scholarly journals NADPH Oxidase ClNOX2 Regulates Melanin-Mediated Development and Virulence in Curvularia lunata

2020 ◽  
Vol 33 (11) ◽  
pp. 1315-1329
Author(s):  
Fen Wang ◽  
Weida Gao ◽  
Jiaying Sun ◽  
Xiuwen Mao ◽  
Kexin Liu ◽  
...  
Keyword(s):  
Cell Wall ◽  
Signaling Pathway ◽  
Hyphal Growth ◽  
Conidial Germination ◽  
Mitogen Activated Protein Kinase ◽  
Ros Generation ◽  
Deletion Mutants ◽  
Curvularia Lunata ◽  
Kinase Gene ◽  
Melanin Biosynthesis

The role of NADPH oxidases (NOXs) in pathogenesis and development in the Curvularia leaf spot agent Curvularia lunata remains poorly understood. In this study, we identified C. lunata ClNOX2, which localized to the plasma membrane and was responsible for reactive oxygen species (ROS) generation. Scavenging the ROS production inhibited the conidial germination and appressorial formation. The ClNOX2 and ClBRN1 deletion mutants were defective in 1,8-dihydroxynaphthalene (DHN) melanin accumulation, appressorial formation, and cellulase synthesis and exhibited lower virulence. However, disruption of the ClNOX2 and ClBRN1 genes facilitated hyphal growth, enhanced stress adaptation to cell-wall-disrupting agents, and promoted developmental processes such as conidiation, conidial germination, and pseudothecium and ascus formation. Interestingly, loss of ClM1, the cell wall integrity (CWI) mitogen-activated protein kinase gene in C. lunata, led to morphology and pathogenicity phenotypes similar to ClNOX2 and ClBRN1 deletion mutants such as abnormal conidia, fewer appressoria, less melanin, increased hyphal growth, and enhanced tolerance to Congo red (CR). These results indicated that the ClNOX2 gene plays an important role in C. lunata development and virulence via regulating intracellular DHN melanin biosynthesis. Quantitative reverse-transcription PCR revealed that the ClNOX2-related ROS signaling pathway and ClM1-mediated CWI signaling pathway are cross-linked in regulating DHN melanin biosynthesis. Our findings provide new insights into how ClNOX2 participates in pathogenesis and development in hemibiotrophic plant fungal pathogens. [Formula: see text] Copyright © 2020 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

scholarly journals The CfMK1 Gene Regulates Reproduction, Appressorium Formation, and Pathogenesis in a Pear Anthracnose-Causing Fungus

2022 ◽  
Vol 8 (1) ◽  
pp. 77
Author(s):  
Chaohui Li ◽  
Weibo Sun ◽  
Shulin Cao ◽  
Rongxian Hou ◽  
Xiaogang Li ◽  
...  
Keyword(s):  
Cell Wall ◽  
Germination Rate ◽  
Hyphal Growth ◽  
Pathogenic Fungi ◽  
Mitogen Activated Protein Kinase ◽  
Economic Losses ◽  
Deletion Mutants ◽  
Appressorium Formation ◽  
Mapk Cascades ◽  
Mitogen Activated Protein

Colletotrichum fructicola, the causal agent of pear anthracnose, causes significant annual economic losses. Mitogen-activated protein kinase (MAPK) cascades are highly conserved signal transduction pathways that play a crucial role in mediating cellular responses to environmental and host signals in plant pathogenic fungi. In this study, we identified an ortholog of the FUS3/KSS1-related MAPK gene, CfMK1, and characterized its function in C. fructicola. The Cfmk1 deletion mutants exhibited poorly developed aerial hyphae, autolysis, no conidial mass or perithecia on solid plates. However, the conidiation of the Cfmk1 mutant in PDB liquid medium was normal compared with that of the wild type (WT). Conidia of the Cfmk1 mutant exhibited a reduced germination rate on glass slides or plant surfaces. The Cfmk1 deletion mutants were unable to form appressoria and lost the capacity to penetrate plant epidermal cells. The ability of the Cfmk1 mutants to infect pear leaves and fruit was severely reduced. Moreover, RNA sequencing (RNA-seq) analysis of the WT and Cfmk1 mutant was performed, and the results revealed 1886 upregulated and 1554 downregulated differentially expressed genes (DEGs) in the mutant. The DEGs were significantly enriched in cell wall and pathogenesis terms, which was consistent with the defects of the Cfmk1 mutant in cell wall integrity and plant infection. Overall, our data demonstrate that CfMK1 plays critical roles in the regulation of aerial hyphal growth, asexual and sexual reproduction, autolysis, appressorium formation, and pathogenicity.

scholarly journals Novel Mitogen-Activated Protein Kinase MpkC of Aspergillus fumigatus Is Required for Utilization of Polyalcohol Sugars

