Cereals frost resistance correlates with an integral indicators of content of low-molecular-weight protective compounds and activity of antioxidant enzymes

Author(s):  
O. I. Horielova ◽  
◽  
N. I. Ryabchun ◽  
M. A. Shkliarevskyi ◽  
A. M. Reznik ◽  
...  

Along with specific adaptive reactions, universal defense reactions, in particular activation of antioxidant system, are of great importance for plant survival under cold conditions. We have studied a relationship among the content of low-molecular-weight protective compounds with antioxidant properties (proline, soluble carbohydrates, flavonoids), the activity of antioxidant enzymes (superoxide dismutase, catalase, and guaiacol peroxidase) in seedlings of winter wheat, rye and triticale, and frost resistance of etiolated seedlings and adult plants at tillering stage. It was found that there was a fairly close correlation between the frost resistance of seedlings and adult cereal plants (r = 0,78). It was shown that a pronounced relationship between individual indicators of antioxidant system functioning in unhardened seedlings and their frost resistance was not found. After 6-day hardening of seedlings at 2-4°C, there was a high correlation between the total indicator of the enzymatic antioxidant system (the sum of normalized indicators of superoxide dismutase, peroxidase, and catalase activity) and their frost resistance (r = 0,86), but the correlation coefficient of this index with frost resistance of plants in tillering phase was significantly lower (r = 0,47). At the same time, a high correlation was found between the content of low-molecular-weight protectors in hardened seedlings and frost resistance of tillering adult plants (r = 0.89). The closest correlation was observed between the integral normalized indicator, comprising the sum of normalized values of antioxidant enzymes activity and the content of low-molecular-weight protectors in hardened seedlings, and frost resistance of seedlings (r = 0,94) and plants in tillering phase (r = 0,89). A presence of specific features in the functioning of antioxidant system during cold adaptation of cereal seedlings was established. Rye is characterized by a high content of low-molecular-weight protective compounds; at the same time, increased activity of antioxidant enzymes - superoxide dismutase and catalase - was noted in wheat seedlings. In triticale, depending on the genotype, the values of both enzymatic antioxidant activity and the content of low-molecular-weight protectors varied.

Author(s):  
Alexandr I. Kokorev ◽  
◽  
Yuriy E. Kolupaev ◽  
Maxim A. Shkliarevskyi ◽  
Anna A. Lugovaya ◽  
...  

Polyamines are plant metabolites involved in many processes under physiologically normal and stressful conditions. Cadaverine is one of the least studied plant polyamines. The relationship between its physiological effects and the formation of signaling mediators, in particular, reactive oxygen species (ROS), has hardly been specially studied. The aim of this work was to study the possible protective effect of cadaverine on wheat (Triticum aestivum L.) seedlings under heat stress and its relationship with the formation and detoxification of ROS by antioxidant enzymes. Etiolated seedlings of soft winter wheat variety Doskonala were used in the work. We treated three-day-old seedlings with cadaverine at concentrations ranging from 0.05 to 2.5 mM by adding it to the root incubation medium. In some variants of the experiment, we treated seedlings with a hydrogen peroxide scavenger dimethylthiourea (DMTU - 150 μM), a diamine oxidase inhibitor aminogunidine (1 mM) or an inhibitor NADPH oxidase imidazole (10 μM), as well as the indicated inhibitors in combination with cadaverine. The hydrogen peroxide content and the activity of antioxidant enzymes were determined in the roots of seedlings a certain time after treatment with the studied compounds. One day after the treatment of seedlings with cadaverine, ROS antagonists, and a combination of effectors, the seedlings were subjected to damaging heating in a water thermostat (10 min at 45 °C). 24 h after heating, we assessed the content of the products of lipid peroxidation (LPO) in the roots and, after 3 days, the survival of seedlings. Incubation in the presence of cadaverine increased the resistance of seedlings to damaging heat (See Fig. 1). The highest relative number of surviving seedlings was observed in the variant with 1 mM cadaverine treatment. Under the effect of cadaverine, the content of hydrogen peroxide in the roots increased (See Fig. 2). We observed a noticeable effect 1-4 h after the start of treatment, with a maximum after 2 h. Treatment of seedlings with a scavenger of hydrogen peroxide DMTU removed the manifestation of the effect of an increase in the content of H2 O2 in the roots caused by the action of cadaverine (See Fig. 3). This effect was also completely eliminated by the diamine oxidase inhibitor aminoguanidine and was almost unchanged in the presence of the NADPH oxidase inhibitor imidazole. The effect of heat stress on seedlings caused an increase in the content of the LPO products in them. Treatment with cadaverine markedly reduced this manifestation of oxidative stress. The antioxidant DMTU and the diamine oxidase inhibitor aminoguanidine largely neutralized the protective effect of cadaverine (See Fig. 4a). At the same time, the NADPH oxidase inhibitor imidazole had almost no effect on the manifestation of the effect of cadaverine on the LPO products content in roots. Under the influence of DMTU and aminoguanidine, but not imidazole, the positive effect of cadaverine on the survival of seedlings after damaging heating was also leveled out (See Fig. 4b). The treatment of seedlings with cadaverine caused a change in the activity of antioxidant enzymes in the roots (superoxide dismutase - SOD, catalase, and guaiacol peroxidase) (See Fig. 5). DMTU and aminoguanidine neutralized the effect of cadaverine-induced increase in the activity of catalase and guaiacol peroxidase, but had almost no effect on the increase in SOD activity in roots induced by this diamine (See Fig. 6). The NADPH oxidase inhibitor imidazole did not significantly affect the manifestation of the effect of increasing the activity of antioxidant enzymes when seedlings are treated with cadaverine. We can conclude that one of the signaling mediators involved in the regulation activity of catalase and guaiacol peroxidase and in the induction of heat resistance of wheat seedlings by exogenous cadaverine is hydrogen peroxide, which is formed during the oxidation of cadaverine by diamine oxidase. At the same time, the modification of SOD activity in the roots of wheat seedlings with cadaverine, apparently, can occur without the participation of ROS.


