounts of SOD, CAT, and APX enzymes increased when combined with melatonin and SNP in comparison to the control. Therefore, melatonin and SNP can be recommended as an effective and very useful combination in the resistance of gerbera cut flower to salt stress conditions.

 The ability to tolerate cold will not be possible without stopping or inducing sleep, which is one of the important steps in the life cycle of plants in temperate regions. This period is one of the important factors in preventing cold damages in winter and spring in temperate regions. Various studies in controlled conditions on plants have shown that in plants, when entering and leaving this period, various changes occur in materials such as proteins, enzymes and hormones. In order to control the harmful effects of active oxygen species, plants have defense mechanisms. Catalase, peroxidase and superoxide dismutase enzymes are a defensive team whose common goal is to defend against the destructive effects of active oxygen species. This study was carried out to determine the chill requirement and its relationship with the changes in the activity of antioxidants enzymes and proline.

 The experiment was conducted at agricultural Research Station of Khalat-Pooshan and the Laboratory of Flower Biology and Physiology of Fruit Growth in the Department of Horticulture, Faculty of Agriculture, Tabriz University in 2015-2016. Flower buds needed for testing were selected from ‘Siah Shabestar’, Zard Mashhad, Zoodras cultivars and a local genotype of sour cherry. Once a month, enough buds were harvested and until the experiments began, they were kept inside the freezer inside an aluminum foil at -80 ° C. In order to estimate the chill requirement, four replicates (4 geographic directions) from each cultivar and from each replication four branches with the same length and diameter were removed. The amount of chilling accumulation and chilling requirement in each month was calculated according to Utah model. In order to estimate fresh weight, four replicates in each cultivar were selected and in each replication five buds were selected from different parts of the branch. The statistical design used in the determination of the chill requirement was a randomized complete block design. Enzymatic and proline data were analyzed in a completely randomized design as factorial

 Chill requirement: Based on the Utah model, the chill requirement of sweet and sour cherry cultivars contains Zard Mashhad, Zoodras and Siah Shabestar were calculated 752, 780, 867 and 961 CU, respectively. There was a significant difference in the activity of superoxide dismutase enzymes between cultivars and different sampling times at 1% probability level. Siah Shabestar cultivars with the highest chill requirement had the lowest SOD enzymatic activity and Zard Mashhad and Zoodras were intermediate cultivars in terms of enzymatic activity. Sour cherries, which had the least chill requirement, showed the highest levels of SOD enzyme activity. This is consistent with the results of some researchers regarding apricot stated that the low chill apricot cultivars had the highest SOD enzymatic activity. The sour cherry had the highest amount of POX enzymatic activity with the least amount of chill requirement, and also Siah Shabestar has the least chill requirement. Like the two previous enzymes, the activity of catalase was highest in sour cherries and the lowest was observed in Siah Shabestar. In terms of the presence of free proline, there was no significant difference between the Zard Mashhad cultivars and Zoodras, while there was a significant difference between these two cultivars and Sour Cherry and Siah Shabestar. Zoodras cultivar has the highest and our cherry has the lowest amount of free proline. Between different cultivars, in terms of fresh weight of buds, there is a significant difference at 1% probability level before and after placement in the growth chamber. The increase in fresh weight of sour cherry and Zard Mashhad, Zoodras and Siah Shabestar cultivars were 25, 27, 31.5 and 33%, respectively. The highest fresh weight before and after placement in growth chamber was observed in Siah Shabestar and sour cherry was the lowest. In all the cultivars, the activity of all three enzymes were initially at maximum (369 CU), then, with the cooling of the air and the initiation of deep dormancy, the activity of these enzymes were greatly reduced (820 CU) and then again increased in the activity of this enzyme (963 CU), which is similar to other studies.

