Generation and scavenging of reactive oxygen species in wheat flag leaves under combined shading and waterlogging stress

2012 ◽  
Vol 39 (1) ◽  
pp. 71 ◽  
Author(s):  
Huawei Li ◽  
Jian Cai ◽  
Fulai Liu ◽  
Dong Jiang ◽  
Tingbo Dai ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Antioxidative Enzymes ◽  
Reductase Activity ◽  
Reactive Oxygen ◽  
Kernel Weight ◽  
Maximum Efficiency ◽  
Monodehydroascorbate Reductase ◽  
Photochemical Quenching ◽  
Oxygen Species ◽  
Psii Photochemistry

Wheat (Triticum aestivum L.) plants were subjected to combined waterlogging and shading (WS) at 0–7, 8–15, 16–23 and 24–31 days after anthesis (DAA). WS at 0–7, 8–15, 16–23 and 24–31 DAA caused a yield loss of 17.18%, 14.98%, 7.93% and 7.05%, respectively. These losses were related to reductions in post-anthesis photoassimilate accumulation and 1000-kernel weight. WS reduced net photosynthetic rate (Pn), the maximum efficiency of PSII photochemistry under dark adaptation, actual photosynthetic efficiency and the photochemical quenching coefficient, but increased the quantum yield of quenching. WS caused enhanced concentrations of malondialdehyde and H2O2, and an increased superoxide anion release. Superoxide dismutase and catalase activity were stimulated at 4 days after the onset of WS at 0–7 and 8–15 DAA, but decreased at 8 days after the onset of WS at 0–7, 8–15 and 16–23 DAA. Ascorbate peroxidase, glutathione reductase, dehydroascorbate reductase and monodehydroascorbate reductase activity increased during 0–8 days after the onset of WS at 0–7, 8–15 and 16–23 DAA. At 16–24 DAA, Pn, the level of reactive oxygen species and activity of the antioxidative enzymes fully recovered in plants subjected to WS at 0–7 DAA, but only partially recovered under WS at 8–15 DAA. Expression of the photosythesis-responsive genes RcaB and Cab, and the antioxidative enzyme-related genes Mn-SOD, Cu/Zn-SOD, CAT and GR were consistent with the performance of Pn and the activity of the antioxidative enzymes.

Ascorbate and glutathione metabolism during development and desiccation of orthodox and recalcitrant seeds of the genus Acer

2007 ◽  
Vol 34 (7) ◽  
pp. 601 ◽  
Author(s):  
Stanislawa Pukacka ◽  
Ewelina Ratajczak
Keyword(s):  
Reactive Oxygen Species ◽  
Desiccation Tolerance ◽  
Reactive Oxygen ◽  
Redox Status ◽  
Seed Maturation ◽  
Monodehydroascorbate Reductase ◽  
Acer Pseudoplatanus ◽  
Oxygen Species ◽  
Norway Maple ◽  
Glutathione Cycle

The ascorbate–glutathione system was studied during development and desiccation of seeds of two Acer species differing in desiccation tolerance: Norway maple (Acer platanoides L., orthodox) and sycamore (Acer pseudoplatanus L., recalcitrant). The results showed remarkable differences in the concentration and redox balance of ascorbate and glutathione between these two kinds of seeds during development, and a significant dependence between glutathione content and acquisition of desiccation tolerance in Norway maple seeds. There were relatively small differences between the species in the activities of enzymes of the ascorbate–glutathione cycle: ascorbate peroxidase (APX, EC 1.11.1.11), monodehydroascorbate reductase (MR, EC 1.6.5.4), dehydroascorbate reductase (DHAR, EC 1.8.5.1), and glutathione reductase (GR, EC 1.6.4.2). At the end of seed maturation, ascorbic acid content and the activities of the above enzymes was about the same in both species The electrophoretic pattern of APX isoenzymes was also similar for both species, and the intensity of the bands decreased at the end of seed maturation in both species. When sycamore seeds were desiccated to a moisture content of less than 26%, there was a marked decrease in seed viability and an increase in the production of reactive oxygen species. During desiccation, Norway maple seeds had a more active defence system, which was reflected in a higher glutathione content, a higher glutathione redox status, a higher ascorbate redox status, and higher activities of APX, MR, DHAR, GR and GPX (glutathione peroxidase). During desiccation, sulfhydryl-to-disulfide transition into proteins was more intense in Norway maple seeds than sycamore seeds. All of these results suggest that, in orthodox seeds, the ascorbate–glutathione cycle plays an important role in the acquisition of tolerance to desiccation, in protein maturation, and in protection from reactive oxygen species.

