Defects in the Ferroxidase That Participates in the Reductive Iron Assimilation System Results in Hypervirulence in Botrytis Cinerea

ABSTRACT The plant pathogen Botrytis cinerea is responsible for gray-mold disease, which infects a wide variety of species. The outcome of this host-pathogen interaction, a result of the interplay between plant defense and fungal virulence pathways, can be modulated by various environmental factors. Among these, iron availability and acquisition play a crucial role in diverse biological functions. How B. cinerea obtains iron, an essential micronutrient, during infection is unknown. We set out to determine the role of the reductive iron assimilation (RIA) system during B. cinerea infection. This system comprises the BcFET1 ferroxidase, which belongs to the multicopper oxidase (MCO) family of proteins, and the BcFTR1 membrane-bound iron permease. Gene knockout and complementation studies revealed that, compared to the wild type, the bcfet1 mutant displays delayed conidiation, iron-dependent sclerotium production, and significantly reduced whole-cell iron content. Remarkably, this mutant exhibited a hypervirulence phenotype, whereas the bcftr1 mutant presents normal virulence and unaffected whole-cell iron levels and developmental programs. Interestingly, while in iron-starved plants wild-type B. cinerea produced slightly reduced necrotic lesions, the hypervirulence phenotype of the bcfet1 mutant is no longer observed in iron-deprived plants. This suggests that B. cinerea bcfet1 knockout mutants require plant-derived iron to achieve larger necrotic lesions, whereas in planta analyses of reactive oxygen species (ROS) revealed increased ROS levels only for infections caused by the bcfet1 mutant. These results suggest that increased ROS production, under an iron sufficiency environment, at least partly underlie the observed infection phenotype in this mutant. IMPORTANCE The plant-pathogenic fungus B. cinerea causes enormous economic losses, estimated at anywhere between $10 billion and $100 billion worldwide, under both pre- and postharvest conditions. Here, we present the characterization of a loss-of-function mutant in a component involved in iron acquisition that displays hypervirulence. While in different microbial systems iron uptake mechanisms appear to be critical to achieve full pathogenic potential, we found that the absence of the ferroxidase that is part of the reductive iron assimilation system leads to hypervirulence in this fungus. This is an unusual and rather underrepresented phenotype, which can be modulated by iron levels in the plant and provides an unexpected link between iron acquisition, reactive oxygen species (ROS) production, and pathogenesis in the Botrytis-plant interaction.

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Production and scavenging of reactive oxygen species both affect reproductive success in male and female Drosophila melanogaster

Biogerontology ◽

10.1007/s10522-021-09922-1 ◽

2021 ◽

Author(s):

Biz R. Turnell ◽

Luisa Kumpitsch ◽

Klaus Reinhardt

Keyword(s):

Reactive Oxygen Species ◽

Drosophila Melanogaster ◽

Reactive Oxygen ◽

Cellular Aging ◽

Ros Production ◽

Oxygen Species ◽

Wild Type ◽

Ros Scavenging ◽

Respiratory Pathway ◽

Male And Female

AbstractSperm aging is accelerated by the buildup of reactive oxygen species (ROS), which cause oxidative damage to various cellular components. Aging can be slowed by limiting the production of mitochondrial ROS and by increasing the production of antioxidants, both of which can be generated in the sperm cell itself or in the surrounding somatic tissues of the male and female reproductive tracts. However, few studies have compared the separate contributions of ROS production and ROS scavenging to sperm aging, or to cellular aging in general. We measured reproductive fitness in two lines of Drosophila melanogaster genetically engineered to (1) produce fewer ROS via expression of alternative oxidase (AOX), an alternative respiratory pathway; or (2) scavenge fewer ROS due to a loss-of-function mutation in the antioxidant gene dj-1β. Wild-type females mated to AOX males had increased fecundity and longer fertility durations, consistent with slower aging in AOX sperm. Contrary to expectations, fitness was not reduced in wild-type females mated to dj-1β males. Fecundity and fertility duration were increased in AOX and decreased in dj-1β females, indicating that female ROS levels may affect aging rates in stored sperm and/or eggs. Finally, we found evidence that accelerated aging in dj-1β sperm may have selected for more frequent mating. Our results help to clarify the relative roles of ROS production and ROS scavenging in the male and female reproductive systems.

