Profile of the in vitro secretome of the barley net blotch fungus, Pyrenophora teres f. teres

Plant pathogen interactions are governed by a molecular interchange in which effectors, secreted by the pathogen, are key players. Effectors are yet to be characterised in Pyrenophora teres f. teres, an important pathogen of barley. Proteins contributing to culture filtrate phytotoxicity were identified by chromatographic fractionation followed by mass spectrometry-based proteomics. Among the most prevalent proteins in the active fractions were glycosidases (20%), peptidases (8%), other hydrolases (8%) and a high proportion of proteins without functional annotations (30%). Furthermore, additional proteins were predicted to be similar to known chitin binding, ribonuclease-like and kinase effectors along with a hypothetical protein which was predicted to be an effector. We discuss the known properties of the groups of proteins identified in this study and their possible roles in the plant-pathogen interaction. The dataset of proteins presented is a valuable resource for discovering potential effector proteins in net blotch disease, and informs further genetic and in planta studies to dissect the molecular interactions of barley and P. teres f. teres.