The results of present study demonstrate the potential of an aqueous extract from Tagetes erecta in inducing the activity and additional isoforms of defenseenzymes of Solanum lycopersicum, not only at the site of application but also away from it (in the distal untreated leaves). This could possibly be brought about by the induction of a signal transduction mechanism mediated by secondary messengers which eventually results into the de novo expression of such defenseenzymes in the host. The induction of these enzymes could be instrumental in enhancement of host resistance against a large array of pests and pathogens.
In chilli leaf tissues, no significant difference were observed in peroxydase, PAL and PPO activity among treatments and control. All the treatments (1, 2, 3, 4 and 5) prduced defence enzymes because of the activation of defense system in chilli plants by exogenous chemical elecitors. Due to the viral infection plants treated with distilled water and control also produced four defenseenzymes. An important finding from our study revealed that all tested chemical inducers had positive effects on plant disease control in chilli plants. Tomato plants did not show symptoms it could be the tomato seeds are resistant to disease or the environmental conditions are not suitable for development of disease in tomato plants. Elicitors can be used to activate plant defensive systems at desired times; however, generally they should be applied prior to having a pest-problem so that the plant will have the best opportunity for resisting pests . Elicitors will probably not be effective in all plants since defensive systems vary with plant variety.
host from invasion by fungal pathogen and they are integral components of a general disease resistance mechanism (Verburg and Huynh, 1997). Ratnam et al. (2001) reported that with the treatment of salycilic acid (5 mM) observed an increased amount of phenol content in plant and less severity of disease the plants and developed induced systemic resistance. Trichoderma species, necro trophic mycoparasites easily isolated from the soil, are efficient in controlling plant pathogens, especially those with resistance structures, because they act through several antagonism mechanisms such as antibiosis, antibiotic production, competition, and induction of resistance in addition to growth promotion of some plants (Howell, 2003). Chitra (2004) has documented Bio control agents inoculated groundnut seeds has developed induced systemic resistance against A. alternata. Savitha (2004) observed induced systemic resistance against Alternaria blight in sesame, by seed treatment of salicylic acid and Psuedomonas fluorescens. Karthikeyan et al. (2005) reported that isolate of Psuedomonas fluorescens was found to inhibit the growth of the pathogen Alternaria palandui leaf blight in onion with the foliar spray of talc based formulation. Thus, showing treated plants showed significant increase in levels of defenseenzymes in compared to untreated plants. Chen yu et al. (2014) reported that the activity of defense related enzymes enhanced drastically including peroxidases, polyphenol oxidases and Phenylalnine ammonia lyase and induces resistance against Pencillium expansum when treated with GABA and its affectivity was high when GABA at 100 µg/ ml inoculated 24 hrs before pathogen inoculation. The above mentioned supportive findings to the present investigation done it can be concluded that in management of Alternariaster blight of sunflower induced systemic resistance is one of the best methods to enhance the production of defenseenzymes and increase resistance towards the infection. Table 4. Effect of different inducers on catalase activity in different genotypes of sunflower at
Chitosan, a polycationic biopolymer consisting of glucosamine and N-acetylglucosamine units, is found in large amounts in nature and is one of the most prevalent biological inducers which increases plants tolerance to different biotic stresses. This substance is found in insects, and most of fungi, yeast and has been proved as generally regarded as safe compound with no environmental hazards and is not toxic to mammals . The effect of chitosan on plant fungal pathogens have been reported by various research groups . These investigations have revealed that when applied before pathogen infection, chitosan is more effective compared to cases it was applied after the pathogen was developed in plant tissues. The efficiency of chitosan on disease suppression is dependent to the application dose and the virulence of the pathogen . Moret et al.  investigated the controlling effects of chitosan against cucumber powdery mildew and reported that chitosan induced plant defense responses through overexpression of defenseenzymes i.e., chitinases, chitosanases and beta- glucanases as well as increased lignin and callose deposition.
observed in the combination treatments ofTh16 + Th5 + Pf1 followed by Th16 + Th15 and Th16 + Pf1 (Fig. 7). Untreated control, or inoculated with the pathogen alone did not show any remarkable change in the activity of phenolic substances. These results clearly indicate that the defenseenzymes and PR proteins were more activated in the mixtures of bacterial bio-formulations treated plants thus strengthening the pepper veins against the abiotic stress.
