Oligogalacturonide Application Increases Resistance to Fusarium Head Blight in Durum Wheat

Fusariosis causes substantial yield losses in wheat crop worldwide and compromises food safety because of the presence of toxins associated to fungal disease. Among the current approaches to crop protection, the use of elicitors able to activate natural defense mechanisms in plants represents a strategy gaining increasing attention. Several studies indicate that applications of plant cell wall-derived elicitors, such as oligogalacturonides (OGs) derived from partial degradation of pectin, induce local and systemic resistance against plant pathogens. The aim of this study was to establish the efficacy of OGs in protecting durum wheat, characterized by an extreme susceptibility to Fusarium graminearum. To evaluate the functionality of OGs, spikes and seedlings of cv. Svevo were inoculated with OGs, F. graminearum spores and a co-treatment of both. Results demonstrated that OGs are active elicitors of wheat defenses, triggering typical immune marker genes and determining regulation of fungal genes. Moreover, bioassays on spikes and transcriptomic analyses on seedlings showed that OGs can regulate relevant physiological processes in Svevo with dose-dependent specificity. Thus, the OG sensing system plays an important role in finetuning immune signaling pathways in durum wheat.