Multiple avirulence paralogues in cereal powdery mildew fungi may contribute to parasite fitness and defeat of plant resistance.

Powdery mildews, obligate biotrophic fungal parasites on a wide range of important crops, can be controlled by plant resistance (R) genes, but these are rapidly overcome by parasite mutants evading recognition. It is unknown how this rapid evolution occurs without apparent loss of parasite fitness....

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Main Authors: Ridout, C, Skamnioti, P, Porritt, O, Sacristan, S, Jones, J, Brown, J
Format: Journal article
Language:English
Published: 2006
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author Ridout, C
Skamnioti, P
Porritt, O
Sacristan, S
Jones, J
Brown, J
author_facet Ridout, C
Skamnioti, P
Porritt, O
Sacristan, S
Jones, J
Brown, J
author_sort Ridout, C
collection OXFORD
description Powdery mildews, obligate biotrophic fungal parasites on a wide range of important crops, can be controlled by plant resistance (R) genes, but these are rapidly overcome by parasite mutants evading recognition. It is unknown how this rapid evolution occurs without apparent loss of parasite fitness. R proteins recognize avirulence (AVR) molecules from parasites in a gene-for-gene manner and trigger defense responses. We identify AVR(a10) and AVR(k1) of barley powdery mildew fungus, Blumeria graminis f sp hordei (Bgh), and show that they induce both cell death and inaccessibility when transiently expressed in Mla10 and Mlk1 barley (Hordeum vulgare) varieties, respectively. In contrast with other reported fungal AVR genes, AVR(a10) and AVR(k1) encode proteins that lack secretion signal peptides and enhance infection success on susceptible host plant cells. AVR(a10) and AVR(k1) belong to a large family with >30 paralogues in the genome of Bgh, and homologous sequences are present in other formae speciales of the fungus infecting other grasses. Our findings imply that the mildew fungus has a repertoire of AVR genes, which may function as effectors and contribute to parasite virulence. Multiple copies of related but distinct AVR effector paralogues might enable populations of Bgh to rapidly overcome host R genes while maintaining virulence.
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spelling oxford-uuid:55203805-b8e5-4af9-9406-4ac205014a3b2022-03-26T16:42:06ZMultiple avirulence paralogues in cereal powdery mildew fungi may contribute to parasite fitness and defeat of plant resistance.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:55203805-b8e5-4af9-9406-4ac205014a3bEnglishSymplectic Elements at Oxford2006Ridout, CSkamnioti, PPorritt, OSacristan, SJones, JBrown, JPowdery mildews, obligate biotrophic fungal parasites on a wide range of important crops, can be controlled by plant resistance (R) genes, but these are rapidly overcome by parasite mutants evading recognition. It is unknown how this rapid evolution occurs without apparent loss of parasite fitness. R proteins recognize avirulence (AVR) molecules from parasites in a gene-for-gene manner and trigger defense responses. We identify AVR(a10) and AVR(k1) of barley powdery mildew fungus, Blumeria graminis f sp hordei (Bgh), and show that they induce both cell death and inaccessibility when transiently expressed in Mla10 and Mlk1 barley (Hordeum vulgare) varieties, respectively. In contrast with other reported fungal AVR genes, AVR(a10) and AVR(k1) encode proteins that lack secretion signal peptides and enhance infection success on susceptible host plant cells. AVR(a10) and AVR(k1) belong to a large family with >30 paralogues in the genome of Bgh, and homologous sequences are present in other formae speciales of the fungus infecting other grasses. Our findings imply that the mildew fungus has a repertoire of AVR genes, which may function as effectors and contribute to parasite virulence. Multiple copies of related but distinct AVR effector paralogues might enable populations of Bgh to rapidly overcome host R genes while maintaining virulence.
spellingShingle Ridout, C
Skamnioti, P
Porritt, O
Sacristan, S
Jones, J
Brown, J
Multiple avirulence paralogues in cereal powdery mildew fungi may contribute to parasite fitness and defeat of plant resistance.
title Multiple avirulence paralogues in cereal powdery mildew fungi may contribute to parasite fitness and defeat of plant resistance.
title_full Multiple avirulence paralogues in cereal powdery mildew fungi may contribute to parasite fitness and defeat of plant resistance.
title_fullStr Multiple avirulence paralogues in cereal powdery mildew fungi may contribute to parasite fitness and defeat of plant resistance.
title_full_unstemmed Multiple avirulence paralogues in cereal powdery mildew fungi may contribute to parasite fitness and defeat of plant resistance.
title_short Multiple avirulence paralogues in cereal powdery mildew fungi may contribute to parasite fitness and defeat of plant resistance.
title_sort multiple avirulence paralogues in cereal powdery mildew fungi may contribute to parasite fitness and defeat of plant resistance
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