2006 ◽  
Vol 5 (11) ◽  
pp. 1934-1940 ◽  
Author(s):  
Guadalupe Reyes ◽  
Angela Romans ◽  
C. Kim Nguyen ◽  
Gregory S. May
Keyword(s):  
Carbon Source ◽  
Aspergillus Fumigatus ◽  
Hyphal Growth ◽  
Mitogen Activated Protein Kinase ◽  
Deletion Mutants ◽  
Mrna Levels ◽  
Hypertonic Stress ◽  
Mitogen Activated Protein ◽  
Stress Oxidative ◽  
Mapk Gene

ABSTRACT The genome of Aspergillus fumigatus has four genes that encode mitogen-activated protein kinases (MAPKs), sakA/hogA, mpkA, mpkB, and mpkC. The functions of the MpkB and MpkC MAPKs are unknown for A. fumigatus and the closely related and genetically amenable species Aspergillus nidulans. mpkC deletion mutants of A. fumigatus were made and their phenotypes characterized. The mpkC deletion mutants were viable and had normal conidial germination and hyphal growth on minimal or complete media. This is in contrast to deletion mutants with deletions in the closely related MAPK gene sakA/hogA that we previously reported had a nitrogen source-dependent germination phenotype. Similarly, the growth of the mpkC deletion mutants was wild type on high-osmolarity medium. Consistent with these two MAP kinase genes regulating different cellular responses, we determined that the mpkC deletion mutants were unable to grow on minimal medium with sorbitol or mannitol as the sole carbon source. This result implicates MpkC signaling in carbon source utilization. Changes in mRNA levels for sakA and mpkC were measured in response to hypertonic stress, oxidative stress, and a shift from glucose to sorbitol to determine if there was overlap in the SakA and MpkC signaling pathways. These studies demonstrated that SakA- and MpkC-dependent patterns of change in mRNA levels are distinct and have minimal overlap in response to these environmental stresses.

scholarly journals A Mitogen-Activated Protein Kinase Gene (MGV1) in Fusarium graminearum Is Required for Female Fertility, Heterokaryon Formation, and Plant Infection

2002 ◽  
Vol 15 (11) ◽  
pp. 1119-1127 ◽  
Author(s):  
Zhanming Hou ◽  
Chaoyang Xue ◽  
Youliang Peng ◽  
Talma Katan ◽  
H. Corby Kistler ◽  
...  
Keyword(s):  
Cell Wall ◽  
Sexual Reproduction ◽  
Fusarium Graminearum ◽  
Magnaporthe Grisea ◽  
Molecular Mechanisms ◽  
Female Fertility ◽  
Mitogen Activated Protein Kinase ◽  
Kinase Gene ◽  
Heterokaryon Formation ◽  
Plant Infection

Fusarium graminearum is an important pathogen of small grains and maize in many areas of the world. Infected grains are often contaminated with mycotoxins harmful to humans and animals. During the past decade, F. graminearum has caused several severe epidemics of head scab in wheat and barley. In order to understand molecular mechanisms regulating fungal development and pathogenicity in this pathogen, we isolated and characterized a MAP kinase gene, MGV1, which is highly homologous to the MPS1 gene in Magnaporthe grisea. The MGV1 gene was dispensable for conidiation in F. graminearum but essential for female fertility during sexual reproduction. Vegetative growth of mgv1 deletion mutants was normal in liquid media but reduced on solid media. Mycelia of the mgv1 mutants had weak cell walls and were hypersensitive to cell wall degrading enzymes. Interestingly, the mgv1 mutants were self-incompatible when tested for heterokaryon formation, and their virulence was substantially reduced. The ability of the mutants to accumulate trichothecene mycotoxins on inoculated wheat was also greatly reduced. Our data suggest that MGV1 in F. graminearum is involved in multiple developmental processes related to sexual reproduction, plant infection, and cell wall integrity.

scholarly journals MAPK cascades mediating Trichoderma brevicrassum strain TC967 against phytopathogen Rhizoctonia solani

2021 ◽  
Author(s):  
Yi Zhang ◽  
Wen-Ying Zhuang
Keyword(s):  
Cell Wall ◽  
Rhizoctonia Solani ◽  
Biological Control Agent ◽  
Hyphal Growth ◽  
Control Agent ◽  
Mitogen Activated Protein Kinase ◽  
Cell Wall Degrading Enzymes ◽  
Gene Expressions ◽  
Fungal Cell ◽  
Mapk Cascades