Fenugreek seeds are widely used in Asia and other places of the world for their nutritive and medicinal properties. In Asia, Fenugreek seeds are also widely recommended for the geriatric populations. Here, we evaluated for the first time the effect of fenugreek seed feed supplementation on the liver antioxidant defense systems in aging mice. The study was conducted on 12 months aged mice which were given fenugreek seed dietary supplement. We have evaluated the activities of various antioxidant defenseenzymes like superoxide dismutase (SOD), glutathione reductase (GR), and glutathione peroxidase (GPx), and estimated the phenolics and free radical scavenging properties in mice liver upon fenugreek supplementation. The estimation of SOD, GPx and GR activities in aged mice liver revealed a significant (P<0.01) difference among all the liver enzymes. Overall, this study reveals that fenugreek seed dietary supplementation has a positive effect in on the activities of the hepatic antioxidant defenseenzymes in the aged mice.
Abstract: We investigated the integrated response of antioxidant defenseenzymes (total superoxide dismutase (TotSOD), manganese-containing superoxide dismutase (MnSOD), copper-zinc-containing superoxide dismutase (CuZnSOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GR) and phase II biotransformation enzyme, glutathione- S-transferase (GST)) in the liver and white muscle of females of European hake (Merluccius merluccius L.) from the Adriatic Sea (Montenegro) in winter and spring. The activity of GSH-Px in the liver was significantly increased, while GST activity was decreased in spring compared to the winter. In white muscle, the activities of TotSOD and CuZnSOD were increased, while the activities of MnSOD, CAT, GSH-Px, GR and GST were decreased in spring when compared to the matching values in winter. The activities of TotSOD and CuZnSOD in winter were markedly lower in the muscle than in the liver, while the activity of MnSOD in the muscle was higher when compared to the liver. Principal component analysis (PCA) revealed clear separation of the investigated antioxidant biomarkers between tissues and seasons, while the integrated biomarker response (IBR) showed that the most intensive antioxidant biomarker response was in the liver in spring. Star plots of IBR showed a dominant contribution of glutathione-dependent biomarkers (GSH-Px, GR and GST) and CAT in both tissues and seasons with respect to SOD isoenzymes. All enzyme activities (except MnSOD) were greater in the liver in comparison to the white muscle. Our results show that the liver possesses a greater capacity to establish and maintain homeostasis under changing environmental conditions in winter and spring. At the same time, seasonal effects are more pronounced in muscle tissue. Key words: antioxidant enzymes; marine fish; oxidative stress; seasonal; tissues
All three strains of laboratory rats used in this study reacted on the injection of Cd, but not on the exposition to Cd in water. Ognjanovic et al. (2003) observed increased activity of antioxidant defenseenzymes: copper zinc containing superoxide dismutase, catalase, glutathione peroxidase, gluta- thione reductase, and glutathione S-transferase as a response of male Wistar rats to acute exposure to Cd (0.4 mg Cd/kg of body mass). For glutathione reductase activity, the increase has been observed with the increase of applied Cd concentration for all three strains, in agreement with the literature (Ognjanovic et al. 2003; Flora et al. 2008). In the case of GST activity, a more complex dependence was observed. This could be explained by differ- ent function of these enzymes. In GST measure- ment, strain LE appeared as the most sensitive to Cd exposition – the increase of GST activity was significant already after the intraperitoneal ap- plication of 0.6 mg per 100 g body weight.
Since literatures support generation of free radicals during post ischemic/hypoxic period, here hypoxia followed by reoxygenation is dealt with as the single problem. Subsequently, as brain shows regional variations in its function and metabolic activities an attempt was made to study effect of hypoxia reoxygenation in five brain regions ie cerebrum, cerebellum, medulla, hippocampus and hypothalamus. The changes in the antioxidant defenseenzymes such as superoxide dismutase, catalase and glutathione peroxidase activity and lipid peroxidation levels in brain associated with hypoxia-reoxygenation was analyzed in this study.
