جستجوی مقالات مرتبط با کلیدواژه "catalase" در نشریات گروه "منابع طبیعی"

A large part of Iran is affected by arid and semi-arid climate and drought has caused many problems in the agricultural sector. The present study aimed to investigate the characteristics of melon under drought stress conditions using animal manure and bentonite. This experiment was conducted as a split-factorial based on a randomized complete block design with three replications in Hirmand city, Iran, during the two cropping years of 2019-2020. Experimental treatments include irrigation after 25, 50, and 75% soil moisture discharge as the main plot and application of bentonite at levels of 2, 3, and 4 t.ha-1 and application of animal manure at the rate of 20, 30, and 40 ton.ha-1 were considered as subplots. According to the results, in the first year of the experiment, fruit yield increased by 2.02 times compared to the control under 50% soil moisture discharge with the application of 4 t.ha-1 of bentonite with 20 ton.ha-1 of animal manure. The results showed that the fruit yield in irrigation conditions after draining 50% of soil moisture with the application of 4 t.ha-1 of bentonite along with 20 ton.ha-1 of animal manure in the first year of the experiment with an average of 2.20 ton.ha-1 and 74.1% compared to the control showed an increase. In order to achieve higher fruit yield, irrigation after draining 50% of soil moisture, application of 4 t.ha-1 of bentonite and 20 ton.ha-1 of animal manure are suggested for cultivation in Hirmand region. In this experiment, the greater effectiveness of fruit weight and yield in the first year can be attributed to the faster growth of shoots and the availability of more nutrients due to the release of manure elements for plant use and the effect of soil interactions in the first year, and the improvement of physical conditions and Soil and plant chemistry in the second year under irrigation conditions after draining 50% of soil moisture. The reason for the higher fruit yield due to the consumption of animal manure can be the result of the vegetative growth caused by the increase in the availability of nutrients, which causes photosynthesis and the production of more photosynthetic substances, followed by the presence of more vascular elements to transfer the cultivated substances to the fruit of the plant. Based on the obtained results, the increase in drought stress increased the activity of catalase and peroxidase enzymes, and the animal manure increased the activity of enzymes to defend the plant under drought stress conditions, in other words, the plant decomposes hydrogen peroxide and increases tolerance against radicals. The effect of animal manure on plant growth can be largely attributed to mineral nutrients, especially absorbed nitrogen. In addition to this, increasing the decomposition of organic materials and mineralization of phosphorus in organic materials and converting them into usable form for plants plays a key role in the soil phosphorus cycle, and along with the use of bentonite, it strengthens the physical, chemical and biological structure of the soil, and finally By increasing the amount of water and the availability of nutrients available to the plant, it has a positive effect on the process of photosynthesis and can increase the length and width of the fruit. According to the results of the experiment, in order to achieve the desired results, irrigation after draining 50% of the soil moisture, application of 4 tons per hectare of bentonite and 20 tons per hectare of manure are suggested for cultivation in Hirmand region.

This study was conducted as a factorial experiments based on a completely randomized design with two factors cultivars (Modena and Okapi), aging level (0, 24 and 72 hours at temperature of 40˚c and relative humidity of saturated) and four replications to evaluate germination rate and percentage (GP), vigor index (SV), electrical conductivity (EC), catalase (CAT), ascorbate peroxides (APX), glutathione reductase (GR) and S-nitrosothiol (SNO) at the Ferdowsi University of Mashhad, 2019-20. Accelerated Aging (AA) treatments made significant decline in germination indices and biochemical characteristics (except EC) of canola seeds. Also, Modena cultivar was stronger in germination traits while Okapi cultivar was better in biochemical activities, which can be explained by difference in the primary genetic of the cultivars. According to the results, in the treatments of 72 hours of AA compared to the control, GP has decreased by 86%, CAT 88%, APX 89% and SNOs 36%. On the top of that, there was a positive correlation between SNOs and enzymes. In conclusion, Nitric oxide (NO) is likely to indirectly affect the antioxidant enzymes by SNOs in aged canola seeds. Seed aging targets the cell physiology by reducing the activities of antioxidant enzymes and NO and therefore increasing the rate of cell mortality.