Trichoderma brevicrassum strain TC967 is a novel biological control agent (BCA) against the plant pathogen Rhizoctonia solani and promotes plant growth. MAPK (mitogen-activated protein kinase) cascades were involved in biocontrol by Trichoderma, but functions of each MAPK in regulating biocontrol have not been characterized in one Trichoderma. In this study, we assembled and annotated the genome of strain TC967, and identified its three MAPK gene sequences. Functions of Fus3-, Slt2- and Hog1-MAPK in strain TC967 were dissected. The three MAPKs were all involved in hyphal growth. The Hog1-MAPK was essential for conidiation and tolerance to hyperosmotic stress. The Fus3- and Slt2-MAPK both mediated cell-wall integrity (CWI) and activities of chitinase and protease. The Fus3- and Hog1-MAPK mediated response to oxidative stress. Our biocontrol assays demonstrated that the Fus3- and Slt2-MAPK mutants were considerably more effective in disease control than the wild-type strain. RNA-seq analysis revealed that MAPK collectively played a major role in regulating biocontrol-related gene expressions, including of the genes in charge of secondary metabolism, fungal cell wall-degrading enzymes (FCWDEs) and small secreted cysteine-rich proteins (SSCPs).

scholarly journals Pleiotropic Function of the Putative Zinc-Finger Protein MoMsn2 in Magnaporthe oryzae

2014 ◽  
Vol 27 (5) ◽  
pp. 446-460 ◽  
Author(s):  
Haifeng Zhang ◽  
Qian Zhao ◽  
Xianxian Guo ◽  
Min Guo ◽  
Zhongqiang Qi ◽  
...  
Keyword(s):  
Cell Wall ◽  
Magnaporthe Oryzae ◽  
Stress Responses ◽  
Zinc Finger Protein ◽  
Affinity Purification ◽  
Hyphal Growth ◽  
Mitogen Activated Protein Kinase ◽  
Phenotypic Characterization ◽  
Cell Wall Biosynthesis ◽  
Appressorium Formation

The mitogen-activated protein kinase MoOsm1–mediated osmoregulation pathway plays crucial roles in stress responses, asexual and sexual development, and pathogenicity in Magnaporthe oryzae. Utilizing an affinity purification approach, we identified the putative transcriptional activator MoMsn2 as a protein that interacts with MoOsm1 in vivo. Disruption of the MoMSN2 gene resulted in defects in aerial hyphal growth, conidial production, and infection of host plants. Quantitative reverse transcription-polymerase chain reaction analysis showed that the expression of several genes involved in conidiophore formation was reduced in ΔMomsn2, suggesting that MoMsn2 might function as a transcriptional regulator of these genes. Subsequently, MoCos1 was identified as one of the MoMsn2 targets through yeast one-hybrid analysis in which MoMsn2 binds to the AGGGG and CCCCT motif of the MoCOS1 promoter region. Phenotypic characterization showed that MoMsn2 was required for appressorium formation and penetration and pathogenicity. Although the ΔMomsn2 mutant was tolerant to the cell-wall stressor Calcofluor white, it was sensitive to common osmotic stressors. Further analysis suggests that MoMsn2 is involved in the regulation of the cell-wall biosynthesis pathway. Finally, transcriptome data revealed that MoMsn2 modulates numerous genes participating in conidiation, infection, cell-wall integrity, and stress response. Collectively, our results led to a model in which MoMsn2 mediates a series of downstream genes that control aerial hyphal growth, conidiogenesis, appressorium formation, cell-wall biosynthesis, and infection and that also offer potential targets for the development of new disease management strategies.

scholarly journals Rutin Protects against Pirarubicin-Induced Cardiotoxicity through TGF-β1-p38 MAPK Signaling Pathway

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Yadi Wang ◽  
Yang Zhang ◽  
Bo Sun ◽  
Qing Tong ◽  
Liqun Ren
Keyword(s):  
Signaling Pathway ◽  
P38 Mapk ◽  
Cell Apoptosis ◽  
Dose Range ◽  
Mapk Signaling ◽  
Positive Control ◽  
Mapk Signaling Pathway ◽  
Cardioprotective Effect ◽  
Mitogen Activated Protein Kinase ◽  
Ros Generation

We investigated the potential protective effect of rutinum (RUT) against pirarubicin- (THP-) induced cardiotoxicity. THP was used to induce toxicity in rat H9c2 cardiomyoblasts. Positive control cells were pretreated with a cardioprotective agent dexrazoxane (DZR) prior to treatment with THP. Some of the cells were preincubated with RUT and a p38 mitogen-activated protein kinase (MAPK) inhibitor, SB203580, both individually and in combination, prior to THP exposure. At a dose range of 30–70 μM, RUT significantly prevented THP-induced reduction in cell viability; the best cardioprotective effect was observed at a dose of 50 μM. Administration of RUT and SB203580, both individually as well as in combination, suppressed the elevation of intracellular ROS, inhibited cell apoptosis, and reversed the THP-induced upregulation of TGF-β1, p-p38 MAPK, cleaved Caspase-9, Caspase-7, and Caspase-3. A synergistic effect was observed on coadministration of RUT and SB203580. RUT protected against THP-induced cardiotoxicity by inhibition of ROS generation and suppression of cell apoptosis. The cardioprotective effect of RUT appears to be associated with the modulation of the TGF-β1-p38 MAPK signaling pathway.

