scholarly journals A Genomic Approach to Develop a New qPCR Test Enabling Detection of the Pyricularia oryzae Lineage Causing Wheat Blast

Plant Disease ◽  
2020 ◽  
Vol 104 (1) ◽  
pp. 60-70 ◽  
Author(s):  
Maud Thierry ◽  
Pierre Gladieux ◽  
Elisabeth Fournier ◽  
Didier Tharreau ◽  
Renaud Ioos
Keyword(s):  
Genomic Analysis ◽  
High Sensitivity ◽  
Fungal Species ◽  
Emerging Diseases ◽  
Pyricularia Oryzae ◽  
Blast Disease ◽  
South American ◽  
Analytical Sensitivity ◽  
Wheat Blast ◽  
Pcr Test

Rapid detection is key to managing emerging diseases because it allows their spread around the world to be monitored and limited. The first major wheat blast epidemics were reported in 1985 in the Brazilian state of Paraná. Following this outbreak, the disease quickly spread to neighboring regions and countries and, in 2016, the first report of wheat blast disease outside South America was released. This Asian outbreak was due to the trade of infected South American seed, demonstrating the importance of detection tests in order to avoid importing contaminated biological material into regions free from the pathogen. Genomic analysis has revealed that one particular lineage within the fungal species Pyricularia oryzae is associated with this disease: the Triticum lineage. A comparison of 81 Pyricularia genomes highlighted polymorphisms specific to the Triticum lineage, and this study developed a real-time PCR test targeting one of these polymorphisms. The test’s performance was then evaluated in order to measure its analytical specificity, analytical sensitivity, and robustness. The C17 quantitative PCR test detected isolates belonging to the Triticum lineage with high sensitivity, down to 13 plasmid copies or 1 pg of genomic DNA per reaction tube. The blast-based approach developed here to study P. oryzae can be transposed to other emerging diseases.

scholarly journals Pyricularia graminis-tritici sp. nov., a new Pyricularia species causing wheat blast

2016 ◽  
Author(s):  
V.L. Castroagudín ◽  
S.I. Moreira ◽  
D.A.S. Pereira ◽  
S.S. Moreira ◽  
P.C. Brunner ◽  
...  
Keyword(s):  
Phylogenetic Analyses ◽  
Pyricularia Oryzae ◽  
Blast Disease ◽  
Sympatric Populations ◽  
Wheat Blast ◽  
Worldwide Distribution ◽  
Signal Grass ◽  
Morphological Differences ◽  
Urochloa Brizantha ◽  
Clade 1

AbstractAbstract Pyricularia oryzae is a species complex that causes blast disease on more than 50 species of poaceous plants. Pyricularia oryzae has a worldwide distribution as a rice (Oryza) pathogen and in the last 30 years emerged as an important wheat (Triticum) pathogen in southern Brazil. We conducted phylogenetic analyses using 10 housekeeping loci for 128 isolates of P. oryzae sampled from sympatric populations of grasses growing in or near wheat fields. Phylogenetic analyses grouped the isolates into three major clades. Clade 1 comprised isolates associated only with rice and corresponds to the previously described rice blast pathogen P. oryzae pathotype Oryza (PoO). Clade 2 comprised isolates associated almost exclusively with wheat and corresponds to the previously described wheat blast pathogen P. oryzae pathotype Triticum (PoT). Clade 3 contained isolates obtained from wheat as well as other Poaceae hosts. We found that Clade 3 is distinct from P. oryzae and represents a new species, Pyricularia graminis-tritici, (Pgt). No morphological differences were observed among these species, but a distinctive pathogenicity spectrum was observed. Pgt and PoT were pathogenic and highly aggressive on Triticum aestivum (wheat), Hordeum vulgare (barley), Urochloa brizantha (signal grass) and Avena sativa (oats). PoO was highly virulent on the original rice host (Oryza sativa), and also on wheat, barley, and oats, but not on signal grass. We conclude that blast disease on wheat and its associated Poaceae hosts in Brazil is caused by multiple Pyricularia species. Pyricularia graminis-tritici was recently found causing wheat blast in Bangladesh. This indicates that P. graminis-tritici represents a serious threat to wheat cultivation globally.

