Nitric Oxide-Mediated Modulation of Functional Iron Status in Iron-Deficient Maize Plants

2019 ◽  
Vol 5 (02) ◽  
pp. 78-83
Author(s):  
Rajesh Kumar Tewari

Nitric oxide is reported to alleviate Fe-deficiency effects, possibly by enhancing the functional Fe status of plants. Study describes changes in leaf tissue Fe status and consequent modulation of oxidative stress and antioxidant defense in Fe-deficient maize (Zea mays L.) plants supplied with NO. Supply of sodium nitroprusside (SNP), but not of sodium ferrocyanide (SF), caused regreening of leaves, syntheses of chlorophylls and carotenoids and increased activities of hydrogen peroxide-scavenging heme-Fe enzymes and lipid peroxidation, decreased SOD activity and hydrogen peroxide concentration. Though SNP or SF appears to donate Fe and increase leaf active Fe, the later did not induce increases in chlorophyll and carotenoids, and therefore NO appears to have a role in Fe nutrition irrespective of total or active Fe status of plants.

2020 ◽  
Vol 9 (40) ◽  
pp. 2970-2975
Author(s):  
Rohit John Chaudhary ◽  
Bharti Kwatra Uppal

BACKGROUND Severe oxidative stress has been reported in TB patients because of infection associated with malnutrition and poor immunity. Mycobacteria can induce reactive oxygen species (ROS) production by activating phagocytes, and enhanced ROS production may promote tissue injury and inflammation. We wanted to compare the effect of antioxidant administration in the outcome of ATT treatment between the test and the control group. METHODS This perspective study was conducted in the Departments of Biochemistry and Chest Medicine, CMC & Hospital. Hundred patients (fifty controls and fifty tests) who were diagnosed as pulmonary tuberculosis and started on DOT therapy under RNTCP during this period were included in the study. Each participant in the study was subjected to the following test at the first visit, 2nd month and 6th month follow up (biochemical markers Nitric oxide, SOD, Glutathione Peroxidase and Vitamin E levels). Statistical analysis was done using SPSS version. RESULTS The results were based on four categories (male / female, alcoholic / non-alcoholic, smoker / non-smoker, and younger / older age group). Females had responded better with greater fall in percentage of nitric oxide values (69 %) than males (64.1 %). The mean of SOD activity (277.5 + / - 31.5) was more in smokers than non-smokers (261.3 + / - 36.0) & percentage fall of nitric oxide in smokers (65 %) & non-smokers (67 %). In alcoholics the percentage fall of nitric oxide (68.3 %) was higher with more SOD activity (Mean 278.7 + / - 27.6) than non-alcoholics (Mean 256 + / - 38.0) indicating a positive correlation of smoking & alcoholism with tuberculosis. Younger age group responded better with more fall in the percentage of nitric oxide (67 %) & mean SOD activity (265.8 + / - 30.1) than older age group. CONCLUSIONS Antioxidant supplementation reduces oxidative stress, improves the effectiveness of ATT therapy, and thus helps in improving the outcome in pulmonary tuberculosis. KEY WORDS Pulmonary TB, ATT (Anti-Tubercular Treatment), Antioxidants & Free Radicals


2010 ◽  
Vol 103 (2) ◽  
pp. 205-215 ◽  
Author(s):  
Jian Sun ◽  
Lisi Li ◽  
Meiqin Liu ◽  
Meijuan Wang ◽  
Mingquan Ding ◽  
...  

2017 ◽  
Vol 12 (1) ◽  
pp. 323-331 ◽  
Author(s):  
Mirza Hasanuzzaman ◽  
Kamrun Nahar ◽  
Md. Shahadat Hossain ◽  
Taufika Islam Anee ◽  
Khursheda Parvin ◽  
...  

2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
Jiying Jiang ◽  
Shuna Yu ◽  
Zhengchen Jiang ◽  
Cuihong Liang ◽  
Wenbo Yu ◽  
...  