2019 ◽  
Vol 26 (4) ◽  
pp. 56-65
Author(s):  
М. M. Tlish ◽  
Е. К. Popandopulo

Aim. The paper studies the dynamics of the indicators defi ning the antioxidant system (AOS) and endogenous intoxication in patients with microbial eczema (ME) prior to and following treatment.Materials and methods. The experimental group consisted of patients with ME (n=30) and the control group comprising somatically healthy individuals (n=30). In this study, we determined the components of the antioxidant defence system in blood plasma and erythrocyte suspension, as well as assessed endogenous intoxication.Results. The study revealed an imbalance of indicators refl ecting the severity of oxidative stress and endogenous intoxication in patients suffering from ME. Prior to receiving treatment, the experimental group, as compared to the control group, exhibited an increase in catalase activity (CAT) up to 35.93 [32.50; 38.22] mmol / (min • l) (p < 0.001) and glutathione peroxidase (GPx) up to 1194.27 [1069.50; 1375.78] μmol / (min • l) (p < 0.001). In addition, there was a decrease in the activity of superoxide dismutase (SOD) to 13.28 [11.35; 14.10] u/l (p < 0.001), glutathione reductase (GR) to 501.46 [479.77; 542.52] mmol / (min • l) (p < 0.001) and the concentration of reduced glutathione to 1.64 [1.59; 1.78] μmol / ml (p = 0.043). We observed no statistically signifi cant changes in the total antioxidant activity (TAA) of blood plasma (0.59 [0.55;0.62] mg/l; р = 0.375) and the sulphhydryl groups (0.44 [0.41;0.47] ODU; р =0.111). The patients with ME exhibited the syndrome of endogenous intoxication (SEI), accompanied by an increase in the content of medium and low molecular weight molecules in plasma to 12.19 [11.20; 13.37] arb. u. (p < 0.001), with their content in erythrocytes being relatively normal – 15.23 [14.26; 16.44] arb. u. (p = 0.005). Following the treatment, changes in the studied parameters were of a multidirectional character in relation to the control values. An increased level of CAT and GPx (р <0,001), as well as lower values of SOD and GR, continued to be observed (р < 0.001). The TAA in serum (p = 0.308), sulphhydryl groups (p = 0.111) and reduced glutathione (p = 0.107) did not differ signifi cantly from the control values. The treatment did not reverse the SEI: the content of medium and low molecular weight molecules continued to increase in both plasma and erythrocytes, as compared to the control values (p < 0.001 in both cases).Conclusion. The obtained data confi rm the failure of mechanisms underlying antioxidant defence in patients with ME. Despite the attempt of its compensation by increasing the catalase activity, SOD control values were still not reached. An increase in the GPx activity along with a decrease in GR was observed, which could have lead, in turn, to a decrease in the concentration of reduced glutathione. The failure of the antioxidant defence mechanisms is also indicated by an increase in the content of medium and low molecular weight molecules, as well as by the development of the SEI, resulting from the excessive formation of reactive oxygen species and the inability of the antioxidant system to neutralise them.