Microgreens are immature vegetables with green leaves that can be harvested and consumed shortly after the appearance of the first true leaves. Basically, the part that appears above the root is used as a fresh vegetable for salads. They are more nutritious than their adult plants. In this study, basil (Ocimum basilicum) seeds were used to produce microgreens. Pythium spp. such as Pythium ultimum is one of the diseases that limits the cultivation of many microgreens.

Ten endophytic bacteria were isolated from the roots of some adult plants of the Lamiaceae family (including basil, Phlomis aucheri and rosemary). Basil seeds were disinfected with 1% sodium hypochlorite for two minutes and then washed five times with distilled water and dried at room temperature. For each treatment, 20 seeds with three replications were placed in two layers of sterile filter paper inside petri dishes and transferred to an incubator with a temperature of 21 ° C and a humidity of 65 to 70%. In the initial pretest to select the best bacteria in terms of growth stimulus characteristics, three traits of germinated seeds percentage, seedling height and wet weight at a common bacterial concentration (5×107 cfu/ml) were evaluated. Antifungal activity against P. ultimum was performed in mix of PDA and NA medium. Bacterium was detected using 16S rRNA region primers: 27F and 1492r. Several growth factors and biochemical changes including total phenol, peroxidase and catalase were investigated.

None of the bacteria showed a direct antifungal effect against P. ultimum in the laboratory. Among the bacteria, isolate GF1 showed more effects of growth stimulation than other bacteria. All growth traits showed a significant increase in the level of 5% probability in both bacterial isolate GF1 concentrations compared to the control, so that the least observed changes in the increase of each growth factor was above 50%. The highest increase in both concentrations was related to seed length vigor and germination vigor. In some cases, a significant difference was observed between the two concentrations of GF1 isolate. None of the bacteria showed a direct antifungal effect against P. ultimum in the laboratory. Sequencing of 16S region of ribosomal genes showed that the bacterium is Rhizobium sp. . This bacterium (in two concentrations of 5×107 and 5×106) had a significant effect of improving the weight loss of microgreens, the disease severity and disease incidence caused by P. ultimum in comparison with the control. Biochemical analysis showed that total phenol, catalase and peroxidase were significantly increased in microgreens inoculated with this bacterium. The results related to changes in total phenol, catalase and peroxidase after 14 days and at the same time with microgreen harvest showed that the bacteria in both concentrations were able to increase the amount of total phenol and defense enzymes in the microgreens. The concentrations used by the bacteria showed a significant difference in all cases, but the low concentration was also able to increase the amount of total phenol and enzymes compared to the control. Changes in total phenol, catalase and peroxidase in almost all cases from highest to lowest included the following treatments: high concentration of bacteria and fungus, low concentration of bacteria and fungus, high concentration of bacteria, low concentration of bacteria, fungus alone and the control which did not contain any microbial treatment. However, in the case of catalase, the changes resulting from inoculation of the pathogenic fungus alone and the changes resulting from the use of bacteria at lower concentrations were almost equal and did not show a significant difference.

In this study, unlike many similar studies that aim at biological control. The initial screening of bacteria with useful potential in agriculture was not based on antifungal properties. Rather, the primary goal was to increase germination and microgreen growth factors. Since the goal of biological control is ultimately to increase efficiency of crop yield by disease control, it makes sense to prioritize growth-promoting characteristics that directly affect the efficiency. This study showed that the endophytic bacterium, Rhizobium sp. GF1, without direct antifungal effect using inducing resistance mechanism and increasing the plant's defense compounds is able to significantly control the disease. In this study, bacterium was obtained that have a dual useful ability in the fields of plant protection and vegetable growing.