scholarly journals Bacillus Cyclic Lipopeptides Iturin and Fengycin Control Rice Blast Caused by Pyricularia oryzae in Potting and Acid Sulfate Soils by Direct Antagonism and Induced Systemic Resistance

2021 ◽  
Vol 9 (7) ◽  
pp. 1441
Author(s):  
Van Bach Lam ◽  
Thibault Meyer ◽  
Anthony Arguelles Arias ◽  
Marc Ongena ◽  
Feyisara Eyiwumi Oni ◽  
...  
Keyword(s):  
Rice Blast ◽  
Induced Systemic Resistance ◽  
Pyricularia Oryzae ◽  
Blast Disease ◽  
Systemic Resistance ◽  
Acid Sulfate Soils ◽  
Acid Sulfate ◽  
Wide Range ◽  
Bacillus Spp ◽  
Sulfate Soils

Rice monoculture in acid sulfate soils (ASSs) is affected by a wide range of abiotic and biotic constraints, including rice blast caused by Pyricularia oryzae. To progress towards a more sustainable agriculture, our research aimed to screen the biocontrol potential of indigenous Bacillus spp. against blast disease by triggering induced systemic resistance (ISR) via root application and direct antagonism. Strains belonging to the B. altitudinis and B. velezensis group could protect rice against blast disease by ISR. UPLC–MS and marker gene replacement methods were used to detect cyclic lipopeptide (CLiP) production and construct CLiPs deficient mutants of B. velezensis, respectively. Here we show that the CLiPs fengycin and iturin are both needed to elicit ISR against rice blast in potting soil and ASS conditions. The CLiPs surfactin, iturin and fengycin completely suppressed P. oryzae spore germination resulting in disease severity reduction when co-applied on rice leaves. In vitro microscopic assays revealed that iturin and fengycin inhibited the mycelial growth of the fungus P. oryzae, while surfactin had no effect. The capacity of indigenous Bacillus spp. to reduce rice blast by direct and indirect antagonism in ASS conditions provides an opportunity to explore their usage for rice blast control in the field.

Hemimycena longipleurocystidiata (Mycenaceae, Agaricomycetes), a new species from the Argentinean Atlantic Forest 

Phytotaxa ◽  
2014 ◽  
Vol 177 (1) ◽  
pp. 49 ◽  
Author(s):  
Nicolás Niveiro ◽  
Orlando Fabian Popoff ◽  
Edgardo Albertó
Keyword(s):  
New Species ◽  
Atlantic Forest ◽  
Fungal Species ◽  
South American ◽  
A New Species

The Atlantic Forest is the second largest South American tropical-subtropical rainforest and one of the most diverse ecosystems on earth. Hemimycena longipleurocystidiata, a fungal species collected in the Argentinean Atlantic forest, is proposed as new. It is characterized by its whitish and large basidiomata with large pleuro- and cheilocystidia. The species is here described and illustrated and a key is provided to the Hemimycena species known from Argentina.

scholarly journals Studying of Cultural Properties of Pyricularia oryzae Cav. Strains in the South of Russia

2021 ◽  
Vol 12 (1) ◽  
pp. 21-28
Author(s):  
Dmitry Nartymov ◽  
Evgeny Kharitonov ◽  
Elena Dubina ◽  
Sergey Garkusha ◽  
Margarita Ruban ◽  
...  
Keyword(s):  
Pyricularia Oryzae ◽  
Blast Disease ◽  
The South ◽  
Directional Growth ◽  
Rice Plants ◽  
Affected Plant ◽  
Cultural Traits ◽  
Plant Form ◽  
Using Data

This article presents the results of the development of a methodology for describing the main morphological and cultural traits of the Pyricularia oryzae Cav. strains widespread in the south of Russia. At the same time, the types of traits are identified and listed, which make it possible to unambiguously determine the uniqueness and variety of the pathogen. The relationships and patterns established using cluster and statistical analysis make it possible to identify the conditions for the development of a pathogen that determine its predominant forms. Thus, research shows that leaf forms of P. oryzae strains isolated from rice plants with leaf form of blast disease have an equally directional growth pattern of a colony with a felt structure, and strains isolated from neck-affected plant form often produce a zone of a colony with a clumpy structure. The classification of cultural traits will make it possible to obtain scientifically grounded and comparable data that can be used in the analysis of the interaction of P. oryzae strains with rice plants on various varieties and in various agro-technological conditions in order to improve and rationalize agricultural activities. The study opens up the possibility of using data in breeding, making it possible to identify forms of a pathogen that infect certain varieties.

