Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 11/2/2020
Publication Date: 11/4/2020
Citation: Hao, G., Tiley, H.C., Usgaard, T.R., McCormick, S.P. 2020. Chitin-triggered immunity in wheat and barley and its role during Fusarium head blight [abstract].
Technical Abstract: Fusarium graminearum is the primary causal agent of Fusarium head blight (FHB) on wheat and barley. FHB not only reduces grain yield, but also contaminates grain with various mycotoxins, predominately DON. DON acts as a virulence factor to promote the fungus pass the wheat rachis node that is a critical barrier for FHB resistance. The production of reactive oxygen species (ROS) is one of the earliest defense responses during plant and pathogen interactions. Chitin, a main component of fungal cell wall, can trigger ROS burst and plant immunity. A few studies demonstrated that hydrogen peroxide, a key player of ROS, induces DON production in F. graminearum, however, the complex roles of ROS during Fusarium and plant interactions remain unclear. In this study, we investigated ROS triggered by chitin in FHB resistant and susceptible wheat and barley. We discovered that no ROS burst was detected in chitin-treated wheat leaves, in contrast, ROS was triggered by chitin in barley leaves. We further examined ROS production in different wheat and barley tissues. Higher ROS burst was induced by chitin in wheat rachis node compared to other floral structures including lemma and palea. Higher ROS responses were observed in FHB resistant wheat varieties compared to susceptible varieties after chitin treatments. We are investigating defense marker genes expression in chitin treated wheat rachis nodes and determining their relationship with FHB severity and DON content. This study will provide novel information on ROS signaling during FHB pathogenesis and develop FHB and mycotoxin control strategies by enhancing plant immunity.