In order to evaluate mycorrhizal fungi on physiological characteristics and drought resistance in current almond (Prunus amygdalus) rootstock, a factorial experiment was conducted as a randomized complete block design in three replications in agricultural and natural research center of Shahrekoard. The treatments consist of two level of mycorrhizal fungi (M0: without and M1 with using of mycorrhizal fungi), four kinds of rootstock (bitter, local Shorab 2, GF and GN) and four levels of water deficit stress (I1: without stress as a control, I2: 20, I3: 40 and I4: 60 percent of depletion of plant available water). The results revealed that the maximum amounts of the studied characteristics except leaf proline were obtained from GF rootstock. The studied characteristics were increased from I1 to I4 treatment. Using of mycorrhizae fungi in deficit treatments caused to significantly increase in root and leaf proline, root soluble sugars and the activity of catalase and peroxidase enzymes. The maximum amount of root soluble sugars and leaf proline were obtained from GF+M1 and GN+M0 treatments respectively. The highest and lowest levels of catalase and peroxidase enzymes activity were obtained from I4+M1 and GF+I4 treatments. The maximum and minimum amounts of leaf soluble sugars were obtained from GN+I4+M0 and GN+I1+M1 treatments respectively. Inoculums with mycorrhizal fungi caused to increase rootstocks resistance to water deficit stress. Based on these experiment results the highest resistance to water deficit stress was obtained from GF rootstock.

Milk thistle contains flavonolignan silymarin in its fruits, making it one of the most important medicinal plants for protecting the liver and treating a variety of liver diseases, such as hepatitis and liver diseases containing toxins. The drought resistance mechanisms of medicinal plants, such as milk thistle, are of critical importance. The investigation of the effect of drought stress on the activity of antioxidant enzymes will aid in the identification of these mechanisms. Water stress modifies plant behavior via its effect on plant metabolism and consequently has a substantial effect on plant production. The biosynthesis pathway of secondary metabolites is altered by environmental stresses, altering the production and concentration of active substances in plants. In addition to playing a crucial role in defense mechanisms, secondary metabolites are an important source of bioactive compounds. However, flavonoids not only have antioxidant activity via the release of free radicals, but they also regulate cellular pathways in the defense of plants against environmental stresses, alter plant metabolism, and have a significant impact on plant production. In order to determine the effect of drought stress on the physiological and biochemical characteristics of milk thistle, treatments of 100%, 75%, 50%, and 25% water requirement were applied in a greenhouse in the village of Shandel, city of Hirmand. There were multiple harvesting stages, including 6 and 13 weeks after planting. Measurements included dry weight, fresh weight, chlorophyll a, chlorophyll b, carotenoids, proteins, proline levels, and antioxidant enzyme activity. First, the data were examined for normality in Minitab software version 18, using the Smearnof Columnograph method to determine data normality, and then the errors were examined for normality to confirm data normality. Then, analysis of variance of all traits and comparison test of Duncan were performed at 5% level with SAS software version 9.2 (SAS 2010).  The analysis of variance revealed significant differences in harvest time, irrigation level, and the interaction between harvest time and irrigation level. In both harvest stages, the concentration of carotenoids began to decrease as the level of stress increased. The amount of chlorophyll a at the stage 6 weeks after planting was less than at the stage 13 weeks after planting, but its amount decreased with increasing stress at both stages. The levels of protein and proline also increased as the level of stress increased. The activity of antioxidant enzymes also increased as the intensity of stress increased, to the point where 100% of water requirements reached the minimum value and 25% reached the maximum value. Due to the fact that most oxidative enzymes in this study increased in response to stress, it can be concluded that catalase, superoxide dismutase, guaiacol peroxidase, polyphenol oxidase, and ascorbate peroxidase can eliminate ROS in this plant. Therefore, milk thistle has a good adaptation to drought stress, which is likely due to the reduction of oxidative damage caused by the activation of the antioxidant system and the accumulation of osmolytes such as proline and protein. These modifications are a form of adaptation to stress conditions. The majority of traits were affected by growth stage and stress level. The levels of protein and proline increased with increasing stress intensity. Most antioxidant enzymes, including catalase, ascorbate peroxidase, and superoxide dismutase, increased in activity under the influence of stress. According to these findings, milk thistle responds to drought stress by increasing proteins and amino acids, decreasing photosynthetic pigments, and increasing the activity of antioxidant enzymes, among other mechanisms. Also, because the amount of metabolites in this plant increases with increasing drought stress, it is possible to determine the stress tolerance threshold of this plant, cultivate it on a large scale, and apply stress to increase secondary metabolites.

