The sensitivity of Canadian wheat genotypes to the necrotrophic effectors produced by Pyrenophora tritici-repentis. Issue 2 (3rd April 2017)

• Record Type: Journal Article
• Authors: Tran, Van Anh; Aboukhaddour, Reem; Strelkov, Ileana Silva; Bouras, Noureddine; Spaner, Dean; Strelkov, Stephen E.
• Is Part Of: Canadian journal of plant pathology. Volume 39:Issue 2(2017)
• Page Start: 149
• Page End: 162
• Publication Date: 2017-04-03
• Subjects: host-specific toxins -- necrotrophic effectors -- Pyrenophora tritici-repentis -- sensitivity -- wheat; blé -- effecteur nécrotrophe -- Pyrenophora tritici-repentis -- toxines spécifiques de l'hôte -- sensibilité; Plant diseases -- Canada -- Periodicals; Plant diseases -- Periodicals; 632.05
• DOI: 10.1080/07060661.2017.1339125
• Languages: English
• ISSNs: 0706-0661

Abstract

Abstract: Pyrenophora tritici-repentis (Ptr), the cause of tan spot of wheat, is a foliar pathogen of economic importance worldwide. Tan spot development is associated with the production of necrotrophic effectors (Ptr ToxA, Ptr ToxB and Ptr ToxC) that serve as fungal pathogenicity and/or virulence factors. The objective of this study was to investigate the sensitivity to each of these effectors in a collection of 100 Canadian wheat cultivars representing all wheat classes and developed over a century by various Canadian breeding programmes. Heterologously expressed, His-tagged Ptr ToxA and Ptr ToxB, and spore germination fluids possessing putative Ptr ToxC activity, were produced and used to screen the cultivars for sensitivity. Of the 100 wheat cultivars tested, 92 were sensitive to at least one effector, 68 were sensitive to Ptr ToxA, 63 were sensitive to Ptr ToxC and 24 were sensitive to Ptr ToxB. Only eight cultivars were insensitive to all three effectors. These results reflect the widespread sensitivity in Canadian wheat cultivars to these necrotrophic effectors, with sensitivity to Ptr ToxA and the putative Ptr ToxC found consistently to be more common than Ptr ToxB sensitivity. The predominance of Ptr ToxA and Ptr ToxC sensitivity in Canadian wheat is consistent with the prevalence of races 1 (Ptr ToxA + Ptr ToxC producer) and 2 (Ptr ToxA producer) of Ptr in North America, and could reflect a competitive advantage for Ptr ToxA-producing isolates in the pathogen population.