High-sensitivity troponin assays: analytical and clinical aspects

2016 ◽  
Vol 51 (4) ◽  
pp. 315-320
Author(s):  
Magdalena Krintus
Keyword(s):  
Myocardial Infarction ◽  
Clinical Symptoms ◽  
High Sensitivity ◽  
Reference Population ◽  
Clinical Aspects ◽  
Analytical Sensitivity ◽  
Reference Limit ◽  
Highly Sensitive ◽  
Time Required ◽  
Highly Sensitive Troponin

Cardiac troponins are considered the most sensitive and specific biomarkers for the diagnosis of acute coronary syndromes (ACS). According to the Third Universal Definition of Acute Myocardial Infarction, the diagnosis requires a rise / or fall of troponin concentration with at least one value exceeding the 99th percentile upper reference limit (URL) in a reference population with the coexistence of clinical symptoms of ischemia. The introduction of highly sensitive assays has resulted in lower detection limits for the concentration of troponin, allowing for early diagnosis of, as well as the detection of quantifiable concentrations of this biomarker in healthy subjects. According to current guidelines, the use of high-sensitivity tests can shorten the time required to make clinical decisions from the current 3-6 hours to 1-2 hours. The use of highly sensitive troponin assays also carries other potential benefits associated with their predictive value, as well as challenges that include reduced specificity for myocardial infarction, lack of standardization or the presence of biological variability. Given the increasing availability of new, highly sensitive troponin assays we should be aware that their increased analytical sensitivity and precision is accompanied by accurate clinical assessment of the patient, and takes into account other non-cardiac causes of their increased concentrations.

scholarly journals Identificação de progênies de arroz resistentes à brusone no Estado de São Paulo, em 1976/77

Bragantia ◽  
1985 ◽  
Vol 44 (1) ◽  
pp. 311-329
Author(s):  
Jaciro Soave ◽  
Luiz Ernesto Azzini ◽  
Octávio Bento de Almeida Camargo ◽  
Armando Pettinelli Júnior ◽  
Mauro Sakai
Keyword(s):  
Rice Blast ◽  
Sao Paulo ◽  
Pyricularia Oryzae ◽  
Rice Blast Disease ◽  
Blast Disease ◽  
São Paulo

Este trabalho apresenta os resultados das pesquisas realizadas para a avaliação da resistência à brusone (Pyricularia oryzae Cav.) dos principais materiais de sequeiro e irrigado do programa de melhoramento genético do Instituto Agronômico do Estado de São Paulo, e de genótipos exóticos, introduzidos de diversos países, visando à obtenção de cultivares de arroz resistentes àquela limitante doença fúngica. Os testes foram realizados em condições de campo, em canteiros padronizados para reação uniforme a P. oryzae, e a avaliação das plantas foi feita através da observação dos sintomas visuais deixados pela doença, aos quais foram atribuídas notas de 1 a 7, conforme a escala de notas adotadas no "Symposium on the rice blast disease", em 1963. Sessenta e três germoplasmas de arroz de sequeiro e trinta de cultivo irrigado foram testados quanto à resistência à brusone na folha, nas seguintes localidades paulistas: Itararé, Mococa, Pariquera-Açu, Pindamonhangaba, Pindorama e Ribeirão Preto. Foram ainda avaliados 102 genótipos exóticos de arroz visando à detecção de fontes de resistência à brusone nas mesmas localidades, além de Campinas. Somente cinco cultivares de sequeiro, GS-73-164, GS-73-165, GS-73-94, IAC-25 e GS-73-17, e dois cultivares de arroz irrigado, IAC-120 e Pinda F-3-7, embora suscetíveis, apresentaram comportamento satisfatório quanto à brusone. Dos genótipos exóticos testados, vinte e sete foram indicados como fontes de resistência à brusone no Estado de São Paulo.

scholarly journals Conidia sporulation of Pyricularia oryzae in segments of wheat plants under six different temperatures

