Host-selective toxins, Ptr ToxA and Ptr ToxB, as necrotrophic effectors in the Pyrenophora tritici-repentis-wheat interaction

• Published in: New Phytologist Vol. 187; no. 4; pp. 911 - 919
• Main Authors: Ciuffetti, Lynda M., Manning, Viola A., Pandelova, Iovanna, Betts, Melania Figueroa, Martinez, J. Patrick
• Format: Journal Article Book Review
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01-09-2010; Blackwell Publishing; Blackwell Publishing Ltd; Wiley Subscription Services, Inc
• Subjects: Ascomycota - genetics; Ascomycota - pathogenicity; biological resistance; Cell death; Chloroplasts; Disease; Disease resistance; effector; Effectors; Fungal Proteins - genetics; Fungal Proteins - physiology; Fungi; Genes, Fungal - physiology; Genetic loci; Host-Pathogen Interactions - genetics; host-selective toxins; inverse gene-for-gene; Mycotoxins; Pathogenicity; Pathogens; Phytopathology; Plant Diseases - microbiology; Ptr ToxA; Ptr ToxB; Pyrenophora; Pyrenophora tritici-repentis; Reactive oxygen species; Receptors; Research review studies; Research Reviews; susceptibility; tan spot of wheat; Toxins; Triticum - microbiology; Virulence
• ISSN: 0028-646X; 1469-8137
• DOI: 10.1111/j.1469-8137.2010.03362.x

Host-selective toxins (HSTs) are effectors produced by some necrotrophic pathogenic fungi that typically confer the ability to cause disease. Often, diseases caused by pathogens that produce HSTs follow an inverse gene-for-gene model where toxin production is required for the ability to cause disease and a single locus in the host is responsible for toxin sensitivity and disease susceptibility. Pyrenophora tritici-repentis represents an ideal pathogen for studying the biological significance of such inverse gene-for-gene interactions, because it displays a complex race structure based on its production of multiple HSTs. Ptr ToxA and Ptr ToxB are two proteinaceous HSTs produced by P. tritici-repentis that are structurally unrelated and appear to evoke different host responses, yet each toxin confers the ability to cause disease. This review will summarize the current knowledge of how these two dissimilar HSTs display distinct modes of action, yet each confers pathogenicity to P. tritici-repentis.