In Trichoderma, mycoparasitism is one of major mechanism involved in their antagonistic activity against phytopathogens. Multiple enzymes play crucial role in mycoparasitic interaction. In this study, lytic and defenseenzymes were selected for in silico studies to improve their potential functional aspects. Due to lack of experimental structures of lytic and defence enzyme, in silico structural analysis was performed using homology modelling approach and further validated. Prediction of motifs in protein sequences allows studying conserved patterns throughout the evolutionary process. In silico identification and prediction of potential of binding site is very crucial feature of structure-based drug designing. But, here in this study, prediction of different ligand binding sites, u sin g chemical probes will provide to stu dy interaction between ligands and enzymes to improve the efficacy of biological experiment for the development of small compounds which increases the catalytic mechanism of enzymes, involves in mycoparasitism and will lead to destruction of phytopathogens. Acknowledgements
Peroxidase and polyphenol oxidase are important in the defence mechanism against pathogens, through their role in the oxidation of phenolic compounds to quinines, causing increasing in antimicrobial activity. Therefore, they may be directly involved in stopping pathogen development (Quiroga et al., 2000; Melo et al.,2006). Similarly, systemic resistance was enhanced in response to R. solanacearum inoculated tomato due to high accumulation of defenseenzymes in Trichoderma treated seedlings (Vanitha et al., 2009). However, as both peroxidase and polyphenol oxidase increases there was significant reduction in the activity of phenylalanine ammonia lyase, suggesting competition between these two enzymes and PAL or both PER and PPO suppresses the activity of PAL. Additionally, activity of PAL seems to deplete the amount of total phenols accumulated or metabolized phenolic contents in the cells of pepper seedlings as the days of assay progresses.
Plant hormones are the principal signaling components that regulate cell development and function of plants. Furthermore, current research demonstrated the role of hormones in signaling networks that control mitochondrial function and its biogenesis. Mitochondria play an important role in plant metabolism via ATP energy source through oxidative phosphorylation synthesis and other metabolic reactions. These energy blocks generated in the mitochondria provide fuel for the plant responses to biotic and abiotic stresses (Berkowitz et al., 2016). Ethylene, jasmonic acid, and salicylic acid are the featured hormonesthat interact in the defense metabolism of superior plants against pathogen attack. The jasmonic acid (JA) and ethylene (ET) act together for the regulation and activation of plant defense mechanisms against pathogens, insects, and herbivores (Lorenzo et al., 2002; Does et al., 2013; Kazan, 2015). Likewise, salicylic acid (SA) is associated with activation of proteins that assist in plant defense (Glazebrook et al., 2005) and acts as a key signaling in response of superior plants. Moreover, JA has importance in response to pathogens diversity in local and systemic (Zheng et al., 2012; Kang et al., 2014). The levels of JA and AS present variation in levels among plants and also in different tissues within the same plant (Cho et al., 2013). Ethylene has controlling action regarding the responses of other plant hormones, such as JA, SA, abscisic acid, auxin, and cytokinin (Guo and Ecker, 2005). The ET in combination with JA is required for the activation of many plant defense genes, particularly with respect to necrotrophic microorganisms. However for biotrophicmicro organisms, ethylene production generally increases plant response to pathogen attack. In
We now compare the business cycle facts observed for the series with those moments implied from the model simulation. In Table 6 we compile a selection of statistical moments for the U.S., using annual data from 1939 to 2014. Panel [a] presents the volatility of detrended series. The standard deviations of the data indicate a drastic moderation in all series, which reduces volatility by a factor ranging from 2 (consumption) to 14 (defense spending). There are also remarkable changes in the correlation coefficients for all cases, as shown in panel [b]. For instance, the correlation of output with consumption increases during the second sample, and the output-investment correlation shifts from counter- to procyclical, which could reflect a crowding-out effect from fiscal expansions during the first sample. While the correlation of non-defense spending with output changes from negative to positive between samples, that of defense spending does the opposite. In both cases, the correlation is weak in the second period. Finally, the negative correlations of debt and prices strengthen in the second sample.
