scholarly journals Cyclic Nucleotide-Gated Ion Channel 6 Mediates Thermotolerance in Arabidopsis Seedlings by Regulating Hydrogen Peroxide Production via Cytosolic Calcium Ions

2021 ◽  
Vol 12 ◽  
Author(s):  
Wenxu Wang ◽  
Jiaojiao Zhang ◽  
Lijuan Ai ◽  
Dan Wu ◽  
Bing Li ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Ion Channel ◽  
Calcium Ions ◽  
Cyclic Nucleotide ◽  
Cytosolic Calcium ◽  
Plant Responses ◽  
Wild Type ◽  
Chain Reactions ◽  
Polymerase Chain Reactions ◽  
In The Wild

We previously reported the involvement of cyclic nucleotide-gated ion channel 6 (CNGC6) and hydrogen peroxide (H2O2) in plant responses to heat shock (HS). To demonstrate their relationship with plant thermotolerance, we assessed the effect of HS on several groups of Arabidopsis (Arabidopsis thaliana) seedlings: wild-type, cngc6 mutant, and its complementation line. Under exposure to HS, the level of H2O2 was lower in the cngc6 mutant seedlings than in the wild-type (WT) seedlings but obviously increased in the complementation line. The treatment of Arabidopsis seeds with calcium ions (Ca2+) increased the H2O2 levels in the seedlings under HS treatment, whereas treatment with a Ca2+ chelator (EGTA) inhibited it, indicating that CNGC6 may stimulate the accumulation of H2O2 in a manner dependent on an increase in cytosolic Ca2+ ([Ca2+]cyt). This point was verified by phenotypic observations and thermotolerance testing with transgenic plants overexpressing AtRbohB and AtRbohD (two genes involved in HS-responsive H2O2 production), respectively, in a cngc6 background. Real-time reverse transcription-polymerase chain reactions and Western blotting suggested that CNGC6 enhanced the gene transcription of HS factors (HSFs) and the accumulation of HS proteins (HSPs) via H2O2. These upon results indicate that H2O2 acts downstream of CNGC6 in the HS signaling pathway, increasing our understanding of the initiation of plants responses to high temperatures.

scholarly journals Escherichia coli MutM Suppresses Illegitimate Recombination Induced by Oxidative Stress

Genetics ◽  
1999 ◽  
Vol 151 (2) ◽  
pp. 439-446 ◽  
Author(s):  
Masaaki Onda ◽  
Katsuhiro Hanada ◽  
Hirokazu Kawachi ◽  
Hideo Ikeda
Keyword(s):  
Oxidative Stress ◽  
Escherichia Coli ◽  
Hydrogen Peroxide ◽  
Dna Damage ◽  
Double Strand Breaks ◽  
Illegitimate Recombination ◽  
Recombination Analysis ◽  
Wild Type ◽  
Strand Breaks ◽  
In The Wild

Abstract DNA damage by oxidative stress is one of the causes of mutagenesis. However, whether or not DNA damage induces illegitimate recombination has not been determined. To study the effect of oxidative stress on illegitimate recombination, we examined the frequency of λbio transducing phage in the presence of hydrogen peroxide and found that this reagent enhances illegitimate recombination. To clarify the types of illegitimate recombination, we examined the effect of mutations in mutM and related genes on the process. The frequency of λbio transducing phage was 5- to 12-fold higher in the mutM mutant than in the wild type, while the frequency in the mutY and mutT mutants was comparable to that of the wild type. Because 7,8-dihydro-8-oxoguanine (8-oxoG) and formamido pyrimidine (Fapy) lesions can be removed from DNA by MutM protein, these lesions are thought to induce illegitimate recombination. Analysis of recombination junctions showed that the recombination at Hotspot I accounts for 22 or 4% of total λbio transducing phages in the wild type or in the mutM mutant, respectively. The preferential increase of recombination at nonhotspot sites with hydrogen peroxide in the mutM mutant was discussed on the basis of a new model, in which 8-oxoG and/or Fapy residues may introduce double-strand breaks into DNA.

scholarly journals RpoS-Dependent Stress Response and Exoenzyme Production in Vibrio vulnificus

