scholarly journals Nitric Oxide Improves the Tolerance of Pleurotus ostreatus to Heat Stress by Inhibiting Mitochondrial Aconitase

2019 ◽  
Vol 86 (5) ◽  
Author(s):  
Ludan Hou ◽  
Mengran Zhao ◽  
Chenyang Huang ◽  
Xiangli Wu ◽  
Jinxia Zhang
Keyword(s):  
Gene Expression ◽  
Nitric Oxide ◽  
Heat Stress ◽  
Oxidative Damage ◽  
Pleurotus Ostreatus ◽  
Seasonal Temperature ◽  
Respiratory Pathway ◽  
Edible Fungi ◽  
Content Type ◽  
Heat Stress Response

ABSTRACT Pleurotus ostreatus is widely cultivated in China. However, its cultivation is strongly affected by seasonal temperature changes, especially the high temperatures of summer. Nitric oxide (NO) was previously reported to alleviate oxidative damage to mycelia by regulating trehalose. In this study, we found that NO alleviated oxidative damage to P. ostreatus mycelia by inhibiting the protein and gene expression of aconitase (ACO), and additional studies found that the overexpression and interference of aco could affect the content of citric acid (CA). Furthermore, the addition of exogenous CA can induce alternative oxidase (aox) gene expression under heat stress, reduce the content of H2O2 in mycelium, and consequently protect the mycelia under heat stress. An additional analysis focused on the function of the aox gene in the heat stress response of mycelia. The results show that the colony diameter of the aox overexpression (OE-aox) strains was significantly larger than that of the wild-type (WT) strain under heat stress (32°C). In addition, the mycelia of OE-aox strains showed significantly enhanced tolerance to H2O2. In conclusion, this study demonstrates that NO can affect CA accumulation by regulating aco gene and ACO protein expression and that CA can induce aox gene expression and thereby be a response to heat stress. IMPORTANCE Heat stress is one of the abiotic stresses that affect the growth and development of edible fungi. Our previous study found that exogenous NO had a protective effect on mycelia under heat stress. However, its regulatory mechanism had not been elucidated. In this study, we found that NO altered the respiratory pathway of mycelia under heat stress by regulating aco. The results have enhanced our understanding of NO signaling pathways in P. ostreatus.

Allele-Specific Expression and Evolution of Gene Regulation Underlying Acute Heat Stress Response and Local Adaptation in the Copepod Tigriopus californicus

2020 ◽  
Vol 111 (6) ◽  
pp. 539-547
Author(s):  
Sumaetee Tangwancharoen ◽  
Brice X Semmens ◽  
Ronald S Burton
Keyword(s):  
Gene Expression ◽  
Heat Stress ◽  
Stress Response ◽  
Local Adaptation ◽  
F1 Hybrids ◽  
Specific Expression ◽  
Heat Stress Response ◽  
Acute Heat Stress ◽  
Number Of Genes ◽  
Allele Specific

Abstract Geographic variation in environmental temperature can select for local adaptation among conspecific populations. Divergence in gene expression across the transcriptome is a key mechanism for evolution of local thermal adaptation in many systems, yet the genetic mechanisms underlying this regulatory evolution remain poorly understood. Here we examine gene expression in 2 locally adapted Tigriopus californicus populations (heat tolerant San Diego, SD, and less tolerant Santa Cruz, SC) and their F1 hybrids during acute heat stress response. Allele-specific expression (ASE) in F1 hybrids was used to determine cis-regulatory divergence. We found that the number of genes showing significant allelic imbalance increased under heat stress compared to unstressed controls. This suggests that there is significant population divergence in cis-regulatory elements underlying heat stress response. Specifically, the number of genes showing an excess of transcripts from the more thermal tolerant (SD) population increased with heat stress while that number of genes with an SC excess was similar in both treatments. Inheritance patterns of gene expression also revealed that genes displaying SD-dominant expression phenotypes increase in number in response to heat stress; that is, across loci, gene expression in F1’s following heat stress showed more similarity to SD than SC, a pattern that was absent in the control treatment. The observed patterns of ASE and inheritance of gene expression provide insight into the complex processes underlying local adaptation and thermal stress response.

scholarly journals Roles for Sphingolipid Biosynthesis in Mediation of Specific Programs of the Heat Stress Response Determined through Gene Expression Profiling