In order to investigate the effect of mycorrhiza biofertilizer on physiological traits, nutrient uptake and economic yield of lettuce under drought stress conditions, a split plot layout based on a randomized complete block design with three replications was conducted at University of Hormozgan.Experimental factors were included water stress levels as the main factor in three levels including irrigation of lettuce plants based on providing 50, 75 and 100% of RAW, equal to mild and moderate deficit irrigation and control respectively, and mycorrhiza fertilizer, it consists of three species of Glumos intraradices, G. mosseae and G. fasciculatum, at 0, 5, 10 and 20 g.m-2 as sub factor. The studied traits included physiological traits (chlorophyll a, b and total, maximum photosystem II efficiency (Fv/Fm) and catalase activity, relative leaf water content) leaf P and K content and economical yield of lettuce. The results of this study showed that water stress and mycorrhiza fertilizer significantly affected physiological traits of lettuce. With increasing in water stress level, leaf chlorophyll a, b and total content, maximum photosystem II efficiency (Fv/Fm), leaf relative water content, P and K content and overall economical yield of lettuce were decreased, While catalase activity was significantly increased under this condition. Application of mycorrhiza fertilizer under water stress conditions could improve physiological traits and nutrient content, so that in moderate water stress condition, application of 20 gm-2 of mycorrhiza fertilizer significantly increases the activity of catalase, Fv/Fm, chlorophyll a and total content, relative leaf water content compared with no fertilizer application.

This research was carried out to evaluate the storage of wheat seed which produced under different conditions of water deficit and application of chemical nitrogen and biological fertilizers as the first factor was water deficit in milky stage, drought stress at dough stage and without stress (control), and nitrogen fertilizer resources in Urea fertilizer 100%, 75%, 50% and 25% of plant requirement with nitroxin and nitragin. The second factor was storage conditions in 7 and 14% seed moisture within 20 and 4 °C storage, and the third factor was the storage period at 50, 100, 150 and 200 days. The results showed that the content of soluble protein and seed vigor index in seeds that received nitroxin and nitragin fertilizers with 25% urea, by increasing the water deficit, from 1.208 to 0.581 mg/g fresh weight and from 1.945 to 0.376 increased relative to 100% urea, respectively. The amount of catalase activity in seeds with drought stress and biofertilizer was higher and its activity increased at higher storage temperatures. In general, if the irrigation of the maternal plant is discontinued at the seed dough stage and the plant is fed with integrated of chemical and biological fertilizers, then the seed produced had more storage capability.

To study the effect of bio-priming on germination, growth and physiological indices of pumpkin under salinity a factorial experiment in a completely randomized design was conducted in three replications. Experimental treatments were salinity at four levels (zero, 40, 80 and 120 mM) and biological pre-treated at eight levels (control, inoculation with Trichoderma harzianum fungi, Azoto bio-fertilizer, phosphate bio-fertilizer, both bio-fertilizer, combination of fungi and azoto bio-fertilizer, combination of fungi and phosphate bio-fertilizer, fungi and both bio-fertilizer). Phosphate biofertilizer threatment had maximum positive effect on percent germination with increasing the salinity. In combination of fungi and phosphate biofertilizer with increasing the salinity levels reduced fewer the germination coefficient. Low levels of salinity had positive effect on growth indices and caused increase that this indices. Maximum seedling length in different levels of salinity obtained in combination of both biofertilizers treatment. Maximum amount of vigor weighted index obtained in fungi treatment and increasing of salinity level caused that reduced this trait. With increasing of salinity level reduced dry weight of seedling and was maximum amount in fungi treatment. The use of microorganisms caused that reduced the negative effect of salinity. With salinity increasing increased the amount of antioxidant enzymes and the use of biopriming treatments more increased the amount of these enzymes in compared to control which show these treatments was effective in reduction of salinity effect by means of increasing the enzymes. Using of microorganisms with more increasing antioxidant enzymes in compared to control caused reduction of negative effect of salinity stress.