Oxidative stress plays an important role in the pathogenesis of liver diseases. N-Acetyl-serotonin (NAS) has been reported to protect against oxidative damage, though the mechanisms by which NAS protects hepatocytes from oxidative stress remain unknown. To determine whether pretreatment with NAS could reduce hydrogen peroxide- (H2O2-) induced oxidative stress in HepG2 cells by inhibiting the mitochondrial apoptosis pathway, we investigated the H2O2-induced oxidative damage to HepG2 cells with or without NAS using MTT, Hoechst 33342, rhodamine 123, Terminal dUTP Nick End Labeling Assay (TUNEL), dihydrodichlorofluorescein (H2DCF), Annexin V and propidium iodide (PI) double staining, immunocytochemistry, and western blot. H2O2produced dramatic injuries in HepG2 cells, represented by classical morphological changes of apoptosis, increased levels of malondialdehyde (MDA) and intracellular reactive oxygen species (ROS), decreased activity of superoxide dismutase (SOD), and increased activities of caspase-9 and caspase-3, release of cytochrome c (Cyt-C) and apoptosis-inducing factor (AIF) from mitochondria, and loss of membrane potential (ΔΨm). NAS significantly inhibited H2O2-induced changes, indicating that it protected against H2O2-induced oxidative damage by reducing MDA levels and increasing SOD activity and that it protected the HepG2 cells from apoptosis through regulating the mitochondrial apoptosis pathway, involving inhibition of mitochondrial hyperpolarization, release of mitochondrial apoptogenic factors, and caspase activity.


2011 ◽  
Vol 301 (6) ◽  
pp. H2227-H2234 ◽  
Author(s):  
Livius V. d'Uscio ◽  
Leslie A. Smith ◽  
Zvonimir S. Katusic

In the present study, we used the hph-1 mouse, which displays GTP-cyclohydrolase I (GTPCH I) deficiency, to test the hypothesis that loss of tetrahydrobiopterin (BH4) in conduit and small arteries activates compensatory mechanisms designed to protect vascular wall from oxidative stress induced by uncoupling of endothelial nitric oxide synthase (eNOS). Both GTPCH I activity and BH4 levels were reduced in the aortas and small mesenteric arteries of hph-1 mice. However, the BH4-to-7,8-dihydrobiopterin ratio was significantly reduced only in hph-1 aortas. Furthermore, superoxide anion and 3-nitrotyrosine production were significantly enhanced in aortas but not in small mesenteric arteries of hph-1 mice. In contrast to the aorta, protein expression of copper- and zinc-containing superoxide dismutase (CuZnSOD) was significantly increased in small mesenteric arteries of hph-1 mice. Protein expression of catalase was increased in both aortas and small mesenteric arteries of hph-1 mice. Further analysis of endothelial nitric oxide synthase (eNOS)/cyclic guanosine monophosphate (cGMP) signaling demonstrated that protein expression of phosphorylated Ser1177-eNOS as well as basal cGMP levels and hydrogen peroxide was increased in hph-1 aortas. Increased production of hydrogen peroxide in hph-1 mice aortas appears to be the most likely mechanism responsible for phosphorylation of eNOS and elevation of cGMP. In contrast, upregulation of CuZnSOD and catalase in resistance arteries is sufficient to protect vascular tissue from increased production of reactive oxygen species generated by uncoupling of eNOS. The results of our study suggest that anatomical origin determines the ability of vessel wall to cope with oxidative stress induced by uncoupling of eNOS.


Biologia ◽  
2011 ◽  
Vol 66 (5) ◽  
Author(s):  
Meltem Akbas ◽  
Tugrul Doruk ◽  
Serhat Ozdemir ◽  
Benjamin Stark

AbstractIn Escherichia coli, Vitreoscilla hemoglobin (VHb) protects against oxidative stress, perhaps, in part, by oxidizing OxyR. Here this protection, specifically VHb-associated effects on superoxide dismutase (SOD) and catalase levels, was examined. Exponential or stationary phase cultures of SOD+ or SOD− E. coli strains with or without VHb and oxyR antisense were treated with 2 mM hydrogen peroxide without sublethal peroxide induction, and compared to untreated control cultures. The hydrogen peroxide treatment was toxic to both SOD+ and SOD− cells, but much more to SOD− cells; expression of VHb in SOD+ strains enhanced this toxicity. In contrast, the presence of VHb was generally associated in the SOD+ background with a modest increase in SOD activity that was not greatly affected by oxyR antisense or peroxide treatment. In both SOD+ and SOD− backgrounds, VHb was associated with higher catalase activity both in the presence and absence of peroxide. Contrary to its stimulatory effects in stationary phase, in exponential phase oxyR antisense generally decreased VHb levels.