Combined effect of beauvericin and T-2 toxin on antioxidant defence systems in cherry tomato shoots

2014 ◽  
Vol 7 (2) ◽  
pp. 207-215 ◽  
Author(s):  
C. Paciolla ◽  
A. Florio ◽  
G. Mulè ◽  
A.F. Logrieco
Keyword(s):  
Reactive Oxygen Species ◽  
Biological Activities ◽  
Fusarium Species ◽  
Reactive Oxygen ◽  
Monodehydroascorbate Reductase ◽  
Combined Effects ◽  
Oxygen Species ◽  
Cherry Tomato ◽  
Chemical Structures ◽  
Glutathione Cycle

During their life cycle, plants can undergo simultaneous attack by different pathogens that produce various toxins. It is well known that in some plant-fungal interactions, mycotoxins play an important role in pathogenesis and induce a reactive oxygen species increase. Plants counteract the overaccumulation of reactive oxygen species by reinforcing their defence systems. The mycotoxins T-2 toxin (T-2) and beauvericin (BEA) are produced by some Fusarium species and have different chemical structures, mechanisms of action and biological activities. In this study, the individual and combined effects of these two toxins on defence systems, such as the ascorbate-glutathione cycle and peroxidases, were evaluated in cherry tomato shoots. Hydrogen peroxide content as an index of oxidative stress was also measured. Inhibitory effects on ascorbate peroxidase, dehydroascorbate reductase and ascorbate, and stimulatory effects on glutathione reductase, monodehydroascorbate reductase and reduced glutathione were observed when tomato plants were simultaneously treated with BEA and T-2. The trend of these biochemical parameters highlight the presence of a range of defence mechanisms activated by plants in response to mycotoxins. The interaction between BEA and T-2 resulting in synergistic and/or antagonistic effects on the studied defence systems is also discussed. It is concluded that the effects of these mycotoxins alone are not predictive of their combined effects.

Lymphokine-activated killer cell susceptibility in epirubicin-resistant and parental human non-small cell lung cancer (NSCLC)

Biologia ◽  
2007 ◽  
Vol 62 (2) ◽  
Author(s):  
Aysun Ozkan
Keyword(s):  
Reactive Oxygen Species ◽  
Defense Mechanism ◽  
Reductase Activity ◽  
Combined Treatment ◽  
Killer Cell ◽  
Reactive Oxygen ◽  
Fold Increase ◽  
Negative Control ◽  
Lak Cells ◽  
Oxygen Species

AbstractThe aim of this study was to evaluate that: (i) epirubicin-HCl (EPI) and lymphokine-activated killer (LAK) cells cytotoxicity may be mediated by free radical generation; and (ii) resistant H1299 cells may be more sensitive to combined treatment of LAK cells plus EPI than the LAK or EPI treatment alone. Viability of H1299 cells treated with EPI, LAK and LAK plus EPI was measured using the MTT test. Amount of glutathione (GSH), protein content and enzymatic activity were measured by spectrophotometer. Glutathione S-transferase (GST)-pi expression in the cells was determined by western blot analysis. LAK plus EPI combined treatment increased susceptibility of H1299 WT and H1299 EPI(R) (300-fold EPI resistant) cells to LAK cell cytotoxicity. The resistance of H1299 EPI(R) cells to EPI appears to be associated with a developed tolerance to free radicals, most likely because of a 2-fold increase in NADPH-dependent-cytochrome-P450 reductase (NADPH-CYP reductase) activity, 11-fold GST activity and 11-and 7-fold augmented selenium dependent and independent glutathione peroxidase (GSH-Px) activity, respectively. Amount of GST-pi in H1299 EPI(R) cells is statistically different from negative control and H1299 WT (p < 0.01). It is proposed that production of reactive oxygen species and hydrogen peroxide by the treatment of EPI and LAK cells can cause cytotoxicity of H1299 WT and H1299 EPI(R) cells. Superoxide dismutase, catalase, GSH-Px, GST, NADPH-CYP reductase and GSH must be considered as part of the intracellular antioxidant defense mechanism of H1299 WT and H1299 EPI(R) cells against reactive oxygen species. Combined treatment of EPI plus LAK cells caused the increasing cytotoxicity on the H1299 EPI(R) cells.

scholarly journals Priming with γ-Aminobutyric Acid against Botrytis cinerea Reshuffles Metabolism and Reactive Oxygen Species: Dissecting Signalling and Metabolism

Antioxidants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1174
Author(s):  
Henry Christopher Janse van Rensburg ◽  
Wim Van den Ende
Keyword(s):  
Reactive Oxygen Species ◽  
Nitrate Reductase ◽  
Botrytis Cinerea ◽  
Reductase Activity ◽  
Reactive Oxygen ◽  
Aminobutyric Acid ◽  
Guaiacol Peroxidase ◽  
Oxygen Species ◽  
Biotic Stresses ◽  
Ros Burst