2001 ◽  
Vol 14 (3) ◽  
pp. 306-317
Author(s):  
Nadezhda S. Shimalina ◽  
◽  
Natal'ya A. Orekhova ◽  
Vera N. Pozolotina

There are many studies addressing plant responses to radioactive and chemical contamination of soils, but few works have been devoted to comparison of biological effects in the areas affected by these human-induced factors. Ionizing radiation and heavy metals have different mechanisms of interaction with biota. Both factors, however, are capable of increasing the generation of reactive oxygen species, which cause enzyme malfunction and cell structure damage. The efficiency of antioxidant systems plays an important role in plant resistance to these impacts. The present study offers a comparative evaluation of prooxidant/antioxidant balance in seed progeny of Plantago major L. growing in the East Ural Radioactive Trace (EURT), in the zone affected by operation of the Karabash Copper Smelter (KCS), and in the reference sites. Lipid peroxidation was assessed by determining malondialdehyde. Evaluation of the antioxidant system was based on the activities of superoxide dismutase, catalase, and total peroxidase, and on the content of low-molecular-weight antioxidants. The study showed that the prooxidant and antioxidant statuses of seed progeny of P. major from the contaminated sites were different from the reference samples and from each other. The pooled EURT sample exhibited a prooxidant shift relative to the reference samples, i. e. not only malondialdehyde but also activities of superoxide dismutase and catalase and the content of low-molecular-weight antioxidants were higher than in the reference samples. Malondialdehyde content in seedlings from the KCS zone did not differ from the reference values; superoxide dismutase and catalase activities were decreased whereas peroxidase activity was higher compared to the activities of these enzymes in the reference samples. Thus, the differences in the plant adaptive responses to ionizing radiation and heavy metals are caused by the dissimilarities in the induction of reactive oxygen species


Author(s):  
Philip O. Amira ◽  
Adebayo S. Daramola ◽  
Mike O. Sanni

Liver is a vital organ present in vertebrates, which has a wide range of functions including aiding of digestion, detoxification and protein biosynthesis. But the ability of the liver to perform these functions can be compromised by numerous substances it is daily exposed to, including certain medicinal agents which when taken in over doses. Liver damage, just like many other diseased conditions can lead to oxidative stress, especially when the body’s antioxidant system is overwhelmed by the free radicals thus generated. A major component of this antioxidant system are the natural antioxidant enzymes superoxide dismutase and catalase manufactured in the body, which provide an important defense against free radicals usually generated in diseased conditions. Most synthetic anti-hepatotoxicity drugs available present serious side effects and are generally out of reach of the common man. Consequently, the effect of administration of aqueous extract of Anacardium occidentale stem bark on the activities of superoxide dismutase and catalase in some tissues of acetaminophen-induced hepatotoxic rats was investigated. There was a significant (p < 0.05) reduction in the activities of superoxide dismutase and catalase in the serum, liver, kidney and heart of the hepatotoxic rats. However, treatment of hepatotoxic rats with aqueous extract of Anacardium occidentale stem bark led to a significant (p < 0.05) increase in the activities of superoxide dismutase and catalase in the serum, liver, kidney and heart of acetaminophen-induced hepatotoxic rats.


2014 ◽  
Vol 2 (2) ◽  
pp. 88-92 ◽  
Author(s):  
Jafar Abili ◽  
Sajjad Zare

Salinity is one of the major stresses in arid and semi-arid regions causing adverse effects at physiological, biochemical, and molecular levels, limiting crop productivity. In this research, three canola cultivars (Licord, Talayeh, Zarfam) were compared at 5 salinity levels (control, 50, 100, 150 and 200 mM) for their catalase, guaiacol peroxidase, superoxide dismutase activity,proline and yield in a completely randomized design with 3 replications. In our study, we found that NaCl concentrations greater than 150 and 200 mM caused the irreversible disorders. Increased salt concentrations led to significant changes in the levels of antioxidative enzymes and proline in three canola cultivars. Also, yield rates in three varieties decreased in the presence of NaCl concentrations.


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