Antioxidants ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1556
Author(s):  
Md Atikur Rahman ◽  
Ahmad Humayan Kabir ◽  
Yowook Song ◽  
Sang-Hoon Lee ◽  
Mirza Hasanuzzaman ◽  
...  

Iron (Fe) deficiency impairs photosynthetic efficiency, plant growth and biomass yield. This study aimed to reveal the role of nitric oxide (NO) in restoring Fe-homeostasis and oxidative status in Fe-deficient alfalfa. In alfalfa, a shortage of Fe negatively affected the efficiency of root andshoot length, leaf greenness, maximum quantum yield PSII (Fv/Fm), Fe, S, and Zn accumulation, as well as an increase in H2O2 accumulation. In contrast, in the presence of sodium nitroprusside (SNP), a NO donor, these negative effects of Fe deficiency were largely reversed. In response to the SNP, the expression of Fe transporters (IRT1, NRAMP1) and S transporter (SULTR1;2) genes increased in alfalfa. Additionally, the detection of NO generation using fluorescence microscope revealed that SNP treatment increased the level of NO signal, indicating that NO may act as regulatory signal in response to SNP in plants. Interestingly, the increase of antioxidant genes and their related enzymes (Fe-SOD, APX) in response to SNP treatment suggests that Fe-SOD and APX are key contributors to reducing ROS (H2O2) accumulation and oxidative stress in alfalfa. Furthermore, the elevation of Ascorbate-glutathione (AsA-GSH) pathway-related genes (GR and MDAR) Fe-deficiency with SNP implies that the presence of NO relates to enhanced antioxidant defense against Fe-deficiency stress.


2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Mohammad Shah Jahan ◽  
Sheng Shu ◽  
Yu Wang ◽  
Zheng Chen ◽  
Mingming He ◽  
...  

Abstract Background Melatonin is a pleiotropic signaling molecule that plays multifarious roles in plants stress tolerance. The polyamine (PAs) metabolic pathway has been suggested to eliminate the effects of environmental stresses. However, the underlying mechanism of how melatonin and PAs function together under heat stress largely remains unknown. In this study, we investigated the potential role of melatonin in regulating PAs and nitric oxide (NO) biosynthesis, and counterbalancing oxidative damage induced by heat stress in tomato seedlings. Results Heat stress enhanced the overproduction of reactive oxygen species (ROS) and damaged inherent defense system, thus reduced plant growth. However, pretreatment with 100 μM melatonin (7 days) followed by exposure to heat stress (24 h) effectively reduced the oxidative stress by controlling the overaccumulation of superoxide (O2•−) and hydrogen peroxide (H2O2), lowering the lipid peroxidation content (as inferred based on malondialdehyde content) and less membrane injury index (MII). This was associated with increased the enzymatic and non-enzymatic antioxidants activities by regulating their related gene expression and modulating the ascorbate–glutathione cycle. The presence of melatonin induced respiratory burst oxidase (RBOH), heat shock transcription factors A2 (HsfA2), heat shock protein 90 (HSP90), and delta 1-pyrroline-5-carboxylate synthetase (P5CS) gene expression, which helped detoxify excess ROS via the hydrogen peroxide-mediated signaling pathway. In addition, heat stress boosted the endogenous levels of putrescine, spermidine and spermine, and increased the PAs contents, indicating higher metabolic gene expression. Moreover, melatonin-pretreated seedlings had further increased PAs levels and upregulated transcript abundance, which coincided with suppression of catabolic-related genes expression. Under heat stress, exogenous melatonin increased endogenous NO content along with nitrate reductase- and NO synthase-related activities, and expression of their related genes were also elevated. Conclusions Melatonin pretreatment positively increased the heat tolerance of tomato seedlings by improving their antioxidant defense mechanism, inducing ascorbate–glutathione cycle, and reprogramming the PAs metabolic and NO biosynthesis pathways. These attributes facilitated the scavenging of excess ROS and increased stability of the cellular membrane, which mitigated heat-induced oxidative stress.


Sign in / Sign up

Export Citation Format

Share Document