2003 ◽  
Vol 69 (10) ◽  
pp. 6114-6120 ◽  
Author(s):  
A. Hülsmann ◽  
T. M. Rosche ◽  
I.-S. Kong ◽  
H. M. Hassan ◽  
D. M. Beam ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Stress Response ◽  
Mutant Strain ◽  
Environmental Changes ◽  
Vibrio Vulnificus ◽  
High Sensitivity ◽  
Striking Difference ◽  
Wild Type ◽  
Hydrolytic Activities ◽  
In The Wild

ABSTRACT Vibrio vulnificus is an estuarine bacterium capable of causing rapidly fatal infections through both ingestion and wound infection. Like other opportunistic pathogens, V. vulnificus must adapt to potentially stressful environmental changes while living freely in seawater, upon colonization of the oyster gut, and upon infection of such diverse hosts as humans and eels. In order to begin to understand the ability of V. vulnificus to respond to such stresses, we examined the role of the alternate sigma factor RpoS, which is important in stress response and virulence in many pathogens. An rpoS mutant of V. vulnificus strain C7184o was constructed by homologous recombination. The mutant strain exhibited a decreased ability to survive diverse environmental stresses, including exposure to hydrogen peroxide, hyperosmolarity, and acidic conditions. The most striking difference was a high sensitivity of the mutant to hydrogen peroxide. Albuminase, caseinase, and elastase activity were detected in the wild type but not in the mutant strain, and an additional two hydrolytic activities (collagenase and gelatinase) were reduced in the mutant strain compared to the wild type. Additionally, the motility of the rpoS mutant was severely diminished. Overall, these studies suggest that rpoS in V. vulnificus is important for adaptation to environmental changes and may have a role in virulence.

Modulation of frequency and height of cytosolic calcium spikes by plasma membrane anion channels in guard cells

2021 ◽  
Author(s):  
Md Tahjib-Ul-Arif ◽  
Shintaro Munemasa ◽  
Toshiyuki Nakamura ◽  
Yoshimasa Nakamura ◽  
Yoshiyuki Murata
Keyword(s):  
Plasma Membrane ◽  
Stomatal Closure ◽  
Anion Channel ◽  
Guard Cells ◽  
Cytosolic Calcium ◽  
Peak Height ◽  
Extracellular Calcium ◽  
Wild Type ◽  
Anion Channels ◽  
In The Wild

Abstract Cytosolic calcium ([Ca2+]cyt) elevation activates plasma membrane anion channels in guard cells, which is required for stomatal closure. However, involvement of the anion channels in the [Ca2+]cyt elevation remains unclear. We investigated the involvement using Arabidopsis thaliana anion channel mutants, slac1-4 slah3-3 and slac1-4 almt12-1. Extracellular calcium induced stomatal closure in the wild-type plants but not in the anion channel mutant plants whereas extracellular calcium induced [Ca2+]cyt elevation both in the wild-type guard cells and in the mutant guard cells. The peak height and the number of the [Ca2+]cyt spike were lower and larger in the slac1-4 slah3-3 than in the wild-type and the height and the number in the slac1-4 almt12-1 were much lower and much larger than in the wild-type. These results suggest that the anion channels are involved in the regulation of [Ca2+]cyt elevation in guard cells.

Differentiation between wild-type and vaccines strains of varicella zoster virus (VZV) based on four single nucleotide polymorphisms

2017 ◽  
Vol 145 (12) ◽  
pp. 2618-2625
Author(s):  
L. JIN ◽  
S. XU ◽  
P. A. C. MAPLE ◽  
W. XU ◽  
K. E. BROWN
Keyword(s):  
Single Nucleotide Polymorphisms ◽  
Varicella Zoster Virus ◽  
Nucleotide Polymorphisms ◽  
Wild Type ◽  
Single Nucleotide ◽  
Chain Reactions ◽  
Varicella Zoster ◽  
Polymerase Chain Reactions ◽  
Set Up ◽  
The Uk

