Effect of Reactive Oxygen Species on Plant Pathogens in planta and on Disease Symptoms

ABSTRACTOxygenous terpenoids are active components of many medicinal plants. However, current studies that have focused on enzymatic oxidation reactions cannot comprehensively clarify the mechanisms of oxygenous terpenoid synthesis and diversity. This study shows that an endophytic bacterium can trigger the generation of reactive oxygen species (ROS) that directly increase oxygenous sesquiterpenoid content and diversity inAtractylodes lancea.A. lanceais a famous but endangered Chinese medicinal plant that contains abundant oxygenous sesquiterpenoids. Geo-authenticA. lanceaproduces a wider range and a greater abundance of oxygenous sesquiterpenoids than the cultivated herb. Our previous studies have shown the mechanisms behind endophytic promotion of the production of sesquiterpenoid hydrocarbon scaffolds; however, how endophytes promote the formation of oxygenous sesquiterpenoids and their diversity is unclear. After colonization byPseudomonas fluorescensALEB7B, oxidative burst and oxygenous sesquiterpenoid accumulation inA. lanceaoccur synchronously. Treatment with exogenous hydrogen peroxide (H2O2) or singlet oxygen induces oxidative burst and promotes oxygenous sesquiterpenoid accumulationin planta. Conversely, pretreatment of plantlets with the ROS scavenger ascorbic acid significantly inhibits the oxidative burst and oxygenous sesquiterpenoid accumulation induced byP. fluorescensALEB7B. Furtherin vitrooxidation experiments show that several oxygenous sesquiterpenoids can be obtained from direct oxidation caused by H2O2or singlet oxygen. In summary, this study demonstrates that endophytic bacterium-triggered ROS can directly oxidize oxygen-free sesquiterpenoids and increase the oxygenous sesquiterpenoid content and diversity inA. lancea, providing a novel explanation of the mechanisms of oxygenous terpenoid synthesisin plantaand an essential complementarity to enzymatic oxidation reactions.

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Reactive oxygen species scavenging by hemin-based nanosheets reduces Parkinson’s disease symptoms in an animal model

Chemical Engineering Journal ◽

10.1016/j.cej.2021.134356 ◽

2021 ◽

pp. 134356

Author(s):

Li Lei ◽

Qiuxia Tu ◽

Ling Jiao ◽

Song Xiang ◽

Li Wang ◽

...

Keyword(s):

Reactive Oxygen Species ◽

Parkinson’S Disease ◽

Parkinson's Disease ◽

Animal Model ◽

Reactive Oxygen ◽

Oxygen Species ◽

Disease Symptoms

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Differential Function of Endogenous and Exogenous Abscisic Acid during Bacterial Pattern-Induced Production of Reactive Oxygen Species in Arabidopsis

International Journal of Molecular Sciences ◽

10.3390/ijms20102544 ◽

2019 ◽

Vol 20 (10) ◽

pp. 2544 ◽

Cited By ~ 2

Author(s):

Leitao Tan ◽

Qiuping Liu ◽

Yufeng Song ◽

Guangzhen Zhou ◽

Linli Luan ◽

...

Keyword(s):

Reactive Oxygen Species ◽

Abscisic Acid ◽

Plant Disease Resistance ◽

Plant Pathogens ◽

Reactive Oxygen ◽

Defense Responses ◽

Dual Function ◽

Oxygen Species ◽

Exogenous Aba ◽

Endogenous Aba

Abscisic acid (ABA) plays important roles in positively or negatively regulating plant disease resistance to pathogens. Here, we reassess the role of endogenous and exogenous ABA by using: 35S::ABA2, a previously reported transgenic Arabidopsis line with increased endogenous ABA levels; aba2-1, a previously reported ABA2 mutant with reduced endogenous ABA levels; and exogenous application of ABA. We found that bacterial susceptibility promoted by exogenous ABA was suppressed in 35S::ABA2 plants. The 35S::ABA2 and aba2-1 plants displayed elevated and reduced levels, respectively, of bacterial flagellin peptide (flg22)-induced H2O2. Surprisingly, ABA pre-treatment reduced flg22-induced H2O2 generation. Exogenous, but not endogenous ABA, increased catalase activity. Loss of nicotinamide adenine dinucleotide phosphate oxidase genes, RBOHD and RBOHF, restored exogenous ABA-promoted bacterial susceptibility of 35S::ABA2 transgenic plants. In addition, endogenous and exogenous ABA had similar effects on callose deposition and salicylic acid (SA) signaling. These results reveal an underlying difference between endogenous and exogenous ABA in regulating plant defense responses. Given that some plant pathogens are able to synthesize ABA and affect endogenous ABA levels in plants, our results highlight the importance of reactive oxygen species in the dual function of ABA during plant-pathogen interactions.

