Control of rice blast disease caused by Magnaporthe oryzae by application of antifungal nanomaterials from Emericella nidulans

Metabolites of Emericella nidulans (EN) were separated by chromatographic methods from crude hexane included emericellin and sterigmatocystin, while crude ethyl acetate found demethylsterigmatocystin. These metabolites proved to be antagonistic to Magnaporthe oryzae, the causal agent of rice blast. Crude extracts and nano-particles derived from EN inhibited M. oryzae. The ethyl acetate crude extract derived inhibited M. oryzae with an effective dose (ED50) of 66 μg/mL. The nanoparticles showed better inhibition of M. oryzae than crude extracts at low concentrations. Nanoparticles, namely from crude ethyl acetate, crude methanol and crude hexane of EN were active against M. oryzae with ED50 of 4.2 μg/mL, 4.5 μg/mL, 8.9 μg/mL, respectively. It detected sakuranetin (rate of flow value is 0.09) in nano-EN treated rice leaves. These nanoparticles inhibited M. oryzae and acted as a new elicitor to induce immunity.

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

Plant Disease ◽

10.1094/pdis-92-4-0504 ◽

2008 ◽

Vol 92 (4) ◽

pp. 504-507 ◽

Cited By ~ 1

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.

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Osa-miR162a balances rice yield and resistance to Magnaporthe oryzae

10.21203/rs.2.22473/v1 ◽

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.

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

10.1101/2020.12.10.420794 ◽

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.

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

Fungal Biology - Blast Disease of Cereal Crops ◽

10.1007/978-3-030-60585-8_10 ◽

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

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

Plant Disease ◽

10.1094/pdis-12-17-1873-re ◽

2019 ◽

Vol 103 (1) ◽

pp. 132-136 ◽

Cited By ~ 3

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.

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INHIBITION ACTIVITY OF CLEOME SPECIES EXTRACT ON ONION GUEST ROOT

International Journal of Applied Pharmaceutics ◽

10.22159/ijap.2019.v11s3.m0007 ◽

2019 ◽

pp. 1-2

Author(s):

SUTTHIDUEAN CHUNHAKARN ◽

PRAKAIDAO YINGSANGA ◽

LADA MATHURASA

Keyword(s):

Root Growth ◽

Ethyl Acetate ◽

Crude Extract ◽

Inhibitory Activity ◽

Crop Productivity ◽

Distilled Water ◽

Crude Extracts ◽

Cleome Spinosa ◽

Whole Plants ◽

Potent Inhibitory Activity

Objective: Biological control is useful in agricultural. Allelopathy plays an important factor in crop productivity. The effect of allelopathy is able to produce and release allelochemicals or phytochemicals to inhibit or stimulate seed germination, seeding growth, shoot and root growth of other crops. The aim of this study was to evaluate the inhibitory activity of Cleome viscose and Cleome spinosa extracts on onion guest roots length.Methods: The whole plants of C. viscose and C. spinosa were extracted with dichloromethane, ethyl acetate, methanol and distilled water, respectively. Each group of onion guests was sprayed at various concentrations as 100, 200, 400, 800 and 1600 parts per million for the treatment. The root growth was measured every day for 1 month.Results: At concentration of 1600 ppm, methanol crude extract of C. spinose showed the highest percent inhibitory activity value of 91.68. Ethyl acetate and methanol crude extracts of C. viscose showed strong inhibitory activity with percentage values of 90.17 and 90.90, respectively, at concentration of 1600 ppm. Moreover, the methanol extract of C. viscose and C. spinosa evaluated higher inhibitory activity than other solvent. However, distilled water crude extract of C. spinose showed weak inhibitory activity with the percentage value of 40.05 at concentration of 1600 ppm.Conclusions: In this study, the methanol crude extract of C. spinose showed potent inhibitory activity on root growth. Moreover, ethyl acetate and methanol crude extracts of C. viscose evaluated strong inhibitory activity. C. viscose and C. spinosa extracts possessed allelochemicals for postharvest biology and technology in plants.

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Antifungal activity of microbial nanoparticles derived from Chaetomium spp. against Magnaporthe oryzae causing rice blast

Plant Protection Science ◽

10.17221/41/2019-pps ◽

2020 ◽

Vol 56 (No. 3) ◽

pp. 180-190

Author(s):

Jiaojiao Song ◽

Kasem Soytong ◽

Somdej Kanokmedhakul ◽

Kwanjai Kanokmedhakul ◽

Supattra Poeaim

Keyword(s):

Antifungal Activity ◽

Thin Layer ◽

Thin Layer Chromatography ◽

Magnaporthe Oryzae ◽

Rice Blast ◽

Spore Production ◽

Etoac Extract ◽

Rice Leaves ◽

Chaetomium Elatum ◽

Layer Chromatography

The Magnaporthe oryzae isolate PO2 was proven to cause rice blast var. PSL 2 in this study. Chaetomium elatum, Chaetomium lucknowense and Chaetomium brasiliense were antagonised to M. oryzae. The hexane extract of C. brasiliense gave the highest inhibition of the spore production with an ED50 of 35 ppm, the EtOAC extract of C. lucknowense inhibited the spore production at 57 ppm and the EtOAC extracts of C. elatum inhibited the spore production at 106 ppm. The nano-CLM (C. lucknowense) inhibited the spore production at 5.24 ppm, the nano-CBH (C. brasiliense) inhibited the spore production at 6.86 ppm and the nano-CEE (C. elatum) inhibited the spore production at 7.89 ppm. The rice leaves treated with nano-CBH from C. brasiliense produced Sakuranertin and Oryzalexin B as seen on the thin layer chromatography where the Rf value was 0.08 assumed to be Sakuranertin, and the Rf value of 0.28 supposed to be Oryzalexin B. It was found that the nanoparticles act as elicitors to induce immunity in rice plants through the production of phytoalexin.

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Magnaporthe oryzae and Rice Blast Disease

Cellular and Molecular Biology of Filamentous Fungi ◽

10.1128/9781555816636.ch37 ◽

2014 ◽

pp. 591-606 ◽

Cited By ~ 4

Author(s):

Chang Hyun Khang ◽

Barbara Valent

Keyword(s):

Magnaporthe Oryzae ◽

Rice Blast ◽

Rice Blast Disease ◽

Blast Disease

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

Antioxidants ◽

10.3390/antiox9080655 ◽

2020 ◽

Vol 9 (8) ◽

pp. 655 ◽

Cited By ~ 1

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.

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