Link to home

Validation of a conserved effector associated with avirulence on Harbin and Tifang barley

Nathan Wyatt: North Dakota State University

<div>Net form net blotch (NFNB) is a foliar disease of barley caused by the fungal pathogen <em>Pyrenophora teres </em>f. <em>teres</em>. Although economically important, little is known of the molecular mechanisms involved in this host-pathogen interaction. <em>P. teres </em>f. <em>teres</em> bi-parental mapping populations have been used to investigate the avirulence/virulence loci contributing to NFNB disease. These loci commonly harbor small secreted proteins (SSPs) that have been shown in many systems to be effectors used to manipulate the host defense. The pathogen population 15A × 0-1 was used to map a genetic locus (<em>AvrHar</em>) associated with avirulence on Harbin and Tifang barley with avirulence being contributed by isolate 15A. Here, using a genome wide association study approach (GWAS) with a <em>P. teres </em>f. <em>teres </em>global population, we identified a strong marker trait association with avirulence on Tifang barley that maps to the same <em>AvrHar</em> region. The strongest associated SNP marker is located within the 5’UTR of a small secreted protein (SSP). Comparative analysis of this SSP between 15A and 0-1 revealed a six bp in-frame indel that results in the insertion of the amino acids alanine and aspartic acid in the virulent 0-1 isolate. Functional validation of this effector gene via split marker gene knock out, gain-of-function transformation, and heterologous expression will be presented.</div>