scholarly journals Cadmium interference with iron sensing reveals transcriptional programs sensitive and insensitive to reactive oxygen species

2021 ◽  
Author(s):  
Samuel A McInturf ◽  
Mather A Khan ◽  
Arun Gokul ◽  
Norma A Castro-Guerrero ◽  
Ricarda Hoehner ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Expression Profiling ◽  
Reactive Oxygen ◽  
Essential Element ◽  
Gene Clusters ◽  
Fe Deficiency ◽  
Induced Responses ◽  
Oxygen Species ◽  
Fe Homeostasis ◽  
Cd Exposure

Abstract Iron (Fe) is an essential micronutrient whose uptake is tightly regulated to prevent either deficiency or toxicity. Cadmium (Cd) is a non-essential element that induces both Fe-deficiency and toxicity; however, the mechanisms behind these Fe/Cd-induced responses are still elusive. Here we explored Cd and Fe-associated responses in wildtype Arabidopsis and in a mutant that over-accumulates iron (opt3-2). Gene expression profiling revealed a large overlap between transcripts induced by Fe deficiency and Cd exposure. Interestingly, the use of opt3-2 allowed us to identify additional gene clusters originally induced by Cd in wildtype but repressed in the opt3-2 background. Based on the high levels of H2O2 found in opt3-2 we propose a model where reactive oxygen species prevent the induction of genes that are induced in wildtype by either Fe deficiency or Cd. Interestingly, a defined cluster of Fe-responsive genes was found to be insensitive to this negative feedback, suggesting that their induction by Cd is more likely the result of an impaired Fe sensing. Overall, our data suggest that Fe-deficiency responses are governed by multiple inputs and that a hierarchical regulation of Fe homeostasis prevents the induction of specific networks when Fe and H2O2 levels are elevated.

scholarly journals Reactive Oxygen Species coordinate the transcriptional responses to iron availability in Arabidopsis

2020 ◽  
Author(s):  
Claudia von der Mark ◽  
Rumen Ivanov ◽  
Monique Eutebach ◽  
Veronica G Maurino ◽  
Petra Bauer ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Reactive Oxygen ◽  
Fe Deficiency ◽  
Plant Responses ◽  
Dependent Manner ◽  
Oxygen Species ◽  
Loss Of Function ◽  
Transcriptional Responses ◽  
Fe Homeostasis ◽  
Regulatory Loop

Abstract Reactive oxygen species play a central role in the regulation of plant responses to environmental stress. Under prolonged iron (Fe) deficiency, increased levels of hydrogen peroxide (H2O2) initiate signaling events, resulting in the attenuation of Fe acquisition through the inhibition of FER-LIKE IRON DEFICIENCY-INDUCED TRANSCRIPTION FACTOR (FIT). As this H2O2 increase occurs in a FIT-dependent manner, our aim was to understand the processes involved in maintaining H2O2 levels under prolonged Fe deficiency and the role of FIT in this process. We identified CAT2 gene, encoding one of the three Arabidopsis catalase isoforms, as regulated by FIT. CAT2 loss-of-function plants displayed severe susceptibility to Fe deficiency and greatly increased H2O2 levels in roots. Analysis of the Fe homeostasis transcriptional cascade revealed that H2O2 influences the gene expression of downstream regulators FIT, BHLHs of group Ib and POPEYE (PYE), however H2O2 did not affect their upstream regulators, such as BHLH104 and ILR3. Our data shows that FIT and CAT2 participate in a regulatory loop between H2O2 and prolonged Fe deficiency.

scholarly journals Transcriptomic analysis revealed reactive oxygen species scavenging mechanisms associated with ferrous iron toxicity in aromatic Keteki Joha rice

2021 ◽  
Author(s):  
Preetom Regon ◽  
Sangita Dey ◽  
Mehzabin Rehman ◽  
Amit Kumar Pradhan ◽  
Bhaben Tanti ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Transcription Factors ◽  
Abiotic Stress ◽  
Ferrous Iron ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Ros Scavenging ◽  
Iron Transporter ◽  
Ros Homeostasis ◽  
Fe Homeostasis

Lowland acidic soils with water-logged regions are often affected by ferrous iron (Fe2+) toxicity, a major yield-limiting factor of rice production. The Reactive Oxygen Species (ROS) was hypothesized to be crucial under severe Fe2+ toxicity conditions. However, molecular mechanisms and associated ROS homeostasis genes are still not well-explored. In this study, a comparative RNA-Seq based transcriptome analysis was conducted to understand the Fe2+ toxicity tolerance mechanism in aromatic Keteki Joha. About 69 Fe homeostasis related genes and their homologs were identified, where most of the genes were downregulated. Differentially expressed genes (DEGs) are associated with biological processes- response to stress, stimulus and abiotic stimulus. DEGs involved in the Biosynthesis of amino acids, RNA degradation, Glutathione metabolism etc. were induced, whereas, Phenylpropanoid biosynthesis, Photosynthesis, and Fatty acid elongation were inhibited. The Mitochondrial iron transporter (OsMIT), Vacuolar Iron Transporter 2 (OsVIT2), Ferritin (OsFER), Vacuolar Mugineic Acid Transporter (OsVMT), Phenolic Efflux Zero1 (OsPEZ1), Root Meander Curling (OsRMC), Nicotianamine synthase (OsNAS3), etc. were upregulated in different tissues suggesting the importance of Fe retention and sequestration for detoxification. However, several antioxidants, ROS scavenging genes and abiotic stress-responsive transcription factors indicate ROS homeostasis as one of the most important defense mechanisms under severe Fe2+ toxicity. The CAT, GSH, APX, MDHAR, DHAR, GR were upregulated. Moreover, abiotic stress-responsive transcription factors NAC, MYB, ARF, bZIP, WRKY, C2H2-ZFP were also upregulated. Accordingly, ROS homeostasis has been proposed to be an important defense mechanism under such conditions. Thus, our results will enrich the knowledge of understanding Fe-homeostasis in rice.

