Differential expression of proteins in response to the interaction between the pathogen Fusarium graminearum and its host, Hordeum vulgare.

Using proteomic techniques, a study aimed at isolating and identifying proteins associated with resistance to fusarium head blight (FHB) was conducted on six barley genotypes of varying resistance. At anthesis, barley spikelets were point inoculated with Fusarium graminearum macroconidial suspensions or mock inoculum. In total, 43 acidic protein spots out of 600 were detected 3 days postinoculation to be differentially expressed due to FHB and were identified. Identification of proteins responsive to FHB included those associated with oxidative burst and oxidative stress response, such as malate dehydrogenase and peroxidases, and pathogenesis-related (PR). An increase in abundance of PR-3 or PR-5 could be associated with the resistant genotypes CI4196, Svansota, and Harbin, as well as the intermediate resistant genotype CDC Bold. On the contrary, the susceptible genotype Stander showed a decrease in abundance of these acidic PR-proteins. In the susceptible and intermediate resistant genotypes Stander and CDC Bold, as well as CI4196, the increased abundance of proteins associated with an oxidative response might have prepared the terrain for saprophytic fungal invasion. On the contrary, in the resistant sources Harbin and Svansota we did not observed change in abundance of these proteins. Not a single significant change in acidic protein abundance could be detected in Chevron. Three distinct response patterns are reported from these six barley genotypes.