2003 ◽  
Vol 278 (32) ◽  
pp. 30328-30338 ◽  
Author(s):  
L. Ashley Cowart ◽  
Yasuo Okamoto ◽  
Francisco R. Pinto ◽  
Jason L. Gandy ◽  
Jonas S. Almeida ◽  
...  
Keyword(s):  
Gene Expression ◽  
Heat Stress ◽  
Stress Response ◽  
Gene Expression Profiling ◽  
Expression Profiling ◽  
Heat Stress Response ◽  
Sphingolipid Biosynthesis

scholarly journals Expression of the Laccase Gene from a White Rot Fungus in Pichia pastoris Can Enhance the Resistance of This Yeast to H2O2-Mediated Oxidative Stress by Stimulating the Glutathione-Based Antioxidative System

2012 ◽  
Vol 78 (16) ◽  
pp. 5845-5854 ◽  
Author(s):  
Yang Yang ◽  
Fangfang Fan ◽  
Rui Zhuo ◽  
Fuying Ma ◽  
Yangmin Gong ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Gene Expression ◽  
Pichia Pastoris ◽  
Oxidative Damage ◽  
White Rot ◽  
Antioxidative System ◽  
White Rot Fungus ◽  
Laccase Gene ◽  
Content Type ◽  
Glutamylcysteine Synthetase

ABSTRACTLaccase is a copper-containing polyphenol oxidase that has great potential in industrial and biotechnological applications. Previous research has suggested that fungal laccase may be involved in the defense against oxidative stress, but there is little direct evidence supporting this hypothesis, and the mechanism by which laccase protects cells from oxidative stress also remains unclear. Here, we report that the expression of the laccase gene from white rot fungus inPichia pastoriscan significantly enhance the resistance of yeast to H2O2-mediated oxidative stress. The expression of laccase in yeast was found to confer a strong ability to scavenge intracellular H2O2and to protect cells from lipid oxidative damage. The mechanism by which laccase gene expression increases resistance to oxidative stress was then investigated further. We found that laccase gene expression inPichia pastoriscould increase the level of glutathione-based antioxidative activity, including the intracellular glutathione levels and the enzymatic activity of glutathione peroxidase, glutathione reductase, and γ-glutamylcysteine synthetase. The transcription of the laccase gene inPichia pastoriswas found to be enhanced by the oxidative stress caused by exogenous H2O2. The stimulation of laccase gene expression in response to exogenous H2O2stress further contributed to the transcriptional induction of the genes involved in the glutathione-dependent antioxidative system, includingPpYAP1,PpGPX1,PpPMP20,PpGLR1, andPpGSH1. Taken together, these results suggest that the expression of the laccase gene inPichia pastoriscan enhance the resistance of yeast to H2O2-mediated oxidative stress by stimulating the glutathione-based antioxidative system to protect the cell from oxidative damage.

scholarly journals Melatonin alleviates heat-induced damage of tomato seedlings by balancing redox homeostasis and modulating polyamine and nitric oxide biosynthesis

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Mohammad Shah Jahan ◽  
Sheng Shu ◽  
Yu Wang ◽  
Zheng Chen ◽  
Mingming He ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Gene Expression ◽  
Nitric Oxide ◽  
Hydrogen Peroxide ◽  
Heat Stress ◽  
Heat Shock ◽  
Defense Mechanism ◽  
Enzymatic Antioxidants ◽  
Tomato Seedlings ◽  
Glutathione Cycle

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.

scholarly journals Macrophages Promote Oxidative Metabolism To Drive Nitric Oxide Generation in Response to Trypanosoma cruzi

2016 ◽  
Vol 84 (12) ◽  
pp. 3527-3541 ◽  
Author(s):  
Sue-jie Koo ◽  
Imran H. Chowdhury ◽  
Bartosz Szczesny ◽  
Xianxiu Wan ◽  
Nisha J. Garg
Keyword(s):  
Gene Expression ◽  
Nitric Oxide ◽  
Trypanosoma Cruzi ◽  
Oxidative Metabolism ◽  
Cytokine Profile ◽  
No Production ◽  
Metabolic State ◽  
Content Type ◽  
Tnf Α ◽  
Ifn Γ