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Somatic production of reactive oxygen species does not predict its production in sperm cells across Drosophila melanogaster lines

BMC Research Notes ◽

10.1186/s13104-021-05550-7 ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

Biz R. Turnell ◽

Luisa Kumpitsch ◽

Anne-Cécile Ribou ◽

Klaus Reinhardt

Keyword(s):

Reactive Oxygen Species ◽

Drosophila Melanogaster ◽

Reactive Oxygen ◽

Future Research ◽

Ros Production ◽

Oxygen Species ◽

Loss Of Function ◽

Wild Type ◽

Ros Scavenging ◽

Transport Chain

Abstract Objective Sperm ageing has major evolutionary implications but has received comparatively little attention. Ageing in sperm and other cells is driven largely by oxidative damage from reactive oxygen species (ROS) generated by the mitochondria. Rates of organismal ageing differ across species and are theorized to be linked to somatic ROS levels. However, it is unknown whether sperm ageing rates are correlated with organismal ageing rates. Here, we investigate this question by comparing sperm ROS production in four lines of Drosophila melanogaster that have previously been shown to differ in somatic mitochondrial ROS production, including two commonly used wild-type lines and two lines with genetic modifications standardly used in ageing research. Results Somatic ROS production was previously shown to be lower in wild-type Oregon-R than in wild-type Dahomey flies; decreased by the expression of alternative oxidase (AOX), a protein that shortens the electron transport chain; and increased by a loss-of-function mutation in dj-1β, a gene involved in ROS scavenging. Contrary to predictions, we found no differences among these four lines in the rate of sperm ROS production. We discuss the implications of our results, the limitations of our study, and possible directions for future research.

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The Characterization of TA-289, a Novel Antifungal from Fusarium sp.

10.26686/wgtn.16992670 ◽

2021 ◽

Author(s):

◽

Natelle C H Quek

Keyword(s):

Oxidative Stress ◽

Reactive Oxygen Species ◽

Cell Cycle ◽

Cell Death ◽

Reactive Oxygen ◽

Chemical Diversity ◽

Mitochondrial Morphology ◽

Ros Production ◽

Oxygen Species ◽

Wild Type

<p>Natural products offer vast structural and chemical diversity highly sought after in drug discovery research. Saccharomyces cerevisiae makes an ideal model eukaryotic organism for drug mode-of-action studies owing to ease of growth, sophistication of genetic tools and overall homology to higher eukaryotes. Equisetin and a closely related novel natural product, TA-289, are cytotoxic to fermenting yeast, but seemingly less so when yeast actively respire. Cell cycle analyses by flow cytometry revealed a cell cycle block at S-G2/M phase caused by TA-289; previously described oxidative stress-inducing compounds causing cell cycle delay led to further investigation in the involvement of equisetin and TA-289 in mitochondrial-mediated generation of reactive oxygen species. Chemical genomic profiling involving genome-wide scans of yeast deletion mutant strains for TA-289 sensitivity revealed sensitization of genes involved in the mitochondria, DNA damage repair and oxidative stress responses, consistent with a possible mechanism-of-action at the mitochondrion. Flow cytometric detection of reactive oxygen species (ROS) generation caused by TA-289 suggests that the compound may induce cell death via ROS production. The generation of a mutant strain resistant to TA-289 also displayed resistance to a known oxidant, H2O2, at concentrations that were cytotoxic to wild-type cells. The resistant mutant displayed a higher basal level of ROS production compared to the wild-type parent, indicating that the resistance mutation led to an up-regulation of antioxidant capacity which provides cell survival in the presence of TA-289. Yeast mitochondrial morphology was visualized by confocal light microscopy, where it was observed that cells treated with TA-289 displayed abnormal mitochondria phenotypes, further indicating that the compound is acting primarily at the mitochondrion. Similar effects observed with equisetin treatment suggest that both compounds share the same mechanism, eliciting cell death via ROS production in the mitochondrial respiratory chain.</p>

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Lung endothelial cell proliferation with decreased shear stress is mediated by reactive oxygen species

AJP Cell Physiology ◽

10.1152/ajpcell.00094.2005 ◽

2006 ◽

Vol 290 (1) ◽

pp. C66-C76 ◽

Cited By ~ 48

Author(s):

Tatyana Milovanova ◽

Shampa Chatterjee ◽

Yefim Manevich ◽

Irina Kotelnikova ◽

Kris DeBolt ◽

...

