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 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.

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 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 Carolina Foxtail (Alopecurus carolinianus): Susceptibility and Suitability as an Alternative Host to Rice Blast Disease (Magnaporthe oryzae [formerly M. grisea])

Plant Disease ◽  
2008 ◽  
Vol 92 (4) ◽  
pp. 504-507 ◽  
Author(s):  
Y. Jia ◽  
D. Gealy ◽  
M. J. Lin ◽  
L. Wu ◽  
H. Black
Keyword(s):  
Magnaporthe Oryzae ◽  
Rice Blast ◽  
Rice Blast Disease ◽  
Blast Disease ◽  
Artificial Inoculation ◽  
Rice Cultivars ◽  
Alternative Host ◽  
Lesion Development ◽  
Disease Symptoms ◽  
Rice Leaves

Carolina foxtail (Alopecurus carolinianus) has not been reported to host Magnaporthe oryzae. A collection of Carolina foxtail obtained from several Arkansas locations over a 4-year period was inoculated with four races of the fungus under greenhouse conditions and, in all cases, inoculation resulted in the formation of irregular, yellow and brown lesions without obvious gray centers that are characteristic for blast on rice. Differences in these lesions were not observed among our collection. These lesions appeared to differ from typical blast lesions on inoculated rice leaves but were evident following artificial inoculation of Carolina foxtail in the greenhouse. M. oryzae races that differed in pathogenicity toward rice cultivars also displayed differences in lesion development on Carolina foxtail. The most virulent race on rice cultivars also produced lesions most rapidly on Carolina foxtail. These lesions developed more quickly on Carolina foxtail than on the most susceptible rice cultivars tested, including a susceptible California cultivar, M202. M. oryzae isolates cultured from these lesions in the infected Carolina foxtail caused typical disease symptoms of blast on inoculated rice cultivars. We suggest that Carolina foxtail is a new and previously unrecognized host for the blast pathogen.

Confirming and Identifying New Loci for Rice Blast Disease Resistance using Magnaporthe oryzae Field Isolates in the US

Crop Science ◽  
2015 ◽  
Vol 55 (6) ◽  
pp. 2620-2627 ◽  
Author(s):  
Junjie Xing ◽  
Melissa H Jia ◽  
James C. Correll ◽  
Longping Yuan ◽  
Huangfeng Deng ◽  
...  
Keyword(s):  
Disease Resistance ◽  
Magnaporthe Oryzae ◽  
Rice Blast ◽  
Rice Blast Disease ◽  
Blast Disease ◽  
Field Isolates ◽  
The Us

scholarly journals PAF104, a Synthetic Peptide to Control Rice Blast Disease by Blocking Appressorium Formation in Magnaporthe oryzae

2013 ◽  
Vol 26 (12) ◽  
pp. 1407-1416 ◽  
Author(s):  
Aarón Rebollar ◽  
Belén López-García
Keyword(s):  
Magnaporthe Oryzae ◽  
Synthetic Peptide ◽  
Rice Blast ◽  
Surface Protein ◽  
Inhibitory Effect ◽  
Rice Blast Disease ◽  
Blast Disease ◽  
Appressorium Formation ◽  
Hydrophobic Surfaces

Magnaporthe oryzae is the most devastating pathogen of rice and the main cause of crop losses worldwide. The successful management of blast disease caused by this fungus is a clear necessity. The synthetic peptide PAF104 has been characterized by its inhibition of M. oryzae appressorium formation on hydrophobic surfaces. Growth and the ability of conidia to germinate was not affected by PAF104, indicating the lack of toxicity on fungal conidia. The addition of the cutin monomer 1,16-hexadecanediol does not interfere with the inhibitory effect of PAF104 on in vitro hydrophobic surfaces. On the other hand, inhibition of appressorium formation by PAF104 was nullified by the exogenous addition of cAMP. Our results suggest that PAF104 affects the Pmk1 pathway by repression of the gene expression of MoMSB2, which encodes a sensing surface protein, and the mitogen-activated protein/extracellular signal-regulated kinase kinase kinase MST11. The pathogenicity of M. oryzae was reduced after PAF104 treatment specifically blocking appressorium formation. Our results support PAF104 as a promising compound to control rice blast disease by blocking a specific target related to appressorium formation, a process essential for infection of rice leaves. Moreover, PAF104 is proposed as a lead compound to develop novel specific fungicides with improved properties.

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