scholarly journals eIF3k Domain-Containing Protein Regulates Conidiogenesis, Appressorium Turgor, Virulence, Stress Tolerance, and Physiological and Pathogenic Development of Magnaporthe oryzae Oryzae

2021 ◽  
Vol 12 ◽  
Author(s):  
Lili Lin ◽  
Jiaying Cao ◽  
Anqiang Du ◽  
Qiuli An ◽  
Xiaomin Chen ◽  
...  
Keyword(s):  
Stress Tolerance ◽  
Filamentous Fungi ◽  
Magnaporthe Oryzae ◽  
Vegetative Growth ◽  
Fungal Pathogens ◽  
Translation Initiation Factor ◽  
Blast Disease ◽  
Initiation Factor ◽  
Host Pathogen Interaction ◽  
Host Pathogen

The eukaryotic translation initiation factor 3 (eIF3) complex consists of essential and non-essential sub-complexes. Non-essential eIF3 complex subunits, such as eIF3e, eIF3j, eIF3k, and eIF3l, modulate stress tolerance and enhance the lifespan of Neurospora crassa and Caenorhabditis elegans. However, there is limited knowledge of the role of the non-essential eIF3 sub-complex in the pathophysiological development of plant fungal pathogens. Here, we deployed genetic and biochemical techniques to explore the influence of a hypothetical protein containing eIF3k domain in Magnaporthe oryzae Oryzae (MoOeIF3k) on reproduction, hyphae morphogenesis, stress tolerance, and pathogenesis. Also, the targeted disruption of MoOeIF3k suppressed vegetative growth and asexual sporulation in ΔMoOeif3k strains significantly. We demonstrated that MoOeIF3k promotes the initiation and development of the rice blast disease by positively regulating the mobilization and degradation of glycogen, appressorium integrity, host penetration, and colonization during host–pathogen interaction. For the first time, we demonstrated that the eIF3k subunit supports the survival of the blast fungus by suppressing vegetative growth and possibly regulating the conversions and utilization of stored cellular energy reserves under starvation conditions. We also observed that the deletion of MoOeIF3k accelerated ribosomal RNA (rRNA) generation in the ΔMoOeif3k strains with a corresponding increase in total protein output. In summary, this study unravels the pathophysiological significance of eIF3k filamentous fungi. The findings also underscored the need to systematically evaluate the individual subunits of the non-essential eIF3 sub-complex during host–pathogen interaction. Further studies are required to unravel the influence of synergetic coordination between translation and transcriptional regulatory machinery on the pathogenesis of filamentous fungi pathogens.

scholarly journals Genome Sequence Resource of Magnaporthe oryzae Laboratory Strain 2539

2020 ◽  
Vol 33 (8) ◽  
pp. 1029-1031
Author(s):  
Meilian Chen ◽  
Baohua Wang ◽  
Guodong Lu ◽  
Zhenhui Zhong ◽  
Zonghua Wang
Keyword(s):  
Genome Sequence ◽  
Magnaporthe Oryzae ◽  
Genome Assembly ◽  
Laboratory Strain ◽  
Model System ◽  
Blast Disease ◽  
High Quality ◽  
Host Pathogen Interaction ◽  
Host Pathogen ◽  
High Quality Genome

Magnaporthe oryzae causes blast disease on more than 50 species of monocot plants, including important crops such as rice, millet, and most recently wheat. Additionally, it is an important model system for studying host-pathogen interaction. Here, we report a high-quality genome assembly and annotation of a laboratory strain 2539 of M. oryzae, which is a widely used progeny of a rice-infecting isolate and a grass-infecting isolate. The genome sequence of strain 2539 will be useful for studying the evolution, host adaption, and pathogenicity of M. oryzae, which will be beneficial for a better understanding of the mechanisms of host-pathogen interaction.

scholarly journals Translation Initiation Factor eIF4E Positively Modulates Conidiogenesis, Appressorium Formation, Host Invasion and Stress Homeostasis in the Filamentous Fungi Magnaporthe oryzae

