scholarly journals A Histone Deacetylase, Magnaporthe oryzae RPD3, Regulates Reproduction and Pathogenic Development in the Rice Blast Fungus

mBio ◽  
2021 ◽  
Author(s):  
Song Hee Lee ◽  
Mohamed El-Agamy Farh ◽  
Jaejoon Lee ◽  
Young Taek Oh ◽  
Eunbyeol Cho ◽  
...  
Keyword(s):  
Histone Deacetylase ◽  
Magnaporthe Oryzae ◽  
Rice Blast ◽  
Fungal Pathogens ◽  
Blast Disease ◽  
Gene Encoding ◽  
Content Type ◽  
Cellular Processes ◽  
Evolutionarily Conserved ◽  
Severe Growth

RPD3 is an evolutionarily conserved class I histone deacetylase (HDAC) that plays a pivotal role in diverse cellular processes. In filamentous fungal pathogens, abrogation of the gene encoding RPD3 results in either lethality or severe growth impairment, making subsequent genetic analyses challenging. Magnaporthe oryzae is a causal agent of rice blast disease, which is responsible for significant annual yield losses in rice production.

scholarly journals Ubiquitination in the rice blast fungus Magnaporthe oryzae: from development and pathogenicity to stress responses

2022 ◽  
Vol 4 (1) ◽  
Author(s):  
Yu Wang ◽  
Nan Yang ◽  
Yunna Zheng ◽  
Jiaolin Yue ◽  
Vijai Bhadauria ◽  
...  
Keyword(s):  
Magnaporthe Oryzae ◽  
Stress Responses ◽  
Rice Blast ◽  
Protein Localization ◽  
26S Proteasome ◽  
Blast Disease ◽  
Deubiquitinating Enzymes ◽  
Post Translational Modification ◽  
Protein Protein Interaction ◽  
Cellular Processes

AbstractUbiquitination is a vital protein post-translational modification (PTM) prevalent in eukaryotes. This modification regulates multiple cellular processes through protein degradation mediated by the 26S proteasome or affecting protein–protein interaction and protein localization. Magnaporthe oryzae causes rice blast disease, which is one of the most devastating crop diseases worldwide. In M. oryzae, ubiquitination plays important roles in growth, pathogenicity, stress response and effector-mediated plant-pathogen interaction. In this review, we summarize the roles of ubiquitination components in the above biological processes of M. oryzae, including single- or multi-subunit E3s, E2s, components of 26S proteasome and also deubiquitinating enzymes. The essential function of ubiquitination in plant-fungus interaction is also discussed. Moreover, this review presents several issues related to the ubiquitination system in M. oryzae, which need to be further explored in future researches.

scholarly journals Role of Two Metacaspases in Development and Pathogenicity of the Rice Blast Fungus Magnaporthe oryzae

mBio ◽  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jessie Fernandez ◽  
Victor Lopez ◽  
Lisa Kinch ◽  
Mariel A. Pfeifer ◽  
Hillery Gray ◽  
...  
Keyword(s):  
Cell Death ◽  
Food Security ◽  
Life Cycle ◽  
Magnaporthe Oryzae ◽  
Rice Blast ◽  
Rice Blast Disease ◽  
Blast Disease ◽  
Complex Life Cycle ◽  
Content Type