2020 ◽  
Vol 50 (4) ◽  
Author(s):  
Marcos Kovaleski ◽  
João Leodato Nunes Maciel ◽  
Gustavo Bilibio dos Santos ◽  
Alieze Nascimento da Silva ◽  
Carolina Cardoso Deuner
Keyword(s):  
High Temperature ◽  
Petri Dish ◽  
Pyricularia Oryzae ◽  
Causal Agent ◽  
Temperature Conditions ◽  
Wheat Blast ◽  
Conidia Production ◽  
Different Temperatures

ABSTRACT: Wheat blast is known for developing itself more intensely under relatively high temperature conditions but many aspects related to its epidemiology remain unknown. The objective of this research was to evaluate the sporulative capacity of Pyricularia oryzae Triticum (Pot), the causal agent of wheat blast, in tissues of wheat plants under different temperatures degrees. Wheat plants of the cultivar Anahuac 75, susceptible to blast, were inoculated in the stage of flowering with conidial suspensions (105 conidia/mL) of the Pot isolates Py 12.1.209 and Py 12.1.132. Seven days after the inoculation, plants were cut in the following segments: leaves, stems and rachis (with blast severity ranging from 40 to 60%). Groups of each one of the three plant segments with the lesions were disposed in Petri-dish moist chambers, that were submitted to six different temperature treatments (18, 21, 24, 27, 30 and 33 °C). The most appropriate model that related the conidia production with temperature was identified in the evaluations conducted with stems. The established equations allowed identifying that the highest production of conidia of Pot occurs between 24 and 27 °C.

scholarly journals Interpretations of Antibody Responses toSalmonella enterica Serotype Enteritidis gm Flagellin in Poultry Flocks Are Enhanced by a Kinetics-Based Enzyme-Linked Immunosorbent Assay

1998 ◽  
Vol 5 (4) ◽  
pp. 550-555 ◽  
Author(s):  
Patrick L. McDonough ◽  
Richard H. Jacobson ◽  
John F. Timoney ◽  
Ahmed Mutalib ◽  
David C. Kradel ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
High Sensitivity ◽  
High Specificity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Analytical Sensitivity ◽  
Department Of Agriculture ◽  
Trace Back ◽  
Elisa Format ◽  
Commercial Poultry ◽  
Computer Controlled

ABSTRACT Many regulatory and diagnostic programs for the detection ofSalmonella enterica serotype Enteritidis infection in commercial poultry flocks have relied on rapid Pullorum agglutination tests to screen birds because of the shared antigens of S. enterica Enteritidis and S. enterica Pullorum and Gallinarum; however, the use of the enzyme-linked immunosorbent assay (ELISA) format affords better analytical sensitivity than crude agglutination tests. In this study, we adapted our earlier conventional indirect ELISA, using gm flagellin as the antigen, to a kinetics-based, computer-controlled ELISA (KELA). The KELA was used to screen for flagellin antibody from three commercial flocks: (i) a large flock involved in a U.S. Department of Agriculture trace back from a humanS. enterica Enteritidis foodborne outbreak (n = 3,209), (ii) a flock infected with the endemicS. enterica Enteritidis serotype but which also had multiple other salmonella serotypes (n = 65), and (iii) an S. enterica Pullorum-infected flock (n = 12). The first flock (S. entericaEnteritidis prevalence of 2.45% based on culture) provided a field test of the KELA and allowed the calculation of diagnostic sensitivity (D-Sn) and diagnostic specificity (D-Sp). With a cutoff of 10 (used for screening flocks [i.e., high sensitivity]), the KELA has a D-Sn of 95.2% and a D-Sp of 18.5%; with a cutoff of 140 (used in confirmatory flock testing [i.e., high specificity]), the KELA has a D-Sn of 28.0% and a D-Sp of 99.1%. We found that with a cutoff of 60 (D-Sn = 63.1%; D-Sp = 91.6%), we could eliminate reactions in the KELA caused by other non-S. enterica Enteritidis salmonellae. The KELA was also compared to two commercial rapid Pullorum tests, the Solvay (D-Sn = 94.9%; D-Sp = 55.5%) and the Vineland (D-Sn = 62.0%; D-Sp = 75.3%).

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