scholarly journals Hybrid Heme Peroxidases from Rice Blast Fungus Magnaporthe oryzae Involved in Defence against Oxidative Stress

Antioxidants ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 655 ◽  
Author(s):  
Marcel Zámocký ◽  
Anna Kamlárová ◽  
Daniel Maresch ◽  
Katarína Chovanová ◽  
Jana Harichová ◽  
...  
Keyword(s):  
Magnaporthe Oryzae ◽  
Rice Blast ◽  
Soluble Starch ◽  
Blast Disease ◽  
Binding Motif ◽  
Carbohydrate Binding ◽  
Paramagnetic Resonance ◽  
State Dependent ◽  
Fold Induction ◽  
Heme Peroxidases

Hybrid B heme peroxidases are recently discovered unique oxidoreductases present solely in the fungal kingdom. We have investigated two typical representatives from Magnaporthe oryzae—one of the most dangerous phytopathogens known as a causal agent of the rice blast disease. First, we focused on native expression of two detected hyBpox paralogs by the means of reverse-transcription quantitative real-time PCR. Our results indicate a 7-fold induction of the MohyBpox1 transcript in a medium with H2O2 and a 3-fold induction in a medium with peroxyacetic acid. For the MohyBpox2 paralog the induction patterns were up to 12-fold and 6.7-fold, respectively. We have successfully expressed the shorter gene, MohyBpox1, heterologously in Pichia pastoris for detailed characterization. Observed biochemical and biophysical properties of the highly purified protein reveal that a typical HyBPOX is significantly different from previously investigated APx-CcP hybrids. This newly discovered secretory peroxidase reveals a Soret maximum at 407 nm, Q bands at 532 and 568 nm, CT band at 625 nm and a purity number of 1.48. Electron paramagnetic resonance (EPR) analysis suggests a mixture of high and low spin species in the ferric state dependent on calcium contents. Steady-state kinetic data reveal the highest peroxidase activity with ABTS, 5-aminosalycilate and efficient oxidation of tyrosine. MoHyBPOX1 as a fusion protein consists of two domains. The longer conserved N-terminal peroxidase domain is connected with a shorter C-terminal domain containing a carbohydrate binding motif of type CBM21. We demonstrate the capacity of MoHyBPOX1 to bind soluble starch efficiently. Potential involvement of hybrid peroxidases in the pathogenicity of M. oryzae is discussed.

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.

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.

Morphological and molecular characterization of Magnaporthe oryzae causing rice blast disease in Odisha

2018 ◽  
Vol 55 (3) ◽  
pp. 467 ◽  
Author(s):  
Chinmayee Sahu ◽  
Manoj Kumar Yadav ◽  
Gayatree Panda ◽  
S Aravindan ◽  
Ngangkham Umakanta ◽  
...  
Keyword(s):  
Molecular Characterization ◽  
Magnaporthe Oryzae ◽  
Rice Blast ◽  
Rice Blast Disease ◽  
Blast Disease ◽  
Morphological And Molecular Characterization

scholarly journals Effector-Mediated Suppression of Chitin-Triggered Immunity by Magnaporthe oryzae Is Necessary for Rice Blast Disease

2012 ◽  
Vol 24 (1) ◽  
pp. 322-335 ◽  
Author(s):  
Thomas A. Mentlak ◽  
Anja Kombrink ◽  
Tomonori Shinya ◽  
Lauren S. Ryder ◽  
Ippei Otomo ◽  
...  
Keyword(s):  
Magnaporthe Oryzae ◽  
Rice Blast ◽  
Rice Blast Disease ◽  
Blast Disease

scholarly journals Equol, a Clinically Important Metabolite, Inhibits the Development and Pathogenicity of Magnaporthe oryzae, the Causal Agent of Rice Blast Disease

Molecules ◽  
2017 ◽  
Vol 22 (10) ◽  
pp. 1799 ◽  
Author(s):  
Jiaoyu Wang ◽  
Ling Li ◽  
Yeshi Yin ◽  
Zhuokan Gu ◽  
Rongyao Chai ◽  
...  
Keyword(s):  
Magnaporthe Oryzae ◽  
Rice Blast ◽  
Causal Agent ◽  
Rice Blast Disease ◽  
Blast Disease

scholarly journals The mitotic spindle mediates nuclear migration through an extremely narrow infection structure of the rice blast fungus Magnaporthe oryzae

2021 ◽  
Author(s):  
Mariel A. Pfeifer ◽  
Chang Hyun Khang
Keyword(s):  
Magnaporthe Oryzae ◽  
Mitotic Spindle ◽  
Rice Blast ◽  
Mechanistic Model ◽  
Nuclear Migration ◽  
Blast Disease ◽  
Cellular Structures ◽  
Blast Fungus ◽  
Single Nucleus ◽  
Migration Event

The blast fungus, Magnaporthe oryzae, causes severe destruction to rice and other crops worldwide. As the fungus infects rice, it develops unique cellular structures, such as an appressorium and a narrow penetration peg, to permit successful invasion of host rice cells. Fundamental knowledge about these cellular structures and how organelles, such as the nucleus, are positioned within them is still emerging. Previous studies show that a single nucleus becomes highly stretched during movement through the narrow penetration peg in an extreme nuclear migration event. Yet, the mechanism permitting this nuclear migration event remains elusive. Here, we investigate the role of the mitotic spindle in mediating nuclear migration through the penetration peg. We find that disruption of spindle function during nuclear migration through the penetration peg prevents development of invasive hyphae and virulence on rice. Furthermore, regulated expression of conserved kinesin motor proteins, MoKin5 and MoKin14, is essential to form and maintain the spindle, as well as, properly nucleate the primary hypha. Overexpression of MoKin5 leads to formation of aberrant microtubule protrusions, which contributes to formation of nuclear fragments within the appressorium and primary hypha. Conversely, overexpression of MoKin14 causes the spindle to collapse leading to the formation of monopolar spindles. These results establish a mechanistic model towards understanding the intricate subcellular dynamics of extreme nuclear migration through the penetration peg, a critical step in the development of rice blast disease.

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.

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