جستجوی مقالات مرتبط با کلیدواژه « پراکسیداز » در نشریات گروه « علوم پایه »

Peroxidases are one of the most applicable enzyem in the fields of industry, medicine and biotechnology. In this study, comprehensive information on the advantages and disadvantages and also applications of plant peroxidases and nanozymes (with peroxidase-like properties), are provided in a categorized manner using of numerous articles. Peroxidase enzymes are belong to the oxidoreductases group which are found in all living organisms and are classified into different classes, one of the most applicable of which is plant peroxidases. However, applications of peroxidases limit by the some factors such as high cost of purification, low stability and degradation by proteases. Todays, in order to overcome these problems, non protein substances or compounds with peroxidase-like properties, such as nanozymes, have been considered. For industrial applications, peroxidases can be provided by purification from various sources, and also their catalytic activities and stabilities can be optimized using various methods such as environmental engineering and protein engineering, whilest these methods are costly and time consuming. Peroxidase-like nanozymes can be prepared from various materials which their catalytic activities and stabilities can be optimized throuth changing of their size, shape and combination with other materials that are usually easy, fast and cheape. At the same time, problems such as storage and degradation by proteases, which are a challenge for enzymes, are not associated with the nanozymes. Overall, it seems in industrial and medical applications, plant peroxidases can replace by nanozymes.

Eryngium caucasicum from the Apiaceae family, is native to the northern regions of Iran and has significant medicinal and nutritional properties. This paper has provided detailed morpho-anatomical characteristics of the leaves, peduncles, leaf tail, stem, and roots of Eryngium caucasicum by bright-field light microscopy. Also, the amount of phenol, flavonoid, and antioxidant activity with a spectrophotometer and the analysis of essential compounds of the aerial part with GC and GCMS have been presented. Morpho-anatomical features include the dicot-like leaves with palmate venation, isolateral mesophyll with palisade tissue on the upper and lower regions of the leaf, and much reduced spongy parenchyma; characteristic arrangement of the mechanical collenchyma tissue, especially in leaves; and characteristic wrinkles in the leaf cuticle. The stem and peduncle with longitudinal ribs contain collenchyma; there is a presence of aerenchyma in the peduncle and root; calcium oxalate druses and secretory channels in all the studied plant parts; and an absence of sclerenchyma in all investigated parts of the plant. The aerial parts of E. caucasicum had 37% essential oil, 53.9 mg of flavonoids per gram of dry matter, 48.79 mg per gram of dry matter, and 62.97 percent antioxidant activity. The main compounds in the essential oil of the aerial part include Piperitone (48.78%), ß-Sesquiphellandrene (12.64%), and (Z)-Falcarinol (7.85%), and (Z) ß-Farnesene (6.36 percent).

Reactive oxygen species (ROS) at low concentrations effectively regulates intracellular pathways such as gene expression. Whereas their high concentrations are involved in the pathogenesis of many diseases by causing oxidative stress and damaging vital macromolecules. Each cell is equipped with an antioxidant defense system to neutralize high levels of ROS. Peroxidase, as an essential antioxidant enzyme, catalyzes the oxidation of various substrates using hydrogen peroxide which is a reactive oxygen species. Since, the caffeine and theobromine are widely consumed daily in the world, and their concentrations affect the activity of many enzymes. Therefore, in the present study, the inhibitory effect of these methylxanthines on peroxidase activity has been examined. The peroxidase activity is measured by a spectrophotometer at 510 nm for 3 minutes with following absorption due to the oxidation of 4-aminoantipyrine in the presence and absence of caffeine and theobromine. In this study, it was observed that both compounds had an inhibitory effect on peroxidase activity. The values of IC50 for theobromine and caffeine were obtained as 0.5 and 0.6 mmol, respectively. Moreover, the values of Km and Vmax showed that both inhibitors acted by an un-competitive mechanism of inhibition. Also, Ki values for theobromine and caffeine were calculated 0.03 and 0.08 mM, respectively. The values of Ki and IC50 for theobromine was lower than those of caffeine indicating that theobromine has a higher inhibition strength and binding affinity to the enzyme-substrate complex. Therefore, it can be concluded that theobromine has a stronger inhibitory effect on peroxidase activity.