Trypanosoma cruziis the causative agent of chronic chagasic cardiomyopathy. Why macrophages (mφs), the early responders to infection, fail to achieve parasite clearance is not known. Mouse (RAW 264.7) and human (THP-1 and primary) mφs were infected for 3 h and 18 h withT. cruziTcI isolates, SylvioX10/4 (SYL, virulent) and TCC (nonpathogenic), which represent mφ stimulation and infection states, respectively. Mφs incubated with lipopolysaccharide and gamma interferon (LPS/IFN-γ) and with interleukin-4 (IL-4) were used as controls. We monitored the cytokine profile (using enzyme-linked immunosorbent assay [ELISA]), reactive oxygen species (ROS; fluorescent probes), nitric oxide (·NO; Griess assay), and metabolic state using a custom-designed mitoxosome array and Seahorse XF24 Analyzer. LPS/IFN-γ treatment of mφs elicited a potent increase in production of tumor necrosis alpha (TNF-α) at 3 h and of ROS and ·NO by 18 h. Upon SYL infection, murine mφs elicited an inflammatory cytokine profile (TNF-α ≫ TGF-β + IL-10) and low levels of ·NO and ROS production. LPS/IFN-γ treatment resulted in the inhibition of oxidative metabolism at the gene expression and functional levels and a switch to the glycolytic pathway in mφs, while IL-4-treated mφs utilized oxidative metabolism to meet energy demands. SYL infection resulted in an intermediate functional metabolic state with increased mitoxosome gene expression and glycolysis, and IFN-γ addition shut down the oxidative metabolism in SYL-infected mφs. Further, TCC- and SYL-stimulated mφs exhibited similar levels of cell proliferation and production of TNF-α and ROS, while TCC-stimulated mφs exhibited up to 2-fold-higher levels of oxidative metabolism and ·NO production than SYL-infected mφs. Inhibiting ATP-coupled O2consumption suppressed the ·NO generation in SYL-infected mφs. Mitochondrial oxygen consumption constitutes a mechanism for stimulating ·NO production in mφs duringT. cruziinfection. Enhancing the oxidative metabolism provides an opportunity for increased ·NO production and pathogen clearance by mφs to limit disease progression.

scholarly journals Regulation of DNA (de)Methylation Positively Impacts Seed Germination during Seed Development under Heat Stress

Genes ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 457
Author(s):  
Jaiana Malabarba ◽  
David Windels ◽  
Wenjia Xu ◽  
Jerome Verdier
Keyword(s):  
Gene Expression ◽  
Heat Stress ◽  
Seed Germination ◽  
Seed Development ◽  
Molecular Mechanisms ◽  
Dna Demethylation ◽  
Mild Stress ◽  
Germination Capacity ◽  
Heat Stress Response ◽  
The Impact

Seed development needs the coordination of multiple molecular mechanisms to promote correct tissue development, seed filling, and the acquisition of germination capacity, desiccation tolerance, longevity, and dormancy. Heat stress can negatively impact these processes and upon the increase of global mean temperatures, global food security is threatened. Here, we explored the impact of heat stress on seed physiology, morphology, gene expression, and methylation on three stages of seed development. Notably, Arabidopsis Col-0 plants under heat stress presented a decrease in germination capacity as well as a decrease in longevity. We observed that upon mild stress, gene expression and DNA methylation were moderately affected. Nevertheless, upon severe heat stress during seed development, gene expression was intensively modified, promoting heat stress response mechanisms including the activation of the ABA pathway. By analyzing candidate epigenetic markers using the mutants’ physiological assays, we observed that the lack of DNA demethylation by the ROS1 gene impaired seed germination by affecting germination-related gene expression. On the other hand, we also observed that upon severe stress, a large proportion of differentially methylated regions (DMRs) were located in the promoters and gene sequences of germination-related genes. To conclude, our results indicate that DNA (de)methylation could be a key regulatory process to ensure proper seed germination of seeds produced under heat stress.

scholarly journals Alternative oxidase gene induced by nitric oxide is involved in the regulation of ROS and enhances the resistance of Pleurotus ostreatus to heat stress

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Ludan Hou ◽  
Mengran Zhao ◽  
Chenyang Huang ◽  
Qi He ◽  
Lijiao Zhang ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Heat Stress ◽  
Signaling Pathway ◽  
Pleurotus Ostreatus ◽  
Alternative Oxidase ◽  
Reduction Process ◽  
Tca Cycle ◽  
Retrograde Signaling ◽  
Cellular Respiration ◽  
Oxidase Gene

