Comparative analysis of phenolic compounds of Canadian barley cultivars reveals potential biomarkers related to Fusarium head blight resistance

Fusarium head blight (FHB) in barley (Hordeum vulgare L.) is the most devastating disease worldwide including western Canada. This disease is not only causing a loss in grain yield, but also a deterioration in grain quality, by producing several mycotoxins such as deoxynivalenol (DON) that are detrimental to human and animal health. Developing FHB resistant cultivar is difficult due to lack of reliable molecular markers and laborious testing. Moreover, specific biomarkers designed to distinguish the FHB resistance in barley genotypes are limited. In this study, several barley cultivars with different resistance to FHB have been grown in FHB artificially infected and non-infected field trials with the aim of investigating their phenolic compound profile and to identify potential biomarkers for selection of barley with resistance to FHB. Grains of each variety tested were harvested and the ground flour was assessed for the presence of DON (infected samples) via the enzyme-linked immunosorbent assay (ELISA). High-performance liquid chromatography (HPLC) analysis was performed using both infected and non-infected samples. Quantitative phenolic compound analysis revealed the changes among varieties tested in non-infected samples, but in general the resistant varieties showed higher amounts of ρ-coumaric acid (PCA), ferulic acid, caffeic acid, catechin and vanillin compared to the susceptible ones. In addition, FHB infected samples of the most susceptible variety showed a significant increase in the accumulation of PCA and ferulic acid suggesting the involvement of these two compounds in the resistance response against FHB.