ABSTRACT Rice blast disease caused by Magnaporthe oryzae is a devastating disease of cultivated rice worldwide. Infections by this fungus lead to a significant reduction in rice yields and threats to food security. To gain better insight into growth and cell death in M. oryzae during infection, we characterized two predicted M. oryzae metacaspase proteins, MoMca1 and MoMca2. These proteins appear to be functionally redundant and can complement the yeast Yca1 homologue. Biochemical analysis revealed that M. oryzae metacaspases exhibited Ca2+-dependent caspase activity in vitro. Deletion of both MoMca1 and MoMca2 in M. oryzae resulted in reduced sporulation, delay in conidial germination, and attenuation of disease severity. In addition, the double ΔMomca1mca2 mutant strain showed increased radial growth in the presence of oxidative stress. Interestingly, the ΔMomca1mca2 strain showed an increased accumulation of insoluble aggregates compared to the wild-type strain during vegetative growth. Our findings suggest that MoMca1 and MoMca2 promote the clearance of insoluble aggregates in M. oryzae, demonstrating the important role these metacaspases have in fungal protein homeostasis. Furthermore, these metacaspase proteins may play additional roles, like in regulating stress responses, that would help maintain the fitness of fungal cells required for host infection. IMPORTANCE Magnaporthe oryzae causes rice blast disease that threatens global food security by resulting in the severe loss of rice production every year. A tightly regulated life cycle allows M. oryzae to disarm the host plant immune system during its biotrophic stage before triggering plant cell death in its necrotrophic stage. The ways M. oryzae navigates its complex life cycle remain unclear. This work characterizes two metacaspase proteins with peptidase activity in M. oryzae that are shown to be involved in the regulation of fungal growth and development prior to infection by potentially helping maintain fungal fitness. This study provides new insights into the role of metacaspase proteins in filamentous fungi by illustrating the delays in M. oryzae morphogenesis in the absence of these proteins. Understanding the mechanisms by which M. oryzae morphology and development promote its devastating pathogenicity may lead to the emergence of proper methods for disease control.

scholarly journals Cellular Dynamics and Genomic Identity of Centromeres in Cereal Blast Fungus

mBio ◽  
2019 ◽  
Vol 10 (4) ◽  
Author(s):  
Vikas Yadav ◽  
Fan Yang ◽  
Md. Hashim Reza ◽  
Sanzhen Liu ◽  
Barbara Valent ◽  
...  
Keyword(s):  
Dna Sequence ◽  
Chromosome Segregation ◽  
Magnaporthe Oryzae ◽  
Rice Blast ◽  
Metaphase Plate ◽  
Blast Disease ◽  
Sequence Motifs ◽  
Content Type ◽  
Kinetochore Assembly ◽  
Blast Fungus

ABSTRACT Precise kinetochore-microtubule interactions ensure faithful chromosome segregation in eukaryotes. Centromeres, identified as scaffolding sites for kinetochore assembly, are among the most rapidly evolving chromosomal loci in terms of the DNA sequence and length and organization of intrinsic elements. Neither the centromere structure nor the kinetochore dynamics is well studied in plant-pathogenic fungi. Here, we sought to understand the process of chromosome segregation in the rice blast fungus Magnaporthe oryzae. High-resolution imaging of green fluorescent protein (GFP)-tagged inner kinetochore proteins CenpA and CenpC revealed unusual albeit transient declustering of centromeres just before anaphase separation of chromosomes in M. oryzae. Strikingly, the declustered centromeres positioned randomly at the spindle midzone without an apparent metaphase plate per se. Using CenpA chromatin immunoprecipitation followed by deep sequencing, all seven centromeres in M. oryzae were found to be regional, spanning 57-kb to 109-kb transcriptionally poor regions. Highly AT-rich and heavily methylated DNA sequences were the only common defining features of all the centromeres in rice blast. Lack of centromere-specific DNA sequence motifs or repetitive elements suggests an epigenetic specification of centromere function in M. oryzae. PacBio genome assemblies and synteny analyses facilitated comparison of the centromeric/pericentromeric regions in distinct isolates of rice blast and wheat blast and in Magnaporthiopsis poae. Overall, this study revealed unusual centromere dynamics and precisely identified the centromere loci in the top model fungal pathogens that belong to Magnaporthales and cause severe losses in the global production of food crops and turf grasses. IMPORTANCE Magnaporthe oryzae is an important fungal pathogen that causes a loss of 10% to 30% of the annual rice crop due to the devastating blast disease. In most organisms, kinetochores are clustered together or arranged at the metaphase plate to facilitate synchronized anaphase separation of sister chromatids in mitosis. In this study, we showed that the initially clustered kinetochores separate and position randomly prior to anaphase in M. oryzae. Centromeres in M. oryzae occupy large genomic regions and form on AT-rich DNA without any common sequence motifs. Overall, this study identified atypical kinetochore dynamics and mapped functional centromeres in M. oryzae to define the roles of centromeric and pericentric boundaries in kinetochore assembly on epigenetically specified centromere loci. This study should pave the way for further understanding of the contribution of heterochromatin in genome stability and virulence of the blast fungus and its related species of high economic importance.