Keyword(s):

Reactive Oxygen Species ◽

Cell Proliferation ◽

Shear Stress ◽

Endothelial Cell ◽

Nadph Oxidase ◽

Reactive Oxygen ◽

Proliferation Index ◽

Ros Production ◽

Oxygen Species ◽

Wild Type

Acute cessation of flow (ischemia) leads to depolarization of the endothelial cell (EC) membrane mediated by KATP channels and followed by production of reactive oxygen species (ROS) from NADPH oxidase. We postulated that ROS are a signal for initiating EC proliferation associated with the loss of shear stress. Flow cytometry was used to identify proliferating CD31-positive pulmonary microvascular endothelial cells (mPMVECs) from wild-type, Kir6.2−/−, and gp91 phox−/− mice. mPMVECs were labeled with PKH26 and cultured in artificial capillaries for 72 h at 5 dyn/cm2 (flow adaptation), followed by 24 h of stop flow or continued flow. ROS production during the first hour of ischemia was markedly diminished compared with wild-type mice in both types of gene-targeted mPMVECs. Cell proliferation was defined as the proliferation index (PI). After 72 h of flow, >98% of PKH26-labeled wild-type mPMVECs were at a single peak (PI 1.0) and the proportion of cells in the S+G2/M phases were at 5.8% on the basis of cell cycle analysis. With ischemia (24 h), PI increased to 2.5 and the ratio of cells in S+G2/M phases were at 35%. Catalase, diphenyleneiodonium, and cromakalim markedly inhibited ROS production and cell proliferation in flow-adapted wild-type mPMVECs. Significant effects of ischemia were not observed in Kir6.2−/− and gp91 phox−/− cells. ANG II activation of NADPH oxidase was unaffected by KATP gene deletion. Thus loss of shear stress in flow-adapted mPMVECs results in cell division associated with ROS generated by NADPH oxidase. This effect requires a functioning cell membrane KATP channel.

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Arabidopsis thaliana constitutively active ROP11 interacts with the NADPH oxidase respiratory burst oxidase homologue F to regulate reactive oxygen species production in root hairs

Functional Plant Biology ◽

10.1071/fp15090 ◽

2016 ◽

Vol 43 (3) ◽

pp. 221 ◽

Cited By ~ 9

Author(s):

Min Yan ◽

Wen Jing ◽

Ni Xu ◽

Like Shen ◽

Qun Zhang ◽

...

Keyword(s):

Reactive Oxygen Species ◽

Arabidopsis Thaliana ◽

Respiratory Burst ◽

Root Hairs ◽

Reactive Oxygen ◽

Ros Production ◽

Oxygen Species ◽

Wild Type ◽

Respiratory Burst Oxidase ◽

Constitutively Active

Reactive oxygen species (ROS) play a key signalling role in cells. Plant NADPH oxidases, also known as respiratory burst oxidase homologues (Rbohs), are well characterised ROS-generating systems. In this study, we found that the constitutively active small guanosine triphosphatase (GTPase) ROP11 (CA-ROP11) interacted with RbohF by using a yeast two-hybrid analysis, a pull-down assay and an in vivo bimolecular fluorescence complementation assay. The mutation of amino acid L336 or L337 in RbohF abolished its interaction with CA-ROP11. Coexpression of CA-ROP11 and wild-type RbohF in Nicotiana benthamiana Domin enhanced ROS production compared with coexpression of CA-ROP11 and mutant RbohF or of dominant negative ROP11 and wild-type RbohF. Moreover, CA-ROP11 overexpression resulted in ROS accumulation and a swollen root hair phenotype in Arabidopsis thaliana (L.) Heynh. The deletion of RbohF partially reduced the increase in ROS in Arabidopsis plants overexpressing CA-ROP11. These results suggest that Arabidopsis ROP11 modulates ROS production by interacting with RbohF in root hairs.