done. The homogenates were centrifuged (12,000 rpm, 20 min, 4 °C), and the total soluble enzyme activities were measured spectrophotometrically in the supernatant (Hafez et al. 2014a). All measurements were carried out at 25 °C, using the model UV-160A spectrophotometer (Shimadzu, Japan). The enzymes’ assay was tested three times. Activity of catalase (CAT) was determined spectro- photometrically according to Aebi (1984). Polyphenol oxi- dase (PPO) activity was determined according to the methods described by Malik and Singh (1980). Changes in the absorbance at 495 nm were recorded every 30 s inter- vals for 3 min. Enzyme activity was expressed as the in- crease in absorbance min −1 g −1 fresh weight. Activity of peroxidase (POX) was directly determined of the crude enzyme extract, according to a typical procedure proposed by Hammerschmidt et al. (1982). Changes in absorbance at 470 nm were recorded at 30 s intervals for 3 min. En- zyme activity was expressed as increase in absorbance min −1 g −1 fresh weight.
Salicylic acid (SA) is plant hormone which is responsible in natural plant defense mechanism in response to pathogen attack and this signaling molecule is helpful in induction of resistance in plants. In case of lack of natural defense mechanism of plants, exogenous treatment of elicitor like SA (salicylic acid) and BTH (Benzothiadiazole) are helpful in the induction of resistance in plants. Enzymatic antioxidants are produced in plants and play an important role in induced systemic acquired resistance, furthermore act as a biochemical marker to evaluate the developing resistance as the result of elicitor application in plants. Mohammadi and Kazemi (2002) reported the increased activities
In the wake of the research community gaining deep understanding about control-hijacking attacks, data-oriented attacks have emerged. Among data-oriented attacks, data structure manipulation attack (DSMA) is a major category. Pioneering research was conducted and shows that DSMA is able to circumvent the most effective defenses against control-hijacking attacks — DEP, ASLR and CFI. Up to this day, only two defense techniques have demonstrated their effectiveness: Data Flow Integrity (DFI) and Data Structure Layout Randomization (DSLR). However, DFI has high performance overhead, and dynamic DSLR has two main limitations. L-1: Randomizing a large set of data structures will significantly affect the performance. L-2: To be practical, only a fixed sub-set of data structures are randomized. In the case that the data structures targeted by an attack are not covered, dynamic DSLR is essentially noneffective. To address these two limitations, we propose a novel technique, feedback-control-based adaptive DSLR and build a system named SALADSPlus. SALADSPlus seeks to optimize the trade-off between security and cost through feedback control. Using a novel feedback-control-based adaptive algorithm extended from the Upper Confidence Bound (UCB) algorithm, the defender (controller) uses the feedbacks (cost-effectiveness) from previous randomization cycles to adaptively choose the set of data structures to randomize (the next action). Different from dynamic DSLR, the set of randomized data structures are adaptively changed based on the feedbacks. To obtain the feedbacks, SALADSPlus inserts canary in each data structure at the time of compilation. We have implemented SALADSPlus based on gcc-4.5.0. Experimental results show that the runtime overheads are 1.8%, 3.7%, and 5.3% when the randomization cycles are selected as 10s, 5s, and 1s respectively.
All data were analyzed with SPSS v.20. Frequencies (%) were calculated for categorical variables and mean (SD) for quantitative variables. Thereafter, two step cluster- ing analysis was run to identify clusters of students with a homogenous groups of ego defense styles, comparable academic performance and reporting similar severity lev- els of anxiety and depressive symptomatology. Individual ego defense mechanisms were introduced as evaluation fields. Quintessentially, the two step clustering algorithm is a scalable cluster analysis that is capable of analyzing both continuous and categorical variables by utilizing the model-based distance measure and automatically retains the optimal number of clusters . All continuous vari- ables were standardized into z-scores before running the cluster analysis . Log-likelihood based distance meas- ure was employed with the best clustering solution based on the Akaike Information Criterion (AIC) . The sil- houette measure of cohesion and separation was used to evaluate the goodness of fit of the clustering solution, where a value > 0.50 represents a good solution .