The stress-inducible non-proteinogenic amino acid γ-aminobutyric acid (GABA) is known to alleviate several (a)biotic stresses in plants. GABA forms an important link between carbon and nitrogen metabolism and has been proposed as a signalling molecule in plants. Here, we set out to establish GABA as a priming compound against Botrytis cinerea in Arabidopsis thaliana and how metabolism and reactive oxygen species (ROS) are influenced after GABA treatment and infection. We show that GABA already primes disease resistance at low concentrations (100 µM), comparable to the well-characterized priming agent β-Aminobutyric acid (BABA). Treatment with GABA reduced ROS burst in response to flg22 (bacterial peptide derived from flagellum) and oligogalacturonides (OGs). Plants treated with GABA showed reduced H2O2 accumulation after infection due to increased activity of catalase and guaiacol peroxidase. Contrary to 100 µM GABA treatments, 1 mM exogenous GABA induced endogenous GABA before and after infection. Strikingly, 1 mM GABA promoted total and active nitrate reductase activity whereas 100 µM inhibited active nitrate reductase. Sucrose accumulated after GABA treatment, whereas glucose and fructose only accumulated in treated plants after infection. We propose that extracellular GABA signalling and endogenous metabolism can be separated at low exogenous concentrations.

scholarly journals The Effect of Environmental pH during Trichothecium roseum (Pers.:Fr.) Link Inoculation of Apple Fruits on the Host Differential Reactive Oxygen Species Metabolism

Antioxidants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 692
Author(s):  
Zhanhong Han ◽  
Zhenyu Wang ◽  
Yang Bi ◽  
Yuanyuan Zong ◽  
Di Gong ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Reactive Oxygen ◽  
Host Susceptibility ◽  
Cell Membrane Permeability ◽  
Monodehydroascorbate Reductase ◽  
Fungal Colonization ◽  
H2o2 Production ◽  
Oxygen Species ◽  
Trichothecium Roseum ◽  
Apple Fruits

Trichothecium roseum is an important postharvest pathogen, belonging to an alkalizing group of pathogens secreting ammonia during fungal growth and colonization of apple fruits. Fungal pH modulation is usually considered a factor for improving fungal gene expression, contributing to its pathogenicity. However, the effects of inoculation with T. roseum spore suspensions at increasing pH levels from pH 3 up to pH 7, on the reactive oxygen species (ROS) production and scavenging capability of the apple fruits, affecting host susceptibility, indicate that the pH regulation by the pathogens also affects host response and may contribute to colonization. The present results indicate that the inoculation of T. roseum spores at pH 3 caused the lowest cell membrane permeability, and reduced malondialdehyde content, NADPH oxidases activity, O2●− and H2O2 production in the colonized fruit. Observations of the colonized area on the 9th day after inoculation at pH 3, showed that the rate of O2●− production and H2O2 content was reduced by 57% and 25%, compared to their activities at pH 7. In contrast, antioxidative activities of superoxide dismutase, catalase and peroxidases of fruit tissue inoculated with spores’ suspension in the presence of a solution at pH 3.0 showed their highest activity. The catalase and peroxidases activities in the colonized tissue at pH 3 were higher by almost 58% and 55.9%, respectively, on the 6th day after inoculation compared to inoculation at pH 7. The activities of key enzymes of the ascorbate-glutathione (AsA-GSH) cycle and their substrates and products by the 9th day after fruit inoculation at pH 3 showed 150%, 31%, 16%, and 110% higher activities of ascorbate peroxidase, monodehydroascorbate reductase, dehydroascorbate reductase and glutathione reductase, respectively, compared to pH 7. A similar pattern of response was also observed in the accumulation of ascorbic acid and dehydroascorbate which showed a higher accumulation at pH 3 compared to the colonization at pH 7. The present results indicate that the metabolic regulation of the pH environment by the T. roseum not only modulates the fungal pathogenicity factors reported before, but it induces metabolic host changes contributing both together to fungal colonization.

scholarly journals Antichagasic Activity of Komaroviquinone Is Due to Generation of Reactive Oxygen Species Catalyzed by Trypanosoma cruzi Old Yellow Enzyme

2005 ◽  
Vol 49 (12) ◽  
pp. 5123-5126 ◽  
Author(s):  
Nahoko Uchiyama ◽  
Zakayi Kabututu ◽  
Bruno K. Kubata ◽  
Fumiyuki Kiuchi ◽  
Michiho Ito ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Life Cycle ◽  
Trypanosoma Cruzi ◽  
Reductase Activity ◽  
Reactive Oxygen ◽  
Semiquinone Radical ◽  
Oxygen Species ◽  
Old Yellow Enzyme ◽  
Interesting Candidate

ABSTRACT A novel potent trypanocidal diterpene, komaroviquinone, was reduced by Trypanosoma cruzi old yellow enzyme (TcOYE) to its semiquinone radical. The reductase activity in trypanosome lysates was completely immunoabsorbed by anti-TcOYE antibody. Since TcOYE is expressed throughout the T. cruzi life cycle, komaroviquinone is an interesting candidate for developing new antichagasic drugs.

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