Silicon (Si) is regarded as one of the beneficial nutrient elements for most plants. Si increases the yield and crop quality and plays an important role in plant resistance against the environmental stresses. With science development and nanoparticle production, their application in different industry such as agriculture has gained much atlention. This research was conducted in a factorial experiment based on a completely randomized design with 3 replications and 4 plants in each replicate. Foliar spray and root application were carried out using 20, 40, 60 and 80 mg L-1 micro- and nano-SiO2 at two growth stages (the first stage in 4-5 leaves of plants and second stage two weeks after first stage). Physiological characteristics including leaf relative water content, leaf and fruit carbohydrate, leaf and fruit nitrate, chlorophyll (a, b, total) and carotenoied and activity of catalase and peroxidase were measured. The results showed that applied treatments did not have any significant effect on leaf relative water content and fruit nitrate, but application of silicon increased significantly leaf and fruit carbohydrate as well as leaf nitrate. Silicon, particularly at the nanoscale, led to a significant increase of chlorophyll a, b and total, but had no significant effect on the amount of carotenoid. Application of silicon led to a significant increase of catalase activity, but had no significant effect on the activity of peroxidase. Totally, application of nano-silicon in comparison with the control and mico-silicon had the positive effects on physiological characteristics of strawberry plants. Overall, in hydroponic culture and greenhouse production of strawberries, according to the results of this research, the application of 60 mg L-1 nano-SiO2 through the root apply method is recommended.

Grapevine fanleaf virus (GFLV) is one of the most important and destructive grapevine viruses worldwide. The virus is a genus Nepovirus and is transmitted by the Xhiphinema index nematode. The present study was conducted to investigate the effect of salicylic acid foliar application on the incidence of GFLV on grapevine (Vitis vinifera L.) plants in the Faculty of Agriculture of Shiraz University in greenhouse conditions in 1398. Treatments included spraying as pretreatment and simultaneous application of salicylic acid and virus (SA + GFLV) on the leaves of biennial seedlings of white seedless cultivar in three concentrations of 50, 100 and 150 mg / l. Seedlings sprayed with potassium phosphate (without virus and salicylic acid treatment) were considered as controls. Comparison of the data mean to the effect of treatments on infected samples with GFLV showed that the highest and lowest disease progression were related to control and salicylic acid spraying before treatment with the virus, respectively. Analysis of physiological parameters showed that viral contamination and salicylic acid treatments affected cellular metabolism such as levels of pigments and proteins. The results of this study showed that the application of different concentrations of salicylic acid significantly increased the protein content of white seedless grapes. In addition, peroxidase activity and plant proline content were induced by virus inoculation simultaneous and post salicylic acid treatment. Therefore, salicylic acid treatment increased plant resistance to GFLV. The results of this study showed significant changes in metabolism and production of secondary metabolites in the plant under the influence of GFLV viral infection with salicylic acid treatments.

Selenium, a non-essential element for plants, is essential for animals as well as human beings. Although the role of selenium in plants is yet to be properly understood, previous researches have shown that this element can affect plant growth and metabolism. In this study, the effect of foliar application of selenium nanoparticles (0, 5, 10, and 20 mg/L) and sodium selenate (0, 5, 10, and 20 mg/L) on the physiological and biochemical responses of bell pepper (Capsicum anumm L.) was investigated. The potential changes in various growth and biochemical indices were evaluated in response to the treatments. According to the results, selenium treatments at concentrations of 10 and 20 mg/L reduced the biomass accumulation in both roots and shoots. These treatments also increased the content of hydrogen peroxide and malondialdehyde. The foliar application of selenium led to the increase of the concentrations of soluble phenols, proline and thiols. The activity of antioxidant enzymes including catalase, peroxidase, ascorbate peroxidase, and polyphenol oxidase were increased in response to the selenium treatments. The protease activity displayed a similar upward trend following the selenium treatments.