SummaryVaricella–zoster virus (VZV) infection (chickenpox) results in latency and subsequent reactivation manifests as shingles. Effective attenuated vaccines (vOka) are available for prevention of both illnesses. In this study, an amplicon-based sequencing method capable of differentiating between VZV wild-type (wt) strains and vOka vaccine is described. A total of 44 vesicular fluid specimens collected from 43 patients (16 from China and 27 from the UK) with either chickenpox or shingles were investigated, of which 10 had received previous vaccination. Four sets of polymerase chain reactions were set up simultaneously with primers amplifying regions encompassing four single nucleotide polymorphisms (SNPs), ‘69349-106262-107252-108111’. Nucleotide sequences were generated by Sanger sequencing. All samples except one had a wt SNP profile of ‘A-T-T-T’. The sample collected from a patient who received vaccine 7–10 days ago, along with VZV vaccine preparations, Zostavax and Baike-varicella gave a SNP profile ‘G-C-C-C’. The results show that this method can distinguish vaccine-derived virus from wt viruses from main four clades, (clades 1–4) and should be of utility worldwide.

The role of catalase in hydrogen peroxide resistance in fission yeast Schizosaccharomyces pombe

1999 ◽  
Vol 45 (2) ◽  
pp. 125-129 ◽  
Author(s):  
Norihiro Mutoh ◽  
Chiaki W Nakagawa ◽  
Kenichiro Yamada
Keyword(s):  
Hydrogen Peroxide ◽  
Schizosaccharomyces Pombe ◽  
Catalase Activity ◽  
Parent Strain ◽  
Normal Growth ◽  
Wild Type ◽  
Catalase Gene ◽  
In The Wild ◽  
High Concentrations

The role of catalase in hydrogen peroxide resistance in Schizosaccharomyces pombe was investigated. A catalase gene disruptant completely lacking catalase activity is more sensitive to hydrogen peroxide than the parent strain. The mutant does not acquire hydrogen peroxide resistance by osmotic stress, a treatment that induces catalase activity in the wild-type cells. The growth rate of the disruptant is not different from that of the parent strain. Additionally, transformed cells that overexpress the catalase activity are more resistant to hydrogen peroxide than wild-type cells with normal catalase activity. These results indicate that the catalase of S. pombe plays an important role in resistance to high concentrations of hydrogen peroxide but offers little in the way of protection from the hydrogen peroxide generated in small amounts under normal growth conditions.Key words: catalase, gene disruption, induced hydrogen peroxide resistance, overexpression, Schizosaccharomyces pombe.

scholarly journals Regulation of Hydrogen Peroxide-Dependent Gene Expression in Rhodobacter sphaeroides: Regulatory Functions of OxyR

2007 ◽  
Vol 189 (10) ◽  
pp. 3784-3792 ◽  
Author(s):  
Tanja Zeller ◽  
Mobarak A. Mraheil ◽  
Oleg V. Moskvin ◽  
Kuanyu Li ◽  
Mark Gomelsky ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Rhodobacter Sphaeroides ◽  
Expression Patterns ◽  
Class Iii ◽  
Wild Type ◽  
Binding Studies ◽  
Regulatory Pathways ◽  
Mutant Strains ◽  
In The Wild

ABSTRACT Genome-wide transcriptome profiling was used to reveal hydrogen peroxide (H2O2)-dependent regulatory mechanisms in the facultatively photosynthetic bacterium Rhodobacter sphaeroides. In this study we focused on the role of the OxyR protein, a known regulator of the H2O2 response in bacteria. The transcriptome profiles of R. sphaeroides wild-type and oxyR mutant strains that were exposed to 1 mM H2O2 for 7 min or were not exposed to H2O2 were analyzed. Three classes of OxyR-dependent genes were identified based on their expression patterns in the wild type of oxyR mutant strains with differing predicted roles of oxidized and reduced OxyR as activators of transcription. DNA binding studies revealed that OxyR binds upstream of class I genes, which are induced by H2O2 and exhibit similar basal levels of expression in the wild-type and oxyR mutant strains. The effect of OxyR on class II genes, which are also induced by H2O2 but exhibit significantly lower basal levels of expression in the wild-type strain than in the mutant, is indirect. Interestingly, reduced OxyR also activates expression of few genes (class III). The role of reduced OxyR as an activator is shown for the first time. Our data reveal that the OxyR-mediated response is fast and transient. In addition, we found that additional regulatory pathways are involved in the H2O2 response.