A factorial experiment was conducted to evaluate the biochemical changes during the soybean seed deterioration based on a completely randomized design. The treatments consisted of germination in two levels of minimum and high quality, three initial seed moisture content (low, medium and high moisture), and two storage conditions were considered including the common storage in Moghan and the controlled storage condition. Indices of germination percentage, vigor and biochemical changes including protein content, soluble sugars, malondialdehyde, catalase and peroxidase enzymes were evaluated. The study of biochemical changes of deteriorated seeds during the storage showed that, with the increase of seeds’ deterioration, the soluble sugars and protein percentage decreased, as well. Moreover, seeds’ storage in poor condition caused a significant decrease in seeds’ soluble sugar and total protein content. Also, the increase of seed moisture was followed by further seed deterioration that significantly decreased the content of soluble sugars and total protein. Significant differences were observed between seeds with different initial germinations and they had significantly higher content of soluble sugars and protein percentages. Furthermore, measuring the amount of malondialdehyde and the activity of catalase and peroxidase enzymes indicated that there exists a significant correlation between the degree of seed deterioration with the level of malondialdehyde and the activity of scavenging enzymes. Overall, along with the decrease of germination and the quality of soybean seeds after the storage, the amount of lipids peroxidation increased and the seed deterioration decreased the activity of catalase and peroxidase enzymes during the storage.

Germination is one of the most sensitive stages of plant life, which is affected by various environmental factors such as temperature and humidity. Because seed standard germination test alone cannot accurately describe seedling emergence in field conditions, seed strain tests such as accelerated aging test (seed deterioration) are used. In this research, germination and biochemical indices of linseed (‌Linum usitatissimum Var. Norman) in moisture potential of 0, -0.2, -0.4, -0.6, -0.8, -1.2 and -1.2 MPa under accelerated aging conditions at temperatures 10, 15, 20, 25, 30 and 35°c were evaluated. The results showed that the percentage and rate of germination and seedling vigor index in accelerated aging and non-accelerated aging respectively were increased by increasing temperature up to 20 and 25 ° C, , then decreasing to 35 ° C. And with decreasing potential water, in terms of accelerated aging, showed its lowest level at any temperature. The amount of soluble protein, catalase activity and proline content of seeds increased with decreasing water potential and accelerated aging effects at each temperature. Also, with increasing temperature, protein content and catalase enzyme activity of Linum usitatissimum seed are increased; proline content of the seed decreased.The results of this study showed that Linum usitatissimumis resistant to high and low temperatures in the early stages of germination under favorable temperature conditions of plants resistant to dehydration and under stress-free conditions.

In order to investigate the effect of priming on the improvement of physiological indices of antioxidant enzymes in soybean seeds, a factorial experiment was conducted in a completely randomized design with three replications at the Seed Science and Technology Laboratory of Tehran University in 2017. The factors studied included two levels of deterioration (48 and 72 hours), three levels of salicylic acid (0, 300, 600 μM) and three times the salicylic acid application (before decay, post-fall, before and after deterioration). The traits measured included antioxidant enzymes (glutathione redactase, superoxide dismutase, catalase, peroxidase, ascorbate peroxidase, glutathione peroxidase, membrane peroxidation or malondialdehyde). The results showed that deterioration level increasing, decrease the antioxidant enzymes activity and increase membrane peroxidation and soybean seed priming with salicylic acid hormone restore the decayed seeds and increase the activity of antioxidant enzymes. The highest activity of ascorbate peroxidase activity was observed at 72 hours with the time of salicylic acid application before and after deterioration at a concentration of 300 μm and 6.98. Reduction of malondialdehyde leakage rate when combined with 300 μM concentration of salicylic acid Was observed at 1.45. The results also showed that the priming at the same time improves the chemical properties of the seeds in the deterioration.