Conclusions :

The results of this study showed that the antioxidant metabolism in plants is influenced by seasonal cycle changes and enzymatic activity changes depending on temperature, so that sour cherry with the least chill requirement has the most activity of the enzyme catalase, peroxidase and superoxide dismutase and Siah Shabestar, which have the most chill requirement, have the least enzymatic activity. Accordingly, the enzymatic antioxidant system activity of the flower buds was relatively high at the beginning of the dormancy period, but decreased during the end of dormancy. Also, the amount of free proline at the end of dormancy and the stage of dormancy breaking was highest and the lowest was in the deep dormancy period.

Rosa chinensis is one of the most important urban landscape plants. One of the main important uprising problem facing urban landscape development and extension is salinity stress caused by excess NaCl in water and soil. Therefore, in the present study the impacts of NaCl salinity stress on some physiological and biochemical features of Rosa chinensis were studied in a factorial experiment based on completely randomized design. Plants were irrigated by saline water (4, 8, and 12 dS m-1) and irrigation water (EC of 0.8 dS m-1, as control) for 40 days. After the mentioned period, some physiological features such as leaf relative water content (RWC), leaf photosynthetic pigment (such as chlorophyll a, chlorophyll b, and carotenoids), beside activity of some enzymes involved in plant resistance to salinity stress (such as catalase, guaiacol peroxidase and superoxide dismutase) and phenol content were measured. Results indicated that leaf relative water content reduced by salinity stress and the reduction was significant at 12 dS m-1. Leaf chlorophyll and carotenoid pigments also showed a significant reduction at 12 dS m-1 salinity level. Salinity stress increased the activity of antioxidant enzymes such as catalase, guaiacol peroxidase and superoxide dismutase. Similarly leaf phenol content of stressed plants increased accordingly as level of salinity stress increased. Catalase and superoxide dismutase activity significantly increased at 12 dS m-1 salinity level, while guaiacol peroxidase and phenol content increment was significant at 8 dS m-1.

In this study, the effects of salicylic acid and methyl jasmonate as two inducers were studied on antioxidant activity, photosynthetic pigments and flavonoids under salinity stress in Chelidonium majus L. This experiment was conducted as a factorial in a completely randomized design with four replications at Imam Khomeini International University during 2017. The elicitors were treated as foliar and mixed with irrigation. The factors studied included elicitors at three levels (distilled water as control, 2 mM salicylic acid, and 100 µM methyl jasmonate), salinity stress at two levels, urban water as control (EC=0.62 ds/m), salinity at 30 mM NaCl (EC=3.36 ds/m), and plant organs at three levels (leaf, root, stem). The analysis of variance showed that the main effects of salinity, elicitors, organs and their interactions were significant for most of the traits. The results of mean comparison for elicitors showed that methyl jasmonate increased carotenoid, flavonoids and anthocyanin. Both salicylic acid and methyl-jasmonate treatments reduced the amount and activity of catalase, superoxide dismutase and guaiacol peroxidase enzymes under salinity stress. In mean comparison of the triple interaction effects, salinity놩扳⥢ acid闦 was the best combination of factors for chlorophyll (1.68 mg.g-1 FW) and carotenoid (0.54 mg.g-1 FW) contents. Also, the maximum content for anthocyanin (5.7 OD.gr-1 FW) was observed in non-salinity駫懊 jasmonate闦 and for flavonoids in salinity麉hormone (3.42 OD.gr-1 FW), non-salinity놩扳⥢ acid (3.27 OD.gr-1 FW) and salinity駫懊 jasmonate (3.2 OD.gr-1 FW) in leaf, respectively. The amount of total protein increased in salinity놩扳⥢ acid (56.72 mg.g-1 FW) and salinity駫懊 jasmonate (53.27 mg.g-1 FW) in contrast to reduction in salinity麉hormone (43.35 mg.g-1 FW). In conclusion, by applying the two mentioned elicitors, greater celandine does not need to increase the antioxidant defense system and will potentially improve the yield of biomass and some secondary metabolites under salinity stress.