scholarly journals Transforming Growth Factor-β1—Modulated Cerebral Gene Expression

2002 ◽  
Vol 22 (9) ◽  
pp. 1114-1123 ◽  
Author(s):  
Sylvain Lesné ◽  
Sophie Blanchet ◽  
Fabian Docagne ◽  
Géraldine Liot ◽  
Laurent Plawinski ◽  
...  
Keyword(s):  
Growth Factor ◽  
Cortical Neurons ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β1 ◽  
Wild Type ◽  
Chain Reactions ◽  
Polymerase Chain Reactions ◽  
Cultured Cortical Neurons ◽  
The Central Nervous System ◽  
Tgf Β1

Transforming growth factor-β1 (TGF-β1) plays a central role in the response of the brain to different types of injury. Increased TGF-β1 has been found in the central nervous system of patients with acute or chronic disorders such as stroke or Alzheimer disease. To further define the molecular targets of TGF-β1 in cerebral tissues, a selection of high-density cDNA arrays was used to characterize the mRNA expression profile of 7,000 genes in transgenic mice overexpressing TGF-β1 from astrocytes as compared with the wild-type line. Selected findings were further evaluated by reverse transcription-polymerase chain reactions from independent transgenic and wild-type mice. Furthermore, the expression pattern of seven selected genes such as Delta-1, CRADD, PRSC-1, PAI-1, Apo-1/Fas, CTS-B, and TβR-II were confirmed in either cultured cortical neurons or astrocytes following TGF-β1 treatment. The authors' observations enlarge the repertoire of known TGF-β1–modulated genes and their possible involvement in neurodegenerative processes.

Role of Cu,Zn-SOD in the synthesis of endogenous vasodilator hydrogen peroxide during reactive hyperemia in mouse mesenteric microcirculation in vivo

2008 ◽  
Vol 294 (1) ◽  
pp. H441-H448 ◽  
Author(s):  
Toyotaka Yada ◽  
Hiroaki Shimokawa ◽  
Keiko Morikawa ◽  
Aya Takaki ◽  
Yoshiro Shinozaki ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Reactive Hyperemia ◽  
Fluorescent Microscopy ◽  
Artery Occlusion ◽  
Wild Type ◽  
Charge Coupled Device ◽  
In The Wild ◽  
Mesenteric Microcirculation

We have recently demonstrated that endothelium-derived hydrogen peroxide (H2O2) is an endothelium-derived hyperpolarizing factor and that endothelial Cu/Zn-superoxide dismutase (SOD) plays an important role in the synthesis of endogenous H2O2 in both animals and humans. We examined whether SOD plays a role in the synthesis of endogenous H2O2 during in vivo reactive hyperemia (RH), an important regulatory mechanism. Mesenteric arterioles from wild-type and Cu,Zn-SOD−/− mice were continuously observed by a pencil-type charge-coupled device (CCD) intravital microscope during RH (reperfusion after 20 and 60 s of mesenteric artery occlusion) in the cyclooxygenase blockade under the following four conditions: control, catalase alone, NG-monomethyl-l-arginine (l-NMMA) alone, and l-NMMA + catalase. Vasodilatation during RH was significantly decreased by catalase or l-NMMA alone and was almost completely inhibited by l-NMMA + catalase in wild-type mice, whereas it was inhibited by l-NMMA and l-NMMA + catalase in the Cu,Zn-SOD−/− mice. RH-induced increase in blood flow after l-NMMA was significantly increased in the wild-type mice, whereas it was significantly reduced in the Cu,Zn-SOD−/− mice. In mesenteric arterioles of the Cu,Zn-SOD−/− mice, Tempol, an SOD mimetic, significantly increased the ACh-induced vasodilatation, and the enhancing effect of Tempol was decreased by catalase. Vascular H2O2 production by fluorescent microscopy in mesenteric arterioles after RH was significantly increased in response to ACh in wild-type mice but markedly impaired in Cu,Zn-SOD−/− mice. Endothelial Cu,Zn-SOD plays an important role in the synthesis of endogenous H2O2 that contributes to RH in mouse mesenteric smaller arterioles.

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