Potential virulence factors in Pyrenophora teres through label-free cellular proteomics analysis

Pyrenophora teres f. teres (Ptt) is the causative agent of net blotch diseases in barley and an economically important pathogen in the barley industry worldwide. To date, however, little is known about the protein expression profile of Ptt, which is important to understand the pathogen behaviour. In this study we report the first cellular proteomics analysis of Ptt. Label-free proteomics was used to quantify the protein expression levels of two parental and one of its progeny isolates from a Ptt cross, grown in culture. One parental isolate of the cross was virulent on the barley variety Prior while the other isolate was avirulent. The progeny isolate used in this study was also virulent on Prior. A total of 3,502 proteins were identified in samples of the three Ptt isolates, of which 99 were found only in the pathogenic isolates, while another 255 proteins were significantly more abundant in the pathogenic isolates compared to the non-pathogenic isolate. Gene ontology analyses of the significant proteins revealed that the proteins increased in pathogenic isolates were involved in fatty acid elongation, biosynthesis of unsaturated fatty acids, glycerophospholipid metabolism, nucleocytoplasmic transport, amino sugar and nucleotide sugar metabolism and metabolic pathways. These protein profiles and the bioinformatic analysis provide new biological information that can be utilised to better understand the pathogenicity of Ptt.