scholarly journals Osa-miR162a balances rice yield and resistance to Magnaporthe oryzae

2020 ◽  
Author(s):  
Xu-Pu Li ◽  
Xiao-Chun Ma ◽  
He Wang ◽  
Yong Zhu ◽  
Xin-Xian Liu ◽  
...  
Keyword(s):  
Magnaporthe Oryzae ◽  
Rice Blast ◽  
Rice Yield ◽  
Blast Resistance ◽  
Blast Disease ◽  
Mirna Biogenesis ◽  
Trade Off ◽  
Rice Blast Resistance ◽  
Defense Related Gene ◽  
Transgenic Lines

Abstract MicroRNAs (miRNAs) play essential roles in rice immunity against Magnaporthe oryzae, the causative agent of rice blast disease. Osa-miR162a targets Dicer-like 1 (DCL1) genes, which play vital roles in miRNA biogenesis and act as negative regulators in rice immunity. Here we demonstrate that Osa-miR162a improves rice immunity against M. oryzae and balances the trade-off between rice yield and resistance. Overexpression of Osa-miR162a compromises rice susceptibility to M. oryzae accompanying enhanced induction of defense-related genes and accumulation of hydrogen peroxide (H2O2). In contrast, blocking miR162 by overexpressing a target mimic of miR162 enhances susceptibility to blast fungus associating with compromised induction of defense-related gene expression and H2O2 accumulation. Moreover, the transgenic lines overexpressing Osa-miR162a display decreased seed setting rate resulting in reduced yield per plant, whereas blocking miR162 leads to an increased number of grains per panicle, resulting in increased yield per plant. Altered accumulation of miR162 had limited impact on the expression of OsDCL1. Together, our results indicate that Osa-miR162a improves rice blast resistance and plays a role in the balance of trade-off between resistance and yield.

scholarly journals Role of two metacaspases in development and pathogenicity of the Rice Blast fungus, Magnaporthe oryzae

2020 ◽  
Author(s):  
Jessie Fernandez ◽  
Victor Lopez ◽  
Lisa Kinch ◽  
Mariel A. Pfeifer ◽  
Hillery Gray ◽  
...  
Keyword(s):  
Cell Death ◽  
Food Security ◽  
Life Cycle ◽  
Magnaporthe Oryzae ◽  
Rice Blast ◽  
Rice Blast Disease ◽  
Blast Disease ◽  
Complex Life Cycle ◽  
Insight Into

ABSTRACTRice blast disease caused by Magnaporthe oryzae is a devastating disease of cultivated rice worldwide. Infections by this fungus lead to a significant reduction in rice yields and threats to food security. To gain better insight into growth and cell death in M. oryzae during infection, we characterized two predicted M. oryzae metacaspase proteins, MoMca1 and MoMca2. These proteins appear to be functionally redundant and are able to complement the yeast Yca1 homologue. Biochemical analysis revealed that M. oryzae metacaspases exhibited Ca2+ dependent caspase activity in vitro. Deletion of both MoMca1 and MoMca2 in M. oryzae resulted in reduced sporulation, delay in conidial germination and attenuation of disease severity. In addition, the double ΔMomca1mca2 mutant strain showed increased radial growth in the presence of oxidative stress. Interestingly, the ΔMomca1mca2 strain showed an increase accumulation of insoluble aggregates compared to the wild-type strain during vegetative growth. Our findings suggest that MoMca1 and MoMca2 promote the clearance of insoluble aggregates in M. oryzae, demonstrating the important role these metacaspases have in fungal protein homeostasis. Furthermore, these metacaspase proteins may play additional roles, like in regulating stress responses, that would help maintain the fitness of fungal cells required for host infection.IMPORTANCEMagnaporthe oryzae causes rice blast disease that threatens global food security by resulting in the severe loss of rice production every year. A tightly regulated life cycle allows M. oryzae to disarm the host plant immune system during its biotrophic stage before triggering plant cell death in its necrotrophic stage. The ways M. oryzae navigates its complex life cycle remains unclear. This work characterizes two metacaspase proteins with peptidase activity in M. oryzae that are shown to be involved in the regulation of fungal growth and development prior to infection by potentially helping maintain fungal fitness. This study provides new insight into the role of metacaspase proteins in filamentous fungi by illustrating the delays in M. oryzae morphogenesis in the absence of these proteins. Understanding the mechanisms by which M. oryzae morphology and development promote its devastating pathogenicity may lead to the emergence of proper methods for disease control.