Portulaca oleracea L. is a medicinal plant of the family Portulacaceae. Salinity stress is one of the most important factors limiting the growth and development of plants, especially in arid and semi-arid regions. Chitosan is a biological elicitor and is a major component of the cell wall of many species of fungi. In this study effects of salinity and chitosan stress on physiological parameters and growth parameters of the Portulaca oleracea L were studied. The experiment was arranged in a randomized complete design with 3 replications. For this purpose, the plant was exposed to different treatments of NaCl (0, 25 and 35 ds m-1), chitosan (0, 0.2 and 0.4 g l-1) Plants were harvested after treatment. Different morphological and physiological parameters were studied for different treatments. By measuring growth parameters and according to broiler and halophytic characteristics of the plant, the salinity 25 ds m-1 as a favorable growth and salinity 35 dsm-1 showed a decrease in growth in the plant. Salinity stress increased catalase enzyme activity, peroxidase, polyphenoloxidase and flavonoid content but reduced anthocyanine. Interaction of salinity and Chitosan increased growth of purslane, phenol, peroxidase, polyphenoloxidase enzyme activity and reduced catalase enzyme activity and anthocyanine content. In this study chitosan is improving agent in stress conditions and improved the physiological and biochemical traits associated with oxidative stress. Considering the growing salinity of the country, it is important to use the elicitors, especially chitosan, as a biopolymer that reduces the effects of salinity stress on the Portulaca oleracea L.

In order to evaluate the effect of various irrigation regimes and different fertilizer combinations on some morphological and physiological traits of Mentha piperita, a greenhouse experiment was carried out at the research greenhouse of Ferdowsi University of Mashhad, during growing season 2017-2018. The experiment was conducted in factorial experiment based on completely randomized design with three replicates. Factors were consisted of different irrigation regimes levels: 100% FC, 75% FC and 50% FC, and different biological and chemical fertilizers combinations including:1-biochemical bacterial NPK + NPP, 2- NPP bio-fertilizer, 3-NPK, 4-micronutrient fertilizer (MIC), 5-MIC + amino acid fertilizer (AP). The results showed that interaction of irrigation regimes and different biofertilizers on Proline had different significant at 5% level. The highest proline amount (0.22 mg /g fresh weight) were obtained in irrigation of 100% FC and NPK + NPP combination fertilizer treatments. Also, the results of variance analysis showed that the main effects of irrigation regimes and fertilizer types on chlorophyll a, chlorophyll b, carotenoid, total chlorophyll, ascorbate enzyme, catalase, peroxidase and essential oil percentage were significant. The results show that biofertilizers application decreased the antioxidant enzymes activity compared to other chemical fertilizers, slowly supply of nitrogen and phosphorus through the use of bio fertilizers during plant growth, likely this could reduce the intensity of stress in plants by providing the balanced plant nutrient and enough energy to grow and survive the plant and the antioxidant enzymes activity has also decreased due to the decrease in stress.

Redroot pigweed (Amaranthus retroflexus L.) is a noxious and cosmopolitan weed that is widely distributed in different parts of the world and competes severely with crops and reduces their growth and yield. The present study was conducted to investigate the effect of drought stress on some morphological and physiological characteristics of redroot pigweed in 2018 and 2019. Treatments included different degrees of drought stress with 5 levels including 100, 75, 50, 25, and 12.5% ​​of pot water content (equivalent to no stress, light stress, moderate stress, high stress, and severe stress). Leaf number, plant height, and leaf dry weight were affected by the interaction of drought stress×years and with increasing drought stress, leaf number, plant height, and leaf dry weight decreased in both years of the experiment. With decreasing the water content of the pot, the activity of catalase and superoxide dismutase increased. The highest levels of catalase and superoxide dismutase activity (110.35 and 1433.33 units of enzyme/mg protein per minute) were observed in the second year under severe stress, respectively. Increasing the intensity of stress decreased the soluble protein content of the plant. Also, drought stress reduced plant chlorophylls a and b content, whereas, carotenoid content increased. The highest amount of carotenoids was observed in both years under severe drought stress conditions. Overall, drought stress in the second year reduced growth in redroot pigweed further but in this year, the enzyme activity ramped up further. Therefore, this plant can modify stresses and maintain its survival by changing its biochemical activity.