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Mutant Kras as a Biomarker Plays a Favorable Role in FL118-Induced Apoptosis, Reactive Oxygen Species (ROS) Production and Modulation of Survivin, Mcl-1 and XIAP in Human Bladder Cancer

Cancers ◽

10.3390/cancers12113413 ◽

2020 ◽

Vol 12 (11) ◽

pp. 3413

Author(s):

Sreevidya Santha ◽

Xiang Ling ◽

Ieman A. M. Aljahdali ◽

Sailee S. Rasam ◽

Xue Wang ◽

...

Keyword(s):

Reactive Oxygen Species ◽

Bladder Cancer ◽

Reactive Oxygen ◽

In Vivo Studies ◽

Parp Cleavage ◽

Ros Generation ◽

Ros Production ◽

Oxygen Species ◽

Wild Type ◽

Kras Mutations

Tumor heterogeneity in key gene mutations in bladder cancer (BC) is a major hurdle for the development of effective treatments. Using molecular, cellular, proteomics and animal models, we demonstrated that FL118, an innovative small molecule, is highly effective at killing T24 and UMUC3 high-grade BC cells, which have Hras and Kras mutations, respectively. In contrast, HT1376 BC cells with wild-type Ras are insensitive to FL118. This concept was further demonstrated in additional BC and colorectal cancer cells with mutant Kras versus those with wild-type Kras. FL118 strongly induced PARP cleavage (apoptosis hallmark) and inhibited survivin, XIAP and/or Mcl-1 in both T24 and UMUC3 cells, but not in the HT1376 cells. Silencing mutant Kras reduced both FL118-induced PARP cleavage and downregulation of survivin, XIAP and Mcl-1 in UMUC3 cells, suggesting mutant Kras is required for FL118 to exhibit higher anticancer efficacy. FL118 increased reactive oxygen species (ROS) production in T24 and UMUC3 cells, but not in HT1376 cells. Silencing mutant Kras in UMUC3 cells reduced FL118-mediated ROS generation. Proteomics analysis revealed that a profound and opposing Kras-relevant signaling protein is changed in UMUC3 cells and not in HT1376 cells. Consistently, in vivo studies indicated that UMUC3 tumors are highly sensitive to FL118 treatment, while HT1376 tumors are highly resistant to this agent. Silencing mutant Kras in UMUC3 cell-derived tumors decreases UMUC3 tumor sensitivity to FL118 treatment. Together, our studies revealed that mutant Kras is a favorable biomarker for FL118 targeted treatment.

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Reactive Oxygen Species: Not Omnipresent but Important in Many Locations

Frontiers in Cell and Developmental Biology ◽

10.3389/fcell.2021.716406 ◽

2021 ◽

Vol 9 ◽

Author(s):

Marc Herb ◽

Alexander Gluschko ◽

Michael Schramm

Keyword(s):

Reactive Oxygen Species ◽

Reactive Oxygen ◽

Redox Balance ◽

Ros Production ◽

Oxygen Species ◽

Cellular Compartment ◽

Whole Cell ◽

Redox Biology ◽

Cellular Source ◽

The One

Reactive oxygen species (ROS), such as the superoxide anion or hydrogen peroxide, have been established over decades of research as, on the one hand, important and versatile molecules involved in a plethora of homeostatic processes and, on the other hand, as inducers of damage, pathologies and diseases. Which effects ROS induce, strongly depends on the cell type and the source, amount, duration and location of ROS production. Similar to cellular pH and calcium levels, which are both strictly regulated and only altered by the cell when necessary, the redox balance of the cell is also tightly regulated, not only on the level of the whole cell but in every cellular compartment. However, a still widespread view present in the scientific community is that the location of ROS production is of no major importance and that ROS randomly diffuse from their cellular source of production throughout the whole cell and hit their redox-sensitive targets when passing by. Yet, evidence is growing that cells regulate ROS production and therefore their redox balance by strictly controlling ROS source activation as well as localization, amount and duration of ROS production. Hopefully, future studies in the field of redox biology will consider these factors and analyze cellular ROS more specifically in order to revise the view of ROS as freely flowing through the cell.

