Differential expression of defense-related genes in susceptible versus resistant barley genotypes challenged with Pyrenophora teres

The fungus Pyrenophora teres f. sp. teres is the causal agent of barley net blotch, a disease responsible for significant yield loss in major production areas throughout the world. In this study, the differential responses of susceptible and resistant barley cultivars upon P. teres infection were investigated in infected seedling leaves at 24 and 96 hours post inoculation using RT-PCR method. Our results showed a notable discrepancy in the expression pattern of the studied genes between susceptible and resistant barley-P. teres interaction. All tested defense-related genes were up-regulated in both resistant and susceptible genotypes as compared with non-inoculated ones. However, expression was often higher in resistant plants, suggesting a possible role for these genes in the defense response. PR2 expression level increased by 6.4 folds after 96 h inoculation in the resistant cultivar as revealed by qRT-PCR. Our preliminary results will strengthen our basic understanding of the genetic mechanisms governing barley susceptibility and resistance to net blotch disease.