Abstract Background In China, during the cultivation process of Pleurotus ostreatus, the yield and quality of fruiting bodies are easily affected by high temperatures in summer. Nitric oxide (NO) plays an important regulatory role in the response to abiotic stress, and previous studies have found that NO can induce alternative oxidase (aox) experssion in response to heat stress (HS) by regulating aconitase. However, the regulatory pathway of NO is complex, and the function and regulation of the aox gene in the response to HS remain unclear. Results In this study, we found that NO affected nicotinamide adenine dinucleotide (NADH) and adenosine triphosphate (ATP) levels, reduced hydrogen peroxide (H2O2) and superoxide anion (O2−) contents, and slowed O2− production. Further RNA-Seq results showed that NO regulated the oxidation-reduction process and oxidoreductase activity, affected the cellular respiration pathway and activated aox gene expression. The function of aox was determined by constructing overexpression (OE) and RNA interference (RNAi) strains. The results showed that the OE-aox strains exhibited obviously improved growth recovery after exposure to HS. During exposure to HS, the OE-aox strains exhibited reduced levels of NADH, the product of the tricarboxylic acid (TCA) cycle, and decreased synthesis of ATP, which reduced the production and accumulation of reactive oxygen species (ROS), whereas the RNAi-aox strains exhibited the opposite result. In addition, aox mediated the expression of antioxidant enzyme genes in the mycelia of P. ostreatus under HS through the retrograde signaling pathway. Conclusions This study shows that the expression of the aox gene in P. ostreatus mycelia can be induced by NO under HS, that it regulates the TCA cycle and cell respiration to reduce the production of ROS, and that it can mediate the retrograde signaling pathway involved in the mycelial response to HS. Graphical abstract

scholarly journals Trehalose alleviates high‐temperature stress in Pleurotus ostreatus by affecting central carbon metabolism

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Zhi-Yu Yan ◽  
Meng-Ran Zhao ◽  
Chen-Yang Huang ◽  
Li-Jiao Zhang ◽  
Jin-Xia Zhang
Keyword(s):  
Gene Expression ◽  
Heat Stress ◽  
High Temperature ◽  
Temperature Stress ◽  
Pleurotus Ostreatus ◽  
Defense Mechanism ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
High Temperature Stress ◽  
Reduced Form ◽  
Protective Agent

Abstract Background Trehalose, an intracellular protective agent reported to mediate defense against many stresses, can alleviate high-temperature-induced damage in Pleurotus ostreatus. In this study, the mechanism by which trehalose relieves heat stress was explored by the addition of exogenous trehalose and the use of trehalose-6-phosphate synthase 1 (tps1) overexpression transformants. Results The results suggested that treatment with exogenous trehalose or overexpression of tps1 alleviated the accumulation of lactic acid under heat stress and downregulated the expression of the phosphofructokinase (pfk) and pyruvate kinase (pk) genes, suggesting an ameliorative effect of trehalose on the enhanced glycolysis in P. ostreatus under heat stress. However, the upregulation of hexokinase (hk) gene expression by trehalose indicated the involvement of the pentose phosphate pathway (PPP) in heat stress resistance. Moreover, treatment with exogenous trehalose or overexpression of tps1 increased the gene expression level and enzymatic activity of glucose-6-phosphate dehydrogenase (g6pdh) and increased the production of both the reduced form of nicotinamide adenine dinucleotide phosphate (NADPH) and glutathione (GSH), confirming the effect of trehalose on alleviating oxidative damage by enhancing PPP in P. ostreatus under heat stress. Furthermore, treatment with exogenous trehalose or overexpression of tps1 ameliorated the decrease in the oxygen consumption rate (OCR) caused by heat stress, suggesting a relationship between trehalose and mitochondrial function under heat stress. Conclusions Trehalose alleviates high-temperature stress in P. ostreatus by inhibiting glycolysis and stimulating PPP activity. This study may provide further insights into the heat stress defense mechanism of trehalose in edible fungi from the perspective of intracellular metabolism.