Salinity stress is one of the major abiotic stresses that have destructive effects on plant productivity and quality. An experiment was conducted to investigate the effects of zinc as alleviating agent under salinity stress on antioxidative system, proteins, proline and growth of Catharanthus roseus (L.) G. Don. at Arak University in 2012 autumn. A number of 49-days-old plants were treated with different concentrations of NaCl (0, 35, 70 and 100mM) alone and in combination with various ZnSO4 concentrations (0, 5 and 10μm) for 21 days. Then, the inhibition percent of 1, 1-diphenyl-2-picrylhydrazyl radical (DPPH), activity of antioxidant enzymes such as superoxide dismutase, catalase and guaiacol peroxidase, proline and protein content and growth parameters were measured. Results showed that zinc application improved shoot length, root depth, root and shoot fresh and dry weight under all salinity treatments. As a result of salinity stress, the inhibition percent of DPPH radical and superoxide dismutase, catalase, guaiacol peroxidase activity and also proline content increased 348.5%, 475.6%, 172.7%, 200% and 364%, respectively but protein content was reduced 33%. Zinc application improved protein content up to 16% in plants under salinity treatment and also reduced the proline content up to 36%. The activity of antioxidant enzymes increased significantly in treated plants with NaCl as compared with those treated with NaCl or Zn alone. These results support the positive effects of Zn application on antioxidant defense system in vinca under salinity. Zinc may act as a scavenger of reactive oxygen species for mitigating the injury on biomembranes under salt stress.

Some crops have the ability to withstand environmental stresses as they prevent further production of oxygen free radicals or cope with the produced free radicals. Accordingly, in order to investigate the effect of mycorrhizal fungi species on eco-physiological characteristics of Hyssopus officinalis L., a factorial experiment based on randomized complete block design was conducted with three replications at the research farm of west Azarbaijan Agricultural and Natural Resources Research Center in 2012. Treatments were species of mycorrhizal fungi (Glomus mousseae, G. intraradicese, G. fasiculatum, G. claroideum, Acaulospora longula and control without mycorrhiza) and four levels of irrigation (irrigation at 80, 70, 60 and 50% field capacity). Results showed the significant effects of irrigation and mycorrhiza on the ascorbate peroxidase, and significant interaction between irrigation and fungi species on the percentage of mycorrhizal colonization, catalase activity and superoxide dismutase. The order of highest colonization of Hyssop root was G. mosseae, G. intraradices, G. fasiculatum, G. claroideum and A. longula compared to control treatment in all irrigation levels. The highest activity of superoxide dismutase and catalase in plants inoculated with G. mosseae, G. fasiculatum, G. fasiculatum and G. claroideum belonged to irrigation at 50, 60, 50 and 50% of field capacity, respectively. However, the highest ascorbate peroxidase belonged to irrigation at 50% field capacity. In conclusion, the results showed that mycorrhizal species affected the amendment of water deficit stress due to the increased antioxidant enzyme activity in order to neutralize the effects of free radicals and cell membrane stability.

Decreasing irrigation via partial root zoon drying (PRD) save water and decreased production expenses. For comparing common irrigation and PRD on tomato cv. Falcato an experiment was designed in Massey University of New Zealand. Treatments were control (irrigation in a Field capacity in each irrigation to whole root zoon) and PRD (irrigation in a half of Field capacity in each irrigation to one side of root zoon). The results were shown that superoxide dismutase and peroxidase activity increased in PRD compare with control. Photosynthesis، mesophyll conductance، photosynthesis water efficiency، fresh and dry weight of root and shoot decreased in PRD. NACE (Nutrient Acquisition Efficiency) of leaf was the highest for Zn and Na and the lowest for P when PRD applied compare with control. Yield indices like MP increased significantly by 63% compare to first harvest. YSI (Yield Stability Index) increased by 46% in third harvest compare with second one. The TOL (Tolerance index) increased by 80% in last harvest compare with first one. GMP (Geometric Mean Productivity) in the second harvest increased by 62% compare to first one.