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Screening Vitis Genotypes for Responses to Botrytis cinerea and Evaluation of Antioxidant Enzymes, Reactive Oxygen Species and Jasmonic Acid in Resistant and Susceptible Hosts

Molecules ◽

10.3390/molecules24010005 ◽

2018 ◽

Vol 24 (1) ◽

pp. 5 ◽

Cited By ~ 2

Author(s):

Mati Rahman ◽

Muhammad Hanif ◽

Ran Wan ◽

Xiaoqing Hou ◽

Bilal Ahmad ◽

...

Keyword(s):

Reactive Oxygen Species ◽

Jasmonic Acid ◽

Botrytis Cinerea ◽

Reactive Oxygen ◽

Fungal Growth ◽

Ros Production ◽

Oxygen Species ◽

Fungal Phytopathogen ◽

Vitis Davidii ◽

High Level

Botrytis cinerea is a necrotrophic fungal phytopathogen with devastating effects on many Vitis genotypes. Here, a screening of 81 Vitis genotypes for leaf resistance to B. cinerea revealed two highly resistant (HR), twelve resistant (R), twenty-five susceptible (S) and forty-two highly susceptible (HS) genotypes. We focused on the HR genotype, ‘Zi Qiu’ (Vitis davidii), and the HS genotype ‘Riesling’ (V. vinifera), to elucidate mechanisms of host resistance and susceptibility against B. cinerea, using detached leaf assays. These involved a comparison of fungal growth, reactive oxygen species (ROS) responses, jasmonic acid (JA) levels, and changes in the anti-oxidative system between the two genotypes after inoculation with B. cinerea. Our results indicated that the high-level resistance of ‘Zi Qiu’ can be attributed to insignificant fungal development, low ROS production, timely elevation of anti-oxidative functions, and high JA levels. Moreover, severe fungal infection of ‘Riesling’ and sustained ROS production coincided with relatively unchanged anti-oxidative activity, as well as low JA levels. This study provides insights into B. cinerea infection in grape, which can be valuable for breeders by providing information for selecting suitable germplasm with enhanced disease resistance.

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Functional Analysis of theTrichoderma harzianum nox1Gene, Encoding an NADPH Oxidase, Relates Production of Reactive Oxygen Species to Specific Biocontrol Activity against Pythium ultimum

Applied and Environmental Microbiology ◽

10.1128/aem.02486-10 ◽

2011 ◽

Vol 77 (9) ◽

pp. 3009-3016 ◽

Cited By ~ 45

Author(s):

M. Montero-Barrientos ◽

R. Hermosa ◽

R. E. Cardoza ◽

S. Gutiérrez ◽

E. Monte

Keyword(s):

Reactive Oxygen Species ◽

Reactive Oxygen ◽

Pythium Ultimum ◽

Eukaryotic Cells ◽

Ros Production ◽

Oxygen Species ◽

Wild Type ◽

Nadph Oxidases ◽

Content Type ◽

Biocontrol Activity

ABSTRACTThe synthesis of reactive oxygen species (ROS) is one of the first events following pathogenic interactions in eukaryotic cells, and NADPH oxidases are involved in the formation of such ROS. Thenox1gene ofTrichoderma harzianumwas cloned, and its role in antagonism against phytopathogens was analyzed innox1-overexpressed transformants. The increased levels ofnox1expression in these transformants were accompanied by an increase in ROS production during their direct confrontation withPythium ultimum. The transformants displayed an increased hydrolytic pattern, as determined by comparing protease, cellulase, and chitinase activities with those for the wild type. In confrontation assays againstP. ultimumthenox1-overexpressed transformants were more effective than the wild type, but not in assays againstBotrytis cinereaorRhizoctonia solani. A transcriptomic analysis using aTrichodermahigh-density oligonucleotide (HDO) microarray also showed that, compared to gene expression for the interaction of wild-typeT. harzianumandP. ultimum, genes related to protease, cellulase, and chitinase activities were differentially upregulated in the interaction of anox1-overexpressed transformant with this pathogen. Our results show thatnox1is involved inT. harzianumROS production and antagonism againstP. ultimum.

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