scholarly journals Alternative Oxidase Gene Induced by Nitric Oxide is Involved in the Regulation of ROS and Enhance the Resistance of Pleurotus Ostreatus to Heat Stress

2020 ◽  
Author(s):  
Ludan Hou ◽  
Mengran Zhao ◽  
Chenyang Huang ◽  
Qi He ◽  
Lijiao Zhang ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Heat Stress ◽  
Signaling Pathway ◽  
Pleurotus Ostreatus ◽  
Alternative Oxidase ◽  
Tca Cycle ◽  
Retrograde Signaling ◽  
Cellular Respiration ◽  
Oxidase Gene ◽  
The Tca Cycle

Abstract Background: Pleurotus ostreatus is easily affected by temperature during its cultivation. Nitric oxide (NO) plays an important regulatory role in the response to abiotic stress, and previous studies have found that NO can induce alternative oxidase (aox) in response to heat stress (HS) by regulating aconitase. However, the regulatory pathway of NO is complex, and the function and regulation of the aox gene in the response to HS remain unclear.Results: In this study, we found that NO affected the NADH and ATP levels, reduced the H2O2 and O2- contents, and slowed the production of O2-. Further RNA-Seq results showed that NO regulated the oxidation-reduction process and oxidoreductase activity, affected the cellular respiration pathway and activated aox gene expression. The function of aox was determined by constructing overexpression (OE) and RNA interference (RNAi) strains. The results showed that the OE-aox strains showed obvious advantages in experiencing growth recovery after exposure to HS. During exposure to HS, the OE-aox strains exhibited reduced levels of NADH, the product of the TCA cycle, and decreased synthesis of ATP, which reduced the production and accumulation of ROS, whereas the RNAi-aox strains exhibited the opposite result. In addition, aox mediated the expression of antioxidant enzyme genes in the mycelia of P. ostreatus under HS through the retrograde signaling pathway. Conclusions: This study shows that the aox gene in P. ostreatus mycelia can be induced by NO under HS, regulates the TCA cycle and cell respiration to reduce the production of ROS, and can mediate the retrograde signaling pathway involved in the mycelial response to HS.

scholarly journals Alternative Oxidase Activity Reduces Stress in Vibrio fischeri Cells Exposed to Nitric Oxide

2018 ◽  
Vol 200 (15) ◽  
Author(s):  
Anne K. Dunn
Keyword(s):  
Nitric Oxide ◽  
Alternative Oxidase ◽  
Vibrio Fischeri ◽  
Membrane Integrity ◽  
Model Organism ◽  
Growth Conditions ◽  
Respiratory Pathway ◽  
Content Type ◽  
Atp Production ◽  
In Cells

ABSTRACT Alternative oxidase (Aox) is a non-energy-conserving respiratory oxidase found in certain eukaryotes and bacteria, whose role in physiology is not entirely clear. Using the genetically tractable bacterium Vibrio fischeri as a model organism, I have identified a role for Aox to reduce levels of stress in cells exposed to oxygen and nitric oxide (NO). In V. fischeri lacking the NO-detoxifying enzyme flavohemoglobin (Hmp), deletion of aox in cells grown in the presence of oxygen and NO results in alterations to the transcriptome that include increases in transcripts mapping to stress-related genes. Using fluorescence-based reporters, I identified corresponding increases in intracellular reactive oxygen species and decreases in membrane integrity in cells lacking aox. Under these growth conditions, activity of Aox is linked to a decrease in NADH levels, indicating coupling of Aox activity with NADH dehydrogenase activity. Taken together, these results suggest that Aox functions to indirectly limit production of ferrous iron and damaging hydroxyl radicals, effectively reducing cellular stress during NO exposure. IMPORTANCE Unlike typical respiratory oxidases, alternative oxidase (Aox) does not directly contribute to energy conservation, and its activity would presumably reduce the efficiency of respiration and associated ATP production. Aox has been identified in certain bacteria, a majority of which are marine associated. The presence of Aox in these bacteria poses the interesting question of how Aox function benefits bacterial growth and survival in the ocean. Using the genetically tractable marine bacterium Vibrio fischeri, I have identified a role for Aox in reduction of stress under conditions where electron flux through the aerobic respiratory pathway is inhibited. These results suggest that Aox activity could positively impact longer-term bacterial fitness and survival under stressful environmental conditions.

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