scholarly journals Evaluation of different aqueous plant extracts against rice blast disease fungus (Magnaporthe oryzae)

2021 ◽  
Vol 22 (3) ◽  
pp. 193-202
Author(s):  
G.O. Agbowuro ◽  
M. Aluko ◽  
A.E. Salami ◽  
S.O. Awoyemi

The antifungal potentials of some medicinal plant leaf extracts have been established against fungal diseases. This research work was conducted to evaluate the effects of aqueous plant leaf extracts of five plants: Apple of Sodom (Calotropis procera), Neem tree (Azadirachta indica), Thorn  Apple/Angel's trumpet (Datura metel), Aleo plant (Aleo vera) and Siam weed (Chromolaena odorata)) at different concentration (25, 50, and 100%) against rice blast disease (Magnaporthe oryzae) in-vitro and in-vivo. The research work was laid out in a split-split plot arrangement using a randomized complete block design with three replications. Data were collected for disease severity, disease incidence, number of tillers per plant, number of filled grains, the weight of 1000 grains, and panicle weight. The data collected were analyzed using IRRI STAR software (IRRI, 1979). Percentage inhibition was significantly higher at higher concentrations for all the aqueous plant extracts as compared to lower concentrations. The field trial result shows that there were significant differences among all the studied traits though at different levels for all the sources of variation. The leaf plant aqueous extracts at all the varied concentrations reduced the rate of disease severity and incidence while the number of tillers per plant, the number of filled grains, the weight of 1000 seeds, and panicle weight increased compared to control. The result revealed that Apple of Sodom (Calotropis procera) is the most efficient in combating rice blast disease followed by Neem tree (Azadirachta indica), Thorn Apple/Angel's trumpet (Datura metel), Aleo plant (Aleo vera), and Siam weed (Chromolaena odorata) in that other. These aqueous plant extracts can be used to manage rice blast disease at a low cost and it is ecofriendly compare to chemical fungicides. Keywords: Disease severity, Magnaporthe oryzae, Medicinal plants, Plant extracts, Rice

2020 ◽  
Author(s):  
Jessie Fernandez ◽  
Victor Lopez ◽  
Lisa Kinch ◽  
Mariel A. Pfeifer ◽  
Hillery Gray ◽  
...  

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.


Author(s):  
Ganesan Prakash ◽  
Asharani Patel ◽  
Ish Prakash ◽  
Kuleshwar Prasad Sahu ◽  
Rajashekara Hosahatti ◽  
...  

Plant Disease ◽  
2019 ◽  
Vol 103 (1) ◽  
pp. 132-136 ◽  
Author(s):  
Xinglong Chen ◽  
Yulin Jia ◽  
Bo Ming Wu

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.


2018 ◽  
Vol 55 (3) ◽  
pp. 467 ◽  
Author(s):  
Chinmayee Sahu ◽  
Manoj Kumar Yadav ◽  
Gayatree Panda ◽  
S Aravindan ◽  
Ngangkham Umakanta ◽  
...  

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

Molecules ◽  
2017 ◽  
Vol 22 (10) ◽  
pp. 1799 ◽  
Author(s):  
Jiaoyu Wang ◽  
Ling Li ◽  
Yeshi Yin ◽  
Zhuokan Gu ◽  
Rongyao Chai ◽  
...  

mBio ◽  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jessie Fernandez ◽  
Victor Lopez ◽  
Lisa Kinch ◽  
Mariel A. Pfeifer ◽  
Hillery Gray ◽  
...  

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.


Plant Disease ◽  
2008 ◽  
Vol 92 (4) ◽  
pp. 504-507 ◽  
Author(s):  
Y. Jia ◽  
D. Gealy ◽  
M. J. Lin ◽  
L. Wu ◽  
H. Black

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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