2021 ◽  
Vol 12 ◽  
Author(s):  
Wajjiha Batool ◽  
Ammarah Shabbir ◽  
Lili Lin ◽  
Xiaomin Chen ◽  
Qiuli An ◽  
...  
Keyword(s):  
Filamentous Fungi ◽  
Translation Initiation ◽  
Magnaporthe Oryzae ◽  
Comprehensive Evaluation ◽  
Phytopathogenic Fungi ◽  
Translation Initiation Factor ◽  
Initiation Factor ◽  
Host Interaction ◽  
Regulatory Machinery ◽  
Biochemical Analyses

Translation initiation factor eIF4E generally mediates the recognition of the 5’cap structure of mRNA during the recruitment of the ribosomes to capped mRNA. Although the eIF4E has been shown to regulate stress response in Schizosaccharomyces pombe positively, there is no direct experimental evidence for the contributions of eIF4E to both physiological and pathogenic development of filamentous fungi. We generated Magnaporthe oryzae eIF4E (MoeIF4E3) gene deletion strains using homologous recombination strategies. Phenotypic and biochemical analyses of MoeIF4E3 defective strains showed that the deletion of MoeIF4E3 triggered a significant reduction in growth and conidiogenesis. We also showed that disruption of MoeIF4E3 partially impaired conidia germination, appressorium integrity and attenuated the pathogenicity of ΔMoeif4e3 strains. In summary, this study provides experimental insights into the contributions of the eIF4E3 to the development of filamentous fungi. Additionally, these observations underscored the need for a comprehensive evaluation of the translational regulatory machinery in phytopathogenic fungi during pathogen-host interaction progression.

scholarly journals Comparative secretome of Magnaporthe oryzae identified proteins involved in virulence and cell wall integrity

2020 ◽  
Author(s):  
Ning Liu ◽  
Linlu Qi ◽  
Manna Huang ◽  
Deng Chen ◽  
Changfa Yin ◽  
...  
Keyword(s):  
Cell Wall ◽  
Magnaporthe Oryzae ◽  
Fungal Pathogens ◽  
Protein Localization ◽  
Potential Effect ◽  
Cell Wall Integrity ◽  
Blast Disease ◽  
Secreted Proteins ◽  
Interspecies Interactions ◽  
Fungal Virulence

AbstractPlant fungal pathogens secrete numerous proteins into the apoplast at the plant–fungus contact sites to facilitate colonization. Only a few secreted proteins were functionally characterized in Magnaporthe oryzae, the fungal pathogen causing rice blast disease worldwide. ALG3 is an α-1, 3-mannosyltransferase function in N-glycan synthesis for secreted N-glycosylated proteins, and the Δalg3 mutants show strong defects in cell wall integrity and fungal virulence, indicating a potential effect on the secretion of multiple proteins. In this study, we compared the secretome of wild type and Δalg3 mutants, and identified 51 proteins that require ALG3 for proper secretion. These are predicted to be involved in metabolic processes, interspecies interactions, cell wall organization, and response to chemicals. The tested secreted proteins localized at the apoplast region surrounding the fungal infection hyphae. Moreover, the N-glycosylation of candidate proteins was significantly changed in the Δalg3 mutant, leading to the reduction of protein secretion and abnormal protein localization. Furthermore, we tested the function of two genes, one is a previously reported M. oryzae gene Invertase 1 (INV1) encoding a secreted invertase, and the other one is a gene encoding an Acid mammalian chinitase (AMCase). The fungal virulence was significantly reduced and the cell wall integrity was altered in the Δinv1 and Δamcase mutant strains. Elucidation of the comparative secretome of M. oryzae improves our understanding of the proteins that require ALG3 for secretion, and of their function in fungal virulence and cell wall integrity.

scholarly journals MoGLN2 Is Important for Vegetative Growth, Conidiogenesis, Maintenance of Cell Wall Integrity and Pathogenesis of Magnaporthe oryzae

2021 ◽  
Vol 7 (6) ◽  
pp. 463
Author(s):  
Osakina Aron ◽  
Min Wang ◽  
Lianyu Lin ◽  
Wajjiha Batool ◽  
Birong Lin ◽  
...  
Keyword(s):  
Cell Wall ◽  
Amino Acid ◽  
Glutamine Synthetase ◽  
Magnaporthe Oryzae ◽  
Vegetative Growth ◽  
Fungal Pathogens ◽  
Cell Wall Integrity ◽  
Fungal Cell ◽  
Barley Leaves ◽  
Living Organisms

