Link to home

Pathogenomic analysis of the wheat pathogen Puccinia striiformis f. sp. tritici populations in the United States reveals key effectors

Becky Lyon: Colorado State University

<div>Stripe rust, caused by the fungal pathogen <em>Puccinia striiformis</em> f. sp. <em>tritici</em> (<em>Pst</em>), is one of the most devastating diseases of wheat and is present in all major wheat-growing regions of the world. Stripe rust has traditionally affected cooler regions with higher moisture levels, such as the U.S. Pacific Northwest, but in the last 15 years its geographic footprint has expanded due to incursions of novel <em>Pst </em>races that have unique and broader virulence profiles, are better adapted to warmer environments, and are more aggressive than previously characterized races. Effectors, a group of virulence proteins deployed by the pathogen to manipulate plant cell structures and functions, might contribute to the aforementioned expansion. To better understand the diversity, distribution and function of <em>Pst</em> effectors in the pathogen population, we collected 16 field <em>Pst</em> isolates from several regions across the U.S. and one <em>Pst </em>isolate from our greenhouse, and sequenced their transcriptomes. We further assessed the transcriptomes for genome-wide effector diversity and differential expression to identify key effectors that likely contribute to the virulence of <em>Pst</em>. These key effectors could be targets for further molecular characterization as well as be used to devise novel surveillance tools and development of host resistance.</div>