جستجوی مقالات مرتبط با کلیدواژه « ascorbate » در نشریات گروه « زیست شناسی »

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.

Drought is one of the most serious threats in agricultural production worldwide, and climate change is likely to exacerbate this threat. In order to evaluate the drought tolerance of different castor ecotypes, a factorial experiment was conducted in a completely randomized design with three replications in Sari Agricultural Sciences and Natural Resources University. The first factor was 22 castor ecotypes and the second factor was drought stress with 5 levels, full irrigation, four levels (irrigation was cuted at the primary of spike growth) (11, 22, 33, 44 days after Irrigation cut off). Experimental traits were included the activity of the antioxidant enzymes Catalase, Guaiacol peroxidase and Ascorbate peroxidase, the biochemical activity of Malondialdehyde (MDA), Proline content, Plant height, stem diameter and number of leaves. Cluster analysis classified the ecotypes into three clusters under normal and drought stress conditions.The results showed that the activity of Catalase, Ascorbate peroxidase, Guaiacol peroxidase, Malondialdehyde and Proline content under drought stress conditions of the third group (Tolerant) compared to the first group (Sensitive) were increased 81.5, 81.87, 70.27, 80.05, 81.87, respectively. On the other hand, the differences between tolerant and sensitive groups at stress conditions in plant height, stem diameter and number of leaves were 74.74, 80.50 and 83.38%, respectively. The highest correlation under drought stress conditions was observed between Catalase and Ascorbate peroxidase (r = 0.997) and the lowest non-significant correlation was observed between proline and plant height (r = 0.292). According to the results, in terms of the studied traits 5 and 19 ecotypes were introduced as drought tolerant ecotypes.

In order to evaluate the effect of ascorbic acid and folic acid on germination parameters under drought and salinity stress, two separate experiments was carried out in completely randomized factorial design with Azar2 Wheat cultivar. In this experiment, wheat seeds were pretreated for 16 hours with concentration of zero (control), 0.5 and 1 mM of ascorbic acid and 25 and 50 μM folic acid. Seeds were then dried at room temperature until the initial weight. To apply drought and salinity stress the solution of polyethylene glycol 6000 at 0 (control), -6 and -12 bar and sodium chloride at zero, 75 and 150 mM concentration were used, , respectively. Subsequently, petri dishes containing wheat seeds were kept at temperature of 24±1°C, 70% relative humidity and darkness condition for 8 days. After the mentioned time, germination percentage, germination rate, root and shoot length and seedling dry weight were measured. The results showed that seed treatment with vitamins, even in favorable conditions, with reduction of the loss of seed reserves, can help more allocation of seed reserves at formation of seedling structure, and cause to generate of stronger seedlings. Under drought and salinity stress conditions, seed treatment with ascorbic and folic acid, by creating appropriate conditions, can prevent damages caused by generate reactive oxygen species or prevent from their production, which the result of its, is the absent expression of oxidative stress on in seed germination. These factors result in increasing growth respiration rate and formation of stronger seedlings. Therefore, increasing the amount of mentioned vitamins in seeds can improve the metabolic function, especially in difficult environmental situations and contribute in better seedling establishment.

Copper is one of the heavy toxic metals that its toxicity is currently under investigation, in different plant types considering physiologic, biological, molecular, cellular and genetic aspects. In this research the copper toxicity effect on some of physiological activity of "Brassica napus L." Hylo 401 and RGS has been student. Seed of Brassica were cultured in hydroponic environmental. Roots and shoots used for evaluation of different treatments: Cu (5, 15, 25μm/l), Cu & AsA (0.5μm/l), Cu & GA3 (0.05μm/l) and Cu, AsA & Ga3 (as above), experiments were done in three replications in each treat group. In both Hyola 401 and RGS following factors were decreased significantly (p<0.05); germination percent, unsoluble sugar, K+ ions (in shoot and root). In both Hyola and RGS following factors were increased significantly (P<0.05) soluble sugar, proline. The finding of the study suggest that upon copper stress, in majority of studied parameters, Hyola 401 was more resistant than RGS. AsA treatment accompanying Cu, attenuated Cu effects on Brassica seedling, however GA3 exaggerated the Cu effects. Collected data were exracted and statistical analysis with SPSS statistical software 14th edition, performed. The results suggest that Cu induces inhibitory effects on growth and some of physiologic activities of plnant.

Drought stress is one of the abiotic stresses that induces reactive oxygen species(ROS) formation in plant tissues. ROS signaling promotes complex networks of antioxidant enzymes. Ascorbic acid is an important buffer protects cellular structures against oxidative attack in plants. Effect of drought stress on catalase (CAT), ascorbate peroxidase (APX) and polyphenol oxidase (PPO) enzyme activities was evaluated in the presence and absence of ascorbate in herbal aromatic plant Pimpinella anisum L. with great value of export that exposed to controlled water deficit. This study was done in flower pot condition. Biochemical and physiological properties measured randomly in control groups and treatments (with drought 60% and 25% of field capacity and ascorbate with concentration of 1.4 mM). Results showed that with increasing stress levels in leaves CAT, APX and PPO enzyme activities increased significantly in the presence and absence of ascorbate. Activity of root CAT and APX with and without ascorbate at the level of drought 60% increased significantly and at the level 25% of field capacity decreased to the level of control. However ascorbate treatment increased significantly the root enzymatic activities in whole stress levels.

In different stress such as salinity, strong oxidant as Reactive Oxygen Species is produced that damages to membrane structure in plant. Different antioxidant as ascorbate scavenger them. In this research Soybean (Glycine max</em> L. cv DPX) in different concentrations of ascorbate (1,2mM) and NaCl (50mM) and the effect of them on germination percentage, radicle length and antioxidant enzymes such as catalase, peroxidase, polyphenol oxidase and ascorbate peroxidase was evaluated. The results of this research showed that in absence of ascorbate and present of NaCl activity of enzymes increased but with increasing of ascorbate, activity of them decreased. Also in present of NaCl germination decreased but in NaCl and ascorbate germination increased significantly.

Salinity stress is an important environmental factor that limits plant growth and production. The harmful effects of salinity on plants have been identified either in the form of plant death or in the form of reduced growth. During salinity stress, various types of reactive oxygen species (ROS) are produced. These radicals give their energy to biological molecules or even react with them and cause their destruction. During salinity stress, protective systems called antioxidant system are activated and control ROS levels in the plant. One of these protective systems is ascorbic acid, which plays an important role in eliminating ROS in plants. In this research, soybean plants were affected by different concentrations of ascorbate (1, 2 mmol) and salt (50 and 150 mmol) and their effects on proline, glycine betaine, phenolic compounds, soluble sugars, sodium and chlorine were evaluated in both aerial and underground parts. it placed. The results of this research showed that in the presence of salt, the amount of sodium, chlorine and the above organic compounds increased, but their amount decreased with the addition of ascorbate.