Location: Cereal Crops ResearchTitle: Functional characterization of the conserved effector AvrHar in Pyrenophora teres f. teres
|WYATT, NATHAN - North Dakota State University|
|RICHARDS, JONATHAN - Louisiana State University|
|BRUEGGEMAN, ROBERT - North Dakota State University|
Submitted to: International Congress on Molecular Plant-Microbe Interactions
Publication Type: Abstract Only
Publication Acceptance Date: 7/14/2019
Publication Date: N/A
Interpretive Summary: .
Technical Abstract: Pyrenophora teres f. teres is the causal agent of net form net blotch (NFNB) on barley. NFNB is an economically important disease in all barley growing regions globally, but little is known of the molecular mechanisms involved in the barley-P. teres f. teres interaction. Recently, a genomic locus was found to be associated with avirulence/virulence on Tifang barley using a genome wide association study (GWAS) approach using a global P. teres f. teres population. This genomic locus was also identified in the P. teres f. teres 15A × 0-1 mapping population corresponding to the virulence/avirulence locus AvrHar. AvrHar is in the sub-telomeric region of chromosome 5 and RNAseq-supported gene models placed several small secreted proteins (SSPs) in this region. The strongest associated SNP marker was located within the 5’ UTR of a SSP gene, seven bases from the start codon. Comparative analysis of the effector gene between the avirulent isolate 15A and the virulent isolate 0-1 revealed a six bp indel resulting in the insertion of an alanine and aspartic acid in the virulent 0-1 isolate. Gene disruption using CRISPR-Cas9-RNP mediated gene editing in isolate 0-1 resulted in a loss of virulence on Tifang as well as 27 barley lines commonly used in differential sets. Site directed gene disruption in isolate 15A had no visible effect on virulence for the same barley lines. AvrHar is present in a global collection of P. teres f. teres and P. teres f. maculata isolates as well as the closely related wheat fungal pathogen Pyrenophora tritici-repentis. Further functional characterization is underway using CRISPR-Cas9 mediated gene editing, and heterologous expression.