Glutamine is a non-essential amino acid that acts as a principal source of nitrogen and nucleic acid biosynthesis in living organisms. In Saccharomyces cerevisiae, glutamine synthetase catalyzes the synthesis of glutamine. To determine the role of glutamine synthetase in the development and pathogenicity of plant fungal pathogens, we used S. cerevisiae Gln1 amino acid sequence to identify its orthologs in Magnaporthe oryzae and named them MoGln1, MoGln2, and MoGln3. Deletion of MoGLN1 and MoGLN3 showed that they are not involved in the development and pathogenesis of M. oryzae. Conversely, ∆Mogln2 was reduced in vegetative growth, experienced attenuated growth on Minimal Medium (MM), and exhibited hyphal autolysis on oatmeal and straw decoction and corn media. Exogenous l-glutamine rescued the growth of ∆Mogln2 on MM. The ∆Mogln2 mutant failed to produce spores and was nonpathogenic on barley leaves, as it was unable to form an appressorium-like structure from its hyphal tips. Furthermore, deletion of MoGLN2 altered the fungal cell wall integrity, with the ∆Mogln2 mutant being hypersensitive to H2O2. MoGln1, MoGln2, and MoGln3 are located in the cytoplasm. Taken together, our results shows that MoGLN2 is important for vegetative growth, conidiation, appressorium formation, maintenance of cell wall integrity, oxidative stress tolerance and pathogenesis of M. oryzae.

scholarly journals MoLAEA Regulates Secondary Metabolism in Magnaporthe oryzae

mSphere ◽  
2020 ◽  
Vol 5 (2) ◽  
Author(s):  
Pallabi Saha ◽  
Suvranil Ghosh ◽  
Subhankar Roy-Barman
Keyword(s):  
Secondary Metabolites ◽  
Secondary Metabolism ◽  
Filamentous Fungi ◽  
Magnaporthe Oryzae ◽  
Antitumor Agents ◽  
Negative Regulator ◽  
Blast Disease ◽  
Penicillin G ◽  
Content Type ◽  
First Time

ABSTRACT Fungi are rich sources of secondary metabolites of pharmaceutical importance, such as antibiotics, antitumor agents, and immunosuppressants, as well as of harmful toxins. Secondary metabolites play important roles in the development and pathogenesis of fungi. LaeA is a global regulator of secondary metabolism and was originally reported in Aspergillus nidulans; however, its role in secondary metabolism in Magnaporthe oryzae has not yet been reported. Here, we investigated the role of a gene homologous to LAEA (loss of AflR expression) of Aspergillus spp. in Magnaporthe oryzae, named M. oryzae LAEA (MoLAEA). Studies on MoLAEA overexpression and knockdown strains have suggested that this gene acts as a negative regulator of sporulation and melanin synthesis. However, it is not involved in the growth and pathogenesis of M. oryzae. Transcriptomic data indicated that MoLAEA regulated genes involved in secondary metabolism. Interestingly, we observed (for the first time, to our knowledge) that this gene is involved in benzylpenicillin (penicillin G) synthesis in M. oryzae. Overexpression of MoLAEA increased penicillin G production, whereas the silenced strain showed a complete absence of penicillin G compared to its presence in the wild type. We also observed that MoLaeA interacted with MoVeA, a velvet family protein involved in fungal development and secondary metabolism, in the nucleus. This study showed that though MoLAEA may not make any contribution in rice blast fungal pathogenesis, it regulates secondary metabolism in M. oryzae and thus can be further studied for identifying other new uncharacterized metabolites in this fungus. IMPORTANCE M. oryzae causes blast disease, the most serious disease of cultivated rice affecting global rice production. The genome of M. oryzae has been shown to have a number of genes involved in secondary metabolism, but most of them are uncharacterized. In fact, compared to studies of other filamentous fungi, hardly any work has been done on secondary metabolism in M. oryzae. It is shown here (for the first time, to our knowledge) that penicillin G is being synthesized in M. oryzae and that MoLAEA is involved in this process. This is the first step in understanding the penicillin G biosynthesis pathway in M. oryzae. This study also unraveled the details of how MoLaeA works by forming a nuclear complex with MoVeA in M. oryzae, thus indicating functional conservation of such a gene across filamentous fungi. All these findings open up avenues for more relevant investigations on the genetic regulation of secondary metabolism in M. oryzae.

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