scholarly journals Up-Regulation of Antioxidants in Tobacco by Low Concentrations of H2O2 Suppresses Necrotic Disease Symptoms

2012 ◽  
Vol 102 (9) ◽  
pp. 848-856 ◽  
Author(s):  
Yaser Mohamed Hafez ◽  
Renáta Bacsó ◽  
Zoltán Király ◽  
András Künstler ◽  
Lóránt Király

Pretreatment of tobacco leaves with low concentrations (5 to 10 mM) of H2O2 suppressed hypersensitive-type necrosis associated with resistance to Tobacco mosaic virus (TMV) or Pseudomonas syringae pv. phaseolicola. The same pretreatment resulted in suppression of normosensitive necrosis associated with susceptibility to Botrytis cinerea. This type of H2O2-mediated, induced disease symptom resistance correlated with enhanced host antioxidant capacity, i.e., elevated enzymatic activities of catalase (CAT), ascorbate peroxidase (APX), and guaiacol peroxidase (POX) after viral and bacterial infections. Induction of genes that encode the antioxidants superoxide dismutase (SOD), CAT, and APX was also enhanced early after TMV infection. Artificial application of SOD and CAT suppressed necroses caused by viral, bacterial, or fungal pathogens similarly as H2O2 pretreatment, implying that H2O2-mediated symptom resistance operates through enhancement of plant antioxidant capacity. Pathogen multiplication was not significantly affected in H2O2-pretreated plants. Salicylic acid (SA), a central component of plant defense, does not seem to function in this type of H2O2-mediated symptom resistance, indicated by unchanged levels of free and bound SA and a lack of early up-regulation of an SA glucosyltransferase gene in TMV-infected H2O2-pretreated tobacco. Taken together, H2O2-mediated, induced resistance to necrotic symptoms in tobacco seems to depend on enhanced antioxidant capacity.

2013 ◽  
Vol 11 (2) ◽  
pp. 123-132
Author(s):  
Dragoljub Miladinović ◽  
Budimir Ilić ◽  
Stevo Najman ◽  
Olga Cvetković ◽  
Aleksandra Šajnović ◽  
...  

AbstractThe aim of this study was to research the seasonal changes of antioxidant enzyme activity and total antioxidant capacity in leaves of Astragalus onobrychis L. subsp. chlorocarpus (Griseb.) S. Kozuharov et D.K. Pavlova. Leaves of A. onobrychis were collected during the different stages of growth and analyzed for antioxidant enzyme activity: superoxide dismutase, catalase, guaiacol peroxidase, glutathione peroxidase. Quantities of malonyldialdehyde, superoxide radicals, and hydroxyl radicals were measured as well as the content of soluble proteins. Furthermore, total antioxidant capacity was determined by the inhibition of chemiluminescence activity of blood phagocytes by leaf extracts. Stages of vegetation significantly affected the accumulation of superoxide radicals, but there were no significant differences in hydroxyl radical quantity and lipid peroxidation levels during vegetation. Soluble proteins vary greatly between different stages of growth. Seasonal changes were found to have an effect on enzymatic activities. During the spring season, guaiacol peroxidase showed the highest levels. Catalase and glutathione peroxidase increased their activities in summer, while, during the autumn season, superoxide dismutase showed maximum activity. On the basis of chemiluminescence assay, it can be concluded that leaf extract of A. onobrychis possesses a significant antioxidant capacity thus protecting plants during environmental stress.


2012 ◽  
Vol 7 (6) ◽  
pp. 1101-1108
Author(s):  
Slavko Kevrešan ◽  
Ivana Maksimović ◽  
Boris Popović ◽  
Dubravka Štajner ◽  
Marina Putnik-Delić ◽  
...  

AbstractThis work presents a study of the effect of foliar and root application of low concentrations (0.1–10 µM) of potassium naphthenate on the antioxidative status of cucumber (Cucumis sativus L.), assessed for both local and systemic organs. Changes in the contents of proline and glutathione indicate that the treatment of plants with potassium naphthenate can be characterized as a mild abiotic stress. The antioxidative system of cucumber plants is sensitive to such treatment, since organs directly exposed to the chemical showed a decrease in total antioxidant activities and an increase in peroxidation. In the organs that were not directly treated, an increase in the total antioxidative activity was observed only at the lowest naphthenate concentration while at higher concentrations this activity tended to decrease. As far as the activities of antioxidant enzymes (guaiacol peroxidase, superoxide dismutase, catalase) are concerned, the responses observed differed between enzymes for a given treatment, but showed similar trends within treated local and untreated systemic organs.