Supplementary irrigation moderates the damage caused by drought stress in rainfed agriculture. Meanwhile, the application of nano fertilizers and methanol as the foliar application can be considered as effective management strategies to improve production under dryland conditions. For this purpose, the effect of supplementary irrigation, nano fertilizer spraying, and methanol foliar spraying was investigated in a split-factorial experiment with four replications. The results showed that the amount of proline (31% and 26%, respectively) and antioxidant enzyme peroxidase (4.6% and 10.5%, respectively) decreased with supplementary irrigation and showed the absorption of high and low consumption essential nutrients and finally increased grain yield. In the absence of supplemental irrigation, no difference was observed between the two treatments of non-foliar spraying and foliar application of peroxidase at all levels of methanol foliar spraying; However, the amount of peroxidase in the conditions of supplementary irrigation in the non-foliar application of nano fertilizer at all levels of methanol foliar application was higher than the foliar application of nano fertilizer. Proline and peroxidase levels were reduced by methanol application in both rainfed and supplementary irrigation conditions. Foliar application of nano fertilizer increased the amount of grain protein (3.3%) by increasing the amount of nitrogen (76%) in the shoot and the amount of grain nitrogen (16%). Element uptake by plants and wheat grain enrichment depended on the type of element and the concentration of methanol in both dryland and supplementary irrigation conditions. In general, supplementary irrigation, nano fertilizer foliar application, and methanol foliar application increased wheat grain yield in dryland conditions, but in supplementary irrigation conditions, grain yield increased by 20% with increasing methanol foliar application and with more consumption Methanol had a decreasing trend; However, in the absence of supplementary irrigation, grain yield increased with increasing methanol foliar application.

The production of reactive oxygen species occurs during the natural metabolism of oxidative-breathing cells. Among reactive oxygen species, hydrogen peroxide is more dangerous to cell life due to its long half-life, meanwhile it is an important regulatory molecule in redox signaling in living things. Peroxidases are one of the key antioxidant enzymes that are widely distributed in nature and promote the oxidation of various electron donor substrates simultaneously with the decomposition of hydrogen peroxide which lead to production of water during reducing hydrogen peroxide and other hydroperoxides. Meanwhile, peroxidases, in addition to their known peroxide inhibitory properties, have physiological oxidizing functions.Based on the chemistry of the active site in the interaction with the peroxide, peroxidases are classified to non-heme and heme bearing peroxidases. The former contains heme in its catalytic center, and the latter has a reactive selenol or thiol in its active site. Iron-based plant peroxidases are divided into three classes I, II and III. Thiol plant peroxidases include glutathione peroxidase and proxy reduxins. The present article explains the structural and metabolic, and properties of peroxidases and provides certain practical procedures for determination of their enzymatic activities.

Prevalence of abiotic and biotic stresses in plants can threaten crop productions. Pistachio as a strategic crop plays an important role among Iran's export items. Today, increasing stresses, especially salinity stress, have many destructive effects. The use of growth stimulants, especially algae, can play an effective role in reducing the negative effects of such stresses. In this regard, this factorial study was conducted based on a completely randomized design with three replications. The first factor includes six treatments: control (cont), beta-carotene 1 mM (A), vitamin E 1 mM (E), beta-carotene and vitamin E (AE), spirulina microalgae extract 0.5% (SP), The mixture of beta-carotene, vitamin E and spirulina (ALL) and the second factor includes two salinity levels: control (S1) and 10 dS/m (S2). The results showed that the effect of salinity on proline, protein, catalase and peroxidase was significant. Salinity stress significantly increased the peroxidase activity in all treatments except beta-carotene and vitamin E. Also, A and E treatments significantly increased the catalase activity. Comparing to control plants, Increase in proline content in all treatments was observed at zero salinity. A significant increase in proline was observed in beta-carotene treatment at high salinity and in other cases it was not significant, which can be considered as the best compound for foliar application of pistachio seedlings under salinity stress.

Lack of rainfall and rising temperatures have caused problems in the agricultural crop cultivation in many areas. Grapevine is one of the most important economic products in horticulture. Due to the importance of grapes as important economic products in horticulture, identification and use of resistant cultivars to drought stress is one of the basic steps and the important goals this plant breeding programs. This research carried out in factorial experiment in randomized complete design with three replications in 2020. Experimental factors was include different levels of drought stress (level four 100, 75, 50 and 25% of water requirement) and grapvine cultivars (Gharashiliq (Ga), Rasmi (Ra), Aghshiliq (Ag), Copake Bogan (Co), Tukilgen (Tu) , Khalili (Kh)). The results of this study showed that with increasing drought stress level in 6 grape cultivars, plant growth parameters, relative leaf water content, photosynthetic pigment content decreased significantly (p <0.01), that the greatest decrease was observed at the stress level of 25% water requirement. Also, increasing drought stress levels the electrolyte leakage, malondialdehyde, total soluble sugars, proline and antioxidant enzymes activity content increased in more cultivars, significantly (p <0.01). Increasing drought stress to 25% field capacity, the highest and lowest leaf area decrease percentage compared to the control were observed in Copake Bogan (68%) and Gharashilig (45%) cultivars, respectively. Among the studied cultivars, the highest and lowest ion leakage content were observed in Aghshilig and Gharashilig cultivars, which had 36% and 32.8%, respectively. The highest proline content was obtained in Gharashilig cultivar (0.14 µmol g-1 FW) and the lowest was obtained in Copake Bogan cultivar (0.067 µmol g-1 FW). Also, The highest and lowest catalase enzyme content among the 6 studied grape cultivars were obtained in Gharashilig cultivar (3.02 µmol g-1 FW.min) and Copake Bogan (1.41 µmol g-1 FW.min). The highest peroxidase enzyme content was obtained in Tukilgen (5.86 µmol g-1 FW.min) and the lowest content in Rasmi (1.39 µmol g-1 FW.min) cultivar. The results showed, Aghshiligh and Copake Bogan cultivars were drought-sensitive and Garashiligh cultivars drought-tolerant and the rest are semi-drought sensitive cultivars.