Drought stress on maternal plant can negatively affect germination characteristics of produced seeds, and micronutrients application in this circumstance may mitigate drought impacts and leads to seeds with higher vigor. This research was conducted as two experiments in 2015 in seed laboratory of Yasouj University. At first experiment the seeds obtained from a former experiment included of three irrigation levels (after 75, 110 and 145 mm evaporation from class A pan) and four foliar applications included of water, zinc sulfate 3000 ppm, boric acid 2000 ppm and mixture of zinc sulfate and boric acid, were evaluated in germination experiments in 30°c. Second experiment was a factorial based on RCD with three replications. First factor was drought stress, by PEG 6000, in three levels (0, -0.2 and -0.4 Mpa), and second factor in eight levels included of seed soaking in water, ZnSo4, H3Bo3 and ZnSo4 + H3Bo3 and seed with high content of Zn , B and Zn+ B and a dry seed as control. First experiment results showed that with delaying in irrigation time, foliar application of micronutrients, compared to water foliar application, significantly increased germination traits. In second experiment, although seed soaking in nutrients, significantly decreased germination indices, but seed with high zinc and boron contents positively affected on germination vigor and antioxidant activities especially under drought stress condition.

In order to evaluate the allelopatic potential of Eucalyptus camaldulesis aquatic extract on antioxidant enzyme activities, cell membrane damage and α-amylase enzyme activity of S. halapense, thisexperiments was conducted in Islamic Azad University, Shoushtar branch at 2012. The experiment was laid out according to a Completely Randomized Design with five replications and six treatments were various concentration of E. camaldulesis aquatic extract (0, 10, 20, 30, 40, 50 and 60%). The results indicated E. camaldulesis aquatic extract application exhibited gradual rise inhibitory effect on seed germination, seedling fresh weight, antioxidants enzymes activities, and α-amylase enzyme activity. Contrary to the previous traits, elevated malondialdehyde concentration and seedling fatty acid in S. halapense seedlings were detected. The minimum α-amylase enzyme activity (3.1 and 3.5  nmol prot -1 min-2 ), seedling fresh weight (0.1 and 0.8 mg) and seed germination (54% and 42 %) showed in 40% and 50% Eucalyptus camaldulesis aquatic extract.  The highest fatty acid (23.6% and 23.1%) was noted at 40% and 50% Eucalyptus camaldulesis aquatic extract. In conclusion, E. camaldulesis aquatic extract decreased seedling growth, α-amylase enzyme activity and cell membrane stability of S. halapense seedling.

This experiment was conducted to evaluate the proline and enzymes changes after termination of chilling requirement and during heat accumulation. Four apricot cultivars including “Tabarzeh”, “Shekarpareh”,”Shamloo” and “Asgarabad” were selected at Khalaat Pooshan Agricultural Research Station, Tabriz University, Iran. In this study, changes in enzyme activity of catalase, peroxidase and superoxide dismutase as well as proline content were measured monthly just after the end of dormancy period until 50% blooming for each cultivar. Analysis of variance (ANOVA) showed that there was a significant difference in enzymes activity within different cultivars. Enzymes activity had the minimum value immediately after terminating chilling requirement while reached the maximum value during the bloom. Comparing the average superoxide dismutase, catalase and peroxidase activity in different cultivars showed that “Asgarabad“ had the highest enzyme activity in March with the 3254 Grow Degree Hour (GDH), while the least amount of enzyme activity was recorded in “Tabarze“ during February with 214 GDH. Also, significant change in proline content was revealed in studied cultivars at different sampling times, so that, the highest and lowest proline contents was observed in “Tabarzeh” with 254 GDH and “Asgaraabad” with 214 GDH, respectively.

Seed priming improves some properties of seedling. The objective of this research was to evaluate the effect of salicylic acid and gibberellins on germination characteristics and changes of biochemically of sunflower seeds under accelerated aging, experimental design was factorial with complete randomized design as base design with 3 replications. The first factor was priming by salicylic acid and gibberellin, secondary factor was combinations 4 levels of aging (0, 2, 4 and 6 days of aging at 41°C). The results showed that the priming and aging effects on germination percentage, germination index, normal seedling percentage, seedling length, vigor index, abnormal seedling percentage, catalase and ascorbate peroxidase were significant, but on mean time to germination not significant. Results showed that, the highest germination characteristics were attained from priming by salicylic acid and gibberellins under non aged conditions. Also, seed priming increases enzyme activity.