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.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 547a-547
Author(s):  
Geunhwa Jung ◽  
James Nienhuis ◽  
Dermot P. Coyne ◽  
H.M. Ariyarathne

Common bacterial blight (CBB), bacterial brown spot (BBS), and halo blight (HB), incited by the bacterial pathogens Xanthomonas campestris pv. phaseoli (Smith) Dye, Pseodomonas syringae pv. syringa, and Pseudomonas syringae pv. phaseolicola, respectively are important diseases of common bean. In addition three fungal pathogens, web blight (WB) Thanatephorus cucumeris, rust Uromyces appendiculatus, and white mold (WM) Sclerotinia sclerotiorum, are also destructive diseases attacking common bean. Bean common mosaic virus is also one of most major virus disease. Resistance genes (QTLs and major genes) to three bacterial (CBB, BBS, and HB), three fungal (WB, rust, and WM), and one viral pathogen (BCMV) were previously mapped in two common bean populations (BAC 6 × HT 7719 and Belneb RR-1 × A55). The objective of this research was to use an integrated RAPD map of the two populations to compare the positions and effect of resistance QTL in common bean. Results indicate that two chromosomal regions associated with QTL for CBB resistance mapped in both populations. The same chromosomal regions associated with QTL for disease resistance to different pathogens or same pathogens were detected in the integrated population.


2013 ◽  
Vol 103 (6) ◽  
pp. 538-544 ◽  
Author(s):  
Glenna M. Malcolm ◽  
Gretchen A. Kuldau ◽  
Beth K. Gugino ◽  
María del Mar Jiménez-Gasco

Much of the current knowledge on population biology and ecology of soilborne fungal pathogens has been derived from research based on populations recovered from plants displaying disease symptoms or soil associated with symptomatic plants. Many soilborne fungal pathogens are known to cause disease on a large number of crop plants, including a variety of important agronomical, horticultural, ornamental, and forest plants species. For instance, the fungus Verticillium dahliae causes disease on >400 host plants. From a phytopathological perspective, plants on which disease symptoms have not been yet observed are considered to be nonhosts for V. dahliae. This term may be misleading because it does not provide information regarding the nature of the plant–fungus association; that is, a nonhost plant may harbor the fungus as an endophyte. Yet, there are numerous instances in the literature where V. dahliae has been isolated from asymptomatic plants; thus, these plants should be considered hosts. In this article, we synthesize scattered research that indicates that V. dahliae, aside from being a successful and significant vascular plant pathogen, may have a cryptic biology on numerous asymptomatic plants as an endophyte. Thus, we suggest here that these endophytic associations among V. dahliae and asymptomatic plants are not unusual relationships in nature. We propose to embrace the broader ecology of many fungi by differentiating between “symptomatic hosts” as those plants in which the infection and colonization by a fungus results in disease, and “asymptomatic hosts” as those plants that harbor the fungus endophytically and are different than true nonhosts that should be used for plant species that do not interact with the given fungus. In fact, if we broaden our definition of “host plant” to include asymptomatic plants that harbor the fungus as an endophyte, it is likely that the host ranges for some soilborne fungal pathogens are much larger than previously envisioned. By ignoring the potential for soilborne fungal pathogens to display endophytic relationships, we leave gaps in our knowledge about the population biology and ecology, persistence, and spread of these fungi in agroecosystems.


Antibiotics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 335
Author(s):  
Anssi Karvonen ◽  
Ville Räihä ◽  
Ines Klemme ◽  
Roghaieh Ashrafi ◽  
Pekka Hyvärinen ◽  
...  

Environmental heterogeneity is a central component influencing the virulence and epidemiology of infectious diseases. The number and distribution of susceptible hosts determines disease transmission opportunities, shifting the epidemiological threshold between the spread and fadeout of a disease. Similarly, the presence and diversity of other hosts, pathogens and environmental microbes, may inhibit or accelerate an epidemic. This has important applied implications in farming environments, where high numbers of susceptible hosts are maintained in conditions of minimal environmental heterogeneity. We investigated how the quantity and quality of aquaculture enrichments (few vs. many stones; clean stones vs. stones conditioned in lake water) influenced the severity of infection of a pathogenic bacterium, Flavobacterium columnare, in salmonid fishes. We found that the conditioning of the stones significantly increased host survival in rearing tanks with few stones. A similar effect of increased host survival was also observed with a higher number of unconditioned stones. These results suggest that a simple increase in the heterogeneity of aquaculture environment can significantly reduce the impact of diseases, most likely operating through a reduction in pathogen transmission (stone quantity) and the formation of beneficial microbial communities (stone quality). This supports enriched rearing as an ecological and economic way to prevent bacterial infections with the minimal use of antimicrobials.