Nowadays, the use of plant growth regulators has increased in improving the resistance of plants to drought stress. Therefore, in order to investigate the effect of salicylic acid on antioxidant enzymes activity and secondary metabolites of Scrophularia striata under water deficit stress, an experiment was conducted as the arrangement in a randomized complete block design with three replications in 2018 at the research greenhouse of Ilam University. Treatments included water deficit stress at four levels (100, 75, 50 and 25% of field capacity) and foliar application with salicylic acid at two levels (0 and 1.5 mM). The results showed that in 75 and 25% of field capacity with salicylic acid, malondialdehyde decreased by 17.81% and 34.04% compared with non-foliar application treatment, respectively. Also, the application of foliar spray reduced the amount of ion leakage under severe drought-stress conditions. Foliar application of salicylic acid increased total phenol content by 20.92, 33.00, 10.84 and 10.19% under 100, 75, 50 and 25%, field capacity, respectively. Under severe drought stress conditions, foliar spray with salicylic acid increased the amount of flavonol and flavonoid compared to the control. With the application of drought stress, catalase enzyme activity increased by 36.09 and 67.65%, respectively, compared to the absence of drought stress. The highest amount of peroxidase activity (1.07 units per mg protein per minute) under 25% of field capacity by application of salicylic acid was observed with the lowest amount of peroxidase activity under 100 per cent of field capacity, respectively. According to the mentioned content, it can be concluded that salicylic acid improved the growth and production of secondary metabolites (Phenol, flavonol and flavonoid) in Scrophularia striata under drought stress and non-stress conditions.

In order to investigate the effects of kaolin foliar application on growth, physiological and biochemical characteristics of some olive cultivars in Dalahu Olive Research Station in Sarpolzahab city, a factorial experiment in a randomized complete block design with three replications and two factors (cultivars) Olive and kaolin concentrations) was done in year 2020. The planting distance was 6.6 m. Experimental materials of this study were 15-year-old trees of six olive cultivars including Amphisis, Seville, Roughani, Manzanillo, Konservolia and Zard. Two stages of complete foliar application of olive trees with kaolin at zero concentrations as control (foliar application with water) and 2 and 4%, in mid-July and August (due to warm and dry weather during this period), And its effects on growth, physiological and biochemical characteristics of olive cultivars were evaluated. Tree care and maintenance operations were applied equally in all treatments. vegetative traits such as growth and diameter of the current-season shoot growth and current-season shoot diameter as well as relative leaf water content, ion leakage, leaf proline content, total soluble sugars and chlorophyll content  and catalase and peroxidase activity were recorded in different treatments and different cultivars.The results showed that the response of olive cultivars to foliar application of different levels of kaolin was different. Foliar application of kaolin improved growth traits, relative leaf water and chlorophyll content of olive cultivars under warm conditions. Also, kaolin used in olive cultivars reduced the accumulation of malondialdehyde, which was associated with increased activity of antioxidant enzymes. In general, the results of this study showed that kaolin spraying can be used to protect olive tree in warm regions.

