Real-time PCR for diagnosing and quantifying co-infection by two globally distributed fungal pathogens of wheat

Co-infections – invasions of a host-plant by multiple pathogen species or strains – are common, and are thought to have consequences for pathogen ecology and evolution. Despite their apparent significance, co-infections have received limited attention; in part due to lack of suitable quantitative to...

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Main Authors: Abdullah, A., Turo, C., Moffat, Caroline, Lopez-Ruiz, Fran, Gibberd, Mark, Hamblin, J., Zerihun, Ayalsew
Format: Journal Article
Published: Frontiers Research Foundation 2018
Online Access:http://hdl.handle.net/20.500.11937/70914
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author Abdullah, A.
Turo, C.
Moffat, Caroline
Lopez-Ruiz, Fran
Gibberd, Mark
Hamblin, J.
Zerihun, Ayalsew
author_facet Abdullah, A.
Turo, C.
Moffat, Caroline
Lopez-Ruiz, Fran
Gibberd, Mark
Hamblin, J.
Zerihun, Ayalsew
author_sort Abdullah, A.
building Curtin Institutional Repository
collection Online Access
description Co-infections – invasions of a host-plant by multiple pathogen species or strains – are common, and are thought to have consequences for pathogen ecology and evolution. Despite their apparent significance, co-infections have received limited attention; in part due to lack of suitable quantitative tools for monitoring of co-infecting pathogens. Here, we report on a duplex real-time PCR assay that simultaneously distinguishes and quantifies co-infections by two globally important fungal pathogens of wheat: Pyrenophora tritici-repentis and Parastagonospora nodorum. These fungi share common characteristics and host species, creating a challenge for conventional disease diagnosis and subsequent management strategies. The assay uses uniquely assigned fluorogenic probes to quantify fungal biomass as nucleic acid equivalents. The probes provide highly specific target quantification with accurate discrimination against non-target closely related fungal species and host genes. Quantification of the fungal targets is linear over a wide range (5000–0.5 pg DNA µl-1) with high reproducibility (RSD = 10%). In the presence of host DNA in the assay matrix, fungal biomass can be quantified up to a fungal to wheat DNA ratio of 1 to 200. The utility of the method was demonstrated using field samples of a cultivar sensitive to both pathogens. While visual and culture diagnosis suggested the presence of only one of the pathogen species, the assay revealed not only presence of both co-infecting pathogens (hence enabling asymptomatic detection) but also allowed quantification of relative abundances of the pathogens as a function of disease severity. Thus, the assay provides for accurate diagnosis; it is suitable for high-throughput screening of co-infections in epidemiological studies, and for exploring pathogen–pathogen interactions and dynamics, none of which would be possible with conventional approaches.
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institution Curtin University Malaysia
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spelling curtin-20.500.11937-709142019-01-15T01:42:24Z Real-time PCR for diagnosing and quantifying co-infection by two globally distributed fungal pathogens of wheat Abdullah, A. Turo, C. Moffat, Caroline Lopez-Ruiz, Fran Gibberd, Mark Hamblin, J. Zerihun, Ayalsew Co-infections – invasions of a host-plant by multiple pathogen species or strains – are common, and are thought to have consequences for pathogen ecology and evolution. Despite their apparent significance, co-infections have received limited attention; in part due to lack of suitable quantitative tools for monitoring of co-infecting pathogens. Here, we report on a duplex real-time PCR assay that simultaneously distinguishes and quantifies co-infections by two globally important fungal pathogens of wheat: Pyrenophora tritici-repentis and Parastagonospora nodorum. These fungi share common characteristics and host species, creating a challenge for conventional disease diagnosis and subsequent management strategies. The assay uses uniquely assigned fluorogenic probes to quantify fungal biomass as nucleic acid equivalents. The probes provide highly specific target quantification with accurate discrimination against non-target closely related fungal species and host genes. Quantification of the fungal targets is linear over a wide range (5000–0.5 pg DNA µl-1) with high reproducibility (RSD = 10%). In the presence of host DNA in the assay matrix, fungal biomass can be quantified up to a fungal to wheat DNA ratio of 1 to 200. The utility of the method was demonstrated using field samples of a cultivar sensitive to both pathogens. While visual and culture diagnosis suggested the presence of only one of the pathogen species, the assay revealed not only presence of both co-infecting pathogens (hence enabling asymptomatic detection) but also allowed quantification of relative abundances of the pathogens as a function of disease severity. Thus, the assay provides for accurate diagnosis; it is suitable for high-throughput screening of co-infections in epidemiological studies, and for exploring pathogen–pathogen interactions and dynamics, none of which would be possible with conventional approaches. 2018 Journal Article http://hdl.handle.net/20.500.11937/70914 10.3389/fpls.2018.01086 http://creativecommons.org/licenses/by/4.0/ Frontiers Research Foundation fulltext
spellingShingle Abdullah, A.
Turo, C.
Moffat, Caroline
Lopez-Ruiz, Fran
Gibberd, Mark
Hamblin, J.
Zerihun, Ayalsew
Real-time PCR for diagnosing and quantifying co-infection by two globally distributed fungal pathogens of wheat
title Real-time PCR for diagnosing and quantifying co-infection by two globally distributed fungal pathogens of wheat
title_full Real-time PCR for diagnosing and quantifying co-infection by two globally distributed fungal pathogens of wheat
title_fullStr Real-time PCR for diagnosing and quantifying co-infection by two globally distributed fungal pathogens of wheat
title_full_unstemmed Real-time PCR for diagnosing and quantifying co-infection by two globally distributed fungal pathogens of wheat
title_short Real-time PCR for diagnosing and quantifying co-infection by two globally distributed fungal pathogens of wheat
title_sort real-time pcr for diagnosing and quantifying co-infection by two globally distributed fungal pathogens of wheat
url http://hdl.handle.net/20.500.11937/70914