Cytotoxicity of mancozeb on Sertoli–germ cell co-culture system: Role of MAPK signaling pathway

2021 ◽  
pp. 074823372110440
Author(s):  
Mohaddeseh Mohammadi-Sardoo ◽  
Ali Mandegary ◽  
Seyed Noureddin Nematollahi-Mahani ◽  
Mahshid Moballegh Nasery ◽  
Mohammad Nabiuni ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Death ◽  
Germ Cell ◽  
Signaling Pathway ◽  
Molecular Mechanisms ◽  
Apoptotic Cell ◽  
Primary Cultures ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Ros Generation

Mancozeb (MZB) is a worldwide fungicide for the management of fungal diseases in agriculture and industrial contexts. Human exposure occurs by consuming contaminated plants, drinking water, and occupational exposure. There are reports on MZB’s reprotoxicity such as testicular structure damage, sperm abnormalities, and decrease in sperm parameters (number, viability, and motility), but its molecular mechanism on apoptosis in testis remains limited. To investigate the molecular mechanisms involved in male reprotoxicity induced by MZB, we used primary cultures of mouse Sertoli–germ cells. Cells were exposed to MZB (1.5, 2.5, and 3.5 μM) for 3 h to evaluate viability by 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay, reactive oxygen species (ROS) generation, and oxidative stress parameters (lipid peroxidation). Cell death and mitogen-activated protein kinase (MAPK) signaling were measured in these cells using flow cytometry and western blotting. In addition, some groups were exposed to N-acetylcysteine (NAC, 5 mM) in the form of co-treatment with MZB. Mancozeb reduced viability and increased the level of intracellular ROS, p38 and c-Jun N-terminal kinases (JNK) MAPK proteins phosphorylation, and apoptotic cell death, which could be blocked by NAC as an inhibitor of oxidative stress. The present study indicated for the first time the toxic manifestations of MZB on the Sertoli–germ cell co-culture. Redox imbalance and p38 and JNK signaling pathway activation might play critical roles in MZB-induced apoptosis in the male reproductive system.

scholarly journals The Aspergillus fumigatuscspA Gene Encoding a Repeat-Rich Cell Wall Protein Is Important for Normal Conidial Cell Wall Architecture and Interaction with Host Cells

2010 ◽  
Vol 9 (9) ◽  
pp. 1403-1415 ◽  
Author(s):  
Emma Levdansky ◽  
Oren Kashi ◽  
Haim Sharon ◽  
Yana Shadkchan ◽  
Nir Osherov
Keyword(s):  
Cell Wall ◽  
Pathogenic Fungus ◽  
Protein A ◽  
Surface Protein ◽  
Hyphal Growth ◽  
Cell Wall Protein ◽  
Conidial Germination ◽  
Host Cells ◽  
Cell Wall Degrading Enzymes ◽  
Content Type

ABSTRACT cspA (for cell surface protein A) encodes a repeat-rich glycophosphatidylinositol (GPI)-anchored cell wall protein (CWP) in the pathogenic fungus Aspergillus fumigatus. The number of repeats in cspA varies among isolates, and this trait is used for typing closely related strains of A. fumigatus. We have previously shown that deletion of cspA is associated with rapid conidial germination and reduced adhesion of dormant conidia. Here we show that cspA can be extracted with hydrofluoric acid (HF) from the cell wall, suggesting that it is a GPI-anchored CWP. The cspA-encoded CWP is unmasked during conidial germination and is surface expressed during hyphal growth. Deletion of cspA results in weakening of the conidial cell wall, whereas its overexpression increases conidial resistance to cell wall-degrading enzymes and inhibits conidial germination. Double mutant analysis indicates that cspA functionally interacts with the cell wall protein-encoding genes ECM33 and GEL2. Deletion of cspA together with ECM33 or GEL2 results in strongly reduced conidial adhesion, increased disorganization of the conidial cell wall, and exposure of the underlying layers of chitin and β-glucan. This is correlated with increasing susceptibility of the ΔcspA, ΔECM33, and ΔcspA ΔECM33 mutants to conidial phagocytosis and killing by human macrophages and hyphal damage induced by neutrophils. However, these strains did not exhibit altered virulence in mice with infected lungs. Collectively, these results suggest a role for cspA in maintaining the strength and integrity of the cell wall.

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