Polycomb repressive complex 2 coordinates with Sin3 histone deacetylase complex to epigenetically reprogram genome-wide expression of effectors and regulate pathogenicity in Magnaporthe oryzae

2021 ◽  
Author(s):  
Zhongling Wu ◽  
Jiehua Qiu ◽  
Huanbin Shi ◽  
Chuyu Lin ◽  
Jiangnan Yue ◽  
...  
Keyword(s):  
Histone Deacetylase ◽  
Magnaporthe Oryzae ◽  
Rice Blast ◽  
Growth Stage ◽  
Invasive Growth ◽  
Polycomb Repressive Complex ◽  
Host Environment ◽  
Polycomb Repressive Complex 2 ◽  
Genome Wide ◽  
Genome Wide Expression

The strict suppression and reprogramming of gene expression are necessary at different development stages and/or in response to environment stimuli in eukaryotes. In Rice Magnaporthe oryzae pathosystem, effectors from pathogen are kept transcriptionally silenced in the vegetative growth stage and are highly expressed during invasive growth stage to adapt to the host environment. However, the mechanism of how such effectors are stably repressed in the vegetative stage and its roles during rice blast infection remain unclear so far. Here, we showed that all subunits of Polycomb Repressive Complex 2 are required for such repression by direct H3K27me3 occupancy and pathogenic process in M. oryzae. Suppression of polycomb-mediated H3K27me3 causes an improper induction of effectors during vegetative growth thus simulating a host environment. Notably, the addition subunit P55 not only acts as the bridge to connect with core subunits to form a complex in M. oryzae, but also recruits Sin3 histone deacetylase complex to prompt H3K27me3 occupancy for stable maintenance of transcriptional silencing of the target genes in the absence of PRC1. In contrast, during invasive growth stage, the repressed state of effectors chromatin can be partially erased during pathogenic development resulting in transcriptional activation of effectors therein. Overall, Polycomb repressive complex 2 coordinates with Sin3 histone deacetylase complex to epigenetically reprogram genome-wide expression of effectors, which act as molecular switch to memorize the host environment from vegetative to invasive growth, thus contributing to the infection of rice blast.

Microconidia: Understanding Its Role in the Fungus Magnaporthe oryzae Inciting Rice Blast Disease

2021 ◽  
pp. 143-150
Author(s):  
Ganesan Prakash ◽  
Asharani Patel ◽  
Ish Prakash ◽  
Kuleshwar Prasad Sahu ◽  
Rajashekara Hosahatti ◽  
...  
Keyword(s):  
Magnaporthe Oryzae ◽  
Rice Blast ◽  
Rice Blast Disease ◽  
Blast Disease

scholarly journals Evaluation of Rice Responses to the Blast Fungus Magnaporthe oryzae at Different Growth Stages

Plant Disease ◽  
2019 ◽  
Vol 103 (1) ◽  
pp. 132-136 ◽  
Author(s):  
Xinglong Chen ◽  
Yulin Jia ◽  
Bo Ming Wu
Keyword(s):  
Disease Severity ◽  
Magnaporthe Oryzae ◽  
Rice Blast ◽  
Growth Stage ◽  
Disease Index ◽  
Blast Disease ◽  
Growth Stages ◽  
Japonica Rice ◽  
Rice Cultivars ◽  
Different Growth Stages