Broccoli has been well known as a plant of high nutritional value. Application of broccoli peroxidase in different areas of clinical biochemistry, biotechnology and food industry enhances the interest for further study on the enzyme. The objective of this study was to evaluate the kinetic parameters of broccoli's peroxidase and their variations in the presence of methanolic extract of some endemic plants from Mazandaran. In this investigation, the crude extract from broccoli was homogenized, centrifuged, precipitated by ammonium sulfate and dialyzed. The enzyme activity was monitored in 414 nm with H2O2 and ABTS in phosphate-citrate buffer. The specific activity of the peroxidase was determined 0.58 U/mg in crude extract and 3.61 U/mg in dialysate. The optimum pH and temperature of the enzyme were obtained 4 and 30°C respectively. The extract of Artemisia tschernieviana, Eryngium caucasicum, Rosmarinus officinalis, Sambucus ebulus, Ligularia persica, Crataegus douglasii, Papaver rhoeas, Viscum album and Allium ursinum were prepared by maceration method. The enzyme activity was measured in presence of the extracts in different concentrations. The kinetic results shown that the extract of Crataegus douglasii, Rosmarinus officinalis, Papaver rhoeas and Artemisia tschernieviana in 33 µg/ml concentration inhibited the enzyme as 88.2, 79.5, 78.6 and 76.3% respectively. The extract of Ligularia persica shown no effect on maximum velocity of reaction while reduced the Km value by 4 times. Allium ursinu showed a partial inhibition on the peroxidase. Therefore, study on these plants for achieving to effectors on broccoli’s peroxidase, with pharmaceutical, agricultural and industrial applications could be recommended.

Allelopathic effect of weeds is one of the important factors limiting the growth and yields in crops. The aim of this study was to investigate the effect of aqueous extract of shoots (leaves and stems) of wild melon (Cucumis melo L.) on growth indices and antioxidant system of rapeseed and its accompanying wild mustard (Sinapis arvensis). This study was conducted as a split-split plot in the form of a randomized complete block design with three replications at the field level. The main plot included the target plant type at two levels (rapeseed RGS cultivar and Sinapis arvensis weed), the sub-plot included the type of organ at two levels (leaf and stem extract of wild melon) and the sub-plot of extract concentration at four levels (0 (control)) 2.5, 5, and 10%). The results showed that with increasing the concentration of wild melon leaf extract, most of the growth parameters in both target plants decreased and the intensity of this decrease was higher on the growth of Sinapis arvensis compared to rapeseed, while wild melon stem extract caused a more severe decrease in rapeseed growth parameters compared with Sinapis arvensis. Also, wild melon stem extract significantly increased catalase activity in canola compared to control and decreased peroxidase while the activity of peroxidase enzyme increased in Sinapis arvensis. Also, the increasing trend of phenolic compounds and decreasing flavonoid compounds of rapeseed leaves with increasing the concentration of extract was more dramatic and intense than Sinapis arvensis. According to the results of this study, the sensitivity of rapeseed and its associated weeds to the extracts of two wild melon organs was not the same, which should be considered in managing the use of plant allelopathy as an herbicide at field level.

Complex disease caused by the root-knot nematode, Meloidogyne javanica, and the fungus, Fusarium oxysporum f. sp. radicis-cucumerinum, has limited cucumber cultivation in Iran. Therefore, access to the nematode-resistant cultivars has a crucial role in disease control. The Assessment of plant defense compounds in the Complex disease helps understand the molecular mechanisms of resistance and the production of nematode-resistant cultivars. After inoculation of the plants in a greenhouse, the peroxidase enzyme and the phenolic compounds were measured using spectrophotometric method. The experiment was conducted based on a factorial completely randomized designed with 14 treatments, including control, fungi alone, nematode alone in four inoculations level viz. 1500, 3000, 4500, and 6000 J2s, fungus + nematode simultaneously, and fungus a week after nematode inoculation with 4 replications. Phenolic compounds increased by %54.74 and %92.34 and peroxidase enzyme activity increased by %50.64 and %63.31 in plants inoculated with fungus alone and nematode alone (6000 larvae) compared to the control, showing that these substances act as defensive compounds in cucumber. Results showed that increasing the nematode population in inoculated plants improved the defense compounds levels.  Inoculation of nematode (6000 larvae) followed by fungus led to %80 and %54.48 increases in phenolic compounds and peroxidase activity, respectively as compared with the control which might be attributed to the synergistic effects of pathogens. The fungi had a more active role than nematodes in increasing the peroxidase compared to the phenolic compounds, which indicated the complex nature of nematode parasitism in the nematode-plant interaction. Decrease in the defense compounds in Negin cultivar (susceptible to Fusarium) and increase in the level of these compounds in Khasib (tolerant to Fusarium) and Dastjerdi (tolerant to nematode) cultivars showed that the production of the defensive compounds may be related to the cucumber resistance to pathogens.