Identification of fusarium head blight resistance related metabolites specific to doubled-haploid lines in barley

Abstract

Fusarium head blight (FHB) and deoxy- nivalenol (DON) mycotoxin produced by Fusarium graminearum reduce barley yield and quality world- wide. Hundreds of quantitative trait loci (QTLs) have been identified in wheat and barley but their functions are largely unknown. Metabolic profiling was applied to better understand the mechanisms of resistance and to identify potential FHB resistance biomarker metab- olites in barley. Four FHB resistant (H15-2, H148-3, H203-2 and H379-2) and one susceptible (H97-2), two-row, purple, doubled-haploid (DH) lines of barley were inoculated with either the pathogen or mock- solution. The disease severity quantified as the area under the disease progress curve (AUDPC) significant- ly varied between the resistant and susceptible geno- types, but not among the resistant genotypes. Neither the amount of DON nor the detoxified product, pro- portion of total DON, was significant among lines. The resistance related (RR, higher in abundance in resistant than in susceptible) metabolites varied in numbers and fold changes among the DH resistant lines. A total of 144 RR constitutive (RRC) and 167 RR induced (RRI) metabolites were selected, of which 39 and 37, respec- tively, were putatively identified. These RR metabolites mainly belonged to six chemical groups: phenylpro- panoids, hydroxycinnamic acid amides, flavonoids, fatty acids, terpenoids, and alkaloids. The specific RR metabo- lites identified in each DH line, the possible mechanisms of resistance in each and their use as potential biomarkers are discussed.