Plants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1095
Author(s):  
Ke Jiang ◽  
Yong Kuang ◽  
Liying Feng ◽  
Yuhao Liu ◽  
Shu Wang ◽  
...  

Chinese chive usually becomes decayed after a short storage time, which was closely observed with the redox imbalance. To cope with this practical problem, in this report, molecular hydrogen (H2) was used to evaluate its influence in maintaining storage quality of Chinese chive, and the changes in antioxidant capacity were also analyzed. Chives were treated with 1%, 2%, or 3% H2, and with air as the control, and then were stored at 4 ± 1 °C. We observed that, compared with other treatment groups, the application of 3% H2 could significantly prolong the shelf life of Chinese chive, which was also confirmed by the obvious mitigation of decreased decay index, the loss ratio of weight, and the reduction in soluble protein content. Meanwhile, the decreasing tendency in total phenolic, flavonoid, and vitamin C contents was obviously impaired or slowed down by H2. Results of antioxidant capacity revealed that the accumulation of reactive oxygen species (ROS) and hydrogen peroxide (H2O2) was differentially alleviated, which positively matched with 2,2-Diphenyl-1-picrylhydrazyl (DPPH) scavenging activity and the improved activities of antioxidant enzymes, including superoxide dismutase (SOD), guaiacol peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX). Above results clearly suggest that postharvest molecular hydrogen application might be a potential useful approach to improve the storage quality of Chinese chive, which is partially achieved through the alleviation of oxidative damage happening during the storage periods. These findings also provide potential theoretical and practical significance for transportation and consumption of perishable vegetables.


2017 ◽  
Vol 74 (5) ◽  
pp. 519 ◽  
Author(s):  
Bela R. Turk ◽  
Benjamin E. Theisen ◽  
Christina L. Nemeth ◽  
Joel S. Marx ◽  
Xiaohai Shi ◽  
...  

Cephalalgia ◽  
1994 ◽  
Vol 14 (3) ◽  
pp. 215-218 ◽  
Author(s):  
T Shimomura ◽  
H Kowa ◽  
T Nakano ◽  
A Kitano ◽  
H Marukawa ◽  
...  

Superoxide dismutase (SOD) is a radical-scavenging enzyme. We determined Cu, Zn-SOD concentrations and activities in platelets from subjects with migraine and tension-type headaches. Thirty migraine without aura (MWoA) patients, 9 migraine with aura (MWA) patients, and 53 tension-type headache patients were selected for study. Thirty healthy volunteers composed the control group. Concentrations of platelet SOD were determined using enzyme-linked immunosorbent assay techniques. The activity of platelet SOD was determined by measuring reductivity of nitroblue tetrazolium. Low concentrations of platelet SOD were found in patients with MWA and MWoA. Platelet SOD activity decreased in MWA patients but not in patients with MWoA or tension-type headaches. These findings suggest vulnerability to oxidative stress in patients with migraine. It is suggested that low platelet SOD levels may play an important role in the etiology of migraine.


1994 ◽  
Vol 40 (8) ◽  
pp. 630-636
Author(s):  
J. I. Pounder ◽  
A. J. Anderson

Survival of pseudomonads during plant colonization may involve bacterial catalases to degrade the hydrogen peroxide produced by the plant. The specific activities of catalases in lysates from two saprophytic isolates of Pseudomonas putida and Pseudomonas fluorescens and three races of Pseudomonas syringae pv. glycinea were similar. To explore the location of the bacterial catalases, cells of the pathogenic and saprophytic pseudomonads were treated with chloroform, which is reported to release periplasmic proteins. Although catalase was released by chloroform treatment, the cytoplasmic enzymes isocitrate dehydrogenase, superoxide dismutase, and glucose-6-phosphate dehydrogenase were also detected. These proteins may have come from lysis of a small proportion of the cells rather than the periplasm. Water treatment of cells also released amounts of protein similar to those derived from chloroform treatment. Similar responses were found from both pathogenic and saprophytic strains. The release of catalase and proteins from the leaf pathogen P. syringae pv. glycinea race 0 and the root-associated saprophyte P. putida decreased as the cultures aged. With P. putida and P. syringae pv. glycinea race 0, the single isozyme of catalase released by water and chloroform treatment also was detected in lysates. Additional catalase isozymes were present in lysates as the cultures aged.Key words: periplasmic proteins, survival.


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