The Different Metabolic Responses of Resistant and Susceptible Wheats to Inoculation

Fusarium head blight (FHB) is a serious wheat disease caused by Fusarium graminearum () Schwabe. FHB can cause huge loss in wheat yield. In addition, trichothecene mycotoxins produced by are harmful to the environment and humans. In our previous study, we obtained two mutants and . Neither of these mutants could synthesize trehalose, and they produced fewer mycotoxins. To understand the complex interaction between and wheat, we systematically analyzed the metabolic responses of FHB-susceptible and -resistant wheat to ddHO, the mutants and wild type (WT) using NMR combined with multivariate analysis. More than 40 metabolites were identified in wheat extracts including sugars, amino acids, organic acids, choline metabolites and other metabolites. When infected by , FHB-resistant and -susceptible wheat plants showed different metabolic responses. For FHB-resistant wheat, there were clear metabolic differences between inoculation with mutants (/) and with ddHO/WT. For the susceptible wheat, there were obvious metabolic differences between inoculation with mutant (/) and inoculation with ddHO; however, there were no significant metabolic differences between inoculation with mutants and with WT. Specifically, compared with ddHO, resistant wheat increased the levels of Phe, p-hydroxy cinnamic acid (p-HCA), and chlorogenic acid in response to mutants; however, susceptible wheat did not. Shikimate-mediated secondary metabolism was activated in the FHB-resistant wheat to inhibit the growth of and reduce the production of mycotoxins. These results can be helpful for the development of FHB-resistant wheat varieties, although the molecular relationship between the trehalose biosynthetic pathway in and shikimate-mediated secondary metabolism in wheat remains to be further studied.