Potentiators of disease during barley infection by Pyrenophora teres f. teres in a susceptible interaction.

Abstract

Pyrenophora teres f. teres (Ptt) is a necrotrophic fungal pathogen and causal agent of net form net blotch (NFNB), a significant disease in barley. RNA-seq data encompassing asymptomatic and subsequent necrotrophic phases of the pathogen was obtained for Ptt isolate W1-1 in a NFNB sensitive cultivar, Baudin. Host genes notably regulated during infection included concerted induction of over half the repertoire of disease resistance genes, together with genes involved in oxidation-reduction processes, characteristic of a hypersensitive response. Several systemic acquired resistance response genes were supressed and there was a complete absence of defence-related thionin gene expression. In Ptt, genes involved in hydrolase activities and cell wall catabolic processes were induced during infection, while nitrate assimilation and response to oxidative stress processes were supressed. Time course data allowed a number of predicted Ptt effector genes with differing expression profiles to be identified that may underlie barley sensitivity to NFNB. Candidate genes involved in the host-pathogen interaction provide a basis for functional characterisation and control strategies based on fungicide or mutation targets, which will facilitate further research aimed at controlling NFNB disease.