Rice blast, caused by the fungus Magnaporthe oryzae, is the most damaging disease for rice worldwide. However, the reactions of rice to M. oryzae at different growth stages are largely unknown. In the present study, two temperate japonica rice cultivars, M-202 and Nipponbare, were inoculated synchronously at different vegetative growth stages, V1 to V10. Plants of M-202 at each stage from V1 to reproductive stage R8 were inoculated with M. oryzae race (isolate) IB-49 (ZN61) under controlled conditions. Disease reactions were recorded 7 days postinoculation by measuring the percentage of diseased area of all leaves, excluding the youngest leaf. The results showed that the plants were significantly susceptible at the V1 to V4 stages with a disease severity of 26.7 to 46.8% and disease index of 18.62 to 37.76 for M-202. At the V1 to V2 stages, the plants were significantly susceptible with a disease a severity of 28.6 to 39.3% and disease index of 23.65 to 29.82 for Nipponbare. Similar results were observed when plants of M-202 were inoculated at each growth stage with a disease severity of 29.7 to 60.6% and disease index of 21.93 to 59.25 from V1 to V4. Susceptibility decreased after the V5 stage (severity 4.6% and index 2.17) and became completely resistant at the V9 to V10 stages and after the reproductive stages, suggesting that plants have enhanced disease resistance at later growth stages. These findings are useful for managing rice blast disease in commercial rice production worldwide.

scholarly journals Label-Free Quantitative Proteomics of Lysine Acetylome Identifies Substrates of Gcn5 in Magnaporthe oryzae Autophagy and Epigenetic Regulation

mSystems ◽  
2018 ◽  
Vol 3 (6) ◽  
Author(s):  
Meiling Liang ◽  
Shulin Zhang ◽  
Lihong Dong ◽  
Yanjun Kou ◽  
Chaoxiang Lin ◽  
...  
Keyword(s):  
Epigenetic Regulation ◽  
Magnaporthe Oryzae ◽  
Posttranslational Modification ◽  
Rice Blast ◽  
Histone Acetyltransferase ◽  
Rice Blast Fungus ◽  
Spore Formation ◽  
Content Type ◽  
Autophagy Induction ◽  
Asexual Spore

ABSTRACT The rice blast fungus Magnaporthe oryzae poses a great threat to global food security. During its conidiation (asexual spore formation) and appressorium (infecting structure) formation, autophagy is induced, serving glycogen breakdown or programmed cell death function, both essential for M. oryzae pathogenicity. Recently, we identified an M. oryzae histone acetyltransferase (HAT) Gcn5 as a key regulator in phototropic induction of autophagy and asexual spore formation while serving a cellular function other than autophagy induction during M. oryzae infection. To further understand the regulatory mechanism of Gcn5 on M. oryzae pathogenicity, we set out to identify more Gcn5 substrates by comparative acetylome between the wild-type (WT) and GCN5 overexpression (OX) mutant and between OX mutant and GCN5 deletion (knockout [KO]) mutant. Our results showed that Gcn5 regulates autophagy induction and other important aspects of fungal pathogenicity, including energy metabolism, stress response, cell toxicity and death, likely via both epigenetic regulation (histone acetylation) and posttranslational modification (nonhistone protein acetylation). IMPORTANCE Gcn5 is a histone acetyltransferase that was previously shown to regulate phototropic and starvation-induced autophagy in the rice blast fungus Magnaporthe oryzae, likely via modification on autophagy protein Atg7. In this study, we identified more potential substrates of Gcn5-mediated acetylation by quantitative and comparative acetylome analyses. By epifluorescence microscopy and biochemistry experiments, we verified that Gcn5 may regulate autophagy induction at both the epigenetic and posttranslational levels and regulate autophagic degradation of a critical metabolic enzyme pyruvate kinase (Pk) likely via acetylation. Overall, our findings reveal comprehensive posttranslational modification executed by Gcn5, in response to various external stimuli, to synergistically promote cellular differentiation in a fungal pathogen.

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