scholarly journals Gene expression profiling of reactive oxygen species (ROS) and antioxidant defense system following Sugarcane mosaic virus (SCMV) infection

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Sehrish Akbar ◽  
Yao Wei ◽  
Yuan Yuan ◽  
Muhammad Tahir Khan ◽  
Lifang Qin ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Transcription Factors ◽  
Mosaic Virus ◽  
Expression Profiling ◽  
Nadh Oxidase ◽  
Reactive Oxygen ◽  
Antioxidant Defense System ◽  
Sugarcane Mosaic Virus ◽  
Oxygen Species ◽  
Transcriptomic Data

Abstract Background Viruses are infectious pathogens, and plant virus epidemics can have devastating consequences to crop yield and quality. Sugarcane mosaic virus (SCMV, belonging to family Potyviridae) is one of the leading pathogens that affect the sugarcane crop every year. To combat the pathogens’ attack, plants generate reactive oxygen species (ROS) as the first line of defense whose sophisticated balance is achieved through well-organized antioxidant scavenging pathways. Results In this study, we investigated the changes occurring at the transcriptomic level of ROS associated and ROS detoxification pathways of SCMV resistant (B-48) and susceptible (Badila) sugarcane genotypes, using Saccharum spontaneum L. genome assembly as a reference genome. Transcriptomic data highlighted the significant upregulation of ROS producing genes such as NADH oxidase, malate dehydrogenase and flavin-binding monooxygenase, in Badila genotype after SCMV pathogenicity. To scavenge the ROS, the Badila genotype illustrated a substantial enhancement of antioxidants i.e. glutathione s-transferase (GST), as compared to its resistant counterpart. GST is supposed to be a key indicator of pathogen attacks on the plant. A remarkably lower GST expression in B-48, as compared to Badila, indicated the development of resistance in this genotype. Additionally, we characterized the critical transcription factors (TFs) involved in endowing resistance to B-48. Among these, WRKY, AP2, NAC, bZIP, and bHLH showed enhanced expression in the B-48 genotype. Our results also confirmed the linkage of transcriptomic data with the enzymatic and qPCR data. The estimation of enzymatic activities for superoxide dismutase, catalase, ascorbate peroxidase, and phenylalanine ammonia-lyase supported the transcriptomic data and evinced higher resistance in B-48 genotype. Conclusion The current study supported the efficiency of the B-48 genotype under SCMV infection. Moreover, comparative transcriptomic data has been presented to highlight the role of significant transcription factors conferring resistance to this genotype. This study provides an in-depth knowledge of the expression profiling of defense mechanisms in sugarcane.

Mitochondria as a source of reactive oxygen species

2009 ◽  
pp. c3 ◽  
Author(s):  
Helena M. Cochemé ◽  
Michael P. Murphy
Keyword(s):  
Reactive Oxygen Species ◽  
Reactive Oxygen ◽  
Oxygen Species

Clinical aspects of reactive oxygen and nitrogen species

2004 ◽  
Vol 71 ◽  
pp. 121-133 ◽  
Author(s):  
Ascan Warnholtz ◽  
Maria Wendt ◽  
Michael August ◽  
Thomas Münzel
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Risk Factor ◽  
Endothelial Dysfunction ◽  
Vascular Tissue ◽  
Rapid Development ◽  
Reactive Oxygen ◽  
Clinical Aspects ◽  
No Production ◽  
Oxygen Species

Endothelial dysfunction in the setting of cardiovascular risk factors, such as hypercholesterolaemia, hypertension, diabetes mellitus and chronic smoking, as well as in the setting of heart failure, has been shown to be at least partly dependent on the production of reactive oxygen species in endothelial and/or smooth muscle cells and the adventitia, and the subsequent decrease in vascular bioavailability of NO. Superoxide-producing enzymes involved in increased oxidative stress within vascular tissue include NAD(P)H-oxidase, xanthine oxidase and endothelial nitric oxide synthase in an uncoupled state. Recent studies indicate that endothelial dysfunction of peripheral and coronary resistance and conductance vessels represents a strong and independent risk factor for future cardiovascular events. Ways to reduce endothelial dysfunction include risk-factor modification and treatment with substances that have been shown to reduce oxidative stress and, simultaneously, to stimulate endothelial NO production, such as inhibitors of angiotensin-converting enzyme or the statins. In contrast, in conditions where increased production of reactive oxygen species, such as superoxide, in vascular tissue is established, treatment with NO, e.g. via administration of nitroglycerin, results in a rapid development of endothelial dysfunction, which may worsen the prognosis in patients with established coronary artery disease.

Fas ligand expression in rat kupffer cells in response to lipopolysaccharide is mediated by reactive oxygen species

2001 ◽  
Vol 120 (5) ◽  
pp. A361-A361
Author(s):  
K UCHIKURA ◽  
T WADA ◽  
Z SUN ◽  
S HOSHINO ◽  
G BULKLEY ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Kupffer Cells ◽  
Fas Ligand ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Ligand Expression
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