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Identifying unique and overlapping roles of reactive oxygen species in rice blast and Southern corn leaf blight

10.32747/2017.7604290.bard ◽

2017 ◽

Author(s):

Benjamin Horwitz ◽

Nicole M. Donofrio

Keyword(s):

Reactive Oxygen Species ◽

Rice Blast ◽

Fungal Pathogens ◽

Plant Pathogens ◽

Reactive Oxygen ◽

Leaf Blight ◽

Confocal Imaging ◽

Oxygen Species ◽

Fungal Genes ◽

Corn Leaf Blight

Plants and their fungal pathogens both produce reactive oxygen species (ROS). CytotoxicROS act both as stressors and signals in the plant-fungal interaction. In biotrophs, a compatible interaction generates little ROS, but is followed by disease. An incompatible interaction results in a strong oxidative burst by the host, limiting infection. Necrotrophs, in contrast, thrive on dead and dying cells in an oxidant-rich local environment. Rice blast, Magnaportheoryzae, a hemibiotroph, occurs worldwide on rice and related hosts and can decimate enough rice each year to feed sixty million people. Cochliobolusheterostrophus, a necrotroph, causes Southern corn leaf blight (SLB), responsible for a major epidemic in the 1970s. The objectives of our study of ROS signaling and response in these two cereal pathogens were: Confocal imaging of ROS production using genetically encoded redox sensor in two pathosystems over time. Forward genetic screening of HyPer sensor lines in two pathosystems for fungal genes involved in altered ROSphenotypes. RNA-seq for discovery of genes involved in ROS-related stress and signaling in two pathosystems. Revisions to the research plan: Library construction in SLB was limited by low transformation efficiency, compounded by a protoplasting enzyme being unavailable during most of year 3. Thus Objective 2 for SLB re-focused to construction of sensor lines carrying deletion mutations in known or candidate genes involved in ROS response. Imaging on rice proved extremely challenging, so mutant screening and imaging were done with a barley-infecting line, already from the first year. In this project, ROS imaging at unprecedented time and spatial resolution was achieved, using genetically-encoded ratio sensors in both pathogens. This technology is currently in use for a large library of rice blast mutants in the ROS sensor background, and Southern corn leaf blight mutants in final stages of construction. The imaging methods developed here to follow the redox state of plant pathogens in the host tissue should be applicable to fungal pathogens in general. Upon completion of mutant construction for SCLB we hope to achieve our goal of comparison between intracellular ROS status and response in hemibiotroph and necrotroph cereal pathogens.

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Tolerance to oxidative stress is associated with both oxidative stress response and inherent growth in a fungal wheat pathogen

Genetics ◽

10.1093/genetics/iyaa022 ◽

2020 ◽

Vol 217 (2) ◽

Cited By ~ 1

Author(s):

Ziming Zhong ◽

Bruce A McDonald ◽

Javier Palma-Guerrero

Keyword(s):

Oxidative Stress ◽

Reactive Oxygen Species ◽

Stress Tolerance ◽

Stress Responses ◽

Plant Pathogens ◽

Reactive Oxygen ◽

Oxygen Species ◽

Zymoseptoria Tritici ◽

Oxidative Stress Tolerance ◽

Animal Pathogens

Abstract Reactive oxygen species are toxic byproducts of aerobic respiration that are also important in mediating a diversity of cellular functions. Reactive oxygen species form an important component of plant defenses to inhibit microbial pathogens during pathogen–plant interactions. Tolerance to oxidative stress is likely to make a significant contribution to the viability and pathogenicity of plant pathogens, but the complex network of oxidative stress responses hinders identification of the genes contributing to this trait. Here, we employed a forward genetic approach to investigate the genetic architecture of oxidative stress tolerance in the fungal wheat pathogen Zymoseptoria tritici. We used quantitative trait locus (QTL) mapping of growth and melanization under axenic conditions in two cross-populations to identify genomic regions associated with tolerance to oxidative stress. We found that QTLs associated with growth under oxidative stress as well as inherent growth can affect oxidative stress tolerance, and we identified two uncharacterized genes in a major QTL associated with this trait. Our data suggest that melanization does not affect tolerance to oxidative stress, which differs from what was found for animal pathogens. This study provides a whole-genome perspective on the genetic basis of oxidative stress tolerance in a plant pathogen.

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Mitochondria as a source of reactive oxygen species

Biochemical Journal ◽

10.1042/bj20090056 ◽

2009 ◽

pp. c3 ◽

Cited By ~ 1

Author(s):

Helena M. Cochemé ◽

Michael P. Murphy

Keyword(s):

Reactive Oxygen Species ◽

Reactive Oxygen ◽

Oxygen Species

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Clinical aspects of reactive oxygen and nitrogen species

Biochemical Society Symposium ◽

10.1042/bss0710121 ◽

2004 ◽

Vol 71 ◽

pp. 121-133 ◽

Cited By ~ 25

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.

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